perf T&F re perf T&F re

instrumentsQuartzlock FOR EFTF & ARMMS 2012www.quartzlock.comPRE-PRINT new 2007 economy ‘1U’ lineinstrumentsnew 2007 economy ‘1U’ ‘1U’ line lineQuartzlock instrumentsnew 2007 economy ‘1U’ lineQuartzlock instruments5Quartzlock SPECIFICATION Quartzlock Concise CatalogueLow phase noise • low drift • high stabilityCompleteOutput10MHz sine 0.7V rms into 50 ohms Low phase noise • low Accuracy drift • high stability ±5x10Quartzlock new Low phase 2007 noise economy • lowdrift • high ‘1U’ stability line-11 at shipment @25°CPhase to Noise (SSB)-100dBc (10Hz)Quartzlock instrumentsLow phase noisePrecise Frequency & Frequency• low drift • high stability-120 dBc (100Hz)Quartzlock -140 dBc (1KHz)Quartzlock Quartzlock Time10MHz • -165 dBc/Hz phase noise • 1 x 10Control Products Control10MHz • -165 dBc/Hz Input Power phase noise • 1 x 10 -12 /s Solutions13W -12 /s Quartzlock Input Voltage Range 10MHz • -165 dBc/Hz phase noise • 1 x 10 -12 90-240V ac/sQuartzlock Warm Time 5 minutesLow 10MHz phase • -165 noise dBc/Hz • low phase drift • noise stability • 1 x 10 -12 to lock @ 25°C/sQuartzlock lowest cost Retrace to highest ±3x10 -11Quartzlock Quartzlock Frequency Control Internal (external ask Quartzlock)performanceUp to 24 outputs from 1 or 2 inputsUp to 24 outputs from Internal 1 2availabletrim inputs range (trimpot) greater than 2x10 -9External trim range greater than 2x10 Quartzlock -9 (0V~5V)Up toQuartzlock24 outputs from 1 or 2 inputsShort term stability10MHz • -165 dBc/Hz phase noise • 1 x 10 -12 3x10Up to 24 outputs from 1 or 2 inputs /s-11 /1s1x10 -11 /10sQuartzlock 3x10 -12 /100s spectrum Quartzlockanalysers, network analysers, frequency /hour/daycounters, signal sources, microwave analysers, Harmonicsdigital storageA4000 scopes. Second HarmonicRedundant RF RF Switch Switch Unit -48 dBcThird HarmonicUp to 24 outputs from 1 or 2 inputsUnit-45 dBcwith RS232 i/o NMEA NTP, lock advice etc.Accurate Foruseusewithwith & Stable RbRbandand Low GPSGPS Noise referencesreferences 10MHz RubidiumFrequency Drift3x10A4000 Redundant RF Switch Unit-12 /day, 3x10 -11 /monthReference Quartzlock signals. 10 -12 to 10 -14 accuracy & stabilityA4000 Redundant StatusRF Monitors Switch Unit Lock and On LEDlevels For use & _ with 125dBc/Hz Rb and GPS @ 1Hz references or _ 178dBc noise floor.Quartzlock For use with Rb can andOperatingcombine GPSTemp. referencesRange-20°C to +50°C any of the from above Temperature Coefficient (ambient) 3x10instruments Quartzlock into can a combine single 1U any unit of to the meet above-10 (-20° to 50°C)£1000 engineStorage Temperature -40° to 70°Cspecified Quartzlock instruments requirements. can into combine a single any 1U unit of to £3000 the to above meetMTBF100,000 hoursspecified A4000 Redundant requirements. RF Switch UnitNew Active & Passive Hydrogen Masers Quartzlock instruments can into combine a single any 1U unit of 'use the tofrommeet above the box'.ConnectorsBNC RF & IEC line supply inputinstruments For use with Rbinto anda GPS single references 1U unit to meetUltra Low Noise Signal Stability AnalyserChoice specified of technologies, requirements. GPS or Rb + _ clean up loop.Size19” Rack 1 U (44mm/1.75”)up specified Superior to 6 outputs. QA requirements.& QC, Quartzlock’s H maser basedNew Ultra Low Noise Distribution laboratory Amplifiers is used in Weight production test of all products. 1.75KgSuperior QA & QC, Quartzlock’s H maser basedNew Very Low Noise Sub-Miniature e-mail:Quartzlock laboratory sales@quartzlock.com Rubidium is used canOscillators in combine production Tel: (44)1803 &anyInstruments862Superior QA & QC, Quartzlock’s Htest 062maser of of the all www:basedproducts. quartzlock.comabovee-mail: sales@quartzlock.com • Tel: (44)1803 862 062 • Fax: (44)1803 867 962 • www.quartzlock.comNew range of Miniature Rubidium instruments Superior laboratory Components QA is used & QC, into and Quartzlock’s a production single Instruments 1U test H unit maser of all to products. based meetVery Low Noise GPS Time & Frequency specified laboratory References isrequirements.used in production test of all products.Active Noise FiltersTiming ModuleSuperior QA & QC, Quartzlock’s H maser basedlaboratory is used in production test of all products.Low phase noise • low dto: control/calibrate/reference

Business valuesTeamVery skilled and experienced people in R&D, production, production test, calibration, QA, QC and business management.Our component suppliers, specialist sub-contractors, assembly services, software experts plus many others who makerunning Quartzlock a pleasure and make an important contribution to the highest quality and performance electronicproducts we design and build.IPRQuartzlock’s Intellectual Property is in our designs, technology and techniques. We invest a large percentage of ourrevenue on R&D to keep ahead of our few competitors. Quartzlock’s list of standard solutions to frequency control andactive noise filtering, DDS, DPLL, synthesizers and other low noise “tools” such as our new CPT physics package, optics,laser and light modulation techniques enable us to meet demanding requests for even higher performance, in smaller,lighter, lower power products.BrandSome 50 years of close to market R&D, high quality manufacturing and test, has painted the Quartzlock brand with anexcellent reputation for reliability and high performance.Active and Passive Hydrogen Maser LaboratoryQuartzlock’s maser based laboratory, commercially unique in the EU, and with very few exceptions elsewhere in the world,give our team the tools needed to do the measurement science essential for the high level of performance our products,R&D and production test require.Product LineQuartzlock specializes in Precise Time and Frequency Control. Quartzlock has the widest range of highest specificationHydrogen Masers, to the lowest cost Rubidium and GPS Disciplined Oscillators.Continuous improvementOur product specialization means that stability (AVAR), drift, spurii and phase noise will all be improved in current andfuture products. Quartzlock products outperform our competitors. More than a third of the products in this catalogue arenew.WarrantiesQuartzlock have a standard three year warranty on Rubidium products (E10-MRX/A10-MRO have two years until end2012 then change to three years). This level of confidence in reliability / MTBF is unique to Quartzlock.FutureTomorrows products will be even more stable and with lower power and phase noise characteristics at lower cost. Largermarket sectors will be entered. Export sales increased. Customer defined products will sit alongside our“industry standard’s”.2Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

IndexOven Controlled Crystal OscillatorsA3-60C Low Noise SC Overtone CO-08 Cased OCXO ..................................................................................................... 7Time and Frequency DistributionA5-8 Ultra Low Noise, High Isolation Primary Reference 8 Output Distribution Amplifier 1U 19" Rack.......................... 8E5000 Low Noise 1U 19” Rack Mount 12 Output Distribution Amplifier (low cost) ..................................................... 10E5-X Desktop Low Noise 6 Output Distribution Amplifier (low cost)........................................................................... 12OEM Timing Products and Signal ‘Clean-up’ (Board level)A6-1PPS 1PPS Disciplined Timing Module........................................................................................................................ 14A6-CPS Digital Phase Locked Clean-up Loop ................................................................................................................. 20Active Noise FilterA6-ANF Primary Reference Active Noise Filter 2U Rack .................................................................................................. 24Test and MeasurementA7-MX Signal Stability Analyser ................................................................................................................................... 28GPS Time and Frequency ReferencesE8-X Desktop GPS Disciplined TCXO Time and Frequency Reference (low cost) ......................................................... 38E8-X OEM OEM GPS Disciplined TCXO Time and Frequency Reference (PCB only).............................................................. 38E8-Y Desk Top GPS Disciplined Low Noise OCXO Time and Frequency Reference ...................................................... 40E8-Y OEM OEM GPS Disciplined Low Noise OCXO Time and Frequency Reference (PCB only)............................................ 40E8000 GPS Disciplined Low Noise OCXO Time and Frequency Reference 1U Rack........................................................ 42E8010 GPS Disciplined Rubidium Time and Frequency Reference 1U Rack.................................................................... 44OEM Rubidium OscillatorsE10-MRX Sub Miniature Atomic Clock OCXO sized Rubidium Oscillator 51 x 51 x 25mm................................................. 46E10-LN Very Low Noise Rubidium Oscillator Module (PCB only) 91 x 55 x 30mm........................................................... 48A10-LPRO Low Profile Rubidium Oscillator ........................................................................................................................ 50A10-Y Ultra Low Noise Rubidium Oscillator ................................................................................................................. 52E10-MRO Miniature Rubidium Oscillator .......................................................................................................................... 54E10-GPS GPS Disciplined Miniature Rubidium Oscillator................................................................................................... 56Atomic Time and Frequency ReferencesA10-M (A10-MX) Rubidium Frequency Reference ........................................................................................................................ 58A1000 1U 19” Rack Mount Rubidium Frequency Reference .........................................................................................60E1000 Low Noise 1U 19” Rack Mount Rubidium Frequency Reference ........................................................................ 62E10-P Portable Desktop Rubidium Frequency Reference ............................................................................................. 64E10-X Compact Desktop Rubidium Frequency Reference ............................................................................................ 66E10-Y series Low Noise 4/8 Output Desktop Rubidium Frequency Reference ........................................................................ 68CH1-75A Active Hydrogen Maser Primary Time and Frequency Reference .........................................................................70CH1-76A Passive Hydrogen Maser Primary Time and Frequency Reference ....................................................................... 74Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com3

New ProductsCH1-75AActive Hydrogen Maser page 70CH1-76APassive Hydrogen Maser page 74A7-MX using A10-MX as referenceA10-MX Rubidium Frequency Reference page 54A5-8 Ultra Low Noise, High Isolation Primary Reference Distribution Amplifier page 8E10-Y Series Desktop Rubidium Frequency Reference page 684Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

E10-MRX Sub Miniature Atomic Clock OCXO sized Rubidium Oscillator page 60Actual sizeE10-LN Very Low Noise Rubidium Oscillator Module – 91 x 55mm page 48E1000 Low Noise 1U 19” Rack Mount Rubidium Frequency Reference page 58E8000 GPS Disciplined Low Noise OCXO Time and Frequency Reference page 42Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com5

Quartzlock’s Journey1964 Saw the first Clive Green & Roger Davis production-run products in RF & microwave frequency “down convertors” and RF VHFsources. These were followed by CW & AM radio transmitters, 600 Watt HF SSB Passive Grid Linear Amplifiers with exceptionally low,cross and inter-modulation products.1970 High power VHF & UHF RF sources for MoD plasma research. RF Test equipment. An SSB, AM, CW TX 1000W single box testsolution with SSB power measurement.1980 True RMS RF power meter with dynamic range from 10mW to 1000W (linear scale), Worlds First TTL Synthesized SignalGenerator (Peter Broadbent) helped keep UK Sonar ahead. A 100MHz Synthesized Signal Generator (Toby Holland under PB) Manual& Automatic modulation meters with phase mod capability. The most compact single portable 230V / 12V dc radiotelephone test set(John Lake, John Bloice, PB, CRG, Peter Ward and others)1990 Exploited early LF Off Air Frequency Standard design with rapid R&D to an industry standard product selling low 1,000’s (PB…Colin Desborough…Graham McCloud/Dr Cosmo Little)2000 Consolidating Rubidium Technology and joined the Hydrogen Maser radio-technology originators and world leaders IEMKvarz. Subsequently sold some 50 Active & Passive H Masers around the world with Quartzlock’s own A5 Ultra Low Noise DistributionAmplifiers & A6 Frequency Convertors. The Quartzlock A7-MX Signal Stability Analyzer production began (CL, WK) A5, A6, A7 earlyA10 Rb, A5000, A8 GPS line followed (Dr Wolfgang Klisch, Hadwin Kramer).2010 New A5000, E1000, E8000, E8010, E8-X, E8-Y, include new A6-CPS technology for low noise & clean technology. 1PPS timingmodule introduced.2012 The introduction of completely new sub-miniature Rb components & Rb instruments with Ultra Low Noise versions available. TheE10-MRX Rb is lowest cost & power, OCXO size with 150g mass. A NMI level E5 Signal Distribution Amplifier (replaces E5) is introduced.Radio telephone test set 1980 10mW–1000W RMS Power Meter Modulation meter 1975 World’s first TTL synthesized signal generator 1970sContact QuartzlockFor all enquiries please contact us via any of the methods below:Head Office & Maser Lab:Quartzlock UK Ltd‘Gothic’Plymouth RoadTotnes, DevonTQ9 5LH EnglandTelephone:+44 (0)1803 862062Facsimile:+44 (0)1803 867962Email:sales@quartzlock.comOr visit our website www.quartzlock.comThe Quartzlock logo is a registered trademark. Quartzlock continous improvement policy: specifications subject tochange without notice and not part of any contract. All IPR and design rights are protected. E&OE. © Quartzlock 20126Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

A3-60SCSC Cut Oven-controlledQuartz Oscillatorn Phase noise -110dBc/Hz @ 1Hz (10MHz)n Phase noise -123dBc/Hz @ 1Hz (5MHz)n Stability 2x10 -12 /s (8x10 -13 /s in benign environment) (10MHz)n Stability 5x10 -13 /s (5MHz)SpecificationFrequencyOutput5 & 10MHz, other frequencies in range 4–20MHz by requestSine wave 7dBm (±2dBm)Features• Very low phase noise• High stability (AVAR)Benefits• Improves considerablyinstrument noise andstability specifications• The basic internalquartz referenceApplications• One of the keycomponents inQuartzlock’s Very LowNoise instrumentsFrequency Ageing Rate per day, at dispatch

A5-81...100MHzDistribution Amplifiern Exhibits low 1/f AM & PM noiseThe Quartzlock A5-8 Distribution Amplifier is a precision distribution amplifier for use with FrequencyStandards or other signals where a need for multiple outputs from a single generator is required.Available in 8 outputs. The A5-8 replaces previous A5 models; the specification has improvedisolation and other parametrics. NB This specification is provisional at time of going to press, finalspecification due June 2012, ask Quartzlock.Features• High Isolation between inputs and outputs• Ultra low phase noise• Ultra high stability• Very low harmonic distortion• Bipolar Junction Amplifiers 24Vdc BBU &/or 90 ...240Vac operationBenefits• Hydrogen Maser compatible performance• Retains original input signal characteristics• 8 outputs• May be supplied with two or three channel inputs• No cross channel interference between outputs formission critical applicationsApplications• Frequency Distribution where the highest levels of stability and lowest levels of phase noise are required• National Standards Laboratories• Calibration Laboratories• Research and Development• Production Test8Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

A5-8Typical Characteristics *No of outputs 8No of inputs1 to 4 (Note mixed frequencies are permitted inone unit)Input characteristicsImpedance:Level:Input SWR:Output CharacteristicsImpedance:Level:Output SWR:Frequency ResponseHarmonicsIsolationa) Output to output:b) Output to input:c) Input to input (crosstalk):Phase Noise @ 10MHz1Hz10Hz>100HzShort term stability@ 10MHz1s10s100sSpurious OutputsBroadband NoiseDelay match between outputsTemp stability of delayPhase change at outputOutput Failure Alarm50 Ohm nominal0dBm to +13dBm adjustable, sine wave110dB at 10MHz >90dB at 100 MHz >90dBat 5MHz >80dB at 10MHz>55dB at 100MHzdBc/Hz-140-150-165

new 2007 economy ‘1U’ lineinstrumentsQuartzlock instrumentsQuartzlock E5000 SPECIFICATION Quartzlock Low phase noise • low drift • high stabilityCompleteOutput Low A Fully phaseSpecified, noise • low AccuracyQuartzlock new 2007 economy drift 1–20MHz • high‘1U’ stabilityLow phase noise • lowdrift • stability lineLow Cost DistributionPhase to NoiseAmplifier(SSB)Quartzlock instrumentsphase noiseFrequency• low drift • high stabilityQuartzlock Quartzlock Quartzlock 10MHz • -165 dBc/Hz Input Power phase noise • 1 x 10 -12 /sControl10MHz• -165 dBc/HzSolutionsn Comprehensive Specification13Wphasen Excellent Short Term Stability & Phase noise Noise • 1 x 10 -12 /s Quartzlock Input 10MHz • -165 dBc/HzVoltage Rangephase noise • 1 x 10 -12 90-240V acn 1MHz – 20MHz Bandwidth/sQuartzlocklowest Low phase noisecost• lowtodrifthighest• high stabilityQuartzlock 10MHz • -165 dBc/Hz phase noise • 1 x 10 -12 /s Quartzlock Quartzlock Up to 24 outputs from 1 or 2 inputsperformance Up to 24 outputs from 1 available2 inputsExternal trim range to:Quartzlock Up tocontrol/calibrate/referenceQuartzlock 24 outputs from 1 or 2 inputsThe E5000 Distribution Amplifier is a Short 1U Rack term Mount stability unit. The E5000 allows a cost and space 3x10 -11 /1s10MHz Up to 24• outputs -165 dBc/Hz from 1phase or 2 inputs noise • 1 x 10 -12 /s Quartzlock outputs of the same frequency. spectrum Quartzlockanalysers, network analysers, frequencycounters, Features signal sources, microwave Benefits analysers, Harmonicsdigital • Compact design• Unity Gain storage A4000 scopes. Second HarmonicRF Switch Unit • -115dBc/Hz @ 1Hz phase noise• 0dBm to 10dBm input• 90dB @ 10MHz IsolationRedundant ThirdRF Harmonic • HighSwitchStabilityUp with toRS232 24 outputs i/o NMEA fromNTP, 1 orlock 2 inputs adviceUnitetc.• High IsolationAccurate Foruseusewithwith & Stable RbRbandand Low GPSGPS Noise referencesFrequency Drift• referencesLow Distortion10MHz RubidiumReference A4000 Redundant signals. 10 -12 RF to 10 Switch -14 accuracy Unit & stabilitylevels & _ 125dBc/Hz @ 1Hz or _ 178dBc noise floor.ApplicationsQuartzlock A4000 Redundant StatusRF MonitorsFor • Industrial use Calibration with Laboratories Rb and GPS references Switch Unit• TelecomsFor use with Rb and GPS references• Test SolutionsOperating Temp. Range• RF Test Benchfrom• Production Test Quartzlock can combine any of the aboveTemperature Coefficient (ambient) 3x10instruments Quartzlock into can a combine single 1U any unit of to the meet above-10 (-20° to 50°C£1000 engineStorage Temperature -40° to 70°Cspecified Quartzlock instruments requirements. can into combine a single any 1U unit of to £3000 the to above meetMTBF100,000 hoursQuartzlock instruments specified A4000 Redundant requirements.can into combine a singleRF Switch any 1U unit of 'use Unit the tofrommeet above the box'ConnectorsBNC RF & IEC line supply inputChoice For useof with technologies, Rb and GPS GPS references or Rb + _ clean up loop.Tel +44 (0)1803 862062Email sales@quartzlock.com10instruments Fax +44 (0)1803 867962 into a single 1U unit to www.quartzlock.com meetspecified requirements.Low phase noise • low10MHz sine 0.7V rms into 50 ohms±5x10 -11 at shipment @25°C-100dBc (10Hz-120 dBc (100Hz-140 dBc (1KHzWarm Time 5 minutes to lock @ 25°CRetrace ±3x10 -11Frequency Control Internal (external ask Quartzlock)Internal trim range (trimpot) greater than 2x10 -9greater than 2x10 -9 (0V~5Vefficient way to distribute reference frequencies throughout a system or lab with virtually no signaldegradation. The standard E5000 accepts input frequencies of 1MHz to 20MHz and provides twelveSize51x10 -11 /10s3x10 -12 /100s/hour/day-48 dBc-45 dBc3x10 -12 /day, 3x10 -11 /monthLock and On LED-20°C to +50°C19” Rack 1 U (44mm/1.75”

E5000SpecificationNo of Outputs 12No of Inputs 1InputcharacteristicsOutputcharacteristicsFrequency responseHarmonicsIsolationShort term stability(at 10MHz)Phase Noise(10 MHz)Spurious outputsBroadband noiseImpedanceLevelInput SWRImpedanceRated outputOutput SWR 70dB at 10MHzOutput to input >90db at 10MHz2 x 10 -13 tau=1sec2 x 10 -14 tau=10sec5 x 10 -15 tau=100secOffset1Hz10Hz100Hz1kHz10kHz & Noise floor< -100dBc< -155 dBc/HzTypical phasenoise,dBc/Hz-132-145-152-158-160Delay matchbetween outputsDelayinput to outputSupplySizePhase Noise< 1 ns< 6ns85 ... 240V ac1U 19” 44 x 483 x 240mmQuartzlock E5-X6Agilent E5500 Carrier: 10E+6 Hz 06 Jun 2011 08:25:52 - 08:27:32-80-90-100-110-120-130-140-150-160-170-180110 100 1K 10K 100K 1ML(f) [ dBc / Hz ] vs f [ Hz ]10MTypical Output to Output StabilityMeasured in 200Hz bandwidthTauAllan Variance1ms10ms100ms1s5s10s100s1,000s5x10 -118x10 -128x10 -132x10 -132x10 -141.5x10 -143x10 -151x10- 1510,000sx10- 16 Ask Quartzlock for plotsTel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com 11

E5-XFully Specified, Low Cost, DesktopDistribution Amplifiern Compact Desktopn 1MHz–20MHz Bandwidthn Comprehensive Specificationn Excellent Short Term Stability & Phase NoiseApprox actual sizeFeatures• Very Low Cost & Very Small Size• 1MHz–20MHz Bandwidth• Comprehensive Specification• Excellent Short Term Stability & Phase Noise• 6 outputsBenefits• +13dBm Output Level• +6dBm to +12dBm• High Stability• Low Distortion• High IsolationApplications• Industrial Calibration Laboratories• Telecoms• Test Solutions• RF Test Bench• Production Test12Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

E5-XSpecificationsNo of outputs 6No of inputs 1Input characteristicsImpedanceLevelInput SWR50 ohm nominal+10dBm nominal+6 dBm to +12 dBm60dBAsk Quartzlock>90db at 10MHz2 x 10 -13 tau=1sec2 x 10 -14 tau=10sec5 x 10 -15 tau=100secTypical phase noise,OffsetdBc/Hz1Hz10Hz100Hz1kHz10kHz100kHz< -100dBc< -155 dBc/Hz< 1ns-132-145-152-158-160-160Phase NoiseQuartzlock E5-X6Agilent E5500-80-90-100-110-120-130-140-150-160-170Carrier: 10E+6 Hz 06 Jun 2011 08:25:52 - 08:27:32-180110 100 1K 10K 100K 1ML(f) [ dBc / Hz ] vs f [ Hz ]10MTypical Output to Output StabilityMeasured in 200Hz bandwidthTauAllan Variance1ms5x10 -1110ms8x10 -12100ms8x10 -131s2x10 -135s2x10 -1410s1.5x10 -14100s3x10 -151,000s1x10 -1510,000s8x10 -16Output to Output StabilityAsk Quartzlock for plots. Typically x10-14/sTel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com 13

A6-1PPSOEM 1PPS Timing Modulen Compact form factorn License availablen Very fast lock to GPSSTOP PRESS Now available as a complete instrumentThis is a PCB level product to control an OCXO or Rubidium oscillator from an external 1PPS.The A6-1PPS uses a 3 state Kalman filter algorithm to measure & correct the frequency offset of theoscillator with respect to the 1PPS input. Time-tagged 1PPS to 200ps resolution &

A6-1PPSA locking module for timingThis module is designed to lock a 10MHz stable oscillator, either OCXO or rubidium, to the 1PPS time marksignal generated from a GPS receiver. The module can be programmed for a wide range of controlled oscillatorparameters, and GPS receivers. The controlled oscillator can be either on or off the board. A stable 1PPS timemark is generated from the controlled oscillator. This can be adjusted to any offset from the GPS 1PPS in 1ns steps.The control algorithm used is designed to give optimum control results and the fastest possible acquisitionfrom switch on.Design strategyThis module is designed to lock a 10MHz stable oscillator, eitheran OCXO or a rubidium, to the 1PPS time mark signal generated froma GPS receiver.There are a number of challenging problems involved in this, asthe data rate by definition is only one measurement per second. Inorder to get sufficient frequency resolution to correct the oscillator, avery long averaging time would be required.Because the 1PPS time mark is a fast rise time logic signal, theonly measurement that is feasible is to time tag the incoming1PPS edge relative to a local clock driven by the controlledoscillator. By calculating the rate of change of the arrival time overa suitable averaging period, the frequency offset of the controlledoscillator can be calculated. An alternative strategy would be to setthe time of the first 1PPS arrival as the zero phase of a phase detectorwith a range of +/- 0.5s. This is equivalent to +/- Pi radians. A phaselock loop would then provide a very slow control of the oscillator.In both systems the timing accuracy and resolution of theincoming 1PPS is important. Modern GPS receivers provide a 1PPSoutput jitter of between 1us RMS for a navigation receiver, to lessthan 7ns RMS for a special timing receiver operating in position holdmode. It is desirable that the timing resolution of the module shouldbe better than this, as otherwise quantization noise would enterthe averaging process and degrade the performance of the system.It would only be possible to compensate for this by increasing theaveraging time. A suitable specification for time resolution is +/- 1ns.To achieve this directly would need a 1GHz clock. A much moresuitable method is an analog time interval expander. This device hasbeen used in many designs of frequency counter starting with theRacal 1992. The principle is that an error pulse is generated whichhas a width equal to the time between the incoming edge to betimed, and the next clock pulse. For example, with a 100ns clock,the error pulse will have a width of between 0 and 100ns. This errorpulse is then used to charge a capacitor or integrator. The capacitoror integrator is then discharges at a much slower rate, say 1/1000of the rate. The resulting stretched pulse is then measured using theavailable clock pulses. The improvement in resolution equals the ratioof the discharge to charge rate. For the example above the resolutionwill be 100ps.The next thing to consider is the choice of the controlalgorithm. This must provide an appropriate control bandwidth sothe short term stability of the controlled oscillator (Allen variance)is optimised over a wide range. The ideal bandwidth will varyconsiderably between a low cost OCXO, and a rubidium.One option is to use a simple phase lock loop. This would bea type 2 second order loop ( ie with an integrator in the loop filter)with a zero to give suitable phase margins for optimum dynamicperformance. However one problem with a phase lock loop is that itmust reduce the initial phase error to zero by changing the frequencyof the VCO. With the very long loop time constant necessary toremove the effect of the GPS time jitter, the eventual settling of theloop could take several days. It is also difficult to extract measures ofperformance from the loop, for example it is difficult to estimate thecurrent frequency error of the VCO. It was felt that a frequencycontrol loop would settle quicker. For a frequency standard we donot mind operating with a fixed phase offset, and there is no need toreduce this to zero.Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com15

A6-1PPS16One possible method of extracting frequency offset fromphase data is a quadratic least squares fit on a block of data.This is a standard method for extracting phase offset, frequencyoffset, and frequency drift from phase difference information. Havingextracted the offset frequency, we can then make a correction to thecontrolled oscillator to remove the offset. If the control constant wasknown exactly, there would be no under or overshoot. The problemwith this method is that we do not know how large to make theblock of data that we analyse. The reliability of the fit is given bythe correlation coefficient, and ideally this should be monitored ona continuous basis. What is required is a continuous least squaresprocess. This is of course, a Kalman filter, and this was the eventualmethod selected for implementing the control algorithm.The Kalman filter will be briefly described in general in a (hopefully)simple way, and then the specific implementation for our problemwill be described in more detail.A block diagram of a Kalman filter is given in figure 1. It is basicallya recursive estimation, based on noisy measurements, of the future“state” of a system . The system is defined as a “state vector” anda “state transition matrix”. The system in our case would be thecontrolled oscillator that we wish to predict, and the state vectorwould contain the phase offset, frequency offset, and frequencydrift variables. The “state transition matrix” defines the differentialeconomical design. The basic ns clock to give a basic ±200 pstiming Tel resolution +44 is (0)1803 400 ns resolution. 862062(one processor cycle at a 10MHzclock frequency). Fax +44 (0)1803A time867962interval expander mustbe calibrated as otherwise aThe time interval expander extendsthe resolution by 2000 the time error pulse rollsglitch will be produced whenoverFig. 2: Kalman filterond, the dead time is used tocalibrate the time expander. Thehardware generates exact pulsesof 100 ns and 500 ns by gatingfrom the 10 MHz clock. Theseare expanded and measured. Therelationship that exists between the state variables over one timeincrement. The concept of a system driven by noise processes isimportant here. If our Rb had absolutely constant drift, its outputphase would be known for all time once the initial drift , frequencyoffset and phase offset had been determined. Data gathered a yearago would have as much validity as data an hour old. If the Kalmanfilter is given this model of the Rb, the results are identical to theleast squares fit of all the data. Of course the quadratic least squaresfit assumes that the Rb can be modelled by three constants.A more realistic physical model would allow the drift to vary.If this varied in a deterministic way, we should add a further termto the state vector to reflect this deterministic process. However ifthe variation was random, we can tell the Kalman filter that thisis so. Note that the filter is only optimum for white gaussian noiseprocesses. However in our case we can model the noise of the Rboscillator more accurately by adding white gaussian noise to eachterm in the state vector. If we add some uncorrelated noise to eachterm in the state vector, we end up with white phase noise, whiteFM noise, and random walk FM noise due to the single and doubleintegration in the model. This is shown in figure 2.The measurements are also assumed to be contaminated withgaussian white noise. In our case we only have one measurement,that is phase offset. We do not know that the main contributer tomeasurement noise, the GPS receiver, is either white or gaussian.16 bit DACs are used, with theoutput However of the fine this tune is a DAC limitation of the simple Kalman filter that we intenddivided by 256 and added tothe to output use. of If the we coarse are sure tune of the characteristics of the measurement noise,DAC. we This can gives include effectively this 24 knowledge by adding more terms to the statebit resolution with an overlapbetween vector. the We coarse are and then fine essentially including the known aspects of thetune measurement DACs. A software in the nor-systemalisation process ensures thatmodel.the fine tune DAC is used fortuning As most well of as the the time. state Only vector, the Kalman filter maintains awhen matrix the controlled that gives oscillator the current variances (mean square error) ofhas drifted out of range of thefine the tune quantities DAC would the coarse in the state vector. These give us current estimatestune DAC need adjusting, withthe of chance the of likely a very small errors glitch in the state vector, in our case variances of phasein offset, the tuning frequency voltage. A precision,low noise, voltage referenceoffset, and frequency drift. These will be very usefulis used for to display supply the to DACs. the user. They also have another use, which will beThe demonstrated microcontroller is provided later. In effect they control the “bandwidth” of thewith an RS232 interface. A simpleset of control codes enablefilter. As more data comes in, the variances decrease, and the filtermonitoring gives more and set weight up of the to the current estimate( which represents thecontrolled oscillator parametersto complete accommodate history a wide range of the data), and less to the current measurement.of controlled The measurement oscillators. A Windowsfront end program will usevariance, which we have to tell the filter, alsothe affects control codes the to “bandwidth”. enable the If we tell the filter that the measurement isoperation of the PLL to be monitorednoisy, with it real reduces time graphs the of bandwidth.performance measures.So far we have considered the Kalman filter as a device for analysingSoftware the incoming design data in an optimum way. However we need toIn control normal operation the Rb the oscillator, auto and reduce the frequency offset tocalibration performs calibrationcycles zero. every An 20 ms. elementary The approximatetime of arrival of the nextmethod would be to write periodic corrections1PPStoinputthe Rbpulsecontrolis known,DAC,soand wait for the Kalman filter to track out thethe resulting calibration cycles discontinuity are paused in the measurements.However there is a muchwhile the 1PPS is measured. Theraw better measurement way. of If the we arrival adjust the frequency offset term in the state vectortime at is the corrected same for time the actual that we correct the Rb , the filter will ignore theexpansion ratio and is scaled tolie correction, in the range -500.000000 and no to extra settling time will be required. In effect we+499999999 ns relative to theinternal are defining clock. the model of the Rb to have a frequency discontinuity atTechnical feature 19The first valid 1PPS edge to arriveafter reset is used to zero theinternal clock. This makes thearrival time initially close to zero,and avoids problems with lackof precision in the floating pointEmail sales@quartzlock.comwww.quartzlock.com

A6-1PPSa particular time, and provided the real Rb has that discontinuity, theKalman filter will see no difference between the model, and what themeasurements are telling it about the real system.Using this technique, we can correct the Rb as often as welike. However if we are uncertain as to the exact value of thecontrol constant, then the correction will undershoot or overshootthe model. Another trick that can be useful is if we know that thereis a measurement discontinuity, but we do not know how largeit is. An example would be if the GPS signal disappears for anyreason. When satellites were reacquired, there could be a phasediscontinuity between the GPS 1PPS and the locking module internalclock. Although we cannot tell the filter the amount or direction ofthe discontinuity, we can tell it that its current estimate of phase iscompletely unreliable. We do this by adding a large number to theappropriate term of the error covariance matrix. The filter then givesmaximum weight to the measurements to reacquire the phase asquickly as possible, however as it thinks its frequency is still accurate,it does not give excessive weight to the rate of change of phasemeasurement, and the frequency covariance hardly rises.The Kalman filter can predict ahead if measurement data fails.In this case both the state vector and the error covariance matrix willbe updated. The previously estimated value of drift will update thefrequency offset automatically. Frequency corrections can be madein the usual way.The error covariances will rise to reflect the lowerconfidence in the predictions as time passes. When measurementsresume, the filter will automatically recover and the error covarianceswill start to fall. Thus the user is always aware of the reliability ofthe frequency output. If an unknown phase step is expected onresumption of measurements, then the phase variance should beaugmented as previously described.Technical details of designThe design is based around a PIC18F6723 microcontroller. This is ahigh end controller with 5 capture/compare modules and 4 timer/counters. The time interval expander is tightly integrated with theprocessor internal peripherals to produce an economical design. Thebasic timing resolution is 400ns (one processor cycle at a 10MHzclock frequency). The time interval expander extends the resolutionby 2000 times. In order to avoid the problems of expanding a pulseof zero width, one cycle of the 10MHz clock (100ns) is added to thetime error pulse. This gives an unexpanded pulse width of 100ns to500ns. After expansion, the pulse is 200us to 1ms. This is timed bythe 400ns clock to give a basic +/-200ps resolution.A time interval expander must be calibrated as otherwise a glitchwill be produced when the time error pulse rolls over from 500ns to100ns, and vice versa. This is caused by the expansion ratio not beingexactly the expected 2000 times. The expansion ratio may drift withtime and temperature.As the incoming 1PPS only needs measuring once per second, thedead time is used to calibrate the time expander. The hardwareTel +44 (0)1803 862062Fax +44 (0)1803 867962generates exact pulses of 100ns and 500ns by gating from the10MHz clock. These are expanded and measured. The calculatedend points of the expanded pulse are used to correct the realmeasurement of the incoming 1PPS. This auto calibration operatescontinuously.The control of the OCXO or other controlled oscillator uses aprecision tuning voltage derived from DtoA convertors . Two 16bit DACs are used, with the output of the fine tune DAC dividedby 256 and added to the output of the coarse tune DAC. This giveseffectively 24 bit resolution with an overlap between the coarse andfine tune DACs. A software normalisation process ensures that thefine tune DAC is used for tuning most of the time. Only when thecontrolled oscillator has drifted out of range of the fine tune DACwould the coarse tune DAC need adjusting, with the chance of avery small glitch in the tuning voltage. A precision, low noise, voltagereference is used to supply the DACs.The microcontroller is provided with an RS232 interface. A simpleset of control codes enable monitoring and set up of the controlledoscillator parameters to accomodate a wide range of controlledoscillators. A Windows front end program will use the control codesto enable the operation of the PLL to be monitored with real timegraphs of performance measures.Software designIn normal operation the auto calibration performs calibration cyclesevery 20ms. The approximate time of arrival of the next 1PPS inputpulse is known, so the calibration cycles are paused while the 1PPS ismeasured. The raw measurement of the arrival time is corrected forthe actual expansion ratio and is scaled to lie in the range -500.000000to +499999999 ns relative to the internal clock.The first valid 1PPS edge to arrive after reset is used to zero the internalclock. This makes the arrival time initially close to zero, and avoidsproblems with lack of precision in the floating point calculationswhich follow.The corrected time tag is sent to the Kalman filter routinewhich runs once every second. The estimate of the controlledoscillator phase, fractional frequency offset, and drift (the statevariables) is updated by the new measurement. Also updated is theerror covariance matrix which provides an indication of the accuracyof the estimate of the state variables.After update of the filter, the frequency correction for the controlledoscillator is calculated. This is done by scaling the Kalman frequencyoffset estimate by the known ( programmed) tuning slope of theoscillator. The correction is then added to the frequency controlregister of the oscillator.The tuning voltage is divided between the coarse and fine tuneDACs as follows: When normalisation is performed, the fine tuneDAC most significant 8 bits are set to mid point ( 80h). The leastsignificant 8 bits of the fine tune DAC are set to the least significantEmail sales@quartzlock.comwww.quartzlock.com 17

A6-1PPS8 bits of the tuning word. The coarse tune DAC is then set to providethe final tuning voltage. During all subsequent tuning, only the finetune DAC is used over its 16 bit range. If the range is exceeded, thenormalisation procedure is repeated.A state machine provides control of locking. After reset the lastvalue of the frequency control register, which has been stored inEEPROM on a regular basis, is restored. This will retune the controlledoscillator to very nearly the correct frequency. The Kalman update isdisabled and the software waits for the following all to occur (state0):a) Rubidium reference warm up input to go low or OCXO supplycurrent to drop below a threshold showing the Rubidium/OCXO haswarmed upb) A 1PPS input capture has occuredThe sofware then requests a reset of the internal clock (state 1). Thiswill normally occur on the next 1PPS to be received.Once a clock reset has occured, the Kalman filter trackingis started, however frequency corrections are not made to thecontrolled oscillator. (state 2) Each capture must be within 50us ofthe first capture, otherwise the reset state is reentered. After 100successful captures, state3 is entered provided the performancemonitor, MEANFREQERROR is below a threshold.falls below a second threshold. At this point the lock indicator isswitched off. (state 4)The following parameters set up the Kalman filter to match thecontrolled oscillator:a) Oscillator noise parameters:S1 variance of random walk FM noiseS2 variance of white FM noiseS3 variance of white phase noiseOC1OC2oscillator tuning constant in fractional frequency/voltmaximum oscillator tuning voltage in volts, assuming 0Vminimumb) 1PPS noise root variance (a function of the GPS receiver used)R measurement noise root variance in secondsThese parameters are programmed over the RS232 interface, and arestored in non volatile memory.The oscillator noise parameters may be obtained from a measuredAllen variance curve using a MathCad modelling program.18The performance monitor, MEANFREQERROR is calculated as follows:The mean of the Kalman frequency offset estimate is calculatedby means of a 5th order exponential filter. ( In the pre lock statethe mean may not be near zero, ie there may be a constant offsetbetween the controlled oscillator and GPS time)After each iteration of the Kalman filter, the current deviation iscalculated by subtracting the current frequency offset estimate fromthe running mean. This value is squared, and divided by the predictedvariance from the error covariance matrix that is maintained by thefilter. This normalises the actual deviation that is seen by the predicteddeviation from the filter. (The predicted deviation only depends uponthe system and measurement noise parameters NOT on the actualbehaviour of the system.)The normalised deviation in then filtered in a 4th order exponentialfilter. During warmup the performance measure will be high, indicatingthat the controlled oscillator is still drifting fast, relative to its predictedsteady state performance. When the controlled oscillator is stable, andthe Kalman filter has settled, the performance measure will drop belowa threshold. At this point frequency corrections will be started. (state 3)In state 3 corrections are made to the controlled oscillator. The filterand oscillator will continue to settle, until the performance monitorTel +44 (0)1803 862062Fax +44 (0)1803 86796218Technical featureFig. 1: Noise model of oscillatorto predict, and the state vectorwould contain the phase offset,frequency offset, and frequencydrift variables. The „state transitionmatrix“ defines the differentialrelationship that existsbetween the state variables overone time increment. The conceptof a system driven by noiseprocesses is important here. Ifour Rb had absolutely constantdrift, its output phase would beknown for all time once the initialdrift, frequency offset andphase offset had been determined.Data gathered a yearago would have as much validityas data an hour old. If theKalman filter is given this modelof the Rb, the results are identicalto the least squares fit of allthe data. Of course the quadraticleast squares fit assumesthat the Rb can be modelledby three constants.A more realistic physical modelwould allow the drift to vary. Ifthis varied in a deterministic way,we should add a further term towith white phase noise, whiteFM noise, and random walkFM noise due to the single anddouble integration in the model.This is shown in figure 2.The measurements are also assumedto be contaminated withgaussian white noise. In our casewe only have one measurement,that is phase offset. We do notknow that the main contributerto measurement noise, the GPSreceiver, is either white or gaussian.However this is a limitationof the simple Kalman filterthat we intend to use. If weare sure of the characteristics ofthe measurement noise, we caninclude this knowledge by addingmore terms to the state vector.We are then essentially includingthe known aspects ofthe measurement in the systemmodel.Email sales@quartzlock.comthe Rb , the filter will ignore thecorrection, and no extra settlingwww.quartzlock.comtime will be required. In effectAs well as the state vector, theKalman filter maintains a matrixthat gives the current variances(mean square error) ofrepresents the complete historyof the data), and less to the currentmeasurement. The measurementvariance, which we haveto tell the filter, also affects the„bandwidth“. If we tell the filterthat the measurement is noisy, itreduces the bandwidth.So far we have considered theKalman filter as a device foranalysing the incoming data inan optimum way. However weneed to control the Rb oscillator,and reduce the frequency offsetto zero. An elementary methodwould be to write periodic correctionsto the Rb control DAC,and wait for the Kalman filterto track out the resulting discontinuityin the measurements.However there is a much betterway. If we adjust the frequencyoffset term in the state vector atthe same time that we correctwe are defining the model of theRb to have a frequency disconovershootttrick that cknow thatment disconot knowexample wsignal disapWhen satellthere couldtinuity betwand the locnal clock. Atell the filterection of thcan tell it tmate of phareliable. Welarge numbterm of thetrix. The fiimum weigments to requickly as pit thinks itscurate, it doweight to thphase measuquency covThe Kalmaahead if meIn this caseand the errowill be updaestimated vdate the frematically. Frcan be madThe error cto reflect thin the prediWhen meathe filter wcover and twill start tois always aity of the fan unknowpected on rurements, t

A6-1PPSSpecificationFrequencyInput Level1PPS InputImpedance:Output Level1PPS Input LevelWidthInput Impedance1PPS Output LevelWidthPreset Offset Of1PPS OutputTiming BaselineExternal TuneVoltage10MHz100mv Pp to 5Vpp(Oscillator off board)500 Ohms13+/-2 dBm(Oscillator on board)5V TTL/Cmos positive edge10us Minimum1000 Ohms5V TTL/Cmos positive edge10ms-500000000 To +499999999 Nsin 1ns StepsSelectable between fixed(minimum jitter) or kalman phaseestimate (maximum accuracy)0 to span, where span is softwareadjustable between 5.8V and 10VSpecificationThe Following Cases Are TypicalControlled Oscillator: Rubidium1PPS Source Passive Hydrogen Maser(Essentially no 1PPS Jitter)Result: Allen Variance100s1000s10,000sControlled Oscillator: Rubidium1PPS SourceCurrentConsumptionSize1x10 -123x10 -131x10 -13Quartzlock E8-Y/E8000 GPS Receiverin Position Hold ModeResult: Allen Variance100s1000s10,000s1x10 -121x10 -128x10 -13150mA Typical (On-board Ocxo)25 x 25 x 5mm (Without Ocxo)Lock IndicatorInterfaceInterface CodesPerformancePower SupplyOn Not LockedOff Locked, Low Phase ErrorShort Flash Every Second Locked,High Phase ErrorSee separate documentSee separate documentThe control performance depends verymuch on the quality of the controlledoscillator and the source of the1PPS synchronizing signal. For thesereasons it is difficult to quote absoluteperformance figures.14 to 30V (On board Ocxo is used)An external Ocxo or Rubidium maybe used.12 To 30V (No on-board Ocxo)The Quartzlock A3 series of SC cut OCXO’s are ideal for use on theA6-1PPS design-in board product. The oscillator performance definesthe 1PPS accuracy.A3 specification is typically:Short term stability AVAR 8x10 -13 /second PN -110dBc/Hz @ 1HzPhase noise-110dBc/Hz @ 1Hz offsetTel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com 19

A6-CPSDPLL, DDS Active Noise Filtern 1MHz to 40MHz output frequencyn 4mHz to 500mHz PLL bandwidthsn Compact OEM board for a wide range of applicationsThe A6-CPS digital phase locked loop (PLL) provides an low noise, very high short term stabilityfiltered output which can be customised to a specific application.The A6-CPS digital PLL may be fitted into the Quartzlock A6 frequency convertor with BVA OCXO,rubidium, GPS or other options.Features• RS232 monitor and control• Pre-defined user bandwidths• Wide range of OCXO supportedApplicationsBenefits• Improved phase noise• Improved short term stability• Low cost solution to upgrade existing designs andreferences• Quick and simple to use and integrate• Time and frequency reference for satellite communication ground stations, CDMA, LTE, DTV & DAB• Frequency referencing of interception and monitoring receivers• Wired and Wireless network synchronization• Secure communications, C4, defence and R&D• Radar & navigation systems• Higher definition in MRI imaging systems20Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

A6-CPSTechnical DescriptionThis module is designed to overcome the disadvantages of narrow band width analog phase lock loops used tolock relatively stable oscillators together, or to generate arbitrary frequencies from a 10MHz reference with goodphase noise, freedom from non harmonically related spurii, and good short term stability.When locking a low noise OCXO to a rubidium reference, forexample, the ideal PLL bandwidth will be very much less than 1Hz,probably in the region of 10 to 100mHz.An analog loop will have a very long time constant integrator, leadingto thermal drift, capacitor dielectric absorption, and operationalamplifier offset drift. In addition, acquisition time of the loop will bevery long, and if there is any frequency error, acquisition may notoccur at all. There is also a problem of providing an effective “in lock”indicator to the user, or for use with associated equipment.The digital loop overcomes all these problems. The long time constantintegrator is replaced by a digital integrator that does not drift at all.A combination of an analog phase detector for low noise, and anextended range phase/frequency detector for certain acquisition canbe used. The loop bandwidth can be set to maximum for acquisition,followed by glitch free reduction to the working bandwidth whenthe phase error becomes small. In addition performance measuresrelated to the phase error in the loop, and the frequency error caneasily be derived and used to indicate lock and bandwidth control.As an additional benefit a hold over mode that keeps the controlledoscillator tuning voltage constant if there should be a reference failurecan be easily provided.In order to generate arbitrary frequencies from a 10MHz reference,a DDS synthesiser is used. This has 36 bit resolution and is clocked at10MHz from the reference. Output frequencies of 1.8MHz to 3.6MHzare availableas the reference input to the digital PLL. This enables the controlledoscillator (OCXO) to have a frequency range of 1.8MHz to 28.8MHz.The resolution at 10MHz output will be 1.45x10-11.Technical details of designThe design uses mixer type phase detectors operating at frequenciesbetween 1.8MHz and 10MHz. A dual phase detector is used withquadrature square wave inputs from the controlled oscillator. Themain input , which is split between the quadrature phase detectors,is a sine wave input at a level between 0 and 13dBm, and is linkselected to either come from the 10MHz reference input, or theoutput of the DDS synthesiser.The sine wave signal from the controlled oscillator is converted to asquare wave using a fast comparator. It is then divided by 2, 4 or 8using digital dividers. A link selects direct, 2,4, or 8 divided signals.The output from the dividers forms the “Q” reference signal to the Qphase detector. A quadrature “I” reference is generated by passingthe Q signal through a programmable delay line, which may be set todelays from 10ns to 137ns, in steps of 0.5ns. This enables quadraturereferences to be generated for phase detector frequencies between1.8MHz and 25MHz.The outputs from the phase detectors are filtered and amplified byDC amplifiers with gain control using digital potentiometers. Thegain is controlled by a software AGC system which tries to keep theinput to the ADCs at optimum levels. The phase detector outputs aresampled by two channels of the 10bit AtoD convertor internal to thePIC 16F689 microcontroller. All other functions of the PLL are carriedout by software.The control of the OCXO or other controlled oscillator uses aprecision tuning voltage derived from DtoA convertors . Two 16 bitDACs are used, with the output of the fine tune DAC divided by256 and added to the output of the coarse tune DAC. This giveseffectively 24 bit resolution with an overlap between the coarse andfine tune DACs. A software normalisation process ensures that thefine tune DAC is used for tuning most of the time. Only when thecontrolled oscillator has drifted out of range of the fine tune DACwould the coarse tune DAC need adjusting, with the chance of avery small glitch in the tuning voltage. A precision, low noise, voltagereference is used to supply the DACs.The microcontroller is provided with an RS232 interface. A simpleset of control codes enable monitoring and set up of the digital PLLparameters to accomodate a wide range of controlled oscillators.A Windows front end program will use the control codes to enablethe operation of the PLL to be monitored with real time graphs ofperformance measures.Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com 21

A6-CPSSoftware designThe input to the software is the sampled I and Q signals from thephase detectors. These are sampled at a 1kHz rate. As the finalbandwidth of the PLL will be less than 1Hz, this oversampling enablesprefiltering to be used which extends the resolution and reducesnoise in the 10bit AtoD convertor internal to the microcontroller.Single pole digital filters are used on both the I and Q channels. Theseare implemented as exponential filters which have a 3dB band widthwhich is a function of the “order” of the filter. Filter orders between0 ( no filter) and 15 are provided. This gives bandwidths between114Hz for order 1, and 4.8mHz for order 15. The filter order is variedas the user selected PLL bandwidth is varied.After prefiltering, the I and Q channels, now at 16 bit resolution, aresubsampled at a rate between 15.625 s/s, and 1.953 s/s dependingon the user bandwidth and lock state of the PLL. The “Q” sampleis now divided by the ”I” sample ( after checking that I>Q) to givea binary fraction. This is used to look up the phase value in a TAN-1look up table. The look up table is used to synthesise two types ofphase detector:a) A phase detector with 16 bit resolution between Pi/2 and -Pi/2.b) A phase/ frequency detector with 16 bit resolution between 2Piand -2Pi. This phase detector is equivalent to the well knowndigital phase/frequency detector. This rolls over between 2Pi and0 for positive cycle slips, and between -2Pi and 0 for negativecycle slips, and will always provide reliable lock if there is a initialfrequency error.The output of the selected phase detector now has digital gainapplied, selectable between 1/256 and 128. After digital gain, thephase value is added into the integrator, which is 32 bits wide.In order to make the loop stable, by providing a phase lead, the phasevalue has proportional term gain applied, also selectable between1/256 and 128. This value is added to the upper 3 bytes of theintegrator to give the tuning voltage (24 bits)The tuning voltage is divided between the coarse and fine tuneDACs as follows: When normalisation is performed, the fine tuneDAC most significant 8 bits are set to mid point ( 80h). The leastsignificant 8 bits of the fine tune DAC are set to the least significant8 bits of the tuning word. The coarse tune DAC is then set to providethe final tuning voltage. During all subsequent tuning, only the finetune DAC is used over its 16 bit range. If the range is exceeded, thenormalisation procedure is repeated. A state machine provides controlof locking. After reset the last value of the integrator, which has beenstored in EEPROM on a regular basis, is restored. This will retune thecontrolled oscillator to very nearly the correct frequency. The loop isthen opened and the software waits for the following all to occur(state 0):a) Rubidium reference warm up input to go high.b) OCXO supply current to drop below a threshold showing theOCXO has warmed upc) A measure |I|+|Q| which is an approximate measure of the signallevel at the phase detector to rise above a threshold.When these conditions are fulfilled, the software attempts to lock theloop (state 1) by selecting the phase frequency detector, maximumbandwidth, and maximum subsample rate. It then closes the loopand waits for another measure, which is |phaseresult|, to drop belowa threshold. The measure |phaseresult| is the modulus of each phasecalculation filtered in an 8th order exponential filter, the bandwidth ofwhich, for the 15.625 s/s subsample rate, equals 9.7mHz.Once the lock threshold for |phaseresult| is reached, the lock state (state 2) is entered. The bandwidth is switched to the users selectedbandwidth, which has been maintained in EEPROM, and the phasedetector is switched over to the narrow band phase detector (Pi/2 to-Pi/2). All the time during normal operation , |phaseresult| is beingcompared to a lower threshold than the lock threshold. If it exceedsthis threshold, state 3 is entered which provides a brief flash of thelock LED to warn the user that the selected bandwidth may be toonarrow for the PLL to track the drift of the controlled oscillator fastenough. This low threshold is currently set at 480ps maximum phaseerror.In extreme cases the lock threshold (4.8ns phase error) may beexceeded, in which case the software assumes lock is lost and reentersstate 1. A further performance measure is calculated, whichis available over the interface. This is the first difference of the phaseerror, filtered in an 8th order exponential filter. It is corrected forsubsample rate, and has a constant sensitivity of 5.8x10-15 per bit. (at 10MHz phase detector frequency)This performance measure gives the mean fractional frequencydifference between the controlled oscillator and the reference, and isuseful for setting up the optimum bandwidth of the PLL.The band width and damping of the PLL is controlled by 4parameters, integrator digital gain, proportional digital gain, prefilterorder, and subsample rate. These are preset for 8 values of userselected bandwidth, and can only be changed by modifying thesoftware. It is possible to temporarily adjust the four individualparameters as part of a test procedure carried out over the RS232interface. The selection of the 4 parameters has been optimisedusing a mathematical model of the PLL modelled as a MATHCADspreadsheet. This could be made available to customers who wishedto readjust the PLL parameters.22Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

A6-CPSSpecificationReference InputFrequencyLevelInput ImpedianceControlled OscillatorFrequencyLevel (external oscillator)Phase NoiseStability Allan VarianceInput ImpedianceExternal Tune VoltagePower SupplyCurrent ConsumptionPLL BandwidthsFrequency Pull inLock IndicatorInterfaceInterface CodesPCB Size10MHz1MHz to 10 MHz100mVpp to 5Vpp1VPP to 5VPP1000 OHMs1MHz to 40MHz1.8MHz to 28.8MHz100mVPP to 5VPPHigh end options-130dBc/Hz @ 1Hz offset-178dBc/Hz @ 10kHz offset8x10 -14 /s500 Ohms(DDS used)(no DDS)(DDS used)(no DDS)(no DDS)(DDS used)Typical option-110dBc/Hz-160dBc/Hzx10 -13 /s0 to SPAN, where SPAN is software adjustable between 5.8V and 10VNotes: a) If DDS is not used, controlled oscillator must be k times higher frequency than refeence,where k is link adjusted to 1,2,4,8b) Either reference or controlled oscillator must be 10MHz to provide microcontroller clock14 to 30V12 to 30V150mA typical50mAon board OCXO is usedno on board OCXO4mHz to 500mHz typical in 8 binary incrementsUp to 7Hz initial frequency errorOnOffShort flash every secondLong flash, short flashon board OCXOtypical (no on board OCXO)Not lockedLocked, low phase errorLocked, high phase errorNo processor clock9.6kbaud, RS232, PC compatible, Windows front end program or USBAsk Quartzlock for separate document94 x 75mm (may be substantially reduced in customised version). OCXO may mount off PCB.Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com 23

A6-ANFActive Noise FilterAtomic Clock Clean up Oscillatorn 1MHz to 40MHz output frequencyn 4mHz to 500mHz PLL bandwidthsn Primary reference compatibleThe A6-ANF Active Noise Filter has an Ultra Low Noise SC OCXO oven-controlled quartz oscillatorwhich is used in Quartzlock’s Active Noise Filter Clean Technology to filter input reference signals.The A6-ANF provides an ultra low noise, very high short term stability filtered output to make asignificant improvement in Rubidium or Ceasium frequency reference.Features• RS232/USB monitor and control• Pre-defined user bandwidths• Comprehensive range of phase noise and STS optionsBenefits• Improved phase noise• Improved short term stability• Low cost solution to upgrade existing references• Quick and simple to use and installApplications• Improved primary reference phase noise• Improved primary reference short term stability24Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

A6-ANFTechnical DescriptionThis module is designed to overcome the disadvantages of narrow band width analog phase lock loops used tolock relatively stable oscillators together, or to generate arbitrary frequencies from a 10MHz reference with goodphase noise, freedom from non harmonically related spurii, and good short term stability.When locking a low noise OCXO to a rubidium reference, forexample, the ideal PLL bandwidth will be very much less than 1Hz,probably in the region of 10 to 100mHz.An analog loop will have a very long time constant integrator,leading to thermal drift, capacitor dielectric absorption, andoperational amplifier offset drift. In addition, acquisition time of theloop will be very long, and if there is any frequency error,acquisition may not occur at all. There is also a problem ofproviding an effective “in lock” indicator to the user, or for usewith associated equipment.The digital loop overcomes all these problems. The long time constantintegrator is replaced by a digital integrator that does not drift at all.A combination of an analog phase detector for low noise, and anextended range phase/frequency detector for certain acquisition canbe used. The loop bandwidth can be set to maximum for acquisition,followed by glitch free reduction to the working bandwidth whenthe phase error becomes small. In addition performance measuresrelated to the phase error in the loop, and the frequency error caneasily be derived and used to indicate lock and bandwidth control.As an additional benefit a hold over mode that keeps the controlledoscillator tuning voltage constant if there should be a reference failurecan be easily provided.In order to generate arbitrary frequencies from a 10MHz reference,a DDS synthesiser is used. This has 36 bit resolution and is clocked at10MHz from the reference. Output frequencies of 1.8MHz to 3.6MHzare availableas the reference input to the digital PLL. This enables the controlledoscillator (OCXO) to have a frequency range of 1.8MHz to 28.8MHz.The resolution at 10MHz output will be 1.45x10-11.Technical details of designThe design uses mixer type phase detectors operating at frequenciesbetween 1.8MHz and 10MHz. A dual phase detector is used withquadrature square wave inputs from the controlled oscillator. Themain input , which is split between the quadrature phase detectors,Tel +44 (0)1803 862062Fax +44 (0)1803 867962is a sine wave input at a level between 0 and 13dBm, and is linkselected to either come from the 10MHz reference input, or theoutput of the DDS synthesiser.The sine wave signal from the controlled oscillator is convertedto a square wave using a fast comparator. It is then divided by 2, 4or 8 using digital dividers. A link selects direct, 2,4, or 8 dividedsignals.The output from the dividers forms the “Q” reference signal to the Qphase detector. A quadrature “I” reference is generated by passingthe Q signal through a programmable delay line, which may be set todelays from 10ns to 137ns, in steps of 0.5ns. This enables quadraturereferences to be generated for phase detector frequencies between1.8MHz and 25MHz.The outputs from the phase detectors are filtered and amplified byDC amplifiers with gain control using digital potentiometers. Thegain is controlled by a software AGC system which tries to keep theinput to the ADCs at optimum levels. The phase detector outputs aresampled by two channels of the 10bit AtoD convertor internal to thePIC 16F689 microcontroller. All other functions of the PLL are carriedout by software.The control of the OCXO or other controlled oscillator uses aprecision tuning voltage derived from DtoA convertors . Two 16 bitDACs are used, with the output of the fine tune DAC divided by256 and added to the output of the coarse tune DAC. This giveseffectively 24 bit resolution with an overlap between the coarse andfine tune DACs. A software normalisation process ensures that thefine tune DAC is used for tuning most of the time. Only when thecontrolled oscillator has drifted out of range of the fine tune DACwould the coarse tune DAC need adjusting, with the chance of avery small glitch in the tuning voltage. A precision, low noise, voltagereference is used to supply the DACs.The microcontroller is provided with an RS232/USB interface. A simpleset of control codes enable monitoring and set up of the digital PLLparameters to accomodate a wide range of controlled oscillators.A Windows front end program will use the control codes to enablethe operation of the PLL to be monitored with real time graphs ofperformance measures.Email sales@quartzlock.comwww.quartzlock.com 25

A6-ANFSoftware designThe input to the software is the sampled I and Q signals from thephase detectors. These are sampled at a 1kHz rate. As the finalbandwidth of the PLL will be less than 1Hz, this oversampling enablesprefiltering to be used which extends the resolution and reducesnoise in the 10bit AtoD convertor internal to the microcontroller.Single pole digital filters are used on both the I and Q channels. Theseare implemented as exponential filters which have a 3dB band widthwhich is a function of the “order” of the filter. Filter orders between0 ( no filter) and 15 are provided. This gives bandwidths between114Hz for order 1, and 4.8mHz for order 15. The filter order is variedas the user selected PLL bandwidth is varied.After prefiltering, the I and Q channels, now at 16 bit resolution, aresubsampled at a rate between 15.625 s/s, and 1.953 s/s dependingon the user bandwidth and lock state of the PLL. The “Q” sampleis now divided by the ”I” sample ( after checking that I>Q) to givea binary fraction. This is used to look up the phase value in a TAN-1look up table. The look up table is used to synthesise two types ofphase detector:a) A phase detector with 16 bit resolution between Pi/2 and -Pi/2.b) A phase/ frequency detector with 16 bit resolution between 2Piand -2Pi. This phase detector is equivalent to the well knowndigital phase/frequency detector. This rolls over between 2Pi and0 for positive cycle slips, and between -2Pi and 0 for negativecycle slips, and will always provide reliable lock if there is a initialfrequency error.The output of the selected phase detector now has digital gainapplied, selectable between 1/256 and 128. After digital gain, thephase value is added into the integrator, which is 32 bits wide.In order to make the loop stable, by providing a phase lead, the phasevalue has proportional term gain applied, also selectable between1/256 and 128. This value is added to the upper 3 bytes of theintegrator to give the tuning voltage (24 bits)The tuning voltage is divided between the coarse and fine tuneDACs as follows: When normalisation is performed, the fine tuneDAC most significant 8 bits are set to mid point ( 80h). The leastsignificant 8 bits of the fine tune DAC are set to the least significant8 bits of the tuning word. The coarse tune DAC is then set to providethe final tuning voltage. During all subsequent tuning, only the finetune DAC is used over its 16 bit range. If the range is exceeded, thenormalisation procedure is repeated. A state machine provides controlof locking. After reset the last value of the integrator, which has beenstored in EEPROM on a regular basis, is restored. This will retune thecontrolled oscillator to very nearly the correct frequency. The loop isthen opened and the software waits for the following all to occur(state 0):a) Rubidium reference warm up input to go high.b) OCXO supply current to drop below a threshold showing theOCXO has warmed upc) A measure |I|+|Q| which is an approximate measure of the signallevel at the phase detector to rise above a threshold.When these conditions are fulfilled, the software attempts to lock theloop (state 1) by selecting the phase frequency detector, maximumbandwidth, and maximum subsample rate. It then closes the loopand waits for another measure, which is |phaseresult|, to drop belowa threshold. The measure |phaseresult| is the modulus of each phasecalculation filtered in an 8th order exponential filter, the bandwidth ofwhich, for the 15.625 s/s subsample rate, equals 9.7mHz.Once the lock threshold for |phaseresult| is reached, the lock state (state 2) is entered. The bandwidth is switched to the users selectedbandwidth, which has been maintained in EEPROM, and the phasedetector is switched over to the narrow band phase detector (Pi/2to -Pi/2). All the time during normal operation, |phaseresult| is beingcompared to a lower threshold than the lock threshold. If it exceedsthis threshold, state 3 is entered which provides a brief flash of thelock LED to warn the user that the selected bandwidth may be toonarrow for the PLL to track the drift of the controlled oscillator fastenough. This low threshold is currently set at 480ps maximum phaseerror.In extreme cases the lock threshold (4.8ns phase error) may beexceeded, in which case the software assumes lock is lost and reentersstate 1. A further performance measure is calculated, whichis available over the interface. This is the first difference of the phaseerror, filtered in an 8th order exponential filter. It is corrected forsubsample rate, and has a constant sensitivity of 5.8x10-15 per bit.(at 10MHz phase detector frequency)This performance measure gives the mean fractional frequencydifference between the controlled oscillator and the reference, and isuseful for setting up the optimum bandwidth of the PLL.The band width and damping of the PLL is controlled by 4parameters, integrator digital gain, proportional digital gain, prefilterorder, and subsample rate. These are preset for 8 values of userselected bandwidth, and can only be changed by modifying thesoftware. It is possible to temporarily adjust the four individualparameters as part of a test procedure carried out over the RS232interface. The selection of the 4 parameters has been optimisedusing a mathematical model of the PLL modelled as a MATHCADspreadsheet. This could be made available to customers who wishedto readjust the PLL parameters.26Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

A6-ANFA6-ANF Typical Stability, Phase Noise and SpuriiFrequency Stability1 to 30s100s1 hour1dayLong Term Stability1 day1 month1 yearPhase Noise dBc/Hz in1Hz BW1Hz10Hz100Hz1kHz10kHzHarmonicsSpuriousWarm Time to 1x10 -9Reference InputFrequencyLevelInput ImpedanceControlled OscillatorFrequencyLevel (external oscillator)External Tune Voltage5 or 10MHz outputs5x10 -13 (options available from 1 ... 2.5x10 -13 )4x10 -135x10 -13x10 -125 or 10MHz outputs5x10 -134x10 -114x10 -1010MHz output-115-146-156-163-168

A7-MXSignal Stability Analyzern Very high resolution:

A7-MXFeatures• Broadband 50kHz–65MHz input with high resolution5 or 10MHz input• Large digital display of phase / relative & absolute frequency• Block storage of data files enables offline analysis• 32,768 data point storage• Crash proof with 24Vdc Battery Back Up• On screen Allan variance and phase noise plots in real time• Measurement error fully specified• Plot print and save functionsBenefits• Unskilled operation• Unequalled performance• External PC enables low cost 2-3 year upgrades• Flexible and easy to use• Saves up to 40% of oscillator R&D timeApplications• Stability analysis of oscillators• Close-in Phase noise analysis• Atomic frequency standard calibration• Active & passive component phase stabilitymeasurement• ADEV, Modified ADEV, TVAR, MTIE etc (with stable 32)• Temperature & Phase testing• Relative & Absolute counter display of Frequency &Phase difference• Precision product characterisation• “National Measurement” level metrology & analysisOutstanding FeaturesThe A7-MX is invaluable in the design of low noise oscillators, atomic frequency standards and passive devices where close in phase noise,freedom from spurii, and phase stability are essential design objectives. The A7-MX is unique in its ability to measure time domain stability ataveraging times from 1ms to weeks, and phase noise from mHz to 500Hz. Discrete spurii can be measured close to the carrier at levels down to-120dBc. The high resolution input operates at 5 or 10MHz. The reference is also at 5 or 10MHz.A lower resolution input is provided which will measure at frequencies between 50kHz and 65MHz. The A7-MX is not limited to researchand development. The real time digital display of fractional frequency offset combined with the high resolution analogue meter makes theproduction setting of all types of frequency standard a simple and rapid operation.Absolute FrequencyFractional Frequency DifferenceStatistics: Max • Min • Mean • Standard DeviationPhase Difference fs • ps • ns • µs • ms • sTel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com 29

A7-MXNarrowband / High Resolution ModeInputsa) Referenceb) Measurement (3 measurement inputs - seenon standard options = A7-MY)c) Input levels:d) Max Freq difference (Filter off):ConnectorsOutputsa) Counter A channelb) Counter B channelc) Counter external referenceFilterNominal 3dB BandwidthsFractional frequency multiplicationSelectableMeasurement resolutionRelative frequency difference modeRMS resolution (filter 200Hz)Measured resolutionHigh multiplierLow multiplierAnalogue Meter Resolution manually selected from 6 rangesFull scale ranges (decade steps)Time constant (linked to range)Time constant multiplierDisplayed NoiseZero driftPhase difference mode(High resolution, Filter 200Hz)RMS resolution (single measurement)Analogue MeterFull scale ranges (decade steps)Displayed noiseZero driftShort-term stability (noise floor)5 or 10MHz sine wave5 or 10MHz sine wave+0dBm to +13dBm into 50ΩLow multiplierHigh multiplierN Type, Front Panel±5x10 -5±5x10 -5±1x10 -5±1x10 -7100kHz square wave CMOS/TTL (frequency mode)10us pulse CMOS/TTL (phase difference mode)10us pulse CMOS/TTL (phase difference mode)10MHz CMOS/TTLSelectable bandwidth IF filter reduces measurement noise200Hz, 60Hz, 10HzHigh multiplier 10 5Low multiplier 10 3A7-MXUsing internal phase/freq. meter (TIC) and Windows softwareDigits/second1x10 -13 /gate time1x10 -12 /gate time±1x10 -7 to ±1x10 -1220ms to 10sx1, x3, x10

A7-MXMeasurement ErrorInput referred self generated spurii10 3 multiplication10 5 multiplicationCorresponding peak phase modulation10 3 multiplication10 5 multiplicationAllan Variance Error (due to each spur)10 3 multiplication10 5 multiplication

A7-MXTypical Narrowband Performance (PSD)Typical Narrowband Typical Performance Narrowband (PSD) Performance (PSD)A7-MX Phase Noise Floor (10MHz) – Narrowband high resolution mode. 500mHz to 500Hz offsetA7-MX Phase Noise Floor (10MHz) – Narrowband high resolution mode. 500mHz to 500Hz offsetA7-MX Phase NoiseFloor (10MHz) –Narrowband highresolution mode.500MHz to 500Hzoffset32A7-MX Phase Noise Floor (10MHz) – Narrowband high resolution mode. 300uHz to 500Hz offsetTel +44 (0)1803 862062Fax +44 (0)1803 867962A7-MX Phase Noise Floor (10MHz) – Narrowband high resolution mode. 300uHz to 500Hz offsetA7-MX Phase NoiseFloor (10MHz) –Narrowband highresolution mode.300uHz to 500Hz offsetEmail sales@quartzlock.comwww.quartzlock.com

TypicalTypicalNarrowbandNarrowbandPerformancePerformanceGraphsGraphs(AVAR)(AVAR)A7-MXTypical Narrowband Performance Graphs (AVAR)A7-MX Allan Variance (10MHz) – Narrowband high resolution mode. 10 -3 s to 10s (red plot is predicted)A7-MX Allan Variance (10MHz) – Narrowband high resolution mode. 10 -3 s to 10s (red plot is predicted)A7-MX Allan Variance(10MHz) – Narrowbandhigh resolution mode.10 -3 s t0 10s (red plot ispredicted)A7-MX Allan Variance (10MHz) – Narrowband high resolution mode. 10 -1 s to 8x10 -4 s (red plot is predicted)A7-MX Allan Variance(10MHz) – Narrowbandhigh resolution mode.10 -1 s t0 8x10 -4 s (red plotis predicted)Tel +44 (0)1803 862062Email sales@quartzlock.comFax A7-MX +44 (0)1803 Allan Variance 867962 (10MHz) – Narrowband high resolution mode. 10 www.quartzlock.com 33-1 s to 8x10 -4 s (red plot is predicted)

Broadband Allan variance noise floor. 100ms to 1000Hz offset (red plot is predicted)Typical Broadband PerformanceGraphs Typical Broadband (PSD & AVAR) PerformanceGraphs (PSD & A7-MX AVAR)Typical Broadband Performance Graphs (PSD & AVAR)Broadband Phase noise floor. 300mHz to 500Hz offsetBroadband Phase noise floor. 300mHz to 500Hz offsetBroadband PhaseNoise Floor 300MHz to500Hz offset34Broadband Allan variance noise floor. 100ms to 1000Hz offset (red plot is predicted)Tel +44 (0)1803 862062Fax +44 (0)1803 867962Broadband AllanVariance Noise Floor.100ms to 1000Hzoffset (red plot ispredicted)Email sales@quartzlock.comwww.quartzlock.com

A7-MXOperational DescriptionThere are two inputs on the front panel. One of these is for thephase/ frequency reference which will often be an atomic frequencystandard. The reference frequency can be 5 or 10MHz with automaticswitching. The other input is for the measurement signal, also 5 or10MHz, also with automatic switching.There are pushbutton controls for phase/frequency mode, multiplierratio , filter selection, sampling rate (tau) and phase reset. There are alsoa number of controls which adjust the analog meter function. There areindicator lights to confirm that the reference and measurement inputsare at the required level, and that the internal phase locked multipliersare locked. The analog meter shows fractional frequency difference withfull scale ranges from +/-1x10-7 to +/-1x10-12, and phase differenceswith full scale ranges from +/10us to +/-100ps.When the instrument is connected to a PC, the control positions areread by the PC and displayed on the virtual control panelOn the rear panel is the broadband frequency input which can bebetween 50kHz and 65MHz. Also on the rear panel are outputs toan external timer/counter, and a switch which adjusts the analoguemeter time constant.The instrument has two main modes, narrowband, high resolution,and broadband. The selection between these modes is made on thePC virtual control panel.In narrowband, high resolution mode, the measured signal must beat 5 or 10MHz. In this mode the instrument uses multiply and mixtechniques to increase the fractional frequency difference ( or phasedifference) between the measured input and the reference. Thisimproves the resolution of the digital phase comparator, and resultsin a theoretical phase resolution of 0.125fs. The actual resolution isnoise limited to about 50fs. The corresponding fractional frequencyresolution is 1x10-13 in one second of measurement time.In broadband mode the multiply and mix is not used. The digital phasecomparator makes direct phase measurements with a resolution of12.5ps. This is comparable to the fastest frequency counters andgives a fractional frequency resolution of 3x10-11 in one second ofmeasurement time, or 2x10-12 with averaging switched on.When connected to a PC, the software provides 4 scalable windows.One of these is the virtual panel and digital display. The other 3 are dataplot, Allan variance plot, and phase spectral density (phase noise) plot.The virtual panel provides control of measurement rate (tau), andmode (narrowband, high resolution, or broadband). Repeaterindicators are provided to show the settings of controls on thephysical instrument. It is possible to store blocks of measurements upto 32768 measurements into a computer file. Once a measurementis started, the instrument will store the complete measurement blockinternally, provide power is maintained. This makes certain that datais never lost, even if the computer crashes and has to be restarted. InTel +44 (0)1803 862062Fax +44 (0)1803 867962order to make sure that a long measurement run is not interrupted bya power failure, the instrument may be powed from a battery supplyof 24V. This will automatically be used if line power should fail.The digital display shows phase or fractional frequency offset dependingupon mode. The units and number of significant digits is adjustable.Averaging mode may be selected from this window. If averaging isoff, the digital phase comparator makes single measurements at theselected sampling rate. If averaging is on, the comparator operatesat the maximum sampling rate of 1ks/s. A block average reduces thedata rate to the slected sampling rate.Dither mode may be selected from this window. Dither is a techniquewhich reduces unavoidable internally generated spurii to below thenoise floor, at the expense of an increase in noise floor. For furtherdetails see operating manual.The data window shows real time accumulation of the data as agraph. The last 8 to 32768 data points may be shown on the graph.A statistics display shows max, min mean, and standard deviation forthe data shown on the graph. The scaling of the y axis may be auto,manual, or max/min.The Allan variance window shows calculated Allan variance for all dataaccumulated since the start of a run. If averaging is off, single phasemeasurements are made at the requested sampling rate and the statisticis true Allan variance. If averaging mode is on, the statistic becomesmodified Allan varaince. The graph title correctly indicates this.The Phase Spectral Density (PSD) window shows phase noise as agraph of L(f) in units of dBc against offset frequency on a log scale.Various window functions and averaging modes are provided. Theroutines are identical to those used in the Industry standard software“Stable32”.The user can select the basic length of the FFT, and also the degree ofoverlap. As data is accumulated, new FFTs are performed on a mix ofold and new data depending on the overlap parameter.Each FFT result can either replace the last graph, be added to a blockaverage, or be used in a continous or exponential average.All FFTs are correctly normalised for bin bandwidth, window ENBW,window coherent gain, and nominal frequency.Frequency data always has a fixed offset removed before being used forthe FFT calculation. Phase data has a fixed slope ramp removed by linearregression. This avoids a large component in the lower frequency binswhich will distort the result, even when windowing is used.A mode is provided for the measurement of discrete components(spurii). In this mode the scale is changed from L(f), dBc/Hz toPower,dBc. Corrections for bin bandwidth and window ENBW areremoved. A flat top window is provided for measurement of discretes,with scallop loss of only 0.01dB.Email sales@quartzlock.comwww.quartzlock.com 35

A7-MXTechnical DescriptionThe principle behind the A7-MX is to increase the resolution of a digital phasemeter. This is achieved by multiplying the frequency to be measured to a higher frequency,and then mixing it down to a lower frequency using a local oscillator derived from thefrequency reference. The principle is illustrated in Figure 1, and has been made the basisof a number of instruments in the past. The relationship is shown for signals down themix/multiply chain for an input signal with a difference of delta f from the reference, andalso for a signal with no frequency difference, but with a phase difference of delta t. (Animportant clarification is that “phase” difference beteween two signals can either bemeasured either in time units or angle units. A measurement in time units does not specifyor imply the frequency of the signals. A measurement in angle units (radians) needs a priorknowledge of the frequency. Throughout this description, phase will be measured in timeunits) It should be noted that a frequency multiplication multiplies a frequency differencebut leaves a phase difference unchanged. Conversely, a mixing process leaves a frequencydifference unchanged, but multiplies a phase difference. When the frequency differencesare converted to fractional frequency differences by dividing by the nominal frequency, itwill be seen that the multiplication factors for frequency and phase are the same.The big disadvantage in the simple approach shown in Figure 1 is that phase drift withtemperature will be excessive. As rate of phase drift is equal to the fractional frequencydifference, the measurement of the frequency of an unknown device will be in error. Forexample, a drift rate of 10ps per second in the first multiplier in the Figure 1 diagram willbe multiplied to 1ns per second at the output. This is equivalent to a 1 x 10 -12 frequencyerror due to drift. Phase drift may occur in mixers and multipliers, but more especially inmultipliers. If harmonic multipliers are used, drift will occur in the analogue filters thatare used to separate the wanted harmonic from the subharmonics and unwanted mixerproducts. If phase lock multipliers are used, phase drift will occur in the digital dividers.To overcome the drift problem, the multiplier/mixer chain is made differential,ie the reference signal is processed in an identical way to the unknown. When the twochannels are subtracted, any drift in the multipliers will cancel. The method of doing thiscan be seen from the functional block diagram of the A7-MX, figure 2. The first stage ofthe processing for both the reference and measurement channels is a multiplication by10 (20 for 5MHz inputs). The multipliers are phase locked loops with a VCXO of 100MHzlocked to the input by dividing by 10 (20 for 5MHz inputs). The phase detectors used aredouble balanced diode mixer type phase detectors. These exhibit the lowest phase driftwith temperature. The dividers used are ECL types with very small propagation delays.The outputs of the dividers are reclocked using a D type flipflop clocked by the 100MHzVCXO signal. In this way the divider delay is made equal to the propagation delay of oneD type, approx 500ps. As a further refinement, the reclocking D types for the referenceand measurement channels are closely thermally coupled. As the divider propagationdelays are equal to the reclocking flipflop delays, the tracking between the reference andmeasurement channels is exceptionally good.The VCXO signals at 100MHz also drive double balanced FET mixers for the first downconversion to 1MHz. The 99MHz LO is common to both the reference and measurementchannels, and is obtained from a 2 way passive inductive type power splitter. The outputfrom the mixers is filtered by diplexer type filters to remove the image at 199MHz andthe signal and LO feed through at 100MHz and 99MHz respectively. The wanted IFs at1MHz are passed without further processing to the second multipliers. The avoidance of IFamplifiers at this point avoids drift which could be substantial as the propagation delay ofthe IF amplifier could be several 100 nanoseconds. IF amplifiers are used for the first IF takeoff points to the IF processing board. The first IFs are used when a multiplication of 103 isselected.The second multipliers are nearly identical to the first multipliers with the difference thatthe phase lock loop dividers divide by 100. This multiplies the first IF of 1MHz to the secondVCXO frequency of 100MHz. The second downconvert is identical to the first, with thesecond IFs being passed to the IF processing board.The first and second multipliers/mixers for the reference and measurement channels arebuilt symmetrically on one PCB (Printed Circuit Board). In order to ensure the best possibletemperature tracking beween the channels, the PCB is in good thermal contact with a thickmetal baseplate. This minimises rapid temperature changes between the channels.The two pairs of IF signals (sine wave) are passed to the IF processing PCB. The two pairsare the outputs from the first and second downconvertors. They correspond to finalmultiplication factors of 103 and 105. Also on the IF processing board is the 99MHz LOgeneration and phase lock. A 10MHz unmultiplied signal is passed to the IF processingboard from the reference channel on the Multiplier board.The 1MHz IFs could be divided down and measured directly by the frequency counter,which would make a time difference measurement between the measurement andreference IF signals. In this way the difference between the channels would be measuredand any drift would cancel. Although this would work for a phase measurement, therewould be no way of making a conventional frequency measurement. The IFs cannot bedirectly subtracted in a mixer as they are both nominally 1MHz, and the nominal differencefrequency would be zero. In order to avoid this problem, the multiplied reference IFis frequency shifted to 900kHz using an LO of 100kHz derived from the unmultipliedreference. The 900kHz is then mixed with the 1MHz measurement channel IF to give afinal IF of 100kHz. This final IF contains the multiplied frequency difference, but drift in themultipliers and phase noise in the common 99MHz LO will have been canceled out.The detailed process is as follows:The 10MHz reference from the multiplier board (this is derived from the reference inputwithout multiplication) is divided by 25 to 400kHz. The 400kHz is then divided by 4 to givetwo quadrature signals at 100kHz. These signals are filtered using low pass filters to give100kHz quadrature sine waves. The 1MHz multiplied reference IF (after limiting) is delayedby 250ns to give quadrature square waves. These operate dual switching mixers with the100kHz quadrature sine waves as the linear inputs. The outputs are combined to form animage reject mixer, with the wanted sideband at 900kHz and the unwanted sideband at1.1MHz. The 900kHz sideband is filtered in an LC bandpass filter to further remove theunwanted sideband and the 1MHz feed through. This output is used as the linear input toa further switching mixer which downconverts the 1MHz multiplied measurement IF (afterlimiting) to the final IF of 100kHz. The final IF is filtered in an LC bandpass filter to removethe unwanted sideband at 1.9MHz and any other mixer products. The measurement andreference channels have now been combined into a single IF of 100kHz with the drift andLO instabilities removed. This IF is now further processed to provide the counter outputs aswill be described in the next paragraphs.The measurement bandwidth of the system has been defined up to this point by theloop bandwidths of the phase lock multipliers and the bandwidth of the 100kHz LC filter.The 3dB bandwidth is about 8kHz. This means that fourier frequencies further displacedfrom the carrier of greater than 5kHz will be attenuated. The phase measurement processessentially samples the phase of the unknown signal relative to the reference at a ratedetermined by the selected tau (selectable from 1ms to 2000sec). As with any samplingprocess, aliasing of higher frequency noise into the baseband will occur. Thus further bandlimiting of the 100kHz IF is desirable before measurement takes place. The A7-MX has acrystal filter following the LC filter with selectable bandwidths of nominally 10Hz, 60Hz,and 200Hz. For most Allan variance plots at least the 200Hz filter should be used. The useof a filter will reduce the noise floor of the instrument which is desirable when measuringvery stable active sources and most passive devices.After the crystal filter the 100kHz IF is limited to a square wave by a zero crossingdetector. This output is made available to the counter A channel when frequency mode isselected. Both the 100kHz IF containing the multiplied frequency difference informationand the 100kHz unmultiplied reference are divided in identical divider chains down to 1kHzto 1mHz in selectable decade steps. The output of the dividers trigger digital (clocked)monostables to generate 10us pulses which are routed to the counter A and B channelswhen phase mode is selected.When the internal digital phase comparator is in use, the phase of both the 100kHzreference and the 100kHz multiplied IFs are measured relative to the unmultiplied 10MHzreference. The digital phase comparator then calculates the resulting phase differenceor fractional frequency offset depending upon the selected mode. The digital phasemeter also applies averaging if selected. It has internal storage sufficient for 32768measurements. The RS232 interface to the computer uses full handshaking to preventdata loss. The internal phase comparator has a resolution of 12.5ps, obtained by using ananalogue pulse expander circuit.The meter circuit also uses the 100kHz IF and 100kHz reference. The basis of the circuitis a differential frequency to voltage convertor. However in order to increase the resolutionof this circuit, a further stage of multiplication and mixing is employed. The 100kHzreference is divided down to 500Hz. This frequency is then multiplied to 4.9995MHz usinga phase lock loop with a divider of 9999. The 100kHz measurement IF is multiplied to5MHz also using a phase lock loop. Finally the 5MHz signal and the 4.9995MHz signal aremixed together to give an IF of 500Hz. An additional fractional frequency multiplicationof 104 results. On the least sensitive meter range this 500Hz IF varies in frequency from0Hz to 1kHz. The 500Hz measurement IF and the 500Hz reference both trigger digitalmonostables which produce very accurate fixed width pulses . These pulses are used togate an accurate positive and negative current into a chopper stabilised summing amplifier.The output of the summing amplifier is a voltage which drives the moving coil centrezero meter. The meter circuit has four decade ranges which in conjunction with the twomultiplication factors of the main comparator results in 6 meter ranges with full scaledeflections of 10 -7 to 10 -12 .The meter time constants are linked to the meter range, however may be increased ifdesired using a switch mounted on the rear panel.36Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

A7-MXA7-MX Block DiagramFigure 1Figure 2Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com 37

E8-X / E8-X OEMGPS Timing & Frequency Referencen Accurate to 25ns RMS UTCn No Driftn High Stabilityn Internationally Traceable StandardApprox actual sizeThe Quartzlock E8-X represents a breakthrough in exceptionally low cost, tracable, calibration-free“GPS” frequency & time standards. These very low cost references maintain the high frequency & timeaccuracy required for demanding applications. This product is available as a PCB level component.Features• 1 x 10 -12 accuracy• 12 Channel GPS Receiver with TRAIM• 10MHz Output• 1PPS OutputBenefits• No calibration required• 12 Channel GPS Receiver provides high accuracy UTC Time & Frequency Reference• Very cost effective• 1 year warranty• Compact form factorApplications• Production Test Frequency Reference• Time & Frequency standard for calibration & RF Laboratories• Frequency Standard for counters, signal generators, Spectrum & Network Analysers• Time & Frequency Reference for satellite communications ground stations CDMA, LTE, DTV & DAB38Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

E8-X / E8-X OEMSpecificationOutputs a) Sinewave 10MHz, 12dBm+/- 2dBm into 50OhmsFrequency AccuracyHarmonicsSpuriib) TTL3.3VCMOS1x10 -12 Long Term

E8-Y / E8-Y OEMGPS Time & Frequency Referencen -110dBc/Hz @ 1Hz offset Phase Noisen Internationally Traceable Standardn Accurate to 25ns RMS UTCn No DriftThe E8-Y GPS provides low noise, traceable, calibration free Time & Frequency Reference. Thesetime and frequency standards maintain high time & frequency accuracy required for demandingapplications. The E8-Y may be considered as a primary reference clock.Features• 10MHz Output• 1PPS Output• 1 x 10 -12 accuracy• RS232 Connection (USB option)• 12 Channel GPS Receiver with TRAIM• Excellent Holdover performanceBenefits• No Calibration required• GPS Traceable Reference• 12 Channel GPS receiver provides high accuracyUTC time & frequency reference• 1 year warranty• NTP option in place of GPS ViewApplications• Time & Frequency Reference for Satellite communication ground stations, CDMA, LTE, DTV & DAB• Production test frequency standard• Time & Frequency standard for calibration & RF laboratories• Frequency reference for counters, signal generators, spectrum & network analysers• Wired & wireless network synchronization40Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

E8-Y / E8-Y OEMSpecificationOutputs a) Sinewave 10MHz, 12dBm +/-2dBm into 50 OhmsHarmonicsSpurii

E8000GPS Master Clock Very Low NoiseFrequency & Timing Primary Reference Sourcen Phase Noise is -110dBc/Hz@1Hz offset as standardn Stability (AVAR) is 8x10 -13/s typicallyn Accuracy 25us, 100us/day holdoverThe Quartzlock E8000 represents a breakthrough in very low noise, traceable, calibration-free GPSfrequency & time standards. These very cost effective references maintain the high frequency andtime accuracy required for demanding applications. Low distortion 10MHz Sine & 1PPS outputs. Ultralow noise options are available.Considerably enhanced surveillance, wired and wireless communications are possible with E8000’smuch lower noise levelsFeatures• 1x10 -12 accuracy• No Drift• Highest Stability available• 1 Year Warranty• Lowest Cost Available• Very long production life & supportBenefits• No calibration required• Traceable Reference, nationally & internationally• External & Internal BBU options• Many options available including NTP Clock Reference Output• ULN options: -115dBc/Hz @ 1Hz offset & -170dBc/Hz @ 100kHz5MHz option has -123dBc/Hz @ 1Hz offset Phase Noise5x10 -13 /s AVAR short term stabilityApplications• Frequency Reference for: Satellite Communication Ground Stations, VHF, UHF & PMR TX, CDMA, Tetra, DTV & DAB,Wired & Wireless network synch• Network Time Protocol use in Financial, Utilities, Security & Communications Timing• OEM• Frequency Standard for: Calibration Labs, Radio Workshops, RF Labs & Production Test• Calibration of: Counters, Frequency Meters, Spectrum & Network/VNA Analysers, Synthesizers& Communication Analysers42Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

E8000SpecificationE8000 VERY LOW NOISE 10MHzOutputs a) Sinewave 10MHz, 12dBm+/- 2dBm into 50OhmsHarmonicsSpurii< -30dBc

E8010GPS Disciplined RubidiumTime & Frequency Referencen No driftn Internationally traceable standardn 110dBc/Hz @ 1Hz phase noise optionn Accurate to 25 Nanoseconds RMS UTCThe E8010 provides a stable and accurate calibration free GPS time and frequency reference withmultiple output signal formats in an easy to install 1U rack mountable chassis.These references maintain high time and frequency accuracy required for demanding applications.Features• 10MHz Output• 1PPS outputs• Network Time Server (NTP) Option• Excellent hold over performance 1us/day• 12 Channel GPS Receiver with TRAIM• 2x10 -12 /s AVAR optionBenefits• No calibration required• GPS traceable reference• Caesium replacement• 12 channel GPS receiver provides high accuracy UTCtime and frequency referenceApplications• Time and frequency reference for satellite communication ground stations, CDMA, LTE, DTV & DAB• Production test frequency standard• Time and frequency standard for calibration and rf laboratories• Frequency standard for counters, signal generators, spectrum and network analysers• Wired and Wireless network synchronization• Stratum 1 primary reference clock44Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

E8010SpecificationOutputs a) Sinewave 10MHz, 12dBm +/-2dBm into 50 OhmsHarmonicsSpurii

E10-MRXRubidium Oscillator –Sub Miniature Atomic Clock (SMAC)n Compact rubidium oscillator for a wide range of applicationsn OCXO form factor and pin outn Low power operationn Ageing 5x10 -10 /yearActual sizeThe E10-MRX rubidium oscillator is a sub miniature atomic clock exhibits normal rubidium oscillatorperformance in a 65cc OCXO style package.This rubidium oscillator has 100x less drift than ocxo’s.With short term stability of 8x10 -12 /s @ 100s this rubidium oscillator provides significant improvementsin performance over.Features• 10MHz output• 2” x 2” x 1” form factor• -95dBc/Hz @10Hz• 5x10 -11 accuracy• 8x10 -12 /s @100sBenefits• Atomic accuracy• Low power consumption• 100x less drift than OCXOsApplications• Stand-alone (free-run) stable frequency source (for UMTS and LTE)• Extended holdover for CDMA, WiMAX and LTE base stations• Stability for various other communication and transmission applications46Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

E10-MRXSpecificationOutputsHarmonicsAccuracyShort Term Stability(AVAR)10MHz Sine, 7~13dBm(HCOMS option)

E10-LNVery Low Noise MiniatureRubidium Oscillator Modulen Very low phase noise -110dBc/Hz @ 1Hzn Low power operationn Ageing 5x10 -10 /yearActual sizeThe E10-LN Very Low Noise Rubidium Oscillator Module is a sub miniature atomic clock withQuartzlock’s A6-CPS ‘active noise filter’ technology. This rubidium oscillator has 100x less drift thanocxo’s. With short term stability of 2x10 -12 /s @ 100s this rubidium oscillator provides significantimprovements in performance over other rubidium components.Ultra Low Noise 100MHz versions for radar and millimetre wave applicationsFeatures• 10MHz output• 91 x 55 x 30mm form factor• -110dBc/Hz @1Hz phase noise• 5x10 -11 accuracy• 5x10 -12 /s @100sBenefits• Very low noise and higher stability in customers’ product• Atomic accuracy• Low power consumption• 100x less drift than OCXOsApplications• Where sizes are restricted this ‘breakthrough’ very low noise rubidium oscillator will enable new applications• LTE• Extended holdover for CDMA, WiMAX and LTE base stations• Higher stability and lower phase noise communication and surveillance applications48Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

E10-LNSpecificationOutputs See optionsAdjustmentMechanical RangeElectrical RangeControl VoltageFactory Setting10MHz, +7dBm into 50Ω, 0.5VRMS2x10 -9 min2x10 -9 min0 ~ 5V±5x10 -11Options to 100MHzFrequency Stability AVAR1s10s100s1 hour2x10 -125x10 -124x10 -136x10 -12Ageing1 day1 month1 year5x10 -125x10 -114x10 -10Phase Noise dBc/Hz in 1Hz BWHarmonics1Hz10Hz100Hz1kHz10kHz

A10-LPROLow Profile Rubidium Oscillatorn High Performance Referencen Three year warrantyn 24V dc 13Wn Excellent stability & drift out to 1hr & 1dayThe A10-LPRO is a compact cost effective OEM Low Profile Rubidium Oscillator Frequency Standardthat maintains the high time & frequency accuracy demanded in applications such as telecoms,aviation, nautical and precision test & measurement. Ideal for mission critical applications. A currentproduction replacement for earlier products. These references maintain high time and frequencyaccuracy required for demanding applications.Features• 10MHz Output• Stability 3 x 10 -12 /100s• Ageing: 5 x 10 -10 /year• 100dBc/Hz @ 10Hz phase noiseBenefits• Simple integration into systems• Fits 1U case• Low Failure riskApplications• Telecom Network Synchronisation• Frequency Calibration• Broadcast• Cellular Wireless Base Stations• Design in frequency reference50Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

A10-LPROStandard SpecificationOutputAdjustmentMechanical rangeElectrical rangeControl rangeFactory settingFrequency StabilityAgingPhase noiseHarmonicsSpuriousWarm time to 1x10 -9Retraceafter 24h off and 1h on,same tempPower SupplyPower at steady state at 25°CFreq offset over output voltagerangeTemperatureOperatingStorageFreq offset over operatingtemperature rangeMagnetic FieldSensitivityAtmospheric PressureApprox MTBF, StationaryMechanical10MHz, +7dBm into 507 OHMS, 5V RMS2x10 -9 min2x10 -9 min0–5V±5x10 -111s10s100s1 day1 day1 month1 year10Hz100Hz1000Hz10000Hz

A10-YUltra Low Noise Rubidium Oscillatorn 10MHz standard version has -110dBc/Hz @ 1Hz phase noisen Uses Quartzlock Digital PLL DDS Clean-up Loop technologyn 5MHz option has -123dBc/Hz @ 1Hz offsetn 100MHz option has -180dBc/Hz noise floorFeatures• Ageing 5x10 -10 /year• Three Year Warranty• Short Term Stability 3x10 -12 /100s• 5x10 -11 accuracyApplications• Security• Low Noise Instrumentation Reference• Radar• Navigation• RF & Microwave Test Solution Reference• Secure CommunicationsBenefitsThe use of ULN-Rb Oscillators enables:• Weak Signal Detection• Low Error Rates• Higher Radar Sensitivity• Higher Definition in MRI Imaging Systems52Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

A10-YSpecificationsOutput(100MHz ULN option)10MHz, +7dBm into 50Ω, 0.5VRMS1MHz to 40MHz output. Option5MHz output (not using DDS).

E10-MROMiniature Rubidium Oscillatorn 1PPS Discipline I/0 Syncn 12V dc 8Wn High Performance Reference, exhibits excellent driftper hour and per dayThe E10-MRO is a compact cost effective Miniature Rubidium Oscillator Frequency Standard thatmaintains the high time and frequency accuracy demanded in applications such as telecoms,aviation, nautical and precision test and measurement.Features• RS232 Interface• Low Phase Noise to -165dBc/Hz (option)• Ageing: 5 x 10 -10 /year• Stability 5 x 10 -12 /100s• 10MHz OutputBenefits• Simple integration into systems• Fits 1U case• Low Failure risk• 2 year WarrantyApplications• Telecom Network Synchronisation• Frequency Calibration• Broadcast• Cellular Wireless Base Stations54Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

E10-MROSpecificationOutputOptional OutputsAccuracyAging10MHzConsult factory±5x10 -11 at shipment @25°C5x10 -12 /day5x10 -11 /monthDimensionsRetrace ≤±3x10 -11Short Term StabilityPhase Noise1s10s100s10Hz100Hz1kHz5x10 -111.6x10 -115x10 -12dBc/Hz-85dBc-125dBc-140dBcInput Power 8W at 12V@25°C, Max 2.5AInput Voltage 12 ±0.5VdcRangeWarm-up 5 minutes to lock @ 25°CFrequency ControlTemperatureMTBFConnectorSizeWeightWarrantyLow Noise OptionE10-MRO LNInternal trim range(trimpot)External trim rangeOperatingTemperatureCoefficient (ambient)Storage100,000 hoursDB-9 Connector, SMA≥2x10 -989 × 76 × 28 (mm 3 ) (190cc)0.25kg max2 years≥2x10 -9(0V~5V)-20°C to +50°C2x10 -10(-20°C to 50°C)-55°C to +85°CThis high performance version exhibitslower phase noise and higher short termstability. A 1PPS locking module is included(see A6-1PPS). Customers may specifylower phase noise than above.Connector InterfaceJ1: SMA, RF OUTPUT J2: DB-91: lock monitor(bit) 2&4: dc return/ground3: locking signal 5: ext C-field (0~5V)6, 8 & 9: NC (Used for RS232 option)7: +12VTel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com 55

E10-GPSGPS Disciplined Rubidium Oscillatorn Low Phase Noisen High Short Term Stabilityn RS232C Digital Monitor & ControlThe E10-GPS Disciplined Rubidium Oscillator is the most cost effective way to maintain the hightime & frequency accuracy required for demanding applications for the OEM manufacturer.This Rubidium Oscillator provides the precision synchronization required by base stations,optical network nodes, and high-speed digital networks.Features• 12V dc operation• Low Distortion• 7 minutes to lock• 10MHz Output• 1PPS OutputBenefits• Cost effective GPS Disciplined Rubidium• 2 year warranty• GPS Traceable Standard• Calibration free• Quick & simple to installApplications• Internal Frequency Reference• Telecom Network Synchronisation• Cellular Wireless Base Stations56Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

E10-GPSSpecificationAccuracyShort Term StabilityPhase NoiseHarmonicsDisciplined to GPSor to EXT. 1PPSHoldover (no GPS)≤3x10 -11 @1s≤1x10 -11 @10s≤3x10 -12 @100s< -100dBc@10Hz< -130dBc@100Hz< -140dBc@1kHz

A10-M (A10-MX)Rubidium Frequency Referencen Low Phase Noisen Ageing

A10-M (A10-MX)SpecificationOutputAdjustmentMechanical RangeElectrical RangeControl VoltageFactory SettingFrequency Stability typical1s10s100sAging1 day1 month1 yearPhase Noise dBc/Hz in 1Hz BW1Hz10Hz100Hz1kHz10kHz10MHz, +7dBm into 50Ω, 0.5VRMS-see options2x10 -9 min2x10 -9 min0 ~ 5V±5x10 -11A10-MSTD3x10 -122x10 -128x10 -13LN2x10 -125x10 -124x10 -13ULN 1 5MHz5x10 -132x10 -134x10 -13A10-MXULN 2 10MHz ULN 3 5MHz1–30s from 1s 8x10 -141x10 -13 to 3 to 30s2.5x10 -13 1.3x10 -133x10 -12 1x10 -12 5x10 -12 5x10 -12 5x10 -125x10 -10 4x10 -10 4x10 -10 4x10 -10 4x10 -104x10 -11 4x10 -11 4x10 -11 4x10 -11 4x10 -11STD-90-120-135-145-150LN-110-139-152-154-154ULN 1 5MHz-123-148-158-165-168ULN 2 10MHz-122-137-143-145-145ULN 3 5MHz-123-140-145-150-155Harmonics

A1000Rubidium Time & Frequency Referencen Low phase noisen Ageing

A1000SpecificationOutputs See optionsAdjustmentMechanical RangeElectrical RangeControl VoltageFactory SettingFrequency StabilityAgeingPhase NoiseHarmonicsSpuriousWarm Timeto 1 x 10 -9Retrace after 24h off &1h on, same tempPower SupplyPower at steady stateat 25CFrequency Offsetover output voltage rangeTemperatureOperatingStorageFreq offsetover operatingtemperature range10MHz, +7dBm into 50Ω, 0.5VRMS Magnetic FieldSensitivityAtmospheric2x10 -9 minPressure2x10 -9 minApprox MTBF,0 ~ 5VStationary±5x10 -111x10 -11MechanicalOptions1s3x10 -1110s1x10 -11100s3x10 -121day8x10 -121 day3x10 -121 month 4x10 -111 year5x10 -10dBc/Hz in 1Hz BW Standard1Hz-7010Hz-100100Hz-1201kHz-14010kHz-145

E1000Rubidium Frequency Referencen Stability (AVAR) 8x10 -13 /s typicallyn Low phase noise 110dBc/Hz offset as standardn Stability (AVAR) 8x10 -13 /s typicallyn Drift5x10 -10 /yearFeatures• Ultra High Performance Reference• Multiple Output Options• Custom Frequency Outputs• Noise Floor – 167dBc/Hz• Ageing - 4x10 -10 /yearBenefits• Stability to 5x10 -13 /s• 10 MHz Standard Output• 1–40 MHz optional• 100 MHz option (-180dBc/Hz NF)• 5 MHz option (-123 dBc/Hz @ 1 Hz)• E1000 uses Quartzlock Active Noise FilterClean TechnologyApplications• Frequency Calibration• Telecom Network Synchronisation• Broadcast – Radio & TV HDTV• Satellite communications• Production Test Reference for instrumentation• Microwave & Radar Test Bench or Test Solution62Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

E1000SpecificationMagnetic FieldOutputs See options 10MHz, +7dBm into 50Ω, 0.5VRMSFreq offset

E10-PCompact PortableRubidium Frequency Referencen Greater than 2 hours battery operationn Operates from car 12vdc outputn Less than 3 minute warm upn Compact form factor 103x55x122mm

E10-PSpecificationsOutputHarmonicsAccuracyShort Term Stability(AVAR)10MHz Sine, 10dBm, ±3dBm

E10-XCompact DesktopRubidium Frequency Referencen Compact light weight portable for a wide range of applicationsn Fast warm timen Low power operationn 12V dc operation (ac plug top adaptor supplied)Actual sizeCompact simple to install atomic frequency reference for use as a general purpose 10MHzrubidium frequency standard.This frequency standard benefits from having Quartzlock’s SMAC (Sub Miniature Atomic Clock)technology built in.Features• 10MHz Output• Ageing

E10-XSpecificationsOutputHarmonicsAccuracyShort Term Stability(AVAR)10MHz Sine, 10dBm, ±3dBm

E10-Y4 & E10-Y8Rubidium Frequency ReferenceLow Noise Multiple Outputsn Eight outputsn -110dBc/Hz @ 1Hz phase noisen Compact light weight portable for a wide range of applicationsn Low drift 5x10 -12 /dayFeatures• 10MHz multiple outputs• Ageing

E10-Y4 & E10-Y8SpecificationMagnetic FieldOutputs – 4 or 8 4 (E10-Y4) or 8 (E10-Y8)Freq offset

CH1-75AActive Hydrogen Masern

CH1-75ASpecificationFrequency OutputsTiming OutputAmplitudeWidthRise timeJitterFrequency stability(Allan Deviation)5MHz,10 MHz and 100 MHz (sine), 1±0.2 V rmsinto 50 Ohm1Hz (1PPS)>2.5V into 50 Ohm10–20ms

CH1-75ACH1-75A Active Hydrogen Maser1 second ≤ 1,5x10 -131 day ≤ 7x10 -16Temperature sensitivity ≤ 1,5x10 -15 /CKVARZ has been developing and manufacturing H-Masers over 40years and has a great experience in this field.This model is the thirdH-Masers generation.During this period of time, more than 500 units have been built.It five times exceeds the number of hydrogen masers produced by allother maser manufactures in the world.The performance specifications of the CH1-75A Active HydrogenMaser exceed those available from any other unit manufacturedworld-wide.The CH1-75A mechanical architecture is focussed on modularconstruction in a tough transportable package. A lightweighttubular aluminium space frame is used in transport and formobile applications.Frequency Stability (Allan Deviation)Frequency Stability (Hadamar Deviation)CH1-75A HydrogenMaser Block Diagram72Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

CH1-75ACH1-75A Active Hydrogen Maser Physics Package SchematicVery efficient beam optics including quadrapole magnet and uniquemultipath collimator.It allows to reduce hydrogen usage to 0.01 mole per annum thussimplifying its vacuum pumping.Autonomous Cavity Auto Tuning – Long-term StabilityThe most recent development to improved performance of the ActiveHydrogen Maser is an advanced Cavity Auto Tuning System, which insuresthe Maser remains centered on the hydrogen line over the long term.The advantages of the cavity auto tuning in the CH1-75A are as follows:• a modulation frequency of 87Hz is approximately three times higherthan that in other auto-tuning systems. As a result, very low spuriouscomponents at frequency modulation of 87Hz are achieved. It is especiallyimportant where the Maser is used for VLBI.• very low temperature sensitivity of the Maser of ~ 1.5x10 -15 / C.Hydrogen pumping is performed by a very efficient getterpump, having extended lifetime (over 15 years). Theadvantages of such a pump are:• no power supply during operation is required• high reliability• small size and weight (5 kg)Very efficient magnetic shielding. Magnetic sensitivity of the Maser is lessthan 1x10 -14 /Oersted. This is achieved thanks to a five-layer magnetic shieldmade of permalloy with initial magnetic permeability of more than 100,000.High temperature frequency stability of the MaserThe hydrogen maser frequency is linearly dependent on the cavity frequency:In order to reduce temperature influence on the cavity frequency, it ismanufactured of a unique glass material, which exhibits virtually zerotemperature coefficient (~1–2x10 -7 /°C).Temperature stabilization of such a cavity with an accuracy of 0.001˚ Callows a decrease in the Maser temperature sensitivity to 5x10 -15 /C evenwithout auto-tuning.Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com 73

CH1-76APassive Hydrogen Masern

CH1-76ASpecificationFrequency Outputs5MHz (sine), 1±0.2V rmsinto 50 OhmTiming Output1Hz (pulse)Amplitude≥2.5V into 50 OhmWidth10–20μsRise time

CH1-76ACH1-76A Passive Hydrogen MaserThe size and weight of the active hydrogen maser in some caseshinder its application, especially in the field conditions.The problem of reducing the active hydrogen maser size isconnected with reduction of microwave cavity size, which results inreduction of its Q-factor.Reduction of cavity Q-factor leads to the failure of the masergeneration conditions, and it goes into amplifying mode, so called“passive” mode. Due to this factor, an idea of creation of a passivehydrogen maser was realised.In 1988 KVARZ created the first industrial Passive Hydrogen Maserin the world (the CH1-76); at the present time KVARZ produces itsimproved version, the CH1-76A.Schematic Picture of a Passive Hydrogen Maser Physics PackagePassive Hydrogen Maser FeaturesA hydrogen atom generation system and a vacuum system of apassive maser are the same as those of an active maser. Their servicelife is 15 years.KVARZ realised the so called “magnetron” cavity constructionwhich is very rigid and insures a passive hydrogen maser suitabilityfor field and space applications.In this instrument, one 12.5 kHz modulation frequency and a freerunninglocal oscillator are used.76Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

CH1-76AAtomic Clock ComparisonsAs for a frequency stability, a passive maser holds a middle position between an active hydrogen maserand a cesium frequency standard.Its stability for measurement time from 1 sec to 100.000 sec is a factor of 10 better than the bestcesium standard – 5071A Primary Frequency Standard (High Performance Cesium Beam Tube).Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com 77

Special ProductsAir Interface SimulatorRadio Path Modelling SystemThis is one example of a customer defined special product designed by Quartzlock.This AIS simulated the air interface between a number of mobile and BTS with interferingmobile and BTS facilities.To discuss your special product requirement please call Quartzlock.78Tel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com

Product Family TreeProductsFrequencyStandardsRubidium2URackMountMetrologyPerformanceA10‐M1URackMountA10001URackMountLowNoiseE1000PortableBaEeryOperatedE10‐PDeskTopE10‐XDeskTopLowNoiseA10‐YOEMLowProfileA10‐LPROOEMUltraLowNoiseA10‐YOEMMiniatureE10‐MR0OEMGPSDisciplinedE10‐GPSOEMPCBMountedE10‐MRXOEMVeryLowNoiseE10‐LNGPS1URackMountDisciplinedOCXOE80001URackMountDisciplinedRubidiumE8010DeskTopDisciplinedTCXOE8‐XDeskTopDisciplinedOCXOE8‐YOEMDisciplinedTCXOE8‐XOEMOEMDisciplinedOCXOE8‐YOEMHydrogenMaserAcRveCH1‐75APassiveCH1‐76AConversionFrequency2URackMountAcRveNoiseFilterA6‐ANF1URackMountE1A6‐2048kHz1URackMount100kHz‐10MHzA6‐0.1‐10MHzTimingOEMDigitalPhaseLockedCleanUpLoopA6‐CPSOEM1PPSLockingModule1PPSDistribuRonHighPerformance8OutputsA5‐8Standard1URackMount12OutputsE50001URackMountPulseE5000PDeskTop6OutputsE5‐XDeskTopPulseE5‐XPMeasurementFrequency&PhaseAnalysisA7‐MXRedundancySwitchA4000RF&MicrowaveAEenuatorsdB32.5dB125dB127PrecisionHousingsPH0PH1PH2PH3PH4PH5PH5MPH6AntennasAcRveLoopAE30‐300GPSMagMountGPSHighGainTel +44 (0)1803 862062Fax +44 (0)1803 867962Email sales@quartzlock.comwww.quartzlock.com79

For all enquiries please contact us via any of the methods below:Head Office & Maser Lab:Quartzlock UK Ltd‘Gothic’Plymouth RoadTotnes, DevonTQ9 5LH EnglandTelephone:+44 (0)1803 862062Facsimile:+44 (0)1803 867962Email:sales@quartzlock.comOr visit our websitewww.quartzlock.comQuartzlock’s new observatory building for our Maser LaboratoryThe Quartzlock logo is a registered trademark. Quartzlock continous improvement policy: specifications subject to change without noticeand not part of any contract. All IPR and design rights are protected. E&OE © Quartzlock 2012Registered in England: 2634800. VAT Registration no. 585 675 582