MPhil thesis of Lo Chi Wa - Department of Electronic & Computer ...

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a) Vob) Vcsc) Igm122113233Fig. 74 (a) Output voltage of LC oscillator; (b) Common source voltage; (c) Current flow into gm cell.(1) without capacitor or common source node connection (2) with capacitor (3) with connectionIn addition to providing larger amplitude and better phase noise, connecting the twocurrent sources can also maintain the matching of the amplitudes of the two coupledoscillators. For example, oscillator A has larger output amplitude and oscillator B hassmaller output amplitude due to the unmatched LC tanks. Since oscillator B has smalleramplitude, it cannot store and release too much current for oscillator A. Oscillator Awill see oscillator B as a small-value capacitor as shown in Fig. 75. On the contrary,oscillator B will see oscillator A as a large-value capacitor. As shown in Fig. 76, whenthe differential output is large, smaller voltage ripples at the common source node andlarger peak current pulse are observed for oscillator B (T2) as compared to those foroscillator A (T1). The amplitudes of both oscillators will be increased due to theparallel capacitors but the amplitude of oscillator B will be increased more due to alarger capacitor connected. This mechanism can reduce the amplitude mismatch of theoscillator due to the mismatch between the two LC tanks. Both increase in amplitude80
and decrease in amplitude mismatch can be observed in simulation (Fig. 77). Thisamplitude control is a result of the parallel capacitor effect only because the averagebias currents in two unmatched oscillators are the same, just like the case with acapacitor in parallel.osc A(larger amplitude)osc B(smaller amplitude)osc Aosc Bosc Bosc AFig. 75 Another view of a matched coupled-LC oscillatorsVoaVobT1 T2 T1 T2Igma.IgmbtimeFig. 76 Amplitudes and currents of the two mistmatched oscillators : T1: period when differentialoutput is large in oscillator A; T2: period when differential output is large in oscillator B81
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A 1.5-V 900-Mhz Monolithic CMOSFast
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A 1.5-V 900-Mhz Monolithic CMOS Fas
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Table of ContentsPageAcknowledgment
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Testing setup......................
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List of FiguresPageFig. 1 Block dia
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Fig. 76 Amplitudes and currents of
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Chapter 1 IntroductionBackgroundWir
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applications because it can provide
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existing monolithic frequency synth
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the receiver frequency band is from
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out-of-bandin-bandout-of-band0dBmin
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Based on the maximum interference,
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carrierdBcspur∆fFig. 8 Frequency
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Spurs requirement (dBc)Frequency of
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The frequency diversity can be perf
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Chapter 3 System DesignPhase-locked
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coarse tuning can be provided by th
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array is now possible. Moreover, th
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performance of the synthesizer 9 .
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signalquantizationnoisea) f b)signa
Page 41 and 42: esolution. The loop bandwidth is 80
Page 43 and 44: the output value between 0 and 0.5,
Page 45 and 46: The coupled-LC oscillators can be v
Page 47 and 48: 890MHzf25MHz243KHz865MHzFig. 23 Tun
Page 49 and 50: onoffCwellClinearCwellClinearCwellC
Page 51 and 52: spirals of similar sizes is around
Page 53 and 54: in Fig. 27a and Fig. 27b, the same
Page 55 and 56: conductance (Gm) and the reciprocal
Page 57 and 58: −19⎛ 900M⎞0.0259×1.6×10 ×
Page 59 and 60: GdoVinFig. 32 Gdo of the proposed L
Page 61 and 62: RzCzIcpCpR4C4a)IcpCzR4B.IcpCpRpC4b)
Page 63 and 64: Usually, capacitors in the filter o
Page 65 and 66: RVinFig. 38 Resistance of NMOS resi
Page 67 and 68: feedback path to prevent the proble
Page 69 and 70: 890MHz25MHz865MHzfA+∆A
Page 71 and 72: High-speed multi-modulus dividerThe
Page 73 and 74: CLKQBQDDBFig. 50 Schematic diagram
Page 75 and 76: ANDgateABclkclkclkclkQBFig. 54 Sche
Page 77 and 78: f o/2 /2,3 /2,3 /2 /2f div/4Combina
Page 79 and 80: next stage, as shown in the Fig. 59
Page 81 and 82: co10bDclkclkFig. 60 Schematic of th
Page 83 and 84: (1-Z -1 ) 23bDQBclkZ -1 (1-Z -1 )2b
Page 85 and 86: X 16clkDclkQBDclkQBFig. 66 Schemati
Page 87 and 88: ~90 oa) b) c)Fig. 68 Different meth
Page 89 and 90: (dotted line). As the oscillation c
Page 91: In practice, it is not desirable to
Page 95 and 96: Current interactionThe two oscillat
Page 97 and 98: equirements. Fortunately, by connec
Page 99 and 100: LC oscillators are put apart to red
Page 101 and 102: Gain mismatch (in %)Two oscillators
Page 103 and 104: equals to1 . By doubling the height
Page 105 and 106: 30 is obtained. It is because the s
Page 107 and 108: The spiral inductor is designed and
Page 109 and 110: oscillators (shown in the upper and
Page 111 and 112: Synthesizer LayoutThe layout and th
Page 113 and 114: Die LayoutFig. 98 shows the die pho
Page 115 and 116: Testing setupThe testing setup show
Page 117 and 118: Resistance (ohms)Freq (Hz)Fig. 101
Page 119 and 120: Resistance (ohms)Freq (Hz)Fig. 105
Page 121 and 122: VaractorFig. 109 shows the testing
Page 123 and 124: Table 5 Summary of parameters of va
Page 125 and 126: Table 6 Summary of N-well substrate
Page 127 and 128: Fig. 120 Quality factor of the swit
Page 129 and 130: The decrease in quality factor is d
Page 131 and 132: Fig. 126 Schematic diagram of the p
Page 133 and 134: Output frequency(MHz)Number of swit
Page 135 and 136: Gain (MHz/V)Tuning voltage (v)Fig.
Page 137 and 138: on the process variation. Therefore
Page 139 and 140: voltage (Vos = Rp x Ios) appeared.
Page 141 and 142: Although the spurs are quite large,
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GMSK signals with 0.3 BT and a bit
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Power spectral density (dB)(b)(a)(c
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Summary of performanceA summary of
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Table 10 Comparison of performances
Page 151 and 152:
As the voltage-controlled oscillato
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Bibliography1 Thomas H. Lee, The De
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MPhil thesis of Lo Chi Wa - Department of Electronic & Computer ...

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