The History of the Development of the Dielectric Resonator Antenna

University ofHoustonThe History of theDevelopment of theDielectric Resonator AntennaStuart A. Long and Ellen M. O’ConnorDepartment of Electrical and Computer EngineeringUniversity of Houston, Houston, TX 77204-4005ICEEA '07 -- Sept 20, 2007 0

OutlineUniversity ofHouston• Origins of idea• Simple theoretical model• Early experimental data• Initial journal papers• More recent DRA research at the University of Houston• Worldwide locations of DRA activityICEEA '07 -- Sept 20, 2007 1

2) Early Development of microstrip antennas at theUniversity of HoustonUniversity ofHouston• Supported by US ArmyResearch Office• Interest in very ruggedradiators for artillery shellsFormulas developed then are stillused for resonant frequencycalculationsae⎧ 2h⎡ ⎛πa ⎞⎤⎫= a⎨1 + ln 1.7726πaε⎢ ⎜ + ⎟ ⎬r2h⎥⎩ ⎣ ⎝⎠⎦⎭1/2ICEEA '07 -- Sept 20, 2007 3

Problems with microstrip antennasUniversity ofHouston• Narrow bandwidth for electricallythin substrates• High frequencies result in• More ohmic losses• Electrically thicker substrates whichsupport surface waves and decrease radiation efficiencyICEEA '07 -- Sept 20, 2007 4

Dielectric resonatorsUniversity ofHouston• Used as elements in microwavecircuits• Energy storage devices• Problem with “leakage”ICEEA '07 -- Sept 20, 2007 5

Idea of a “dielectric resonator” antenna bornUniversity ofHouston• Enhance the “leakage” or radiationto convert an energy storage deviceinto an antenna• Similar geometry to circularmicrostrip, but without a conductingpatch• Can choose dimensions anddielectric constant to enhanceradiationICEEA '07 -- Sept 20, 2007 6

US Army Harry Diamond LaboratoriesUniversity ofHouston• In suburban Washington D.C.(Adelphi, MD)• S. Long received a fellowship for Summer1981 to do a feasibility study for new kinds ofmillimeter wave radiators and guidesICEEA '07 -- Sept 20, 2007 7

2) US Army Harry DiamondUniversity ofHouston• Initial theoretical calculationswere doneICEEA '07 -- Sept 20, 2007 8

3) US Army Harry DiamondUniversity ofHouston• Simple assumption of perfect magnetic conducting wallsfor cylindrical geometryICEEA '07 -- Sept 20, 2007 9

Experimental investigationUniversity ofHouston• Circular cylindrical geometrychosen• Previous use of cylindrical shapein microwave circuit resonators• Experience with circular microstripantennas• Availability of dielectric material• Fred Farrar aided in experimentalworkICEEA '07 -- Sept 20, 2007 10

Antenna designUniversity ofHouston• Diameter held constant(determined by size of rod)• Height, dielectric constant, radialposition of feed probe, and length offeed probe all varied• Dielectric resonator mounted on anconducting ground planeICEEA '07 -- Sept 20, 2007 11

Theory for cylindrical geometryUniversity ofHouston• Input impedance• Resonant frequency• Radiation patternsICEEA '07 -- Sept 20, 2007 12

2) Theory for cylindrical geometryUniversity ofHouston• Input impedance• Resonant frequency• Radiation patternsfnpm21⎧⎪x ⎫np ⎪ ⎡πa ⎤= ⎨ ⎬+ ( 2 + 1)2'2 ⎢mπaμε ⎣ 2 ⎥⎪ ⎪ d ⎦⎩xnp ⎭2ICEEA '07 -- Sept 20, 2007 13

3) Theory for cylindrical geometryUniversity ofHouston• Input impedance• Resonant frequency• Radiation patternsICEEA '07 -- Sept 20, 2007 14

MaterialsUniversity ofHouston• Dielectric rods of diameter 1.0” and 0.25”• Various dielectric constants from ε r=6 to ε r =30• Fabricate by simply cutting off desired height ofresonator• Ultimately discovered that manufacturer’s ε r was notaccurateICEEA '07 -- Sept 20, 2007 15

Fabrication difficultiesUniversity ofHouston• Materials very hard andabrasive• First tried by hand withhacksaw• Then to machinist and powersaw• Finally successful withspecial diamond tipped sawbladesICEEA '07 -- Sept 20, 2007 16

Feed systemUniversity ofHouston• Chose probe feed toemulate the usual microstripantenna feed• Similar fields insideresonator as found in cavity ofmicrostrip• Same problems with drilling holes-needed special drill bits• Wanted feed near edge to excitemode with radiation perpendicular toground planeICEEA '07 -- Sept 20, 2007 17

Measurements – cylindrical geometryUniversity ofHouston• Input impedance• Resonant frequency• Radiation patterns• Varied dimensions to determine behaviorICEEA '07 -- Sept 20, 2007 18

2) Measurements – cylindrical geometry• Input impedance• Resonant frequency• Radiation patterns• Varied dimensions to determinebehaviorUniversity ofHoustonICEEA '07 -- Sept 20, 2007 19

3) Measurements – cylindrical geometry• Input impedance• Resonant frequency• Radiation patterns• Varied dimensions to determinebehaviorUniversity ofHoustonICEEA '07 -- Sept 20, 2007 20

4) Measurements – cylindrical geometry• Input impedance• Resonant frequency• Radiation patterns• Varied dimensions to determinebehaviorUniversity ofHouston Varied height todiameter ratioICEEA '07 -- Sept 20, 2007 21

5) Measurements – cylindrical geometry• Input impedance• Resonant frequency• Radiation patterns• Varied dimensions to determinebehavior Varied ε rUniversity ofHoustonICEEA '07 -- Sept 20, 2007 22

6) Measurements – cylindrical geometryUniversity ofHouston• Input impedance• Resonant frequency• Radiation patterns• Varied dimensions to determine behavior Varied probe lengthICEEA '07 -- Sept 20, 2007 23

ResultsUniversity ofHouston• With proper choice of dimensions and dielectric constant• Antenna that wasEfficient radiatorEasily matched to a 50Ω transmission lineBroad pattern with maximum normal to groundplaneBonus: much larger bandwidth than microstrip antennawhen lower dielectric constants usedICEEA '07 -- Sept 20, 2007 24

Fall 1981University ofHouston• Back at the University of Houston• Mark McAllister, a new PhD student was justready to start his research projectBegan a much more systematic investigationof these cylindrical DRAsICEEA '07 -- Sept 20, 2007 25

Rectangular and hemispherical DRAsUniversity ofHouston• Expanded investigation to includeandrectangularhemisphericalICEEA '07 -- Sept 20, 2007 26

Feed systems for other geometriesUniversity ofHouston• Continued to use probe feedsHemisphericalRectangularICEEA '07 -- Sept 20, 2007 27

Other geometries data: rectangularUniversity ofHoustonICEEA '07 -- Sept 20, 2007 28

2) Other geometries data: hemisphericalUniversity ofHoustonHemisphericalICEEA '07 -- Sept 20, 2007 29

Mark McAllisterUniversity ofHouston• Completed PhD in 1983• Career at Stanford ResearchInstitute and Bell Telephone• Retired from engineeringNow a budding novelistICEEA '07 -- Sept 20, 2007 30

First DRA paperUniversity ofHouston• Submitted April 5, 1982• Published by IEEE Antennas and Propagation,May 1983•Reported results for the cylindrical geometry•Note: Title called it a “Resonant Cylindrical Dielectric CavityAntenna” (RDCA) -- paper now cited over 196 timesICEEA '07 -- Sept 20, 2007 31

Second DRA paperUniversity ofHouston• Reported the rectangular shaped radiatorSubmitted February 7, 1983Published March 17, 1983 in Electronics Letters• Submitted almost one year after the first paper, but actuallypublished slightly before.• Note: Title of Rectangular Dielectric Resonator Antenna wasname that eventually “stuck” and later abbreviated as DRAICEEA '07 -- Sept 20, 2007 32

Hemispherical DRAUniversity ofHouston• Reported the hemispherical shaped radiatorSubmitted June 1984Published in Electronics Letters August 1984•Note: Here called “Resonant Hemispherical Dielectric Antenna”(RDA)ICEEA '07 -- Sept 20, 2007 33

Feed MechanismsUniversity ofHouston• For more “integrated” applicationsfeeds other than probes are moreappropriateRoger Kranenburg, 1988• New graduate student – Roger KranenburgICEEA '07 -- Sept 20, 2007 34

2) Feed MechanismsUniversity ofHouston• Microstrip - Electronics Letters, September 1988ICEEA '07 -- Sept 20, 2007 35

3) Feed MechanismsUniversity ofHouston• Microstrip - Electronics Letters, September 1988ICEEA '07 -- Sept 20, 2007 36

4) Feed MechanismsUniversity ofHouston• Coplanar Waveguide - IEEE Antennas and Propagation,January 1991ICEEA '07 -- Sept 20, 2007 37

5) Feed MechanismsUniversity ofHouston• Coplanar Waveguide - IEEE Antennas and Propagation, January 1991ICEEA '07 -- Sept 20, 2007 38

More recent work at the University of HoustonUniversity ofHouston• Parasitic Strips – Russell Long, Electronics Letters, 2001Russell Long, 2001zdaφGround planeFeedstructureParasitic stripICEEA '07 -- Sept 20, 2007 39

S11 [dB]VSWR2) More recent work at the University of HoustonUniversity ofHouston• Parasitic Strips – Russell Long, Electronics Letters 20015-54-1532-252.0 2.2 2.4 2.6 2.8 2.9Frequency [GHz]Fig 2. Reflection coefficient (S11) versus frequency for varying positionsof parasitic stripNo Parasitic Strip110°130°150°180°12.0 2.2 2.4 2.6 2.8Frequency [GHz]Fig 4. SWR versus frequency for antenna with andwithout parasitic stripWith Parasitic StripNo Parasitic StripICEEA '07 -- Sept 20, 2007 40

University ofHouston3) More recent work at the University of Houston• Mutual Coupling – Robert Dorris, AWPL, 2002Robert Dorris, 2002zθfeeddxaφεyground planeICEEA '07 -- Sept 20, 2007 41

4) More recent work at the University of HoustonzθUniversity ofHoustonεdyfeedaxg round planeφ• Mutual Coupling – Robert Dorris, AWPL, 2002-5Coupling Magnitude (dB)-15-25-35-450 1 2 3 4Distance (Wavelength)Fig. 4 Coupling magnitude versus spacing distance in wavelengths- Measured E-plane- Measured H-plane- Previous E-plane data- Previous H-plane dataICEEA '07 -- Sept 20, 2007 42

5) More recent work at the University of HoustonUniversity ofHouston• Low Profile DRA – Ben Fastenfest, Electronics Letters, 2003Ben Fastenfest, 2003ICEEA '07 -- Sept 20, 2007 43

6) More recent work at the University of HoustonUniversity ofHouston• Low Profile DRA – Ben Fastenfest, Electronics Letters, 2003150Impedance (Ohms)1005002.1 2.2 2.3 2.4 2.5-50Frequency (GHz)Fig 2. Measured impedance vs. frequency for nowell case and for s = 40 mm (a/d = 1.5)150100500-50No Well Re(Zin)No Well Im(Zin)s=40mm Re(Zin)s=40mm Im(Zin)2.1 2.2 2.3 2.4 2.5Fr equency (GHz)Fig 5. Radiation patterns in dB for no well case and for s = 40mm (a/d = 0.5)ICEEA '07 -- Sept 20, 2007 44

University of7) More recent work at the University of Houston Houston• Stacked Embedded DRA – Andrew Walsh, AWPL, 2006Andrew Walsh, 2006ICEEA '07 -- Sept 20, 2007 45

8) More recent work at the University of HoustonUniversity ofHouston• Stacked Embedded DRA – Andrew Walsh, AWPL, 2006250-20Input Reflection Coefficient (dB)20-10Bandwidth (%)1510ε r.upper = 15.2ε r.lower = 6.0-30a = 68.1 %b = 50.7 %c = 59.9 %d = 21.0 %5-4000 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1dlower/d (unitless)Stacked DRAHomogeneous DRAFigure 3. Percent bandwidth vs variation in height of thelower section of the DRA, the permittivity of the top andbottom sections are fixed at 15.2 and 6.0 respectively-502.5 3 3.5 4 4.5 5Frequency (GHz)(a) Embedded Stacked DRA(c) Stacked DRA(b) Core-Plug Embedded DRA(d) Homogeneous DRAFigure 8. Reflection coefficient for antennas previouslyshown in Figure 7 with the corresponding percent bandwidthICEEA '07 -- Sept 20, 2007 46

9) More recent work at the University of HoustonUniversity ofHouston• Multimode Wideband DRA – Chris DeYoung, AWPL, 2006Chris DeYoung, 2006zzl w ahdxyxyICEEA '07 -- Sept 20, 2007 47

10) More recent work at the University of HoustonUniversity ofHoustonzzl w a• Multimode Wideband DRA – Chris DeYoung, AWPL, 2006hdxyxyICEEA '07 -- Sept 20, 2007 48

DRAs: Other institutionsUniversity ofHouston• Shortly after the first papers out of the University OfHouston various groups began publishing DRAarticlesA. Kishk, S. Long, and K.W. LeungICEEA '07 -- Sept 20, 2007 49

DRAs around the worldUniversity ofHoustonICEEA '07 -- Sept 20, 2007 50

DRAs around the worldUniversity ofHoustonUniversity of Houston- Long, Shen and McAllisterICEEA '07 -- Sept 20, 2007 51

DRAs around the worldUniversity ofHoustonSaitama University in Japan- Haneishi and colleaguesICEEA '07 -- Sept 20, 2007 52

2) DRAs around the worldUniversity ofHoustonUniversity of Mississippi- Kishk, Glisson, Kajfiz, Ahn,Eisherbeni, and JunkerICEEA '07 -- Sept 20, 2007 53

3) DRAs around the worldUniversity ofHoustonCommunications Research Centre(CRC) in Ottawa-Ittpiboon, Mongia, Antar,Barthia, Petosa, Cuhaci, and RoscoeICEEA '07 -- Sept 20, 2007 54

4) DRAs around the worldUniversity ofHoustonCity University of Hong Kong-Leung and LukICEEA '07 -- Sept 20, 2007 55

5) DRAs around the worldUniversity ofHoustonThe University of Manchester-Drossos, Wu, and DavisICEEA '07 -- Sept 20, 2007 56

6) DRAs around the worldUniversity ofHoustonMacquarie University, Sydney, Australia.- EsselleICEEA '07 -- Sept 20, 2007 57

7) DRAs around the worldUniversity ofHoustonUniversity of Calcutta- GuhaICEEA '07 -- Sept 20, 2007 58

8) DRAs around the worldUniversity ofHoustonETHEidgenössische Technische Hochschule ZürichSwiss Federal Institute of Technology ZürichETH Zürich- Almpanis, Fumeaux, and VahldieckICEEA '07 -- Sept 20, 2007 59

9) DRAs around the worldUniversity ofHoustonRoyal Military College of Canada-AntarICEEA '07 -- Sept 20, 2007 60

10) DRAs around the worldUniversity ofHoustonInstitute for Infocomm Research, Singapore.- NasimuddinICEEA '07 -- Sept 20, 2007 61

DRA TextbooksUniversity ofHouston• Dielectric Resonator Antennasby K.M. Luk and K.W. Leung• Jun 1, 2002• Research Studies Press• 380 pagesICEEA '07 -- Sept 20, 2007 62

2) DRA TextbooksUniversity ofHouston• Dielectric Resonator AntennaHandbook by A. Petosa• January 31, 2007• Artech House Publishers• 336 pagesICEEA '07 -- Sept 20, 2007 63

Growth of DRA publicationsUniversity ofHoustonThe number of published journalarticles and conference proceedingsis growing each yearICEEA '07 -- Sept 20, 2007 64

2) Growth of DRA publicationsUniversity ofHouston1980’s 1990’s 2000’sICEEA '07 -- Sept 20, 2007 65

The future of DRAsUniversity ofHouston• Idea ahead of its time• As operating frequencies continue to rise, DRAs willbecome much more useful.• Need to develop integration techniques for fabrication• Someday may be as common as microstrip antennasICEEA '07 -- Sept 20, 2007 66

Original DRA samplesUniversity ofHouston• Some of the original DRAs (fabricated atHarry Diamond Labs) for each presenterICEEA '07 -- Sept 20, 2007 67

Bibliography CDUniversity ofHouston• All of the journal articles and conferenceproceedings we could findICEEA '07 -- Sept 20, 2007 68

Remainder of Session 27University ofHouston9:00 AM D. Guha - University of CalcuttaY.M.M. Antar - Royal Military College of CanadaNovel Designs of Dielectric Resonator Antennas for Wireless Communications9:20 AM Y. Ding, K.W. Leung, K.M. Luk - City University of Hong KongCircularly-Polarized DRA-Slot Hybrid Antenna for Dualband Applications9:40 AM Z. Wu – University of ManchesterBroadband Miniaturised Dielectric Resonator Antennas10:00 AM Coffee Break10:20 AM G. Almpanis, C. Fumeaux, and R. Vahldieck - ETH ZürichComparison of the Performance of Double-Step Rectangular DielectricResonator Antennas10:40 AM S. Thirakoune, A. Petosa, A. Ittipiboon – CRC OttawaYagi-like DRA-Loaded Monopole11:00 AM Nasimuddin - Institute for Infocomm Research, SingaporeK. P. Esselle - Macquarie UniversityAchieving high gain and large bandwidth using hybrid DR antennas to feed short hornsICEEA '07 -- Sept 20, 2007 69