IEEE MTT-V056-I01 (2008-01)

264 Pages·2008·32.13 MB·English

by  FANTOMASPING

JANUARY2008 VOLUME56 NUMBER1 IETMAB (ISSN0018-9480)
PAPERS
LinearandNonlinearDeviceModeling
A0–55-GHzCoplanarWaveguidetoCoplanarStripTransition ................................................................
................................................D.E.Anagnostou,M.Morton,J.Papapolymerou,andC.G.Christodoulou 1
CompactLarge-SignalShot-NoiseModelforHBTs............ M.Rudolph,F.Korndörfer,P.Heymann,andW.Heinrich 7
SmartAntennas,PhasedArrays,andRadars
DesignConsiderationsontheMinimumSizeofBroadbandAntennasforUWBApplications ..............................
................................................................................ A.Saitou,K.Aoki,K.Honjo,andK.Watanabe 15
ActiveCircuits,SemiconductorDevices,andICs
AHighlyCompactActiveWidebandBalunWithImpedanceTransformationinSiGeBiCMOS ...........................
.......................................................................................................... B.GodaraandA.Fabre 22
ATwo-PointModulationTechniqueforCMOSPowerAmplifierinPolarTransmitterArchitecture .......................
................................................ A.Shameli,A.Safarian,A.Rofougaran,M.Rofougaran,andF.DeFlaviis 31
SignalGeneration,FrequencyConversion,andControl
A1-V9.7-mWCMOSFrequencySynthesizerforIEEE802.11aTransceivers .......... L.L.K. LeungandH.C.Luong 39
Millimeter-WaveandTerahertzTechnologies
RapidSimulationofLinearPBGMicrostripStructuresUsingtheRayleighMultipoleMethod .............................
...................................................................................................D.E.SchaubandD.R.Oliver 49
WirelessCommunicationSystems
BroadbandActiveReceivingPatchWithResistiveEqualization ...............................................................
..................................... D.Segovia-Vargas,D.Castro-Galán,L.E.García-Muñoz,andV.González-Posadas 56
Frequency-SelectivePredistortionLinearizationofRFPowerAmplifiers .....................................................
................................. P.Roblin,S.K.Myoung,D.Chaillot,Y.G.Kim,A.Fathimulla,J.Strahler,andS.Bibyk 65
AHighlyEfficientandLinearClass-AB/FPowerAmplifierforMultimodeOperation ......................................
.............................................. D.Kang,D.Yu,K.Min,K.Han,J.Choi,D.Kim,B.Jin,M.Jun,andB.Kim 77
(ContentsContinuedonBackCover)
(ContentsContinuedfromFrontCover)
FieldAnalysisandGuidedWaves
AnalysisandExperimentsofCompactFoldedSubstrate-IntegratedWaveguide ..............................................
..................................................................................... W.Che,L.Geng,K.Deng,andY.L.Chow 88
CADAlgorithmsandNumericalTechniques
Stability and Accuracy of a Finite-Difference Time-Domain Scheme for Modeling Double-Negative Media With
High-OrderRationalConstitutiveParameters .......................A.Grande,J.A.Pereda,O.González,andÁ.Vegas 94
CertifiedComputationofOptimalMultibandFilteringFunctions .............. V.Lunot,F.Seyfert,S.Bila,andA.Nasser 105
MixedFinite-ElementTime-DomainMethodforTransientMaxwellEquationsinDoublyDispersiveMedia.............
.................................................................................................. B.DondericiandF.L.Teixeira 113
Efficient Full-Wave Analysis of Multilayer Interconnection Structures Using a Novel Domain
Decomposition–Model-OrderReductionMethod .................................................. S.-H.LeeandJ.-M.Jin 121
PracticalImplementationoftheSpatialImagesTechniquefortheAnalysisofShieldedMultilayeredPrintedCircuits...
............... J.S.Gómez-Díaz,M.Martínez-Mendoza,F.J.Pérez-Soler,F.Quesada-Pereira,andA.Alvarez-Melcón 131
FiltersandMultiplexers
SubstrateIntegratedWaveguideCross-CoupledFilterWithNegativeCouplingStructure .......... X.-P.ChenandK.Wu 142
DesignofDual-BandBandpassFiltersUsingStub-LoadedOpen-LoopResonators ....... P.MondalandM.K.Mandal 150
Quarter-WavelengthSide-CoupledRingResonatorforBandpassFilters ......................................................
................................................................ M.K.M.Salleh,G.Prigent,O.Pigaglio,andR.Crampagne 156
Packaging,Interconnects,MCMs,Hybrids,andPassiveCircuitElements
AnalysisandDesignProcedureofTransmission-LineTransformers...........................................................
......................................................................... P.Gómez-Jiménez,P.Otero,andE.Márquez-Segura 163
ABroadbandPlanarMagic-TUsingMicrostrip–SlotlineTransitions..........................................................
.................................................................... K.U-yen,E.J.Wollack,J.Papapolymerou,andJ.Laskar 172
Analysis and Modeling of Hybrid Planar-Type Electromagnetic-Bandgap Structures and Feasibility Study on Power
DistributionNetworkApplications ........................................................ K.H.KimandJ.E.Schutt-Ainé 178
DesignofTriple-PassbandMicrowaveFiltersUsingFrequencyTransformations ................J.LeeandK.Sarabandi 187
DesignofUltra-WidebandThree-WayArbitraryPowerDividers .............................................. A.M. Abbosh 194
BroadbandLow-CostFrequencyMeters .............................................................. T.SokollandA.F.Jacob 202
PredictionofPassiveIntermodulationFromCoaxialConnectorsinMicrowaveNetworks ..................................
................................................................................ J.Henrie,A.Christianson,andW.J.Chappell 209
InstrumentationandMeasurementTechniques
AMeasurementProcesstoCharacterizeNaturalandEngineeredLow-LossUniaxialDielectricMaterialsatMicrowave
Frequencies ...........................................................................G.Mumcu,K.Sertel,andJ.L.Volakis 217
New Time-Domain Voltage and Current Waveform Measurement Setup for Power Amplifier Characterization and
Optimization ........................................ S.Bensmida,P.Poiré,R.Negra,F.M.Ghannouchi,andG.Brassard 224
Microwave Photonics
Millimeter-WaveFiber-FedWirelessAccessSystemsBasedonDenseWavelength-Division-MultiplexingNetworks ...
............................................................................................. C.-S.Choi,Y.Shoji,andH.Ogawa 232
GraphicalApproachforEvaluatingPerformanceLimitationsinExternallyModulatedAnalogPhotonicLinks...........
...................................................................... F.Bucholtz,V.J.Urick,M.Godinez,andK.J.Williams 242
All-Fiber Full-Duplex Multimode Wavelength-Division-Multiplexing Network for Radio-Over-Multimode-Fiber
DistributionofBroadbandWirelessServices ....................................M.GarcíaLarrodéandA.M.J.Koonen 248
InformationforAuthors ............................................................................................................ 256
CALLSFORPAPERS
SpecialIssueonRFIDHardwareandIntegrationTechnologies ................................................................ 257
JointSpecialIssueonMicrowavePhotonics..................................................................................... 258
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Univ. of Michigan
AnnArbor,MI48109-2122USA DANIELDEZUTTER JENSHAN LIN ZOYA POPOVIC KE-LI WU
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IEEETRANSACTIONSONMICROWAVETHEORYANDTECHNIQUES,VOL.56,NO.1,JANUARY2008 1
A 0–55-GHz Coplanar Waveguide
to Coplanar Strip Transition
Dimitrios E.Anagnostou, Member, IEEE, MattMorton, Student Member, IEEE,
JohnPapapolymerou,SeniorMember,IEEE,and ChristosG. Christodoulou,Fellow,IEEE
Abstract—Abroadbandcoplanarwaveguide(CPW)tocoplanar
strip (CPS) transmission line transition directly integrated with
anRFmicroelectromechanicalsystemsreconfigurablemultiband
antennaispresentedinthispaper.Thistransitiondesignexhibits
verygoodperformanceupto55GHz,andusesaminimumnumber
ofdissimilartransmissionlinesectionsandwirebonds,achieving
alow-lossandlow-costbalancingsolutiontofeedplanarantenna
designs.Thetransitiondesignmethodologythatwasfollowedisde-
scribedandmeasurementresultsarepresented.
Index Terms—Antenna feed, coplanar strip (CPS), coplanar
stripline,coplanarwaveguide(CPW),transition.
I. INTRODUCTION
ADVANCESINreconfigurableantennatechnologyandRF
Fig.1. LayoutofatypicalCPWtoCPStransitionwiththreeair-bridgesor
microelectromechanical systems (RF-MEMS) switches
wirebondsfrom[3].
have recently established new frontiers in antenna design.
In [1], Anagnostou et al. developed a multiband reconfig-
urable self-similar antenna, demonstrating the performance be placed between the feeding cable and the antenna’s termi-
enhancement that can be achieved with the use of self-similar nals. Baluns are often narrowband, and thus can feed planar
(or pre-fractal) antenna designs. A significant issue in the narrowband dipoles. However, to feed wideband or multiband
applicabilityandresearchofsuchconformaldipoleantennasis antennas, a transition (balun) capable of balancing the trans-
their feeding method. Any balanced antenna can be fed using missionlineinamuchbroaderrangeoffrequenciesisneeded.
abalancedtransmissionline.Thecurrentsflowingonthisline Suchbalunsworkbytaperingthecoaxialgroundslowlyintoa
areequalandout-of-phasefromthegeneratortotheantenna’s single-tipconductor,formingatwo-wiretransmissionlineatits
feedpoint.Ifthelineisunbalanced,reflectionsattheantenna’s termination[2].
terminals cause unequal currents to flow on the transmission For our application though, the reconfigurable antenna
line (usually on the outer conductor of the coaxial cable), (shownin[1,Fig.13]),whichcoversvariousfrequenciesfrom
whichradiateinanunpredictablemanner,resultingindistorted 8to25GHz,isfabricatedonaquarterofasiliconwafer with
asymmetrical patterns and erroneous voltage standing-wave feeddimensions300 360 m.Anyinterventionorviaonthe
ratio(VSWR)measurement. dielectric layers at such small scales would affect the antenna
Tobalanceatransmissionline,abalun,adevicethatallows performancebyalargedegree.Asaresult,thetransitionneeds
onlythedifferentialmodeofthecurrentstopassthrough,must to be both wideband and planar in order to feed the antenna
from the same plane. All the above led to the development
of the coplanar waveguide (CPW) to coplanar strip (CPS)
ManuscriptreceivedJanuary19,2006;revisedJune10,2007.Thisworkwas transmissionlinetransitiondescribedbelow.
supportedinpartbytheGeorgiaElectronicDesignCenter,bytheNationalSci-
enceFoundationunderGrantECS0218732andGrantEPSCoR0554609,and
bytheMissionResearchCorporationunderContractSC-0244-0008,UNM-1. II. DESIGNCONCEPTS
D. E. Anagnostou is with the Electrical Engineering Department, South First,a20-GHzCPW–CPStransitionsimilartotheonein[3]
DakotaSchoolofMinesandTechnology,RapidCity,SD57701USA(e-mail:
was designed as shown in Fig. 1. The transition is comprised
[email protected]).
M.MortonandJ.PapapolymerouarewiththeSchoolofElectricalandCom- from a series of symmetric and asymmetric transmission line
puterEngineering,GeorgiaInstituteofTechnology,Atlanta,GA30308USA sections. An “air-bridge” or wire bond is needed before each
(e-mail:[email protected];[email protected]).
asymmetric section discontinuity to suppress any non-CPW
C.G.ChristodoulouiswiththeElectricalandComputerEngineeringDe-
partment,UniversityofNewMexico,Albuquerque,NM87106USA(e-mail: modeandretainthebalanceonthetransmissionline.Theslot
[email protected]). of the CPS ( ) needs to be tapered to match the width of
Colorversionsofoneormoreofthefiguresinthispaperareavailableonline
the one of the two slots of the symmetric CPW ( ), as
athttp://ieeexplore.ieee.org.
DigitalObjectIdentifier10.1109/TMTT.2007.911909 illustratedinsection2ofFig.1.
0018-9480/$25.00©2007IEEE
2 IEEETRANSACTIONSONMICROWAVETHEORYANDTECHNIQUES,VOL.56,NO.1,JANUARY2008
Fig. 2. Simulated S-parameters of the back-to-back initial transition with
600-(cid:22)m-long lines showed very good response up to 20 GHz. A gradual
performancedeclineathigherfrequenciescanbenoticed.
ThesimulatedfrequencyresponseisshowninFig.2,where
agradualperformancedeclineathigherfrequenciescanbeno- Fig.3. CPSandCPWlinecharacteristicimpedanceasitvarieswiththeslot
ticedasthereturnlossbecomessmallerthan10dB.Tosatisfy width(S orS )andthewidthofthemetalconductor(W forthe
CPSline).A20-(cid:22)mslotwasusedintheCPSlineplot.
thedesigngoalsandincreasethetransitionbandwidth,several
alterationsweremade.
A reduction in the number of discontinuities can lead to a throughout the transition. It can also be ex-
reduction in the number of wire bonds. This reduction can be tended to other impedance values due to the fact that the CPS
achieved by careful consideration of the characteristics of the line’scharacteristicimpedance( )isstronglydependent
beginning and ending slots (CPS transmission line slot upon its slot’s width ( ), while the CPW’s characteristic
andCPWslot ,respectively),asshowninFig.1.Forthis impedance depends both on the CPW slot’s width
purpose,weneedtoplacearestrictioninthedesignthatforall ( )andthewidthofitssignalconductor( ),adding
CPWandtheCPSsections,allslotsshouldbeofequalwidth. one degree of freedom to the design. Some relations between
Byapplyingthisrestriction,theslotofsection1( )canbe thecharacteristicimpedance( )ofthedifferentlinesusedhere
designedtobeequalto insections3–5.Onediscontinuity versusthewidthoftheirslot( ,assuming )
ofthetransmissionlineandonewirebond(section2)arethen areshowninFig.3(left -axis).
redundantandeliminated.Sections1and2areunifiedandthe 1) Increasing the width of the CPW slot ( ), increases
air-bridgesofsections2and3aretheonlyonesneeded. thecharacteristicimpedanceoftheCPWline,asillustrated
This imposes the design of CPW and CPS transmission for three different CPW lines with m,
line sections with the exact same slot width (and equal to m, and m, with
), while maintaining the same characteristic impedance m.
throughoutthetransitiontominimizereflections,whichcanbe 2) Increasing the width of the center conductor of the CPW
challenging. lines( )decreasestheircharacteristicimpedance.
ItispossibletoadjusttheCPWlinebyvaryingthewidthsof 3) IncreasingthewidthoftheCPSslot( )increasesthe
itssignalconductor( )andofitsslot( )suchthatits CPStransmissionline’scharacteristicimpedance.
characteristicimpedanceremainsrelativelyconstantandequal 4) Atthesametime,afinite-metalCPStransmissionlinehas
tothatoftheCPStransmissionlineinordertoeliminatetheneed higher thanthe(theoretically)infinite-metalCPStrans-
for taper. When the CPW slot width ( ) is increased, the missionlinewiththesameslotwidth( ).
line’scharacteristicimpedance( )increasesaswell.On ByvaryingthewidthofthemetalpartoftheCPSline( )
theotherhand,increasingthesignalconductor’swidth( ) while maintaining the width of its slot ( ) constant and
causes todecrease.Itisastraightforwardconclusionto equaltothatoftheCPWline(i.e., ),onecanalter
presumethatseveralcombinationsofslotandsignalconductor theCPStransmissionline’scharacteristicimpedancetomatch
widths can lead to a CPW with a specific value of character- that of the CPW line with the same slot width ( ). Thus,
isticimpedance.ThisvalueisequaltotheCPS’scharacteristic thelinesdimensionscanbeadjustedforuniformcharacteristic
impedance,anddependsupontheapplication’sdesignspecifi- impedancethroughoutthetransition.
cations,probepitch,andfabricationequipment’stoleranceand Fig.3showsthevarietyofCPWchoicesonecanuseinatran-
capabilities.Here,a150- m-pitchCPWlinewasusedtomatch sitionforaspecificCPSlineslotwidth( ),which
withthedimensionsfromotherpartsofthesystemandtheRF cannotbesignificantlyvaried.Forexample,thisisachievedby
probes. drawingaverticallinefrom andnotingallCPWand
This methodology was also used to match and balance the CPS lines that are crossed, as long as these lines in the graph
reconfigurable antenna of [1] to , maintaining a havebeenextractedforthesameslotwidth
ANAGNOSTOUetal.:0–55-GHzCPWTOCPS 3
TABLEI
SUBSTRATECROSSSECTION
m).InFig.3,allthreeshownCPWtransmissionlinescan
have ,andanyofthethreeshownsignalcon-
ductorwidths( )canbeusedwiththeirappropriateslot
widths given by the left -axis. The CPS line curves are also
drawnforvariousslotdimensions( )andanapproximate
matchcanbeextractedinavisualmanner.
In particular, for the design described in this study, not all
lines intersected at the same points and, thus, a perfect match
was not achieved. We have used a CPW
Fig.4. FinalCPW–CPStransitionwithdimensionsandnamesofthedifferent
linecharacteristicimpedancewith mslotwidth, transmissionlinesectionsasdefinedinFig.1.Thetotallengthoftheback-to-
whichalsodefinedtheslotwidthoftheCPStransmissionline backconfigurationwas2(cid:1)4300=8600(cid:22)m.
( ).ACPStransmissionlinewiththisslotwidthandfinite
metalwidthof mhascharacteristicimpedance
Thistransitiondesignisimprovedwhencomparedtoexisting
,markedwith“ ”at(55 ,20 m)onFig.3.
ones[3]–[5]inthesense thatitusesa reducednumberofdis-
The quality of matching for different dimensions and im-
continuities (and, thus, wire bonds), leading to better RF per-
pedances can be “visually” extracted from the distance of the
formancewithwiderbandwidth,faster fabricationtime,lower
curves( versus ), between twodifferent transmission
loss,andlowercost.
linecurves.Thecloserthecurvesare,thebetterthematch.For
specific impedance and slot width values, this is equivalent to III. BACK-TO-BACKTRANSITIONDESIGNANDSIMULATIONS
howclosethetwo“ ”marksareinFig.3.
UsingthemethodologydescribedinSectionII,thebroadband
Toimprovematching,theCPStransmissionlinecouldbede-
transitionwasdesignedanditsstructureisshowninFig.4.The
signedwithalower ifwidermetal
designprocedurebeginsatsection5(CPS),goingtowardssec-
m wasused,asindicatedfromtheright -axisofFig.3,
tion1(CPW).Aslotof minsection5isusedand
where the plotted curve is for the CPS transmission line used
maintainedconstant.Additionally,thedimensionsofthebottom
herewith m.Fordifferent widths,different
striparealsokeptconstantduringtheentiretransition.Insec-
curvescanbeplottedtoenabledesignswithothercharacteristic
tion 4, the upper strip of the CPS transmission line is linearly
impedances. The CPW line could also achieve a
narrowedtothecenterstripoftheCPWline,andataperedCPW
withagapof28 m,butthiswouldresultinlargerCPS
groundisaddednextbeginningfromthewidthofthetopCPS
transmissionlinecharacteristicimpedance( ).Analytical
strip until the CPW line becomes symmetric. Both CPW slots
equationsasfunctionsofellipticintegrals[6]wereusedtoob-
are maintained constant at m and the transition
tain starting points for the CPS and CPW transmission lines.
endsinasymmetricCPWdesign.
Thelineswerethensimulatedwithamethodofmomentselec-
TheCPSlineslot anditsconductors’width
tromagneticsimulator.1Fig.3canalwaysbeusedasastarting
werecalculatedfirstandawidth mwasusedto
point, as it gives dimensions and values for the transition sec-
bring closeto50 . Theguide wavelengthwas found
tions, neglecting any mutual coupling with other system com-
tobe mmat7.75GHz, mmat15GHz,and
ponents.ThefinaldimensionsaredescribedinSectionIIIand
mmat24.75GHz.Thecalculatedeffectivedielectric
were chosen as a compromise between the desired impedance
constantwas .Thefinaldesignlayoutisshownin
matching,agoodoverallsystemperformance,whiletakinginto
Fig.4,anddetailedinTableII,alongwiththetransitionofFig.1.
accountthelimitsofthefabricationequipment.
The keen reader may notice some differences between the
Tominimizefabricationcomplexityandmaximizeco-process
theoretical“optimum”valuesthatcanbeextractedfromFig.3
compatibilitywiththeintegrationoftheRF-MEMS,thetransition
andthevaluesusedhere.Thesecanbeattributedtotheuseof
isfabricatedonahigh-resistiveSiwafer,andmadewiththesame
themethodofmomentssoftwareforthefinetuningofthetran-
metallizationandpatterningstepsastheantenna.Underneaththe
sition integrated with the antenna in order to achieve not only
metal(Au)layer,therearethinlayersofSiO andSi N ,asim-
widebandwidth,butalsoagoodsystemperformance.Also,the
posedbythedesignoftheswitches.Thesequenceofdielectric
method of moments software, while it takes into account any
andmetallizationlayersisshowninTableI.
discontinuity effects that analytical equations might disregard,
1IE3DisaregisteredtrademarkoftheZelandCorporation,Fremont,CA. itneglectedthefinitenessofthedielectricsubstrates,extending
4 IEEETRANSACTIONSONMICROWAVETHEORYANDTECHNIQUES,VOL.56,NO.1,JANUARY2008
TABLEII
DIMENSIONSOFTHECPW–CPSTRANSITIONS(INMICROMETERS)
“Init.”isthe0–20-GHztransition,asillustratedinFig.1,modifiedfor
siliconsubstrate.
themtoinfinity.Thisresultedinsignificant(butnotdetrimental)
differences between simulation and measurements, at such di-
mension(micrometer)scales.
Thetransitionasintegratedwiththeantennawasattachedto
a 3400- m-long CPW transmission line section to connect to
theRFprobes.Thisway,theRFprobeheadwaskeptfarfrom
theantennaanditseffectintheradiationpatternwasminimal.
The simulated frequency response of the transition in a
back-to-backconfigurationisshowninFig.5.Theperformance
is very good from dc up to 40 GHz, covering the desired
antennaresonantfrequencies,andexhibitingverylowinsertion
Fig.5. Measuredandsimulatedback-to-backtransitionperformance.(a)Mag-
loss. In the back-to-back configuration, return loss is greater nitudeofinsertionlossandreflectioncoefficient.(b)Groupdelayandinsertion
than 12 dB, while insertion loss is less than 2.8 dB (value at phaseofS forthetransitionwithalltransmissionlinesattached.
23 GHz), which implies that some minimal radiation takes
place,astheoveralllengthgetselectricallylarger.Additionally,
the back-to-back transmission coefficient’s insertion phase is
almost linear, resulting in minimal distortion of the RF signal
from the input until the antenna terminals. Finally, simula-
tions showed that expected values for the integrated (single)
transition return loss and insertion loss were 15 and 1.3 dB,
respectively.ThemeasuredresultsarediscussedinSectionIV.
IV. BACK-TO-BACKTRANSITIONMEASUREMENTS
Thetransition’sperformancecanbepartiallyevaluatedbythe
measured results of the reconfigurable antenna system that it
wasintegratedwith,asshownin[1,Figs.13–15].Amagnified
photographoftheintegratedtransition(Fig.6)showsaslightly
misplaced (right) manual wire bond. The measurement in
[1,Fig.13]showingsomefluctuationsemphasizetheeffortpre-
sented here and justify the need to reduce the number of wire Fig.6. Fabricatedtransitionintegratedwiththeantenna.
bonds on transition designs. In a mass-production application,
themoreaccurateMEMSair-bridgescansubstitutewirebonds
withbetterperformance. stratelossesinthecircuit.Asanymeasurementwillincorporate
Inordertoobtainacompletecharacterization,thetransition theselosses,acorrectevaluationofthetransition’sperformance
wasalsofabricatedinaseparatesiliconwaferinaback-to-back canbemadebysubtractingthemfromthemeasured .Todo
configuration,atthecleanroomfacilitiesoftheGeorgiaInstitute so, transitions with different CPW and CPS transmission line
of Technology, Atlanta, using standard photolithography tech- lengthswerefabricatedandmeasured.Lossesinducedbyorre-
niquesandequipment. lated to the thin metal layer of Au, surface roughness, and di-
Thetransitionisdirectlyconnectedtodifferenttransmission electricthatwererelatedtothesetransmissionlinesectionswere
linesections(CPWandCPS),whichmayaddohmicandsub- calculated.
ANAGNOSTOUetal.:0–55-GHzCPWTOCPS 5
andlow-costmethodtofeedplanarantennadesignsfabricated
onrigid substrates. Thetransition was directlyintegratedwith
anRF-MEMSreconfigurablemultibandantennaandexhibited
verygoodresultsaswell.Finally,byreplacingthewirebonds
with accurately placed and less lossy MEMS air-bridges, and
by minimizing the lengths of the CPW and CPS line sections,
transitiondesignswithlargerbandwidthandverylowlosscan
bedeveloped.
REFERENCES
[1] D.E. Anagnostou, G. Zheng, M. Chryssomallis, J. Papapolymerou,
Fig.7. PhotographandmagnificationofthefabricatedCPW–CPStransition
C.G.Christodoulou,J.Lyke,andG.Ponchak,“Design,fabrication
withthetransmissionlinesectionsattached.
and measurements of a self-similar re-configurable antenna with
RF-MEMSswitches,”IEEETrans.AntennasPropag.(SpecialIssue),
vol.54,no.2,pt.1,pp.422–432,Feb.2006.
[2] J. W. Duncan and V. P. Minerva, “100:1 bandwidth balun trans-
TheCPWlinelossperunitlengthwascalculatedfromaCPW
former,”Proc.IRE,vol.48,no.2,pp.156–164,Feb.1960.
lineusedinthecalibration.Theloss,indecibels/micrometer,for [3] S. G. Mao, C. T. Hwang, R. B. Wu, and C. H. Chen, “Analysis of
everyfrequencywasfound,andfromthat,thelossoftheentire coplanarwaveguide-to-coplanarstriplinetransitions,”IEEETrans.Mi-
crow.TheoryTech.,vol.48,no.1,pp.23–29,Jan.2000.
CPW line section wasderived and subtracted from the overall
[4] T.Chiu,“Abuilding-blockdesignschemeforplanartransmission-line
transition’sperformance.Next,thelossoftheCPSlinesection transitions,”Proc.Inst.Elect.Eng.—Microw.,Antennas,Propag.,vol.
wasfoundinasimilarway. 150,pt.6,pp.405–410,2003.
[5] A.T.Kolsrud,M.-Y.Li,andK.Chang,“Dual-frequencyelectronically
The calculated transition losses are also shown in Fig. 5(a)
tunableCPW-fedCPSdipoleantenna,”Electron.Lett.,vol.34,no.7,
within the measured range from 0 to 60 GHz. With the pp.609–611,Apr.1998.
back-to-back configuration, a low-loss performance was ob- [6] B.C.Wadell,Transmission-LineDesignHandbook. Norwood,MA:
ArtechHouse,1991,pp.83–84.
tained from 2 GHz up to 55 GHz since the insertion loss
is less than 1.9 dB. The bandwidth exceeded the expected
simulated frequency range. Additionally, the insertion phase Dimitrios E. Anagnostou (S’98–M’05) was born
and group delay of the propagated signal were measured and inAthens,Greece,inNovember1975.Hereceived
theDiplomadegreeinelectricalandcomputerengi-
calculated, respectively. Both are plotted in Fig. 5(b). The
neering,fromtheDemocritusUniversityofThrace,
insertion phase varies in a linear way with frequency, as ex- Thrace, Greece, in 2000, and the M.Sc. and Ph.D.
pected, while the group delay is fairly constant with values degreesinelectricalengineeringfromtheUniversity
of New Mexico, Albuquerque, in 2002 and 2005,
between0.067–0.090ns,anaveragevalue ns,and
respectively.
small variance ns . A photograph of the From 2005 to 2006, he was a Post-Doctoral
back-to-back fabricated transition is shown in Fig. 7, where FellowwiththeSchoolofElectricalandComputer
Engineering, Georgia Institute of Technology, At-
the transition itself is shown magnified to better illustrate the
lanta.In2007,hejoinedthefacultyoftheElectricalEngineeringDepartment,
structure’sdetails. SouthDakotaSchoolofMinesand Technology,RapidCity,asanAssistant
Acomparisonbetweensimulatedandmeasuredresultsshows Professor.Hehasauthoredorcoauthoredover30peer-reviewedinternational
journal and conference publications. He has filed two invention disclosures
relatively good agreement in . The largest deviation was
onreconfigurableandultra-wideband(UWB)antennas.Hiscurrentresearch
found at 24 and 37 GHz with 7 , which is a small varia- involvesdirect-writeprintingforthedevelopmentandintegrationofRFcircuits
tionwhenconsideringthecomplexityofthestructure,thedif- onflexiblesubstrates(liquidcrystalpolymer(LCP),Kapton),reconfigurable
and low-cost flexible antennas and RF front-ends, novel antenna designs,
ferentlayers,andthemodelingofthewirebonds.Theinsertion
microwavepackaging,RF-MEMS,neuralnetworks,andimageprocessing.
phase was linear and very similar both in the simulation and Dr.AnagnostouisamemberofEtaKappaNuandtheTechnicalChamber
measurement.Somevariationin canbenoticed.Theelec- ofGreece.Hewastherecipientofthreeresearchandtravelgrantsfrom2003
to2005.HeservedasasessionchairattheIEEEAntennasandPropagation
tromagneticfieldsaremostlyconcentratedinthespacebetween
Society(IEEEAP-S)2006and2007InternationalSymposia.Heservesasa
the metallicconductorsso anedgemeshingwasused. Results reviewerfortheIEEETRANSACTIONSONANTENNASANDPROPAGATIONand
in this case are sensitive to the edge mesh’s size and density, theIEEETRANSACTIONSONMICROWAVETHEORYANDTECHNIQUES.
aswellasthe wirebondsandtheconductingpropertiesofthe
sputteredAu.Allconductorsweresimulatedasperfect,which
isalsoanotherreasonfortheobserveddifference.Thesediffer- Matt Morton (S’02) received the B.S. degree in
encesthoughwereexpectedandprovedtobenoncriticalforthe electrical and computer engineering from the Uni-
versityofKansas,Lawrence,in2002,andtheM.S.
successfuloutcomeofthisstudy.
andPh.D.degreesinelectricalengineeringfromthe
The major advantage of this design when compared to pre- Georgia Institute of Technology, Atlanta, in 2003
vious ones is its broader bandwidth, which is obtained using and2007,respectively.
His research interests include SiGe X-band
a reduced number of wire bonds. The design approach pre-
phaseshiftersformonolithicradartransmit/receive
sented may also be used for transmission lines with different (T/R)modules,low-costRFCMOSreceiverdesign,
valuesofcharacteristicimpedance.Theonepresentedhereex- RF-MEMS phase shifters, broadband RF-MEMS
switch packaging, low-temperature RF-MEMS
hibits very good performance up to 55 GHz with a reduced
packagingtechniquesonorganicliquidcrystalpolymer(LCP),metamaterial
numberoftransmissionlinediscontinuitiesachievingalow-loss crosstalkisolators,andnanoparticlemagneticthinfilms.
6 IEEETRANSACTIONSONMICROWAVETHEORYANDTECHNIQUES,VOL.56,NO.1,JANUARY2008
John Papapolymerou (S’90–M’99–SM’04) re- Christos G. Christodoulou (S’80–M’81–SM’90–
ceived the B.S.E.E. degree from the National F’02) received the B.Sc. degree in physics and
TechnicalUniversityofAthens,Athens,Greece,in mathfromtheAmericanUniversityofCairo,Cairo,
1993,andtheM.S.E.E.andPh.D.degreesfromThe Egypt,in1979,andtheM.S.andPh.D.degreesin
UniversityofMichiganatAnnArbor,in1994and electrical engineering from North Carolina State
1999,respectively. University,Raleigh,in1981and1985,respectively.
From1999to2001,hewasanAssistantProfessor From 1985 to 1998, he was a faculty member
with the Department of Electrical and Computer withtheUniversityofCentralFlorida,Orlando.In
Engineering,UniversityofArizona,Tucson.During 1999, he joined the Electrical and Computer En-
the summers of 2000 and 2003, he was a Visiting gineering Department, University of New Mexico,
ProfessorwiththeUniversityofLimoges,Limoges, Albuquerque,wherehewasChairofthisdepartment
France.From2001to2005,hewasanAssistantProfessorwiththeSchoolof from1999to2005.HeisanAssociateEditoroftheInternationalJournalof
ElectricalandComputerEngineering,GeorgiaInstituteofTechnology,Atlanta, RFandMicrowaveComputer-AidedEngineering.HewasaGuestEditorfor
whereheiscurrentlyanAssociateProfessor.Hehasauthoredorcoauthored theSpecialIssueon“ApplicationsofNeuralNetworksinElectromagnetics”
over140publicationsinpeer-reviewedjournalsandconferences.Hisresearch oftheAppliedComputationalElectromagneticsSociety’sACESJournal.He
interestsincludetheimplementationofmicromachiningtechniquesandMEMS hasauthoredorcoauthoredover250papersinjournalsandconferences.He
devices in microwave, millimeter-wave and terahertz circuits and the devel- hasauthoredorcoauthored12bookchaptersandcoauthoredfourbooks.His
opmentofbothpassiveandactiveplanarcircuitsonsemiconductor(Si/SiGe, researchinterestsaremodelingofelectromagneticsystems,reconfigurablesys-
GaAs)andorganicsubstrates[liquid-crystalpolymer(LCP),low-temperature tems,machinelearningapplicationsinelectromagnetics,andsmartantennas.
co-fired ceramic (LTCC)] for system-on-a-chip (SOC)/system-on-package Dr. Christodoulou is a member of Eta Kappa Nu, The Electromagnetics
(SOP)RFfrontends. Academy(TEA),andCommissionBoftheUnitedStatesNationalCommittee
Dr.Papapolymerouisthevice-chairforCommissionDoftheU.S.National oftheInternationalUnionofRadioScience(USNC/URSI).Heservedasthe
Committee of URSI. He is an associate editor for IEEE MICROWAVE AND general chair of the IEEE Antennas and Propagation Society (AP-S)/URSI
WIRELESSCOMPONENTLETTERSandtheIEEETRANSACTIONSONANTENNAS 1999Symposium,Orlando,FL,astheco-chairoftheIEEE2000Symposium
AND PROPAGATION. During 2004, he was the chair of the IEEE Microwave on Antennas and Propagation for Wireless Communications, Waltham, MA,
Theory and Techniques (MTT)/Antennas and Propagation (AP) Atlanta andtheco-technicalchairfortheIEEEAP-S/URSI2006Symposium,Albu-
Chapter.Hewastherecipientofthe2004ArmyResearchOffice(ARO)Young querque,NM.HeiscurrentlyanassociateeditorfortheIEEETRANSACTIONS
Investigator Award, the 2002 National Science Foundation (NSF) CAREER ON ANTENNAS AND PROPAGATION and the IEEE Antennas and Propagation
Award,theBestPaperAwardpresentedatthe3rdIEEEInternationalConfer- Magazine.HewasappointedanIEEEAP-SDistinguishedLecturerfor2007
enceonMicrowaveandMillimeter-WaveTechnology(ICMMT2002),Beijing, to2009andwaselectedvice-chairfortheAlbuquerqueIEEEAntennasand
China, and the 1997 Outstanding Graduate Student Instructional Assistant Propagation(AP)/MicrowaveTheoryandTechniques(MTT)Chapter.
AwardpresentedbytheAmericanSocietyforEngineeringEducation(ASEE),
TheUniversityofMichiganatAnnArborChapter.Hisstudentwasalsothe
recipientoftheBestStudentPaperAwardpresentedatthe2004IEEETopical
MeetingonSiliconMonolithicIntegratedCircuitsinRFSystems,Atlanta,GA.
IEEETRANSACTIONSONMICROWAVETHEORYANDTECHNIQUES,VOL.56,NO.1,JANUARY2008 7
Compact Large-Signal Shot-Noise Model for HBTs
MatthiasRudolph, Senior Member, IEEE, Falk Korndörfer, PeterHeymann, and
Wolfgang Heinrich, Senior Member, IEEE
Abstract—A new description of the shot noise in HBTs is pro- time delayshaveto be realized by timeconstants, i.e., by
posedthataccountsforthecorrelationofthesources.Itcaneasily definingthegoverningchargesandcurrentsproperly.Hence,a
be included in large-signal models, thus significantly improving
time constant is not directly accessible and would be required
the RF noise description. Common nonlinear bipolar transistor
to be approximated using the charge formulas, as recently
models thus far neglect the correlation, which deteriorates the
model accuracy towards higher frequencies. It is shown that the proposed for the MEXTRAM model [9]. For this reason, the
collector delay in InGaP/GaAs HBTs dominates the shot noise large-signal models available today, in general, neglect the
correlation. Hence, the collector time-delay description of the correlationoftheshot-noisesources.
large-signalmodeliscapableofprovidingsuitablenoisecorrela-
Inthispaper,theapproachof[10],whichwasproposedand
tion time constants. The model is verified against measurements
verified in the linear domain, will be applied to and verified
ofInGaP/GaAsHBTswiththreedifferentepitaxiallayerdesigns.
for a large-signal HBT model. This approach takes advantage
Index Terms—Equivalent circuit, heterojunction bipolar
of proper placement of two noncorrelated shot-noise sources
transistor(HBT),noise,semiconductordevicemodeling,semicon-
in order to realize the correlation implicitly through the large-
ductordevicenoise,shotnoise,whitenoise.
signaldescription.Whileithasalreadybeenshownin[10]that
the nonlinear model topology is well suited for this approach,
I. INTRODUCTION it was still in question whether the nonlinear model provides
therequiredparametervalues.Inshort:isitpossibletodescribe
thenoisecorrelationimplicitlythroughthenonlineartimedelay
THETHEORYofwhitenoisemodelingforbipolartransis-
model?Ifyes,whichpartofthetimedelaymustbetakeninto
tors is well established for several decades [1]–[4]. This
account?
theory has also successfully been adapted to state-of-the-art
ItwillbeshownattheexampleofInGaP/GaAsHBTsthata
GaAsheterojunctionbipolartransistors(HBTs)[5]–[7].
dedicatedHBTmodelindeedyieldsgoodnoisesimulationre-
In the microwave region, there are basically two types of
sults if the shot-noise sources are properly placed. It turns out
noisetobeconsidered:thermalandshotnoise.
that the model for the collector transit time is dominant. Fur-
(cid:127) ThermalnoiseisgeneratedinthepassivepartoftheHBT,
thermore,HBTswiththreedifferentbaseandcollectordesigns
namely,bythecontactandlayerresistances.Itiscrucialto
are investigated regarding the impact of HBT layer design on
useacorrectequivalent-circuittopology,andtoknowthe
the shot-noise correlation. Hence, this investigation also pro-
deviceoperatingtemperature.Besidesthat,thispartofthe
videsexperimentalevidencefortheprominent roleofthe col-
modelisquitestraightforward.
lectordelayinthecorrelationoftheshotnoiseinstate-of-the-art
(cid:127) Shot noise is observed at the pn junctions. It can be de-
HBTs.
scribedbytwosourcesthatarecontrolledbybaseandcol-
lectorcurrents.Thesetwosources,however,arecorrelated II. RFNOISEMODELING
duetotheintrinsictransittime[8].
Here, the traditional small-signal noise models will be re-
The main challenge is the correlation of the shot-noise
viewed.Itwillbehighlightedthatthetwocommontopologies
sources. It can be characterized by a time constant that is, in
relyingonnoncorrelatedsourceseitherunderestimateoroveres-
general, lower than the total intrinsic time delay determined
timatethenoisecorrelationtime[11].Itwillthenbeaddressed
in small-signal extraction. It is, hence, necessary to extract
how nonlinear HBT models approximate time delay, and how
it from noise parameter measurement and it cannot simply
the shot-noise model can be tailored to fit into the nonlinear
be predicted if the small-signal equivalent circuit is known.
equivalent-circuittopology.
Implementing the noise sources in a large-signal model is
even more involved. The correlation time is not a constant A. Shot-NoiseModelsintheLinearDomain
value, but depends on bias. Furthermore, large-signal models
Two shot-noise model topologies for bipolar transistors are
are formulated in the time domain. In general, bias-dependent
shown in Fig. 1. For simplicity, only the very intrinsic part of
the HBT model will be discussed, focusing on the shot-noise
description.Thesmall-signalcurrentgain isdispersive,i.e.,
ManuscriptreceivedJuly10,2007;revisedSeptember13,2007.
M.Rudolph,P.Heymann,andW.HeinricharewiththeFerdinand-Braun-
(1)
InstitutfürHöchstfrequenztechnik(FBH),D-12489Berlin,Germany(e-mail:
[email protected];[email protected];[email protected]).
F. Korndörfer is with Innovationsfor High Performance Microelectronics It is assumed in the following that represents the intrinsic
(IHP),15236Frankfurt(Oder),Germany(e-mail:korndoerfer@ihp-microelec-
base–collectortransittime,while describes
tronics.com).
DigitalObjectIdentifier10.1109/TMTT.2007.911944 theimpactofthebase–emitterjunction.Furthermore,itwillbe
0018-9480/$25.00©2007IEEE