Ultra-Broadband GaAs pHEMT MMIC Cascode Travelling Wave Amplifier

256 Pages·2016·40.13 MB·English

ULTRA-BROADBAND GaAs pHEMT
MMIC CASCODE TRAVELLING WAVE
AMPLIFIER (TWA) DESIGN FOR NEXT
GENERATION INSTRUMENTATION
A THESIS SUBMITTED TO THE UNIVERSITY OF MANCHESTER
FOR THE DEGREE OF DOCTOR OF PHILOSOPHY
IN THE FACULTY OF ENGINEERING AND PHYSICAL SCIENCES
2016
By
PriyaShinghal
SchoolofElectricalandElectronicEngineering
Contents
Abstract 18
Declaration 20
Copyright 21
Dedication 22
Acknowledgements 23
AboutTheAuthor 25
Publications 26
ListofAbbreviations 28
1 Introduction 31
1.1 Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
1.1.1 InstrumentationinMillimeter-WaveFrequencyRange . . . . . . 32
1.1.2 DevelopmentofSystemsforHighDataTransferrates(100Gb/s
andmore) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
1.2 DeviceTechnology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
1.2.1 MESFET,pHEMTandHBT . . . . . . . . . . . . . . . . . . . . . . 36
1.2.2 MaterialProperties: GaAs,InP,GaN,SiGe . . . . . . . . . . . . . . 45
1.2.3 FoundryProcess: 100nmGateLengthWINPP10-10 . . . . . . . 48
1.3 BroadbandAmplifierDesignTechniques . . . . . . . . . . . . . . . . . . 49
1.3.1 ConceptofDistributedAmplification . . . . . . . . . . . . . . . . 50
1.4 TargetSpecificationsforMMICCascodeTWADesign . . . . . . . . . . . 51
1.5 MonolithicMicrowaveIntegratedCircuits(MMICs). . . . . . . . . . . . 51
1.6 ThesisOrganization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
2
2 TravellingWaveAmplifier(TWA)inReview 55
2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55
2.2 HistoricalBackground . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56
2.3 Common-SourceFETTWA . . . . . . . . . . . . . . . . . . . . . . . . . . 60
2.3.1 TheoryofOperation . . . . . . . . . . . . . . . . . . . . . . . . . . 60
2.4 WhyCascode? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
2.4.1 MitigationofMillerEffect . . . . . . . . . . . . . . . . . . . . . . . 62
2.5 DesignParameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
2.5.1 GainandOptimumNumberofCells. . . . . . . . . . . . . . . . . 66
2.5.2 Gate&DrainTransmissionLineandTerminationNetworkDesign 70
2.5.3 PhaseVelocitySynchronization . . . . . . . . . . . . . . . . . . . 79
2.5.4 Stability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
2.6 FigureofMerit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81
2.6.1 Gain-BandwidthProduct . . . . . . . . . . . . . . . . . . . . . . . 81
2.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82
3 On-WaferCalibration&MeasurementandHighFrequencyEffects 83
3.1 S-ParametersofaTwo-PortLinearNetwork . . . . . . . . . . . . . . . . 84
3.1.1 On-WaferS-ParameterMeasurements . . . . . . . . . . . . . . . 86
3.2 On-WaferCalibrationTechniques . . . . . . . . . . . . . . . . . . . . . . 88
3.2.1 Short-Open-Load-Thru(SOLT) . . . . . . . . . . . . . . . . . . . . 89
3.2.2 Through-Reflect-Line(TRL)&MultilineTRL . . . . . . . . . . . 89
3.2.3 Line-Reflect-Match(LRM)&Line-Reflect-Reflect-Match(LRRM) 89
3.3 On-WaferCalibrationStandards . . . . . . . . . . . . . . . . . . . . . . . 91
3.3.1 ImpedanceStandardSubstrate(ISS) . . . . . . . . . . . . . . . . . 91
3.3.2 CustomizedCalibrationStandardsonGaAsWINPP10-10Process 92
3.3.3 CharacterisationofOn-WaferCalibrationStandards . . . . . . . 93
3.4 Calibration&ShiftinMeasurementReferencePlane . . . . . . . . . . . 94
3.4.1 VNAorProbe-TipCalibration . . . . . . . . . . . . . . . . . . . . . 95
3.4.2 On-WaferCalibration . . . . . . . . . . . . . . . . . . . . . . . . . 97
3.4.3 FixtureDe-Embedding . . . . . . . . . . . . . . . . . . . . . . . . . 101
3.5 On-WaferProbingUncertainties . . . . . . . . . . . . . . . . . . . . . . . 101
3.5.1 Case1: HighFrequencyEffectofProbeLandingPosition . . . . 103
3.5.2 Case2: PadCapacitanceDe-Embedding . . . . . . . . . . . . . . 106
3.6 CalibrationResidualErrors . . . . . . . . . . . . . . . . . . . . . . . . . . 108
3.7 OtherOn-WaferMeasurementsandTestSet-Up . . . . . . . . . . . . . . 110
3
3.7.1 On-WaferNoiseParameterMeasurementsto50GHz . . . . . . . 110
3.7.2 On-WaferPowerMeasurementsto110GHz . . . . . . . . . . . . 113
3.8 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113
4 MMICDevicePull-OutsandModelling 115
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115
4.2 Common-SourceandCommon-GateFieldEffectTransistors . . . . . . 116
4.2.1 DCMeasurements . . . . . . . . . . . . . . . . . . . . . . . . . . . 117
4.2.2 S-ParameterMeasurements . . . . . . . . . . . . . . . . . . . . . . 120
4.2.3 IntrinsicParameterExtraction . . . . . . . . . . . . . . . . . . . . 128
4.3 ConventionalandFlippedCascodeCell . . . . . . . . . . . . . . . . . . . 132
4.3.1 EquivalentCircuitAnalysis . . . . . . . . . . . . . . . . . . . . . . 133
4.3.2 S-ParameterMeasurements . . . . . . . . . . . . . . . . . . . . . . 139
4.4 Multi-StackCascodeCell. . . . . . . . . . . . . . . . . . . . . . . . . . . . 140
4.5 SingleStageCascodeAmplifier . . . . . . . . . . . . . . . . . . . . . . . . 141
4.5.1 S-ParameterMeasurement . . . . . . . . . . . . . . . . . . . . . . 142
4.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143
5 Ultra-BroadbandMMICCascodeTWADesignsandResults 145
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 145
5.2 ActiveDevice&OperatingBiasPoint . . . . . . . . . . . . . . . . . . . . 146
5.3 0.01 - 100 GHz 10-Cell 2x12 µm MMIC Cascode Direct Coupled TWA
(DCTWA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
5.3.1 GateandDrainLineDesign . . . . . . . . . . . . . . . . . . . . . . 150
5.3.2 Stability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154
5.3.3 SimulationResultsforDesignBasedonWINPP10-10PDKFET
andPassiveComponentModels . . . . . . . . . . . . . . . . . . . 158
5.3.4 Electro-Magnetic(EM)Simulation,ResultsandLayout . . . . . 161
5.3.5 Measurement and Results of 0.01 - 100 GHz 10-Cell 2x12 µm
MMICCascodeDCTWA . . . . . . . . . . . . . . . . . . . . . . . . 170
5.4 Devicemodelmodificationandimplementation . . . . . . . . . . . . . 174
5.4.1 SingleCascodeCellAnalysis . . . . . . . . . . . . . . . . . . . . . 175
5.4.2 Common-GateFET(CGFET)Analysis . . . . . . . . . . . . . . . . 178
5.4.3 ModifiedFETModel . . . . . . . . . . . . . . . . . . . . . . . . . . 184
5.5 0.01 - 110 GHz 15-Cell 2x10 µm MMIC Cascode Direct Coupled TWA
(DCTWA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186
4
5.5.1 SimulationVsOn-WaferMeasurementResults . . . . . . . . . . 190
5.6 0.01-110GHz15-Cell2x10µm MMICCascodeCapacitivelyCoupled
TWA(CCTWA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193
5.6.1 SimulationVsOn-WaferMeasurementResults . . . . . . . . . . 195
5.7 NoiseinTravellingWaveAmplifiers . . . . . . . . . . . . . . . . . . . . . 200
5.8 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203
6 StackedCascodeTWADesignforOptimizedIsolation 205
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205
6.2 DCAnalysisofSingleandMulti-CascodeCells . . . . . . . . . . . . . . . 207
6.2.1 StackingConcept . . . . . . . . . . . . . . . . . . . . . . . . . . . . 207
6.2.2 VoltageExcursioninLargeSignalOperation . . . . . . . . . . . . 208
6.3 ReverseIsolationOptimization . . . . . . . . . . . . . . . . . . . . . . . . 210
6.3.1 DSCEquivalentCircuitAnalysis . . . . . . . . . . . . . . . . . . . 211
6.3.2 FabricationTechnology . . . . . . . . . . . . . . . . . . . . . . . . 218
6.3.3 MeasuredS-Parameters . . . . . . . . . . . . . . . . . . . . . . . . 220
6.4 ImplementationinTWADesign . . . . . . . . . . . . . . . . . . . . . . . 223
6.5 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227
7 ConclusionandFutureWork 228
7.1 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
7.2 ChallengesAddressed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230
7.2.1 HighFrequencyModelDiscrepanciesforSmallPeripheryFETs . 230
7.2.2 TWAStability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231
7.2.3 AchievingUltra-BroadbandHighReverseIsolation . . . . . . . . 231
7.3 ResearchOutcome . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232
7.4 ResearchLimitation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233
7.5 RecommendationsforFutureWork . . . . . . . . . . . . . . . . . . . . . 233
A FabricatedDevicePull-OutsAndCircuits 251
B ChipAssemblyDiagramsAndShimLayout 253
5
List of Tables
1.1 f Vs f forVariousTransistorTechnologies[14] . . . . . . . . . . . . 42
t max
1.2 MaterialPropertiesofSemiconductors[1][24][25] . . . . . . . . . . . . . 47
1.3 TargetSpecificationsfortheMMICCascodeTWADesign . . . . . . . . 51
5.1 ExtractedIntrinsicParameterValuesfor2x12µmand2x10µmWINPP10-
10pHEMTs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146
5.2 DatalabeldescriptionforFigs.5.34&5.35. . . . . . . . . . . . . . . . . . 176
A.1 List of Fabricated Device Pull-Outs/Circuits with Description of FET
Sizes,DC-BiasPoints,TypeofMeasurementDoneandFrequencyRange
ofMeasurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 251
6
List of Figures
1.1 67GHzPNA-XwithExtensionHeadsto110GHz[5] . . . . . . . . . . . 33
1.2 Application:Wide-BandIsolationamplifierattheInputoftheReceiver
inaVNA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
1.3 BlockDiagramofa40Gb/sTransmitter[9] . . . . . . . . . . . . . . . . . 35
1.4 (a)MESFETCross-SectionalView(b)EquivalentCircuitSuperimposed
onCross-Section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
1.5 (a)MESFETSmall-SignalEquivalentCircuit[15](b)IdealMetal-Semiconductor
EnergyBandDiagram[16] . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
1.6 (a)DC-IVCharacteristics(b)DrainCurrentasaFunctionofGate-Source
Voltagefora0.5µm and1µm GateLengthMESFET[16] . . . . . . . . . 39
1.7 (a)HEMTCross-SectionalView(b)EnergyBandDiagramofHEMTshow-
ingthe2DEGQuantumWellChannel[14] . . . . . . . . . . . . . . . . . 40
1.8 (a)pHEMTCross-SectionalView(b)mHEMTCross-SectionalView(c)
pHEMTEnergyBandDiagramShowing2DEGQuantumWellChannel
FormationatAlGaAsSpacerandInGaAsChannelLayerJunction[14] . 41
1.9 (a)HBTCross-SectionalView(b)EnergyBandDiagramofHBT[14] . . 44
1.10 AverageElectronDriftVelocityv asaFunctionofElectricFieldStrength
d
forGaAs,InPandGaN[26] . . . . . . . . . . . . . . . . . . . . . . . . . . 46
1.11 LayerDefinitionofWINPP10-10Process[28] . . . . . . . . . . . . . . . . 48
1.12 Stack-UpforEMSimulation . . . . . . . . . . . . . . . . . . . . . . . . . . 49
1.13 2−4GHzThreeStageMMICAmplifier[32] . . . . . . . . . . . . . . . . 52
2.1 TubeDistributedAmplifier[38] . . . . . . . . . . . . . . . . . . . . . . . . 57
2.2 FirstGaAsMMICTWA,1982,MTTMuseum[64] . . . . . . . . . . . . . . 58
2.3 Common-SourceTWACircuitDiagram . . . . . . . . . . . . . . . . . . . 61
2.4 SimplifiedSmallSignalEquivalentCircuitofCSFETtoExplaintheMiller
Effect . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
2.5 CircuitDiagramofaCascodeTWA . . . . . . . . . . . . . . . . . . . . . . 64
7
2.6 SimulatedMAGandS-parametercomparisonbetweena2x25µmCS-
FET&CascodecellfromDC-110GHz . . . . . . . . . . . . . . . . . . . 65
2.7 IdealTWAwithLosslessTransmissionLinesandUnilateralActiveDe-
vicesasin[86] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
2.8 Variation of sin(Nθ)/Nsinθ with N. Increasing N reduces ripples at
themid-band . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
2.9 Two-portNetworkterminatedinImageImpedancesZ andZ . . . . 71
i1 i2
2.10 (a)AHalfFilterSection(b)AHalfLowPassSectionRealizedwithLandC 72
2.11 (a) Low pass T Constant-k Filter Section (b) Low pass π Constant-k
FilterSection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74
2.12 (a)m-DerivedTSection(b)LowPassm-DerivedTSection . . . . . . . 75
2.13 ArtificialTransmissionLineMatchedtoOutputbyHalfm-DerivedSec-
tion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75
2.14 FilterSectionwithLosses . . . . . . . . . . . . . . . . . . . . . . . . . . . 76
2.15 TransmissionLineSectionofLengthl,PropagationConstantγ,Char-
acteristicImpedanceZ withTerminalVoltagesandCurrents . . . . . . 77
0
2.16 FilterSectionsImplementedwithLosslessTransmissionLinesofLength
l(a)TSection(b)πSection . . . . . . . . . . . . . . . . . . . . . . . . . . 77
2.17 (a)MicrostripTransmissionLinewithStepDiscontinuity(b)Lumped
equivalentcircuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
3.1 IncidentandReflectedWavesinaTwo-PortNetwork . . . . . . . . . . . 86
3.2 (a) On-Wafer S-Parameter Measurement Set-Up (Representation) (b)
On-Wafer S-Parameter Measurement Set-Up in The mm-Wave Labo-
ratoryatTheUniversityofManchester . . . . . . . . . . . . . . . . . . . 87
3.3 ProbeTipShielding-CoplanarandMicrostrip[97] . . . . . . . . . . . . 88
3.4 Comparison of Calibration Types to a 50 Ω Benchmark Calibration
withReferencePlanesettol [108] . . . . . . . . . . . . . . . . . . . . . 90
m
3.5 (a)ImpedanceStandardSubstrate(ISS)Map[109](b)LRRMCalibra-
tionVerificationusingISS . . . . . . . . . . . . . . . . . . . . . . . . . . . 92
3.6 Microphotograph of (a) Open, Short and Thru On-Wafer Calibration
Standards(b)LoadOn-WaferCalibrationStandard . . . . . . . . . . . . 93
3.7 MeasuredS-parametersinafrequencyrangeof0.045-110GHzofOn-
WaferOpen,Short,Load&ThruStandardsafterLRRMISSCalibration
(a)S (b)S (c)S (dB)and(d)S (dB) . . . . . . . . . . . . . . . . . . 94
11 22 12 21
3.8 VNACalibrationReferencePlane[112] . . . . . . . . . . . . . . . . . . . 95
8
3.9 SystematicErrorsinaVectorNetworkAnalyzer[113] . . . . . . . . . . . 96
3.10 Theeight-termerrormodelofatwo-portVNAin(a)S-Parameterand
(b) error terms representations. The unknown DUT [S] is connected
betweentheerroradapters. Primeanddouble-primeparameterscor-
respond to the forward and reverse measurement directions, respec-
tively[111] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97
3.11 MeasurementReferencePlaneAfterCalibration . . . . . . . . . . . . . . 98
3.12 (a) Planar GSG Probe Ensuring Proper Contact (b) Non-Planar GSG
ProbeShowingOnlyTwoContactMarks . . . . . . . . . . . . . . . . . . 99
3.13 On-WaferLRRMCalibrationVerificationPlot . . . . . . . . . . . . . . . 100
3.14 SchematicofaCascodeCell . . . . . . . . . . . . . . . . . . . . . . . . . . 102
3.15 DescriptionofSystem-1andSystem-2UsedforOn-WaferS-Parameter
Measurementsofa2x25µm CascodeCell . . . . . . . . . . . . . . . . . 102
3.16 Maximum Available Gain (MAG) of the 2x25 µm Cascode Cell when
Measured on System-1 (trace with circles) and System-2 (line trace)
[119] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103
3.17 On-WaferMeasurementofaCascodeCellProbedatInnerandOuter
EdgeoftheGSGPads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
3.18 S (dB) of the 2x25 µm Cascode Cell When Measured on System-
21
1, System-2 with Probes Launched on Inner Edge and System-2 with
ProbesLaunchedonOuterEdge[119] . . . . . . . . . . . . . . . . . . . . 105
3.19 (a)S (b)S ofthe2x25µmCascodeCellWhenMeasuredonSystem-
11 22
1, System-2 with Probes Launched on Inner Edge and System-2 with
ProbesLaunchedonOuterEdge[119] . . . . . . . . . . . . . . . . . . . 106
3.20 ADS Simulation Set-up for Eliminating the Effect of Pad Capacitance
atHighFrequenciesWhenTheDUTisProbedatInnerEdgeonSystem-
2[119] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107
3.21 S (dB) of the 2x25 µm Cascode Cell When Measured on System-1,
21
System-2 with Probes Launched on Inner Edge with Output Pad Ca-
pacitanceDe-Embedded[119] . . . . . . . . . . . . . . . . . . . . . . . . 107
3.22 (a)S (b)S ofthe2x25µmCascodeCellWhenMeasuredonSystem-
11 22
1,System-2withProbesLaunchedonInnerEdgewithOutputPadCa-
pacitanceDe-Embedded[119] . . . . . . . . . . . . . . . . . . . . . . . . 108
3.23 HighFrequencyCalibrationResidualErrorinaISSShortStandardS-
ParameterMeasurementafterLRRMISSCalibration . . . . . . . . . . . 109
9
3.24 DifferenceinFieldDistributionatTheTransitionBetweenProbe-Tip
and RF Pad Related to The Effective (cid:178) of The Substrate at 300 GHz.
Left Hand Side Picture is for GaAs and Right Hand Side Picture is for
Ceramic[122] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110
3.25 VNASystemDiagramforMakingVectorErrorCorrectedNoiseFigure
Measurements[114] . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111
4.1 Small-SignalEquivalentCircuitofapHEMTDevice . . . . . . . . . . . . 117
4.2 MeasuredDC-IVCharacteristicsofa2x12µm CSFET . . . . . . . . . . . 118
4.3 MeasuredDC-IVCharacteristicsofa2x10µm CSFET . . . . . . . . . . 119
4.4 IC-CAPSet-UpforDC-IVMeasurementsofa2x12µm CSFET . . . . . 119
4.5 (a)MeasuredS (dB)for2x12µm CSFETatV =1.0V(b)Measured
21 ds
S (dB)for2x12µmCSFETatV =2.5V,Frequency:0.045-110GHz,
21 ds
V =-0.8Vto0.0Vinstepsof0.1 . . . . . . . . . . . . . . . . . . . . . . 121
gs
4.6 (a)MeasuredS (dB)for2x12µm CSFETatV =1.0V(b)Measured
12 ds
S (dB)for2x12µmCSFETatV =2.5V,Frequency:0.045-110GHz,
12 ds
V =-0.8Vto0.0Vinstepsof0.1 . . . . . . . . . . . . . . . . . . . . . . 121
gs
4.7 (a)MeasuredS (dB)for2x12µm CSFETatV =1.0V(b)Measured
11 ds
S (dB)for2x12µmCSFETatV =2.5V,Frequency:0.045-110GHz,
11 ds
V =-0.8Vto0.0Vinstepsof0.1 . . . . . . . . . . . . . . . . . . . . . . 122
gs
4.8 (a)MeasuredS (dB)for2x12µm CSFETatV =1.0V(b)Measured
22 ds
S (dB)for2x12µmCSFETatV =2.5V,Frequency:0.045-110GHz,
22 ds
V =-0.8Vto0.0Vinstepsof0.1 . . . . . . . . . . . . . . . . . . . . . . 122
gs
4.9 (a)MeasuredS (dB)for2x10µm CGFETatV =2.5V(b)Measured
21 ds
S (dB)for2x10µmCGFETatV =3.5V,Frequency:0.045-110GHz,
21 ds
V =-0.5Vto-0.1Vinstepsof0.1 . . . . . . . . . . . . . . . . . . . . . . 123
gs
4.10 (a)MeasuredS (dB)for2x10µm CGFETatV =2.5V(b)Measured
12 ds
S (dB)for2x10µmCGFETatV =3.5V,Frequency:0.045-110GHz,
12 ds
V =-0.5Vto-0.1Vinstepsof0.1 . . . . . . . . . . . . . . . . . . . . . . 124
gs
4.11 (a)MeasuredS (dB)for2x10µm CGFETatV =2.5V(b)Measured
11 ds
S (dB)for2x10µmCGFETatV =3.5V,Frequency:0.045-110GHz,
11 ds
V =-0.5Vto-0.1Vinstepsof0.1 . . . . . . . . . . . . . . . . . . . . . . 124
gs
4.12 (a)MeasuredS (dB)for2x10µm CGFETatV =2.5V(b)Measured
22 ds
S (dB)for2x10µmCGFETatV =3.5V,Frequency:0.045-110GHz,
22 ds
V =-0.5Vto-0.1Vinstepsof0.1 . . . . . . . . . . . . . . . . . . . . . . 125
gs
10