xxiliV2/HzS(f)spectraldensityover1OhmresistorsLaplacetransformcomplexvariable(s=g+jw)s-parametertwo-port scatterparameters (s11,S12,S21,S22)dBSFDRspurious free dynamic rangedBSNRsignal-to-noise ratioTK(absolute) temperatureThp(s)high-pass transfer functionbasetransittimest5large signal delayTdelaystime constantsof theloop filterT2, T3stime constant determined from spectral purity con-T3.sPsiderationsUnormalized frequency deviation from WoseVIVHzrms voltage noise density originated in the loop filterUn(fm)VVvoltagevVearrierpeak carrier amplitudeVVppeak voltageVVpppeak-to-peak voltageVVmismatchmagnitude of the ripple voltage due to mismatch inthe CP current sourcesVVreversereverse varactor voltageVVrippleripple voltage at the VCO tuning lineVVrmsrms voltageVV2/Hzmean square noise voltage overa bandwidthAfVVrunevoltage at the tuning input of a VCOWmwidthof transistortwo-port admittanceparameters (y11,y12,y21,y22)y-parameterz2impedance2Zr(s)transimpedance of the loopfilter2Z,input impedanceZt2load impedanceZo2output impedance2Zoptoptimal noiseimpedanceS2Z.source impedance2Zocharacteristic impedancetwo-portimpedanceparameters(z11,z12z21,z22)z-parameterrad/sangular frequencyrad/swopen-loopbandwidthwe=2元frad/sangular modulation frequencyWmrad/sangular oscillation frequencyWosc
xxivCIRCUITDESIGNFORRFTRANSCEIVERSAbbreviationsACAlternatingCurrentACPRAdjacentChannelPowerRatioA/DAnalog/DigitalAGCAutomatic Gain ControlAMAmplitudeModulationCCOCurrent Controlled oscillator(C)MOS(Complementary)MetalOxideSemiconductorCNRCarrier to Noise RatioCPCharge-PumpCPCompression PointdBDecibeldBcdB relative to the carrierDCDirect CurrentDECTDigital European Cordless TelephoneD-FFD-type Flip-flopDPODouble PolyDRDynamic RangeDRODielectric Resonator OscillatorDSBDouble-SidebandEDGEEnhancedDataRatesforGSMEvolutionEMCElectromagneticCompatibilityESDElectroStaticDischargeFDDFrequency-Division DuplexFMFrequency ModulationFOMFigure of MeritggNMOSTGroundedGateNMOSTransistorGSMGlobalSystemforMobilecommunicationHBMHuman Body ModelICIntegrated CircuitIFIntermediateFrequencyIPIntercept PointIIPInputReferred InterceptPointIMInter ModulationIRRImageRejection RatioI/OInput/OutputIVQIn-phase/QuadratureLNALow Noise AmplifierLoLocal OscillatorLPFLow-Pass Filter
XXVLTILinearTimeInvariantNQSNon-Quasi StaticOIPOutputReferredInterceptPointPAPowerAmplifierPAEPower Added EfficiencyPFDPhase-FrequencyDetectorPLLPhase-Locked LoopPMPhaseModulationQAMQuadratureAmplitudeModulationrmsRoot-Mean-SquaredRFRadio FrequencyRX-bandReceive BandSAWSurfaceAcoustic WaveSFDRSpurious-FreeDynamic RangeSNRSignal-to-Noise RatioSOASilicon-on-AnythingSSBSingle-SidebandTDDTime-Division DuplexTX-bandTransmit BandUMTSUniversalMobileTelecommunicationsSystemVCOVoltageControlled OscillatorVHFVery High Frequency
Chapter1RF Design: Concepts and TechnologyRadio Frequency (RF)circuitry very often operates at the boundaries of achievable performunce within u purlicular process lechnology This means tha the designers not onlyneed analog circuit design knowledge but must also have a deep understanding of thedevice technologyThe performanceof manyRFdesignsis primarily determined bythequality of the passives used. High quality inductors are certainly difficult to realize insilicon. This chapter starts with a review of commonly used RF terminology and con-cepts.The second part of this chapter treats technology-related issues, with a particularemphasis on passives.1.1RFSPECIFICATIONSAs in many other design domains, RF and microwave designers' specify thebehavior of their circuits using terminology which originates from signal the-ory.In contrast to low and intermediate frequency analog design,however, thespecifications in RF design are usually related to powers instead of voltages.In addition, the small signal behavior is described using s-parameters ratherthan using z-parameters. The result is that analog designers and microwavedesigners often misunderstand each other, even though they are discussing thesamebehavior.Somecommonlyusedterminologyisdiscussedinthis sectionIStrictly speaking, the microwave frequency band is defined from 1 GHz to 30 GHz. Designers working withthese frequencies are therefore referred to as“microwave designers".However, many telecommunicationsystems (i.e. radios) operate in the 0.9 to 3 GHz range, and this frequency band is often mistakenly referredto as the radio frequency (RF) band, hence the name "RF designer".Throughout this book, we will ofteninterchange the names microwave designer and RF designer.1
2CIRCUITDESIGNFORRFTRANSCEIVERSsystemSFigure I.1.Time-invariant system S with load impedance ZL.System S has an inputimpedance Z; and an output impedance Zo.The system is driven by a voltage source Vswithinternal impedanceZs.1.1.1GainOne issue which often leads to misunderstandings between analog designersand microwave specialists is the specification of gain.Analog designers nor-mally use the concept of voltage gain, while RF designers use a broad range ofterminology,relatedtosignalpowers.Consideralinear,memoryless,time-invariant systemSwithaninputimpe-dance Zi,and an output impedance Z..This system is driven by a source withan impedanceZs,and the systemis loaded withan impedanceZt.This situationis depicted in Figure 1.1 and will be used to explain several concepts of gain.Assumethat thc input impcdancc is much higher than the source impedanceand,in the extremecase,thatZ,→ co.Thismeans that no currentwill flowinto system S, and the voltage of the source, Vs, is equal to the voltage at theinput of S, V. Similarly, assuming Z.→ O will give a voltage Vi across theload equal to the output voltage of S,V..This latter voltage is equal to theamplifiedvoltageattheinputofs,V。Vi(1.1)A,=ViV.Here A, is called the (unloaded) voltage gain, and is normally used by analogdesigners.Let us focus on the input of system S and assume that Z, is far from infinity2and hence V,V.Thena currentwill also flow into system S, and we candefinetypes ofpower.To achieve maximumpowertransfer,theload impedancemustbethe conjugate of the sourceimpedance.SupposethatZ+Z,where2For RF frequencies, the input impedance of bipolar and MOS transistors is definitely small compared tothevalueatDCorat lowfrequencies