微波工程讲义

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1、Chapter11Oscillatordesign11.1FeedbackandbasicconceptHartleyandColpittsoscillators11.2Crystaloscillators11.3Electronictuningofoscillatorsvaractordiode11.4Phase-lockedloopclosed-looptransferfunction11.5Frequencysynthesizers11.6One-portnegativeresistanceoscillators11.7Microwavetransisto

2、roscillatorsCBandCGwithfeedbackstructure,3-portS-parameteranditsreduced2-portS-parameterrelation11-1微波工程講義11.1FeedbackandbasicconceptBasics1.Oscillatorconceptnoise®triggeranunstablecircuit®feedbackandactivedeviceamplifiesnearwo®nonlinearactivedeviceatsteadystate®oscillationatwowithou

3、tpowerXYAbYAY=A(X+bY)®closed-loopgainT==X1-bAA:forwardpathgain,bA:loopgainbA=1:oscillationconditionIfb→-b,bA=-1:oscillationcondition11-2微波工程講義Discussion1.HartleyandColpittsoscillatorsfromfeedbackpointofview[][]YV=01V1V44Y1+Y3+Yi-(Y1+Yi)-Y30V1-(Y+Y+g)Y+Y+Y+g+Y-Y-YVY1im12imo2o

4、=21-Y-YY+Y+Y-YV3223LL3Y3V2YLg-(g+Y)-YY+YV2mmoLoL4ifV=0(CE),V=V,Y=0234oY2Y1+Y3+Yi-Y3V1®=-g+YY+YVm32333V33V1V41Y2Y1YiYoY32Y3V2YLgm(V1-V2)Y1Y2V311-3微波工程講義Y1+Y3+Yi-Y3V1Y1+Y3+Yi-Y3=®det=0-g+YY+YV-g+YY+Ym3233m323(Y+Y)(Y+Y+Y)-Y(g-Y)=02313i3m3ifY=G,Y=jB

5、,Y=jB,Y=jBii112233B1B2+B2B3+B1B3=0®oneC,twoLorviceversa...(1)®(g+G)B+BG=0®oneC,oneL........................(2)mi32iggmm(2)®(1+)B+B=0®(1+h)X=-X,h=32fe23feGGii(1)®X+X+X=0®X+X-(1+h)X=012312fe2®X=hX1fe2®XandXofthesamekind,Xbethedifferentkind12311-4微波工程講義331L21C222LColpittsHartley3C3os

6、cillatoroscillatorL1C1X+X+X=0123Vcc11wL1+wL2-=0®w=wC3C3(L1+L2)L2®11C+C12+-wL=0®w=3C3wCwCCCLL121231VccVccClappOscillatorL3L3:betterC2C2frequencyC1C1C3stability11-5微波工程講義2.HartelyandColpittsoscillatorsfromnegativeresistancepointofviewVi=Ii(X1+X2)-Ib(X1-bX2)IIib(I-I)X=Irib1bpX

7、1-bX2bIb®Vi=Ii(X1+X2-X1)X3X1rpX+r1pRV(1+b)XX+(X+X)rL®Z=i=1212prViiIX+ri1pX2X<

8、)im1212gC+