1諧振回路0LC為諧振時(shí)回路儲(chǔ)能和耗能之比即Q；0II0IIQ越大曲線越尖銳01Q202IIQ越大曲線越尖銳000在“小量失諧的情況下”可表示為I220I220IIII000ejIIII000ej000202Q值越大曲線越陡峭，線性范圍越小2路L0OC0OLrC0LC0rOCrGOLG00并聯(lián)回路(|0.7Q0濾波器LqC0C0qrqq1，并聯(lián)諧振頻率為OqLCqqqq3NNNi=o=o=oL=1NkTBINNNi=o=o=oL=1NkTBI六.電子噪聲nnRR(理想)nGnSUoUiFSNooS(f)=2qI；I0U2UNiNi=NN=iFSoooUoUNNRo=o=L=KNpiNo2oRLU2Uoo法2法2I2oN=iNKNpNKNpiNioI2RioLoooNNNNi=o.N=iNNoNNoio=o=SNKkTB.KippoippSi1=Kp(N1)(N1)N=N+F2(N1)(N1)FF1KKKp1p1p24 ..+Ibc＋c+ . .oecY.V.fe ..+Ibc＋c+ . .oecY.V.feb.YreccbeLp21b31cb1oeL1oeLIIVV放大器..Ib .YUYU.febU(Y+U(Y+Y')YK=C=oeL=fe..oeLb113Rb1RLVCLV5eCeb2a352RCVLLC41bUUUU1YppYK=o=o.31.c=p..fe=12feUUUU2pY+Y'p2(Y+Y)1jC++g+p2gjL025=0=0QppYK=12fejC+1+g+p2gp2(Y+)jp2(Y+)1oep21ppY=12fep2Y+jC+1+g+p2g1oejL02LppY=12fe1(p2g+g+p2g)+j[(p2C+C)]1oe02L1oeLppYK=12fep2g+g+p2g1oe02L11=0BfQfL4.雙調(diào)諧高頻小信號(hào)放大器2020B=?帶寬：rK*電壓放大倍數(shù)：K=K.Kvv1v2B11L6Eb1K=0.1K=0.1=11KKKK=K.K.11K=0.1=K=0.1=rB10.742m1率放大器ic－VRVRceLbe－EbEEbciuiccEbt9+9t0cmbbbmbUmbb7*效率：P1IU1a(9)U1*效率：P1IU1a(9)U1oc1Lccecocc1Lo222c1c2c1L2RL=c0cc=oP2IE2a(9)E2P2IE2a(9)E2c0c0c〈Cmbbb'mbCEcclUE一UCEcc89P=PoPcUb欠壓狀態(tài)過壓狀態(tài)bT(jO)=K(jO).F(jO)=1振幅平衡條件相位平衡條件?iiAiiA?UU=UiiAiiAii5.三點(diǎn)式振蕩器的組成原則是“射同余異”VVX2C2XC11XL3(a)VLLL121X1X12X3C3(b)7.準(zhǔn)確度指振蕩器實(shí)際工作時(shí)的頻率和標(biāo)稱頻率之間的偏差，穩(wěn)定度指在一定0fFL9.石英晶體振蕩器可分為并聯(lián)晶體振蕩器(石英晶體工作在串聯(lián)和并聯(lián)諧振頻振蕩器(工作在串聯(lián)諧振頻率附近，諧振時(shí)相當(dāng)于一個(gè)低阻值的短路線)。2.尋求非線性曲線近似函數(shù)的方法很多(化無限項(xiàng)為有限項(xiàng))，如冪級(jí)數(shù)展開法i(t)CBu(t)AQ2Q2101i(t)i(t)CCBu(t)BAuu(t)BAADD21212222i=2gK(t)uLD21--------------------------------------------------------------------u(t)=K(t)u(t)o21---------------------------------------------------------------------i=2gK(t)u(t)LD214444K(t)=costcos3t+cos5t...+(1)n+1cos(2n1)t+...-------------------------------------------------------------------uuAo0U2uEETuuo02u2uTTccccacaAMcacAMcUccccB=2fAMmaxU2U*載波功率：P=cLavcs2cn==m211P2+m2)32.抑制載波的雙邊帶調(diào)幅AMccccccDSBccc業(yè)cDSBAMDSBs載波的單邊帶調(diào)幅集電極調(diào)制時(shí)功放應(yīng)工作在過壓狀態(tài)，基極調(diào)制時(shí)功放應(yīng)工作在欠壓狀態(tài)。122i(t)=g.k(t)[u(t)+u(t)]=g(+costcos3t+......)[u(t)+u(t)]DDccD2幾c3幾cc2幾cUdUdUmLDcD2幾c3幾c6.二極管峰值包絡(luò)檢波器D?u?u(t)o?tURR=m=iI21真??u(t)?t切割失真RR=fpqI*中頻干擾，一階干擾像干擾，二階干擾有用信號(hào)如果消失則干擾也會(huì)消失且任何頻率的強(qiáng)干擾均有可能形成這種干擾，提高前端電路的選擇性有助于抑制這種干擾。生近似中頻的組合分量，從而對(duì)真正的中頻信號(hào)形成干擾。FMfFMfmB2(m1)FMfmaxmax(t)ku(t)kUcostcostccfcfcmcfccf(t)t(t)dtt[kUcost]dttkUfsinttmsintcfccf00u(t)Ucos[tmsint]FMccfu(t)Ucos[tktf(t)dt]FMccf0其中的k稱為調(diào)頻靈敏度，kU稱為最大角頻偏，mkUf稱為調(diào)fmff指數(shù)(最大相偏)；u(t)J(m)cos(n)tFMnfcTR2RC0LL2.相位調(diào)制(單音調(diào)制)t(t)=t+k.u(t)=t+k.Ucost=t+mcostccpcpcpu(t)=Ucos(t+mcost)PMccpu(t)=Ucos[t+k.f(t)]PMccp其中的k稱為調(diào)相靈敏度，=k.U.稱為最大角頻偏，m=k.U稱為pmpppBmkU+)PMpp