1、Rb2Rc+VccuiT+-+-uoC1+C2Rb1ReCeRLRbRc+VccuiT+_+_uoC1RL+_+_C2CEQQCiUIT0 u時，)(ECiIIT 0u時時，)(EBBEUUUEeEIRUBCII阻容耦合共射放大電路阻容耦合共射放大電路RbRc+VccuiT+_+_uoC1RL+_+_C2_阻容耦合共集放大電路阻容耦合共集放大電路RbRs+VccuiT+_+_uoC1RL+_+C2us+_Re具有射極電阻的共射電路具有射極電阻的共射電路Rb2Rc+VccuiT+-uoC1+C2Rb1ReRL 直接耦合兩級放大電路直接耦合兩級放大電路Rb2Rc1+VccuiT1+-+-uoRb1

2、Rc2T2Re2 直接耦合兩級放大電路直接耦合兩級放大電路Rb2Rc1+VccuiT1+-+-uoRb1Rc2T2Re2Rf AuOuIDZUZR1R2RUREFuO AuOuI-+A1R2-+A2uOR3R4uO1uIR1+R1R2R3R4uiu0+R1R2RLR3ui+u0Rf+ufIifiiX0XiXfX對地電壓對地電壓iiXX iXXi+uf+R1R2RLR3ui+u0Rf+duIifidi(a)(b)iuu d)(fiduuu Idii)(fIdiii +R1R2R3R4uiu0uO-+AuIR2R1-+AuIuOR2R1C-+AuIuOR2R1C；則為電壓反饋則為電壓反饋若若,0

3、x ,0u f0 令。則則為為電電流流反反饋饋若若,0 x ,0u f0 +R1R2RLR3ui+u0Rf(a)(b)圖圖（a）中中 0u0 uf0 ，則圖圖（b）中中 0i0 uf0 ，則+uffio41341fuRRRRRu/Ioof33fIRRRIIo+R1R2R3R4uiu0-+A1R2-+A2uOR3R4uO1uIR1ud+-uf+iifR1+VCCuiT1+-C1R2R3+-uoC2T2R4R5R6C3+uf+VCCfIT1+-C1Rc1Re1+-C3T2Re2Rc2RfC2RRs+-usuIuOoIiI6262負(fù)反饋放大電路的四種基本組態(tài)負(fù)反饋放大電路的四種基本組態(tài)-+AuiuO

4、R2R1RLuduf-+usRs+-0u0RLR+-0u當(dāng)當(dāng)RL0L0L0uRRRu0211fuRRRu )(fiduuu，越小，越小，sisuuRu0uf 0u反饋越明顯；反饋越明顯；+R1RsRLR3us+u0RfridIiIfI00I0RLR0I0L000IRRRI當(dāng)當(dāng)RL0f33fIRRRI )(fidIII，時時 當(dāng)當(dāng)0R s 一定，反饋越明顯;一定，反饋越明顯;iI。越大，反饋越明顯越大，反饋越明顯sRdIfI0I 0IidsdruI -+R2RfuoR1Rc+VccuiT-+R2RfuoR1Rc+VccuiT-+R2RfuoR1Rc+VccuiTRe-+R2RfuoR1Rc+Vc

5、cuiTRe6363負(fù)反饋放大電路方塊圖及一般表達(dá)式負(fù)反饋放大電路方塊圖及一般表達(dá)式iXiXfXoXAF fiiXXX ioXXA ofXXF ifXXFA iofXXAFAA1iiiXFAXXA fioXXXF1AFAAf1fAAFFAAAf1，時時 當(dāng)當(dāng) 1 FA1 A Af，時時 當(dāng)當(dāng)0 FA1 。時時，即即0X0 X 0i反反饋饋深深度度 FA1 1 FA1 當(dāng)當(dāng)FA1AAf ioXXA iofXXAA Af負(fù)反饋負(fù)反饋，時時 當(dāng)當(dāng) 1 FA1 正反饋正反饋 Af,自激振蕩自激振蕩F1FAAiUfUiUoUuuAuuF+-+-+-RLoIiUfUiUoUiuAuiF+-+-+-RLiI

6、fIiIoUuiAiuF+-RLoIiIfIiIoUiiAiiF+-RL F1Af iofXXA ofXXF當(dāng)當(dāng)10|1 |FA fofXXF1A fiXX fiUU fiIIufuIR1T1uo-R4+VCCT2I-VCCR2R3T3+-+R5422ofuuRRRUUF 2411RRFUUAuuiouf ufA11101001fiUUo422fURRRU ufAfARb1+VCCT1+-C1Rc1Re1+-C2T2Rc2Re2RfC3iUoUR oU iU fA ufAf1e1eofuuRRRUUF iouffUUAAfiUUuf1efuuRR1F1 ofeefURRRU11usfAfA o

7、f2e2efIRRRIf2e2eofiiRRRIIF 2efiiioiifRR1F1IIA （2） sousfUUAus+VCCT1+-C1Rc1Re1+-C3T2Re2Rc2RfC2RRs+-uIuOoIiIfIfiIIssiRUILc2ooRRIU/sL2c2efRR/RRR1 ufAuf-+AuiuOR2R1RLuD+-+VCCR3iO o3213RIRRRRI11RfRIU1 32131ofuiRRRRRIUF foioufUUUUA LooRUIfiUU1o3213RIRRRR L31321RRRRRR 285210210010 AFAAf12fAF1AFAF1dAdA)(1AdAA

8、F11AdAff 2AF11)( dAAF11dA2f)( AdA AdAff 量量閉環(huán)放大倍數(shù)相對變化閉環(huán)放大倍數(shù)相對變化 AdAff量量開環(huán)放大倍數(shù)相對變化開環(huán)放大倍數(shù)相對變化 AdAiiiIURiiifIUR iUfUiUoXAF+-+-+RiRifRbRif iifRAF1R ibifbiRAF1/RR/RR iUfUiUoXAF+-+-+串聯(lián)負(fù)反饋電路的方塊圖串聯(lián)負(fù)反饋電路的方塊圖RiRifiI iiIUFA1 iiiIUFAU iRFA1 ifiIUU iIfIiIiUAF+-Ri并聯(lián)負(fù)反饋電路的方塊圖并聯(lián)負(fù)反饋電路的方塊圖oXRifiiiIUR iiifIUR iiIUFA11

9、iiiIFAIU fiiIIU FA1Ri 電壓負(fù)反饋電路的方塊圖電壓負(fù)反饋電路的方塊圖0Xi ofUFX fiXXoUAF+-Ro oUFA+-+-oIooofIURooooRUFAUI FA1RIURoooofooRUFA1 0iXofIFXfiXXoUAF+-RooIFA+-oIRofooofIUR ooooIFARUI FA1RUIooooooofRFA1IUR ooRFA1U HmHffj1AA FA1AAHHHfHmmmfFA1fj1FA1A HmmHfffjFA1AA HmHffFA1f mA Fffj1A1ffj1AHmHmHfmfffj1A FA1ffmLLfHLHbwfff

10、f HfLfHfbwfffff AFXiXoXf0tXi0tXf0tXiiXiXfXoXAF0tXo0tXi0tXiuIRc1T1uo-+VCCT2Re1b1T3+Re3Rc2Rb1+-Rc3c1e1c2e2c3e3uIRc1T1uo-Rf+VCCT2I-VCC+Rb2Rc3T3+Re3Rc2- 與、與、與、與、20ioUUAuRfof11fuRRRu (2)fiuu foiouuuuuA 1f1RRR 20RR11f190KRf- u f +uiuoR2R1Rf20K2.2K2K2K5.1K+uiuoR2R1Rf1K10K0.9KR3RL+uiuoR11.2K2KR3R2+3K+uiuo15KRfRL+5.1Kui20UUAiou +uiuoR2R1Rf20K2.2K2K2K5.1K+uiuoR2R1Rf1K10K0.9KR3RL+uiuoR11.2K2KR3R2+3K+uiuo15KRfRL+5.1KufufIifiIifi201RuRui