数字信号处理7

数字信号处理实验实验七：小信号放大器性能分析与仿真班级：姓名：学号：指导老师：2013年11月实验七：小信号放大器性能分析与仿真一.实验原理小信号放大器是电子线路的重要组成部分之一，由于它工作在晶体管的线性区域内，因此又称为线性放大器。

使用MATLAB可以仿真小信号放大器的各种参数，如电压增益.输出阻抗.输入阻抗.频率响应等。

二．实验内容一，function[Av,Ai,Zo,Vb,Ie,E,vo]=amplif2(Rb1,Re 1,Rc1,R1,R2,Rc2,Re3,Rf,h,vs,beta,Ec,Ed,Kp);if nargin<14;kp=1,end;if nargin<13;Ed=15,end;if nargin<12;Ec=24,end;if nargin<11;beta=50,end;if nargin<10;vs=1e-03,end;if nargin<9;h=[1.2e+03 3.37e-4;8027.1e-6];end;if nargin<8;Rf=33e+03;end;if nargin<7;Re3=3.3e+03;end;if nargin<6;Rc2=18e+03;end;if nargin<5;R2=3.9e+03;end;if nargin<4;R1=130;end;if nargin<3;Rc1=100e+03;end;if nargin<2;Re1=100;end;if nargin<1;Rb1=1000e+03;end;hie=h(1,1);hfe=h(2,1);hoe=h(2,2);Rc=hie*Rc1/ (hie+Rc1);T=[hoe+1/Re1 -hoe -1-hfe;-hoe hoe+1/Rc hfe;1 0 hie];V=inv(T)*[0 0vs]';v2=V(2);ib2=v2/hie;Av1=v2/vs;Zi=vs/V(3);Re=Re3/hoe/(Re3+1/hoe);Rc=Rc2/hoe/(Rc2+1/hoe );T=[1/Re -1-hfe;1 hie+Rc];V=inv(T)*[0-hfe*Rc*ib2]';Av2=V(1)/v2;Av0=V(1)/vs;Zo=V(1)/((1+hfe)*hfe*Rc*ib2/(Rc+hie));Zo=absB=Re1/(Rf+Re1);F=1+Av0*B;Av=Av0/F;Zi=Zi*F;Zi=Zi*Rb1/(Zi+Rb1);Zo=Zo/F; vo=Av*vs;Av=[Av Av0 Av1 Av2];ifKp==1;Vbe=.7;ns='Si';else;Vbe=.2;ns='Ge';end ;Z=[Rb1+R2+(1+beta)*Re1-(1+beta)*R2;beta*Rc1-R2Rc1+(1+beta)*(R1+R2)];Ib=inv(Z)*[-Vbe Ed-Vbe]';I1=(1+beta)*Ib(1);I2=(1+beta)*Ib(2);I3=(1+beta)*(Ec-Vbe-Rc2*beta*Ib(2))/(Rc2+(1+ beta)*Re3);I=[I1 I2 I3];I=round(I*1e+04)*.1;V=[Re1*I1 (R1+R2)*I2 Re3*I3]+Vbe;V==round(V*10)*.1;Zi=round(Zi);Zo=round(Zo);Av=round(Av);E=[Ec Ed];Vb=V;Ie=I;format short;Av,Zi,Zo,Vb,Ie,E,vo]=amplif2();1Ed =15Ec =24beta =50vs =1.0000e-003三function[Av,Zi,Zo,V,I,vo]=amplif3(Rb,Rc,Re,R 1,R2,R3,R4,Re3,Zee,h,vs,beta,Ec,Kp);if nargin<14;Kp=1;end;if nargin<13;Ec=12;end;if nargin<12;beta=50;end;if nargin<11;vs=1e-03;end;if nargin<10;h=[1.2e+03 3.37e-4;10027.1e-6];end;if nargin<9;Zee=1e+05;end;if nargin<8;Re3=3300;end;if nargin<7;R4=47;end;if nargin<6;R3=680;end;if nargin<5;R2=2400;end;if nargin<4;R1=4800;end;if nargin<3;Re=68;end;if nargin<2;Rc=560;end;if nargin<1;Rb=4700;end;hie=h(1,1);hfe=h(2,1);hoe=h(2,2);A=[1 0 0 0 0 hie 0;0 0 1 0 0 0 hie];A=[A;(1+Re*hoe) -Re*hoe 0 0 -1 -(1+hfe)*Re 0]; A=[A;0 0 (1+Re*hoe) -Re*hoe -1 0 -(1+hfe)*Re]; A=[A;Zee 0 Zee 0 -(2*Zee+Re) 0 0];A=[A;Rc*hoe -(1+Rc*hoe) 0 0 0 -hfe*Rc 0];A=[A;0 0 Rc*hoe -(1+Rc*hoe) 0 0 -hfe*Rc];V=inv(A)*[vs 0 0 0 0 0 0]';vo=[V(2) V(4)];Av=vo/vs;Av=round(Av*10)*.1; Rb1=1/(1/Rb+1/R2+1/R1);Zi=vs/V(6);Zi=Zi*Rb1/ (Zi+Rb1);Zo=(Rc+hie)/(1+hfe);Zo=round(Zo);Zi=round(Zi );ifKp==1;Vbe=.8;ns='Si';else;Vbe=.2;ns='Ge';end ;A=[(R1+R2+R3)/R3 R1+R2 R2;1 -(1+beta)*R4 0;0 beta -2*(1+beta)];B=inv(A)*[Ec+(R1+R2)/R3*Vbe Vbe 0]';format short;V=[B(1)Ec-R1*((B(1)-Vbe)/R3+B(2)+B(3))-Rb*B(3)Ec-beta*B(3)*Rc];I=[B(3)*(1+beta)(V(3)-Vbe)/Re3];I=round(I*1e+04)*.1;>> [Av,Zi,Zo,V,I,vo]=amplif3()Av =-3.5000 3.5000Zi =1110Zo =17V =1.5426 3.8287 7.7480I =7.7000 2.1000vo =-0.0035 0.0035四function[H,Zi]=amplif4(Ce,C1,C2,Rb1,Rb2,Rc,R e,RL,h,Rs);if nargin<10;Rs=1e+03;end;if nargin<9;h=[1.2e+03 3.37e-4;5027.1e-6];end;if nargin<8;RL=6e+03;end;if nargin<7;Re=1.5e+03;end;if nargin<6;Rc=2e+03;end;if nargin<5;Rb2=6e+03;end;if nargin<4;Rb1=24e+03;end;if nargin<3;C2=20e-06;end;if nargin<2;C1=20e-06;endif nargin<1;Ce=200e-06;end;syms s;hie=h(1,1);hfe=h(2,1);hoe=h(2,2);zt=[hie 0;-hfe/hoe1/hoe];ze=Re/(1+s*Re*Ce);ze=ones(2,2)*ze;Z=zt+ze;A=[Z(1,1) det(Z);1 Z(2,2)]/Z(2,1); Rb=Rb1*Rb2/(Rb1+Rb2);A=[1 Rs+1/s/C1;0 1]*[1 0;1/Rb 1]*A*[1 0;1/Rc 1]*[1 1/s/C2;0 1];A=A*[1 0;1/RL 1];Zi=A(1,1)/A(2,1)-Rs;f=logspace(1,5,101);[b,a]=numden(Zi);b=sym2poly(b);a=sym2poly(a) ;Zi=freqs(b,a,2*pi*f);k=max(abs(Zi+Rs)/Zi);H=k/A(1,1);[b,a]=numden(H);b=sym2poly(b);a=sym2poly(a);H=freqs(b,a,2*pi *f);Av=20*log10(abs(H));Avm=round(max(Av)*10)*.1 ;subplot(211);semilogx(f,Av);grid;zoom xon; xlabel('frequency(Hz)');ylabel('Av(dB)');%title(['Av_m_a_x='num2str(Avm)'(dB)']); subplot(212);semilogx(f,real(Zi),f,imag(Zi)) ;grid;zoom xon;xlabel('frequency(Hx)');ylabel('Zi(Ohm)'); set(gcf,'units','pix','pos',[200,120,560,420 ],'name','Common Emitter Amplifer,BBI2000','num','off');101102103104105253035frequency(Hz)A v (d B )101102103104105-4000-200020004000frequency(Hx)Z i (O h m )五function [H]=amplif5(Cc,ft,Ic,Rb1,Rb2,Rc,RL,Rs,h,rbc);if nargin<10;rbc=5e+06;end ;if nargin<9;h=[1200 3.37e-4;50 27.1e-6];end ;if nargin<8;Rs=1e+03;end ;if nargin<7;RL=6e+03;end ;if nargin<6;Rc=2e+03;end ;if nargin<5;Rb2=6e+03;end ;if nargin<4;Rb1=24e+03;end ;if nargin<3;Ic=2.5;end ;if nargin<2;ft=100e+06;end;if nargin<1;Cc=3e-012;end;syms s;hie=h(1,1);hfe=h(2,1);hoe=h(2,2);gm=Ic/26;hfe=min([hfe .95*hie*gm]);rbe=hfe/gm;rbb=hie-rbe;cbe=gm/(2*pi*ft);Rb=Rb1*Rb2/(Rb1+Rb2);RL1=1/(hoe+1/Rc+1/RL);ybe=1/rbe+s*cbe;zc=1/(1/rbc+s*Cc);A=[1 zc;gm 1]/(1-gm*zc);A=[1 Rs;0 1]*[1 0;1/Rb 1]*[1 rbb;0 1]*[1 0;ybe 1]*A*[1 0;1/RL1 1];H=1/A(1,1);[b,a]=numden(H);b=sym2poly(b);a=s ym2poly(a);f=logspace(3,8,201);H=freqs(b,a,2*pi*f);Av=20*log10(abs(H));Avm=max(Av);I=find(abs(Av-(Avm-3))<.1);I=fix(mean(I));f3db=f(I);Av3db=Av(I);subplot(211);semilogx(f,Av,[f3db f3db],Avm-[0 20],'r:');grid;zoom xon;xlabel('frequency(Hz)');ylabel( 'Av(dB)');tstr=['f_3_d_B=',num2str(round(f3db*1e-04)*. 01),' (MHz)'];tstr=[tstr blanks(6)'Av_0=',num2str(round(Avm*10)*.1),'(dB)']; title(tstr);subplot(212);semilogx(f,angle(H)*180/pi-180);grid;xlabel('frequency(Hz)');ylabel('Phase(a)'); set(gcf,'units','pix','pos',[200,120,560,420 ],'name','Common EmitterAmplifier,BBI2000','num','off');103104105106107108-2002040frequency(Hz)A v (d B )f 3dB =0.71 (MHz) Av 0=29.3(dB)103104105106107108-150-100-50frequency(Hz)P h a s e (a )六 function [H]=amplif6(Cc,ft,Ic,RL,Rs,h,rc,m);if nargin<8;m=0.2;end ;if nargin<7;rc=5e+06;end ;if nargin<6;h=[1200 3.37e-4;50 27.1e-6];end ;if nargin<5;Rs=1e+03;end ;if nargin<4;RL=2e+03;end ;if nargin<3;Ic=2.5;end ;if nargin<2;ft=100e+06;end ;if nargin<1;Cc=3e-012;end;syms s;hie=h(1,1);hfe=h(2,1);a0=hfe/(1+hfe);gm=Ic/26;hfe=min([hfe .95*hie*gm]);re=a0/gm;rbb=hie-hfe/gm;cbe=gm/(2*pi*ft);Ce=cbe/(1+m);ze=1/(1/re+s*Ce);zc=1/(1/rc+s*Cc);A=[rbb+ze rbb*((1-a0)*zc+ze)+zc*ze;1rbb+zc]/(rbb+a0*zc);A=[1 Rs;0 1]*A*[1 0;1/RL 1]H=1/A(1,1);[b,a]=numden(H);b=sym2poly(b);a=s ym2poly(a);f=logspace(3,8,401);H=freqs(b,a,2*pi*f);Av=20*log10(abs(H));Avm=max(Av);I=find(abs(Av-(Avm-3))<.1);I=fix(mean(I));f3db=f(I);Av3db=Av(I);subplot(211);semilogx(f,Av,[f3db f3db],Avm-[0 20],'r:');grid;zoom xon;xlabel('frequency(Hz)');ylabel('Av(dB)'); tstr=['f_3_d_B=num2str(round(f3db*1e-04)*.01 )(MHz)'];tstr=[tstr blanks(6)'Av_0=num2str(round(Avm*10)*.1)(dB)'];title(tstr);subplot(212);semilogx(f,angle(H)*180/pi);gri d;xlabel('frequency(Hz)');ylabel('phase(a)'); set(gcf,'units','pix','pos',[200,120,560,420 ],'name','Common BaseAmplifer,BBI2000','num','off');103104105106107108-20-1010frequency(Hz)A v (d B )f 3dB =num2str(round(f3db*1e-04)*.01)(MHz) Av 0=num2str(round(Avm*10)*.1)(dB)103104105106107108-60-40-20frequency(Hz)p h a s e (a )。