% Plot of the simple emitter follower transfer function equation 5.18 w=10^6:100000:1*10^11; s=i*w; gm=0.077;RL=1000; Cmu=2*10^-12; Cpi=38.8*10^-12; Gp=1/(1000+1950); g_pi=1/1950; GL=1/RL; d=-gm*RL * Gp/(Gp+g_pi); e = 1-Cmu/gm*s; a=(RL*Cmu*Cpi)/(Gp+g_pi); b=(1/(Gp+g_pi))*( RL*(gm + g_pi + Gp)*Cmu + Cpi +Cmu); c=1; % Section for equation 5.20 b2 = (1/(Gp+g_pi))*((1 + RL*(gm + Gp))*Cmu + Cpi); tfl = d * 1./(b2*s + c); tfl_mag = 20*log10(abs(tfl)); tfl_ph = 180*angle(tfl)/(pi); %End section on equation 5.20 tf = d * e ./(a*s.^2 + b*s + c); tf_mag = 20*log10(abs(tf)); tf_ph = 180*angle(tf)/(pi); %tf_phrad = angle(tf); figure(1); subplot(2,1,1) semilogx(w, tf_mag, w , tfl_mag); title('Transfer Function Common Emitter'); xlabel('frequency rad/s'); ylabel('Gain'); grid on; subplot(2,1,2) semilogx(w, tf_ph, w, tfl_ph); title('Transfer Function Common Emitter'); xlabel('frequency rad/s'); ylabel('Phase'); grid on; f=[a, b, c]; g=[-Cmu/gm, 1]; B=[1, -Cmu/gm]; A=[c, b, a];