num=7;den=conv([1,0],[1/6,1]);
den=conv(den,[1/2,1]);
G=tf(num,den);
w=0.01:0.01:1000;
[mag,phase]=bode(G,w);
gamma_cas=40;delta=6;gamma_l=gamma_cas+delta;
n=find(180+phase-(gamma_l)<=0.1);
wgamma_l=n(1)/100;                    
[mag,phase]=bode(G,wgamma_l);
rr=-20*log10(mag);beta=10^(rr/20);
w2=wgamma_l/10;w1=beta*w2;
numc=[1/w2,1];denc=[1/w1,1];Gc=tf(numc,denc),GcG=Gc*G,margin(GcG),beta