G=tf(1,[1,1]); T=1; w=logspace(-1,1,100)';
[nP,dP]=pade(T,5); G_c=feedback(G,tf(nP,dP));
set(G_c,'Td',T); bode(G_c,w)

n=1:6; T=1; G0=tf(1,[1,1]); w=logspace(-1,1,100)'; 
[m,p]=bode(G_c,w); m=m(:); p=p(:);
for i=1:length(n)
   [nP,dP]=pade(T,n(i)); G=G0*tf(nP,dP);
   G_c=feedback(G,1);
   [m1,p1]=bode(G_c,w); m=[m,m1(:)]; p=[p,p1(:)];
end
subplot(211), semilogx(w,20*log10(m))
subplot(212), semilogx(w,p)