w = logspace(-1,2,100);
s = 1i*w;
W = (10*s+10)./(2*s.^4+4*s.^3+30*s.^2+5*s+10);
abs_W = abs(W);
phase_W = phase(W)/pi*180;
subplot(2,1,1);semilogx(w,20*log10(abs_W)); grid;
subplot(2,1,2);semilogx(w,phase_W); grid;

