logspace(-3,6,91)
s = j*w
Gs = (exp(-3*s).*(s.^3+1)./((s.^3)+(s.^2)+3*s))+1./(s+1).^3;
figure(1)
plot(Gs)

lM = 20*log10(abs(Gs));
figure(2);
subplot(2,1,1);
semilogx(w,lM);
grid on

G1 = (s.^3+1)./((s.^3)+(s.^2)+3*s)+1./(s+1).^3;
fi = -w*180/pi + angle(G1)*180/pi;
subplot(2,1,2);
semilogx(w,fi);
grid on