clear all
close all
clc

j = sqrt(-1);
w = logspace(-2,2,1000);
s = j*w;

Gs = (exp(-3.*s).*(s.^3+1) ./ (s.^3 + s.^2 + 3.*s)) + (1./ (s+1).^3);

A = abs(Gs);
Lm = 20*log10(A);
fi = angle(Gs);

figure(1)
plot(Gs)

figure(2)
subplot(2,1,1); semilogx(w,Lm);
subplot(2,1,2); semilogx(w,fi);