Electronic – Program to make bode plot of transfer function

bode plot

For different purposes, I sometimes have to draw an bode plot. I first of would like to know if there is any piece of software which can draw them for me. So I gave in the transfer function and then it gives me the bode plot (both phase and the magnitude). This would save some time at occasions.

Ok, so now the real question. I have the following transfer function.

$$ H(j\omega) = \frac{j \frac{\omega}{\omega_0} }{1 + 3j \frac{\omega}{\omega_0}} $$

The modulus can be calculated as follows (correct me if I am wrong):

$$ |H(j\omega)| = 20 \log_{10}(p) – 20 \log_{10} \left(\sqrt{1+(3p)^2}\right)$$

(where \$ p=\frac{\omega}{\omega_0} \$, with \$ \omega_0=\frac{1}{500 \times 6.37 \times 10^{-7}} \$).

\$ 20 \log_{10}(p) \$, would be easy, but I am not sure how to calculate the second one? How do I calculate the (magnitude) bode plot of \$ -20 \log_{10} \left(\sqrt{1+(3p)^2} \right) \$

Best Answer

I will directly link to the Matlab bode plot section... http://www.mathworks.com/help/ident/ref/bode.html?refresh=true

It works nicely and the program is simple as dirt.