An online Bode plot grapher is presented. The input to the calculator is the transfer function \( H(s) \), where \( s = j \omega \) with \( j = \sqrt{-1} \) and \( \omega \) is the angular frequency in radians per second.

This calculator calculate the amplitude \( A \) and phas \( P \) defined as

Let \( H_r \) be the real part of \( H(s) \) and Let \( H_i \) be the imagianry part of \( H(s) \), hence the amplitude \( A \) and the phase \( P \) are defined as follows:
\[ A = 20 \; \log{10} \sqrt {H_r^2 + H_i^2} \]
\[ P = \arctan 2 (H_i , H_r) \]

Step 1 : Enter the transfer function as a function of \( s \) and press "Enter Expression", then check the expression of \( H(s) \) displayed.

\( H(s) = \)

Step 2 : Enter the domain of values of \( \omega \) : minimum \( \omega_{min} \) and maximum values \( \omega_{max} \).

The computing time depends on the value of \( \omega_{max} \) and the larger it is the more computing time it takes to plot the graph.

\( \omega_{min} \): ( rad/s) \( \omega_{max} \): ( rad/s)

Step 3 : Click on "Plot" ONCE ONLY and wait till the two graphs, amplitude and phase, are displayed.