# Bode Plot Graphing Calculator

 

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.

## Transfer Function and Bode Plot Review

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: $A = 20 \; \log{10} \sqrt {H_r^2 + H_i^2}$ $P = \arctan 2 (H_i , H_r)$

## Bode Plot Grapher

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.