This is represented in the general representation figure given below:Ģ. Magnitude Plot: In this plot, magnitude is represented in logarithmic values against logarithmic values of frequency.įor the transfer function G(jω)H(jω), in order to express the magnitude in logarithmic values, we need to find,Īnd this magnitude in dB is plotted for log 10 ω. So, more simply, we can say that a Bode Plot consists of 2 plots:ġ.

Out of the two plots, one plot corresponds to the magnitude vs frequency while the other corresponds to the phase angle vs frequency response of the system.Īlso, all the 3 parameters on both the plots are sketched for the logarithmic scale. But in bode plot, a logarithmic scale is used in place of normal linear scale.īasically, by the use of a bode plot, a sinusoidal transfer function of a system can be represented by two separate plots. What is a Bode Plot?Īs we have discussed recently that in polar plots a normal linear scale is used for sketching the magnitude vs phase angle response for various values of ω. Bode proposed a different but powerful and helpful method for the purpose of stability analysis of the control system.

However, accommodating all the values of magnitude and phase angle on a linear scale is quite difficult.

In such plots, there is variation in ω from 0 to ∞ for which various values of magnitude and phase angle are achieved. Previously we have seen that the basic form of frequency response curve represents a plot between magnitude and phase angle is sketched for various values of input frequency i.e., ω. Glossary angular coordinate the angle formed by a line segment connecting the origin to a point in the polar coordinate system with the positive radial ( x) axis, measured counterclockwise cardioid a plane curve traced by a point on the perimeter of a circle that is rolling around a fixed circle of the same radius the equation of a cardioid is or limaçon the graph of the equation or If then the graph is a cardioid polar axis the horizontal axis in the polar coordinate system corresponding to polar coordinate system a system for locating points in the plane.In bode plot, logarithmic of magnitude and logarithmic of phase angle are separately plotted for logarithmic values of frequencies.

Pole vs origin graphing