It is usually a combination of a Bode magnitude plot, expressing the magnitude (usually in decibels) of the frequency response, and a Bode phase plot, expressing the phase shift.Īs originally conceived by Hendrik Wade Bode in the 1930s, the plot is an asymptotic approximation of the frequency response, using straight line segments. In electrical engineering and control theory, a Bode plot / ˈ b oʊ d i/ is a graph of the frequency response of a system.
Figure 1B: The Bode plot for a first-order (one-pole) lowpass filter the straight-line approximations are labeled 'Bode pole' phase is 90° lower than for Figure 1A because the phase contribution of the numerator is 0° at all frequencies.
