Bode Plot Generator

A Bode plot is a pair of frequency-response graphs: the magnitude plot shows the system gain in decibels as a function of frequency on a logarithmic scale, and the phase plot shows the phase angle in degrees at the same frequencies. Together they characterize the frequency response of a linear system. SciFig's Bode plot generator creates both graphs from a plain-language transfer function description.

Describe your transfer function — poles, zeros, gain, and natural frequency — in plain language, and SciFig's Bode plot generator computes the magnitude and phase curves and draws both graphs on logarithmic frequency axes. The online Bode plot generator labels gain in decibels and phase in degrees, marks corner frequencies, and shows gain and phase margins so your diagram is immediately interpretable.

Gain margin is the additional gain the system can tolerate before it becomes unstable, measured at the frequency where phase crosses –180 degrees. Phase margin is the additional phase lag before instability, measured at the gain crossover frequency where magnitude is 0 dB. SciFig's Bode plot generator marks both margins on the diagram so stability is visible at a glance.

A Bode plot displays magnitude and phase as two separate graphs against log frequency, making it easy to read gain and phase margins directly. A Nyquist plot traces the complex frequency response as a single curve in the real-imaginary plane and is used to apply the Nyquist stability criterion. SciFig's Bode plot generator produces the dual-graph format most commonly required in control-systems courses and papers.

On the magnitude plot, find where the curve crosses 0 dB — that is the gain crossover frequency. Read the gain margin at –180 degrees phase. On the phase plot, read the phase margin at the gain crossover frequency. Corner frequencies appear where the slope of the magnitude curve changes by ±20 dB per decade. A numeric Bode plot calculator returns these values as bare numbers, whereas SciFig's Bode plot generator labels all of them on the curves themselves so the diagram is self-explanatory.

Bode plots are used in control systems engineering, electrical engineering, signal processing, and mechanical engineering to analyze system stability, filter design, and frequency response. They appear in course reports, journal papers, and thesis chapters covering feedback control, amplifier design, and vibration analysis. SciFig's online Bode plot generator produces export-ready figures for all these contexts.