Bodekäyrää

Bodekäyrä, often referred to as a Bode plot, is a graphical representation of a linear time-invariant (LTI) system's frequency response. It consists of two graphs: one plotting the magnitude of the system's transfer function in decibels (dB) against frequency on a logarithmic scale, and the other plotting the phase angle of the transfer function in degrees against frequency on the same logarithmic scale.

Invented by Hendrik Wade Bode in the 1930s, Bode plots are a fundamental tool in control theory and signal processing for analyzing and designing filters and control systems. They provide a clear visual understanding of how a system responds to different frequencies, including its gain at various frequencies and the phase shift it introduces.

The magnitude plot shows how much the system amplifies or attenuates signals at different frequencies. A flat magnitude response indicates that the system treats all frequencies equally, while a sloping response reveals frequency-dependent amplification or attenuation. The phase plot shows the time delay introduced by the system at different frequencies. Changes in phase are crucial for understanding system stability.

Key features observable in a Bode plot include the cutoff frequency, resonant peaks, and asymptotic behavior. These features help engineers predict system performance, identify potential instability issues, and tune controller parameters for desired responses. Bode plots are widely used in electronics, mechanical engineering, and aerospace for system analysis and design.