Bandpass filter

A bandpass filter is an electronic circuit or device designed to allow signals within a specified frequency range to pass through while attenuating or blocking signals outside of that range. It essentially selects a specific band of frequencies from an input signal while rejecting others.

Bandpass filters are commonly used in various applications such as audio processing, telecommunications, RF (radio frequency) communications, and instrumentation. They can be implemented using various circuit configurations including active filters (those that require a power source) and passive filters (those that do not require a power source).

The characteristics of a bandpass filter are typically defined by its center frequency (the midpoint of the passband), bandwidth (the range of frequencies passed through), and the shape of its frequency response curve (how sharply it attenuates frequencies outside the passband). These characteristics are determined by the specific design parameters of the filter, such as the values of its resistors, capacitors, and inductors.

Bandpass filters find applications in audio equalization, signal processing, radio receivers, and various other fields where selective frequency filtering is required.