Crystal filter

Crystal filters are commonly used in communication devices such as radio receivers.

Crystal filters are used in the intermediate frequency (IF) stages of high-quality radio receivers.

[1] The most common use of crystal filters are at frequencies of 9 MHz or 10.7 MHz to provide selectivity in communications receivers, or at higher frequencies as a roofing filter in receivers using up-conversion.

The cut also determines some temperature characteristics, which affect the stability of the resonant frequency.

Crystal filters can be found today in radio communications, telecommunications, signal generation, and GPS devices.