A crystal filter is an electronic filter that uses quartz crystals for resonators. Quartz crystals are piezoelectric, so their mechanical characteristics can affect electronic circuits.The crystal’s stability and its high Q factor allow crystal filters to have precise center frequencies and steep band-pass characteristics. Typical crystal filter attenuation in the band-pass is approximately 2-3dB. Crystal filters are commonly used in communication devices such as radio receivers. A crystal filter is very often found in the intermediate frequency (IF) stages of high-quality radio receivers.