ceramic filter
Ceramic filters are dielectric filters, comparable to the quartz filter, but their quality is much lower than that of quartz filters. Ceramic filters use specially designed ceramics and are characterized by a steep filter curve.
The bandwidth can range from less than one percent of the resonant frequency to several percent, the impedance is several kilo-ohms, the stopband rejection is 70 dB or more, and the insertion loss is extremely low. Due to the high permittivity of ceramic bodies, ceramic filters can be realized extremely small and for surface mount SMT technology.
Ceramic filters are mainly used in IF amplifiers: in the AM IF with 455 kHzintermediate frequency and a bandwidth of 12 kHz and the FM IF with 10.7 MHz intermediate frequency and 110 kHz bandwidth. In addition, there are miniature versions for frequencies up to 40 GHz or EMC ceramic filters for frequencies up to 18 GHz.