The first part of selecting an RF filter is selecting what technology to use. The main types stocked by Golledge are SAW and Crystal but we also have a range of ceramic resonator and LTCC LC filters. All our SAW and Crystal filters are bandpass types. There is an overlap between Crystal filters and SAW filters between 35MHz and 110MHz. this being the top of the standard crystal filter range and the bottom of the SAW filter range, 70MHz being popular for both SAW filters and crystal filters. For this centre frequency the choice is made my required bandwidth. SAW’s have bandwidths of 50kHz and higher, while crystal filters have bandwidths up to 30kHz.
Our SAW filter range extends up to 3.8GHz. The passband power handling of SAW filters of SAW filters is limited to typically 10dBm with a few models rated up to 20dBm. If you need a filter of higher centre frequency, or greater power handling, then a ceramic resonator filter is a good alternative, with centre frequencies up to 5.8GHz and power handling typically 1W.
LTCC filters come into their own when greater bandwidths then can be offered by SAW filters are required, or the response desired is low pass or high pass.