Bandwidth switchable SAW filters, BSSF, on quartz

Abstract

To reduce frequency band waste, and increase the flexibility in future mobile communication satellites, a SAW (surface acoustic wave) filter bank was designed. The filters can be used either as separate filters, or combined with neighbor filters to form continuous passbands both in amplitude and phase. These are called bandwidth switchable SAW filters (BSSF). The principle involves pure signal vector additions based on symmetries in the common transition band, by controlled amplitude and phase response and equal delay. A SAW filter bank with three filters was manufactured and tested with excellent results.<>