Low-Loss, Narrow-Band SAW Filters on Leaky Substrates

Surface acoustic wave filters operating at 1.6 GHz (GPS range) on 42deg-LiTaO
₃
are presented. The design is based on strong localized acoustical resonances appearing in gaps between long interdigital transducers. Realized low-loss filter has a fractional bandwidth of ~2% with a low insertion loss (~1 dB in the passband) and high rejection levels. We present also a switchable variant with response corresponding to that of two filter tracks connected electrically in series.