A hybrid substrate for a temperature-compensated surface acoustic wave filter

A hybrid substrate that is appropriate for temperature compensation of a surface acoustic wave (SAW) filter is developed. A one-port SAW resonator was fabricated on the hybrid substrate to study its electronic characteristics and thermal stability. The spurious response originating from bulk wave reflection at the layer interface was found to be sufficiently small with a relatively thin piezoelectric layer. The minimum temperature coefficient of frequency (TCF) was -8.4 ppm/°C.