SURFACE ACOUSTIC WAVE RESONATOR AND SURFACE ACOUSTIC WAVE FILTER USING IT

摘要

A Q value of a resonator at a high frequency is improved, and by using such resonator, a filter insertion loss is reduced and filter steepness is improved. The surface acoustic wave resonator is provided with an interdigital transducer and reflecting electrodes on the both sides of the interdigital transducer. On a piezoelectric board, a plurality of the surface acoustic wave resonators are connected in parallel, and all the resonant frequencies of the surface acoustic wave resonators connected in parallel are permitted to be the same. Thus, the resonance Q value is improved, and by configuring the surface acoustic wave filter by using the surface acoustic wave resonator, the insertion loss is reduced and the steepness is improved.