INTERDIGITATED TRANSDUCERS AND REFLECTORS FOR SURFACE ACOUSTIC WAVE DEVICES WITH NON-UNIFORMLY SPACED ELEMENTS

摘要

A surface acoustic wave (SAW) device includes: a substrate, an interdigitated transducer including a plurality of interdigitated fingers disposed on a first surface of the substrate, and a reflector including a plurality of gratings also disposed on the first surface. At least one of: (1) a first group of the interdigitated fingers has a first finger pitch and a first finger metal pitch ratio, and a second group of the interdigitated fingers has a second finger pitch different from the first metal pitch and a second metal pitch ratio different from the first metal pitch ratio; and (2) a first group of the gratings has a first grating pitch and a first grating metal pitch ratio, and a second group of the gratings has a second grating metal pitch different from the first grating metal pitch and a second grating metal pitch ratio different from the first grating metal pitch ratio.

主权项

1. A surface acoustic wave (SAW) device, comprising:
a substrate; and at least a first interdigitated transducer disposed on a first surface of the substrate, wherein the first interdigitated transducer includes a plurality of interdigitated fingers, including at least a first group of first interdigitated fingers having a first finger pitch and a second group of second interdigitated fingers having a second finger pitch which is different from the first finger pitch, and wherein the first group of first interdigitated fingers has a first finger metal pitch ratio, and the second group of second interdigitated fingers has a second finger metal pitch ratio which is different from the first finger metal pitch ratio, and wherein the first group of first interdigitated fingers has a first surface mode resonance frequency, and the second group of second interdigitated fingers has a second surface mode resonance frequency which is substantially the same as the first surface mode resonance frequency.