Interdigitated transducers and reflectors for surface acoustic wave devices with non-uniformly spaced elements

A surface acoustic wave (SAW) device, comprising:

• a substrate;
• at least a first interdigitated transducer including a plurality of interdigitated fingers disposed on a first surface of the substrate;
• and
• at least a first reflector including a plurality of gratings disposed on the first surface of the substrate,
• wherein at least one of:
• (1) a first group of the interdigitated fingers of the first interdigitated transducer has a first finger pitch and a first finger metal pitch ratio, and a second group of interdigitated fingers has a second finger pitch different from the first metal pitch and a second metal pitch ratio which is different from the first metal pitch ratio;
• and the first group of interdigitated fingers has a first surface mode resonance frequency, and the second group of interdigitated fingers has a second surface mode resonance frequency which is substantially the same as the first resonance frequency, and
• (2) a first group of the gratings of the first reflector 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 which is different from the first grating metal pitch ratio, wherein the first group of the gratings has a first grating surface mode resonance frequency, and the second group of the gratings has a second grating surface mode resonance frequency which is substantially the same as the first grating surface mode resonance frequency.