Acoustic wave resonator with reduced size

An acoustic wave resonator, comprising:

• a carrier substrate;
• a layer of dielectric material disposed on an upper surface of the carrier substrate;
• a layer of piezoelectric material disposed above the layer of dielectric material on the upper surface of the carrier substrate, the layer of piezoelectric material including a pair of opposing terminating edges that are coterminous with the layer of dielectric material;
• one or more interdigital transducers disposed on the layer of piezoelectric material;
• and
• a pair of reflector gratings disposed on the layer of piezoelectric material and each including less than eight reflector fingers, the pair of reflector gratings each being positioned adjacent to an adjacent one of the pair of opposing terminating edges of the layer of piezoelectric material such that the reflector gratings oppose each other with the one or more interdigital transducers therebetween, spacing between an edge electrode finger of each of the pair of reflector gratings and the adjacent one of the pair of opposing terminating edges being equal to about λ/8, where λ is a wavelength of an acoustic wave generated by the one or more interdigital transducers during operation.

An acoustic wave resonator, comprising:

• a carrier substrate;
• a layer of dielectric material disposed on an upper surface of the carrier substrate;
• a layer of piezoelectric material disposed above the layer of dielectric material on the upper surface of the carrier substrate, the layer of piezoelectric material including a pair of opposing terminating edges that are coterminous with the layer of dielectric material;
• one or more interdigital transducers disposed on the layer of piezoelectric material;
• a pair of reflector gratings disposed on the layer of piezoelectric material and each including less than eight reflector fingers, the pair of reflector gratings each being positioned adjacent to a respective terminating edge of the layer of piezoelectric material and layer of dielectric material such that the reflector gratings oppose each other with the one or more interdigital transducers therebetween;
• and
• a layer of high impedance material disposed against the opposing terminating edges, the layer of high impedance material having a same thickness as a combined thickness of the layers of dielectric material and piezoelectric material at a point of contact between the layer of high impedance material and the layers of dielectric material and piezoelectric material.