Resonant Inc.
Small transversely-excited film bulk acoustic resonators with enhanced Q-factor

Abstract:

An acoustic resonator device includes a conductor pattern formed on a surface of a piezoelectric plate. The conductor pattern includes a first busbar, a second busbar, and n interleaved parallel fingers of an interdigital transducer (IDT), where n is a positive integer. The fingers extend alternately from the first and second busbars. A first finger and an n'th finger are at opposing ends of the IDT. The conductor pattern also includes a first reflector element proximate and parallel to the first finger and a second reflector element proximate and parallel to the n'th finger. A center-to-center distance pr between the first reflector element and the first finger and between the second reflector element and the n'th finger is greater than or equal to 1.2 times a pitch p of the IDT and less than or equal to 1.5 times the pitch p.