Single cavity acoustic resonators and electrical filters comprising single cavity acoustic resonators

摘要

A single cavity acoustic resonator comprises: a first electrode; a second electrode; a third electrode disposed between the first electrode and the second electrode. The single cavity acoustic resonator also comprises: a first piezoelectric layer disposed between the third electrode and the first electrode, and comprising a first C-axis having an orientation; and a second piezoelectric layer disposed between the third electrode and the second electrode, and comprising a second C-axis having an orientation parallel to the first C-axis. Application of a time varying electrical signal at a drive frequency to either the third electrode or to the first and second electrodes results in a resonance of the single cavity acoustic resonator at twice a fundamental resonant frequency and a cancellation of substantially all even-order mixing products in the single cavity resonator. An electrical filter and a duplexer are also described.