Bulk acoustic resonator structures comprising a single material acoustic coupling layer comprising inhomogeneous acoustic property

Abstract

In accordance with a representative embodiment, a BAW resonator structure comprises: a first BAW resonator comprising a first lower electrode, a first upper electrode and a first piezoelectric layer disposed between the first lower electrode and the first upper electrode; and a second BAW resonator comprising a second lower electrode, a second upper electrode and a second piezoelectric layer disposed between the second lower electrode and the second upper electrode. The BAW resonator structure also comprises a single-material acoustic coupling layer disposed between the first and second BAW resonators. The single-material acoustic coupling layer comprises an inhomogeneous acoustic property across a thickness of the single-material acoustic coupling layer.

Dependencies are inferred from the claim text.