Filter circuitry using ferroelectric tunable acoustic resonator

Abstract

The present disclosure relates to filter circuitry, which includes a first node and a second node, a series resonator coupled between the first node and the second node, and a compensation circuit coupled in parallel with the series resonator and located between the first node and the second node. Herein, the compensation circuit includes a tunable acoustic resonator with at least one transduction structure. The at least one transduction structure includes at least one ferroelectric material, and polarization of the at least one ferroelectric material varies with an electric field across the at least one ferroelectric material. Upon adjusting a direct current voltage applied to the tunable acoustic resonator, the compensation circuit is capable of providing a variable negative equivalent capacitance to at least partially cancel out an equivalent capacitance presented by the series resonator between the first node and the second node.

Dependencies are inferred from the claim text.