US 12,476,613 B2
Filter circuitry using ferroelectric tunable acoustic resonator
Nadim Khlat, Cugnaux (FR)
Assigned to Qorvo US, Inc., Greensboro, NC (US)
Filed by Qorvo US, Inc., Greensboro, NC (US)
Filed on Jul. 27, 2023, as Appl. No. 18/227,033.
Claims priority of provisional application 63/410,413, filed on Sep. 27, 2022.
Prior Publication US 2024/0106412 A1, Mar. 28, 2024
Int. Cl. H03H 9/54 (2006.01); H03H 9/13 (2006.01); H03H 9/17 (2006.01)
CPC H03H 9/542 (2013.01) [H03H 9/133 (2013.01); H03H 9/17 (2013.01)] 20 Claims
OG exemplary drawing
 
1. Filter circuitry comprising:
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; wherein:
the compensation circuit includes a tunable acoustic resonator with at least one transduction structure;
the at least one transduction structure comprises at least one ferroelectric material, wherein polarization of the at least one ferroelectric material varies with an electric field across the at least one ferroelectric material; and
upon adjusting a direct current (DC) 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.