US 12,231,108 B2
Acoustic wave resonator, RF filter circuit and system
Dae Ho Kim, Cornelius, NC (US); Mary Winters, Webster, NY (US); Ramakrishna Vetury, Charlotte, NC (US); and Jeffrey B. Shealy, Davidson, NC (US)
Assigned to Akoustis, Inc., Huntersville, NC (US)
Filed by Akoustis, Inc., Huntersville, NC (US)
Filed on Jun. 23, 2023, as Appl. No. 18/340,764.
Application 18/340,764 is a continuation of application No. 17/944,475, filed on Sep. 14, 2022, granted, now 11,711,064.
Application 17/944,475 is a continuation of application No. 16/541,076, filed on Aug. 14, 2019, granted, now 11,476,825, issued on Oct. 18, 2022.
Application 16/541,076 is a continuation in part of application No. 16/290,703, filed on Mar. 1, 2019, granted, now 10,979,026, issued on Apr. 13, 2021.
Application 16/290,703 is a continuation in part of application No. 16/175,650, filed on Oct. 30, 2018, granted, now 10,979,025, issued on Apr. 13, 2021.
Application 16/541,076 is a continuation in part of application No. 16/175,650, filed on Oct. 30, 2018, granted, now 10,979,025, issued on Apr. 13, 2021.
Application 16/175,650 is a continuation in part of application No. 16/019,267, filed on Jun. 26, 2018, granted, now 10,979,022, issued on Apr. 13, 2021.
Application 16/019,267 is a continuation in part of application No. 15/784,919, filed on Oct. 16, 2017, granted, now 10,355,659, issued on Jul. 16, 2019.
Application 15/784,919 is a continuation in part of application No. 15/068,510, filed on Mar. 11, 2016, granted, now 10,217,930, issued on Feb. 26, 2019.
Prior Publication US 2023/0336139 A1, Oct. 19, 2023
Int. Cl. H03H 9/02 (2006.01); H03H 3/02 (2006.01); H03H 9/17 (2006.01)
CPC H03H 9/02015 (2013.01) [H03H 3/02 (2013.01); H03H 9/02047 (2013.01); H03H 9/173 (2013.01); H03H 2003/025 (2013.01)] 3 Claims
OG exemplary drawing
 
1. An RF filter system, comprising:
a plurality of bulk acoustic wave resonators arranged in a circuit, the circuit including a serial configuration of resonators and a parallel shunt configuration of resonators, the circuit having a circuit response corresponding to the serial configuration and the parallel configuration of the plurality of bulk acoustic wave resonators, each of the resonators of the plurality of resonators comprising:
a reflector;
a support member including a cavity region over the reflector;
a first electrode including tungsten overlying the reflector;
a piezoelectric film including crystalline aluminum scandium nitride overlapping the first electrode and overlying the reflector;
a second electrode including tungsten overlapping the piezoelectric film, overlapping the first electrode, and overlying the reflector; and
a passivation layer including silicon nitride overlying the second electrode, one or more portions of a surface of the support member of at least one resonator of the plurality of bulk acoustic wave resonators defining the cavity region and a portion of the first electrode of the at least one resonator being located within the cavity region defined by the surface of the support member, the support member including the cavity region being a first support member portion, the support member including a second support member portion, the reflector being located in the second support member portion, the first support member portion and the second support member portion including the same material,
wherein the circuit response of the circuit corresponding to the serial configuration and the parallel configuration of the plurality of resonators has a transmission loss from a pass band having a bandwidth corresponding to a thickness of at least one of the first electrode, the piezoelectric film, the second electrode, and the passivation layer.