US 12,308,823 B2
Transversely-excited film bulk acoustic filters with symmetric layout
Ventsislav Yantchev, Sofia (BG)
Assigned to Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Mar. 25, 2024, as Appl. No. 18/614,870.
Application 18/614,870 is a continuation of application No. 17/706,154, filed on Mar. 28, 2022, granted, now 11,967,942.
Application 17/706,154 is a continuation of application No. 17/022,048, filed on Sep. 15, 2020, granted, now 11,349,452.
Application 17/022,048 is a continuation of application No. 16/924,105, filed on Jul. 8, 2020, granted, now 10,868,513.
Application 16/924,105 is a continuation in part of application No. 16/829,617, filed on Mar. 25, 2020, granted, now 10,868,512.
Application 16/829,617 is a continuation of application No. 16/578,811, filed on Sep. 23, 2019, granted, now 10,637,438.
Application 16/578,811 is a continuation in part of application No. 16/230,443, filed on Dec. 21, 2018, granted, now 10,491,192.
Claims priority of provisional application 62/685,825, filed on Jun. 15, 2018.
Claims priority of provisional application 62/701,363, filed on Jul. 20, 2018.
Claims priority of provisional application 62/741,702, filed on Oct. 5, 2018.
Claims priority of provisional application 62/748,883, filed on Oct. 22, 2018.
Claims priority of provisional application 62/753,815, filed on Oct. 31, 2018.
Prior Publication US 2024/0267023 A1, Aug. 8, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. H03H 9/17 (2006.01); H03H 9/02 (2006.01); H03H 9/54 (2006.01); H03H 9/13 (2006.01)
CPC H03H 9/171 (2013.01) [H03H 9/02 (2013.01); H03H 9/54 (2013.01); H03H 9/02015 (2013.01); H03H 9/13 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A filter device comprising:
at least one piezoelectric layer; and
a conductor pattern at a surface of the at least one piezoelectric layer and having a plurality of interdigital transducers (IDTs) that have interleaved fingers for one or more pairs of sub-resonators,
wherein each sub-resonator of the one or more pairs of sub-resonators comprises a plurality of pairs of interleaved fingers that are positioned on the at least one piezoelectric layer and above a respective cavity of a plurality of cavities of the filter device,
wherein each sub-resonator of the one or more pairs of sub-resonators are positioned symmetrically about a central axis of the filter device,
wherein the interleaved fingers of each sub-resonator of at least one pair of sub-resonators has a first plurality of fingers extending from a first busbar that is coupled to an input path of the filter device, and
wherein the interleaved fingers of each sub-resonator of the at least one pair of sub-resonators has a second plurality of fingers extending from a second busbar that is coupled to an output path of the filter device.