US 12,438,523 B2
Crossover reduction for acoustic duplexers by spurious modes
Yu Hui, Pleasanton, CA (US); and Yiliu Wang, Irvine, CA (US)
Assigned to SKYWORKS SOLUTIONS, INC., Irvine, CA (US)
Filed by SKYWORKS SOLUTIONS, INC., Irvine, CA (US)
Filed on Feb. 3, 2023, as Appl. No. 18/164,133.
Claims priority of provisional application 63/307,685, filed on Feb. 8, 2022.
Prior Publication US 2023/0253953 A1, Aug. 10, 2023
Int. Cl. H03H 9/72 (2006.01); H03H 9/02 (2006.01); H03H 9/17 (2006.01); H03H 9/25 (2006.01); H03H 9/56 (2006.01); H03H 9/64 (2006.01); H03H 9/70 (2006.01)
CPC H03H 9/725 (2013.01) [H03H 9/02834 (2013.01); H03H 9/172 (2013.01); H03H 9/25 (2013.01); H03H 9/564 (2013.01); H03H 9/568 (2013.01); H03H 9/6483 (2013.01); H03H 9/706 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A radio frequency duplexer comprising:
a transmit filter including a first plurality of acoustic wave resonators; and
a receive filter including a second plurality of acoustic wave resonators, the transmit filter exhibiting a transmit insertion loss curve that partially overlaps with a receive insertion loss curve of the receive filter, a frequency range of an overlap of the transmit insertion loss curve and the receive insertion loss curve defining a frequency range of crossover of the duplexer, at least one of the first plurality of acoustic wave resonators or the second plurality of acoustic wave resonators including a structure configured to generate a spurious signal at a frequency within the frequency range of the crossover to reduce an amplitude of an interference signal within the frequency range of the crossover, the structure including one of
a surface acoustic wave resonator of one of the first or second plurality of acoustic wave resonators formed with a piezoelectric substrate having a cut angle configured to generate a shear horizontal mode spurious signal having the frequency within the frequency range of the crossover, or
different ones of the surface acoustic wave resonator of one of the first or second plurality of acoustic wave resonators including temperature compensation layers with different thicknesses.