US 11,923,829 B2
Reduced temperature coefficient of frequency at filter transition band while retaining pass-band width
Tomoya Komatsu, Irvine, CA (US); and Joji Fujiwara, Suita (JP)
Assigned to SKYWORKS SOLUTIONS, INC., Irvine, CA (US)
Filed by SKYWORKS SOLUTIONS, INC., Irvine, CA (US)
Filed on Apr. 6, 2021, as Appl. No. 17/223,407.
Application 17/223,407 is a continuation of application No. 16/392,826, filed on Apr. 24, 2019, granted, now 10,979,028.
Claims priority of provisional application 62/667,236, filed on May 4, 2018.
Prior Publication US 2021/0226610 A1, Jul. 22, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. H03H 9/64 (2006.01); H03H 9/72 (2006.01)
CPC H03H 9/6483 (2013.01) [H03H 9/6476 (2013.01); H03H 9/725 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An electronic filter comprising:
a plurality of series arm acoustic wave resonators electrically connected in series between an input port and an output port;
a plurality of parallel arm acoustic wave resonators electrically connected on first sides between respective ones of the plurality of series arm acoustic wave resonators and electrically connected on second sides to ground; and
at least one additional acoustic wave resonator including a first additional acoustic wave resonator electrically connected in parallel with a first one of the plurality of series arm acoustic wave resonators and a second additional acoustic wave resonator electrically connected in parallel with a second one of the plurality of series arm acoustic wave resonators, at least one of the first and second additional acoustic wave resonators having a temperature coefficient of frequency lower than a temperature coefficient of frequency of the acoustic wave resonator to which it is electrically connected in parallel.