US 12,289,101 B2
Duplexer
Yuki Koto, Tokyo (JP)
Assigned to Sanan Japan Technology Corporation, Tokyo (JP)
Filed by Sanan Japan Technology Corporation, Tokyo (JP)
Filed on Aug. 3, 2022, as Appl. No. 17/817,236.
Claims priority of application No. 2021-132392 (JP), filed on Aug. 16, 2021.
Prior Publication US 2023/0047266 A1, Feb. 16, 2023
Int. Cl. H03H 9/72 (2006.01); H03H 9/25 (2006.01); H03H 9/64 (2006.01)
CPC H03H 9/725 (2013.01) [H03H 9/25 (2013.01); H03H 9/6483 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A duplexer, comprising:
a piezoelectric substrate;
a receiving filter formed on the piezoelectric substrate, the receiving filter includes a first plurality of resonators; and
a transmitting filter formed on the piezoelectric substrate, the transmitting filter includes a second plurality of resonators;
wherein one of the first plurality of resonators of the receiving filter is a multi-mode type acoustic wave resonator having a capacitance that is two times or more an average capacitance of other ones of the first plurality of resonators and the second plurality of resonators formed on the piezoelectric substrate, and
wherein the multi-mode type acoustic wave resonator includes a first IDT electrode, a second IDT electrode, a third IDT electrode, a fourth IDT electrode and a fifth IDT electrode adjacently formed in this order, and a number of electrode fingers of the third IDT electrode is more than a sum of numbers of electrode fingers of the first IDT electrode, the second IDT electrode, the fourth IDT electrode, and the fifth IDT electrode.