US 12,255,632 B2
Acoustic wave device, and ladder filter including the same
Kentaro Nakamura, Nagaokakyo (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Nagaokakyo (JP)
Filed on Jul. 21, 2022, as Appl. No. 17/869,809.
Application 17/869,809 is a continuation of application No. PCT/JP2021/003252, filed on Jan. 29, 2021.
Claims priority of application No. 2020-015067 (JP), filed on Jan. 31, 2020.
Prior Publication US 2022/0360252 A1, Nov. 10, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. H03H 9/56 (2006.01); H03H 9/02 (2006.01); H03H 9/145 (2006.01)
CPC H03H 9/568 (2013.01) [H03H 9/02771 (2013.01); H03H 9/02992 (2013.01); H03H 9/14541 (2013.01)] 20 Claims
OG exemplary drawing
 
1. An acoustic wave device comprising:
a substrate including a piezoelectric layer;
a first resonator on the substrate;
a second resonator on the substrate adjacent to the first resonator and having different frequency characteristics than the first resonator; and
a shared reflector on the substrate between the first resonator and the second resonator and defining a reflector for both the first resonator and the second resonator; wherein
the first resonator includes a first interdigital transducer electrode including electrode fingers positioned with a first pitch;
the second resonator includes a second interdigital transducer electrode including electrode fingers positioned with a second pitch;
a lower limit frequency of a stop band of the shared reflector is equal to both a lower limit frequency of a stop band of the first resonator and a lower limit frequency of a stop band of the second resonator, or between the lower limit frequency of the stop band of the first resonator and the lower limit frequency of the stop band of the second resonator; and
an upper limit frequency of the stop band of the shared reflector is equal to both an upper limit frequency of the stop band of the first resonator and an upper limit frequency of the stop band of the second resonator, or between the upper limit frequency of the stop band of the first resonator and the upper limit frequency of the stop band of the second resonator.