US 11,955,949 B2
Resonator, and filter and duplexer having the same
Toshihiko Kawamoto, Osan-si (KR); Ryota Sato, Osan-si (KR); Sang Tai Yu, Osan-si (KR); and Je Cheol Lee, Osan-si (KR)
Assigned to WISOL CO., LTD., Osan-si (KR)
Filed by WISOL CO., LTD., Osan-si (KR)
Filed on May 14, 2021, as Appl. No. 17/320,485.
Claims priority of application No. 10-2020-0060365 (KR), filed on May 20, 2020.
Prior Publication US 2021/0367580 A1, Nov. 25, 2021
Int. Cl. H03H 9/145 (2006.01); H03H 9/25 (2006.01)
CPC H03H 9/145 (2013.01) [H03H 9/25 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A resonator comprising:
an interdigital transducer (IDT) including a first electrode including a first base formed on a piezoelectric substrate and extended in a reference direction, and a plurality of first protrusions connected to the first base and extended in a direction intersecting with the reference direction, and a second electrode including a second base formed on the piezoelectric substrate and extended in the reference direction, and a plurality of second protrusions connected to the second base and extended in a direction intersecting with the reference direction, each of the second protrusions being extended to have any one first protrusion among the plurality of first protrusions inserted between the second protrusion and another second protrusion adjacent to the second protrusion, wherein
a width, along the reference direction, of each of a plurality of first specific protrusions included between one end of the IDT and a first position at a first distance from the one end, among the plurality of first protrusions and the plurality of second protrusions, decreases from a first specific protrusion closest to the first position toward a first specific protrusion closest to the one end.