Patent ID: 11870421
Assignee: SKYWORKS SOLUTIONS, INC.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 18:
19. A wireless device that communicates by a frequency division bidirectional communication at a radio frequency, the wireless device having a duplexer with a transmit filter and a receive filter, at least one of the transmit filter and the receive filter including a surface acoustic wave resonator comprising:
a piezoelectric substrate;
interdigital transducer electrodes disposed on an upper surface of the piezoelectric substrate, the interdigital transducer electrodes including first bus bar electrode regions spaced apart from each other in a transverse direction perpendicular to a propagation direction of a surface acoustic wave to be excited, an overlapping region sandwiched between the first bus bar electrode regions, and gap regions defined between the respective first bus bar electrode regions and the overlapping region in the transverse direction, each of the gap regions including a second bus bar electrode disposed in parallel to a respective first bus bar electrode;
a first dielectric film covering the interdigital transducer electrodes and the upper surface of the piezoelectric substrate for temperature compensation; and
a second dielectric film covering the first dielectric film, the second dielectric film including a trench having portions defined within the gap regions, within the first bus bar electrode regions, and within regions on opposite sides of the first bus bar electrode regions from the overlapping region.