Acoustic wave resonator and duplexer using same
AssigneePanasonic Corporation
InventorsHidekazu Nakanishi, Hiroyuki Nakamura, Tetsuya Tsurunari, Rei Goto, Joji Fujiwara
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Abstract
An acoustic wave resonator includes a piezoelectric body, an IDT electrode for exciting an acoustic wave with wavelength λ, and a dielectric thin film provided so as to cover the IDT electrode. The IDT electrode includes a bus bar electrode region, a dummy electrode region, and an IDT cross region in order from outside. The film thickness of the dielectric thin film above at least one of the bus bar electrode region and the dummy electrode region is smaller than that above the IDT cross region by 0.1λ to 0.25λ. This configuration provides an acoustic wave resonator that reduces transverse-mode spurious emission.
Claims26
An acoustic wave resonator comprising:
- a piezoelectric body;
- an IDT electrode on the piezoelectric body, for exciting an acoustic wave with wavelength λ;
- and
- a dielectric thin film covering the IDT electrode, for propagating a side wave slower than a side wave propagated through the piezoelectric body,
- wherein the IDT electrode includes a bus bar electrode region, a dummy electrode region, and an IDT cross region in an order from outside in a direction in which electrode fingers of the IDT electrode extend, and
- wherein a film thickness of the dielectric thin film above at least one of the bus bar electrode region and the dummy electrode region is smaller than a film thickness of the dielectric thin film above the IDT cross region by 0.1λ to 0.25λ.
An acoustic wave resonator comprising:
- a piezoelectric body;
- an IDT electrode on the piezoelectric body, for exciting an acoustic wave with wavelength λ;
- and
- a dielectric thin film covering the IDT electrode, for propagating a side wave slower than a side wave propagated through the piezoelectric body,
- wherein the IDT electrode includes a bus bar electrode region, a gap region, and an IDT cross region in an order from outside in a direction in which electrode fingers of the IDT electrode extend, and
- wherein a film thickness of the dielectric thin film above at least one of the bus bar electrode region and the gap region is smaller than a film thickness of the dielectric thin film above the IDT cross region by 0.1λ to 0.25λ.
Dependencies are inferred from the claim text.