BULK ACOUSTIC WAVE RESONATOR, FILTER, ELECTRONIC DEVICE, AND METHOD FOR ADJUSTING ELECTROMECHANICAL COUPLING COEFFICIENT

Title:

BULK ACOUSTIC WAVE RESONATOR, FILTER, ELECTRONIC DEVICE, AND METHOD FOR ADJUSTING ELECTROMECHANICAL COUPLING COEFFICIENT

Document Type and Number:

WIPO Patent Application WO/2021/223731

Kind Code:

A1

Abstract:

The present application relates to a bulk acoustic wave resonator, comprising: a substrate, an acoustic mirror, a bottom electrode, a top electrode, and a piezoelectric layer. The top electrode is provided with raised portions at both a top electrode connection end and a non-top electrode connection end, and the top surfaces of the raised portions are above the top surface of an inner side portion of the top electrode; the inner side portion is a convex polygonal area having multiple edges, the raised portions are arranged around the convex polygonal area to form a polygonal electrode frame, and the electrode frame comprises multiple frame edges; the frame edges of the electrode frame have transverse width changes in the acoustic mirror. The present application also relates to a filter, at least one resonator of the filter being the above resonator and having an electromechanical coupling coefficient different from those of other resonators. The present application also relates to an electronic device comprising the above bulk acoustic wave resonator or filter, and a method for adjusting the electromechanical coupling coefficient of the bulk acoustic wave resonator.

Inventors:

BAN SHENGGUANG (CN)
PANG WEI (CN)
XU YANG (CN)

Application Number:

PCT/CN2021/092059

Publication Date:

November 11, 2021

Filing Date:

May 07, 2021

Export Citation:

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Assignee:

ROFS MICROSYSTEM TIANJIN CO LTD (CN)

International Classes:

H03H9/02; H03H9/05; H03H9/17

Foreign References:

CN111786645A	2020-10-16
CN110061712A	2019-07-26
CN111010121A	2020-04-14
US20120326807A1	2012-12-27
US20160126930A1	2016-05-05

Other References: