Lamb wave resonator

Abstract

The invention discloses a Lamb wave resonator. The Lamb wave resonator includes: a piezoelectric layer including two side walls in the second direction; interdigital electrodes including a top electrode located on the upper surface of the piezoelectric layer and a bottom electrode located on the lower surface of the piezoelectric layer, the bottom electrode Both the top electrode and the top electrode include a plurality of fingers in the second direction; a plurality of protruding structures disposed on the lateral sides of the two side walls of the piezoelectric layer; and / or, a plurality of fingers disposed on the bottom electrode and / or, disposed above the plurality of fingers of the top electrode; wherein the plurality of raised structures make the electromechanical coupling coefficient of the transverse mode of the Lamb wave resonator zero. The present invention can significantly eliminate the spurious mode in the Lamb wave resonator by arranging a plurality of protrusion structures on the side wall of the piezoelectric layer or the surface of the interdigital electrodes, thereby avoiding the generation of ripples and burrs in the filter, and improving the The quality of the filter.

Description

technical field [0001] The invention relates to the field of resonators, in particular to a Lamb wave resonator. Background technique [0002] With the growth of human needs, future radio frequency devices need to meet the requirements of miniaturization, low power and multi-function on chip. The MEMS Lamb wave resonator (Lamb wave resonator, LWR), which has been extensively studied in recent years, has its specific acoustic characteristics and resonant structure, and has increasingly become a relatively satisfactory intermediate frequency device. In a Lamb wave resonator, because the symmetric Lamb wave mode S 0 The wave velocity is higher and the dispersion is lower, so it is most commonly used. However, in Lamb wave resonators, near the resonance peak of the main mode, there are often spurious resonance peaks induced by transversely propagating acoustic waves. These spurious modes create ripples and glitches in the filter, degrading the resonator. [0003] The followi...

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Problems solved by technology

[0011] For the above-mentioned problems in related technologies, no effective solution has been proposed yet

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