Radio frequency front-end acoustic resonator

Abstract

The invention provides a radio frequency front-end acoustic resonator which comprises a substrate 1, a bottom electrode 2, a piezoelectric layer 3, an upper electrode 4 and an air cavity 8. The air cavity 8 is formed by the substrate 1 and the piezoelectric layer 3 in a surrounding mode, the bottom electrode 2 is located on the inner side of the piezoelectric layer 3, the upper electrode 4 is located on the outer side of the piezoelectric layer 3, and the upper electrode 4 comprises a plurality of upper electrode units arranged in a comb shape. By adopting the comb-shaped upper electrode structure, the width of the comb-shaped electrode can be changed, and then the frequency of the piezoelectric resonator is adjusted. According to the piezoelectric resonator provided by the invention, multiple resonant frequencies can be realized on a single substrate, so that the piezoelectric resonator has the advantages that the frequency of the resonator can be flexibly and conveniently adjusted, and the like.

Description

technical field [0001] The invention relates to the field of resonators, in particular to a radio frequency front-end acoustic wave resonator. Background technique [0002] RF front-end high-frequency resonators are mainly used in wireless communications, especially 5G communications. With the rapid development of 5G communications, existing resonators can no longer meet the requirements of high frequency or single-chip multi-frequency. For this reason, there is a high-frequency resonator device in the prior art (WO / 2019 / 095640), which proposes to generate resonant sound waves in piezoelectric materials by forming air grooves below the substrate surface. [0003] The disadvantages of the existing technology are: the formation of air grooves under the surface of the substrate will cause the resonator processing technology to be complicated and difficult to control; there is no sound wave isolation measure, which will cause the excited resonant sound waves to leak out toward t...

AI Technical Summary

Problems solved by technology

[0003] The disadvantages of the existing technology are: the formation of air grooves under the surface of the substrate will lead to complex and difficult-to-control resonator processing; there is no sound wave isolation measure, which will cause the excited resonant sound waves to leak out toward the lateral direction, eventually increasing The energy loss of the large resonator; the silicon dioxide layer introduced to achieve temperature compensation performance will reduce the coupling coefficient of the resonator and increase the processing complexity; there is no flexible and diverse way of connecting the bottom electrode and the upper electrode to ground to adjust the coupling coefficient

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