Lamb wave resonator with upper and lower buried electrodes in opposite proportions

Abstract

The invention provides a Lamb wave resonator with upper and lower buried electrodes in opposite proportions. The Lamb wave resonator comprises a substrate made of a high-sound-velocity material; a piezoelectric layer which is located above the substrate made of the high-sound-velocity material, wherein a first interdigital transducer and a second interdigital transducer are arranged on the upper surface and the lower surface of the piezoelectric layer respectively, and interdigital electrodes of the first interdigital transducer and the second interdigital transducer are opposite to each other in the stacking direction across the piezoelectric layer, and have the same electrode width, the same electrode thickness, the same electrode distance and the same excitation sound wave wavelength lambda, wherein the proportions of the interdigital electrodes of the first interdigital transducer and the second interdigital transducer embedded into the piezoelectric layer in the thickness direction are h1 and h2 respectively, and h1 + h2 = 1.

Description

technical field [0001] The invention relates to the field of radio frequency of mobile phones, and more particularly, to a Lamb wave resonator with opposite proportions of upper and lower buried electrodes. Background technique [0002] The development of 5G mobile phone filters requires lower losses, higher frequencies, and larger bandwidths, which pose serious challenges to existing surface acoustic wave (SAW) and bulk acoustic wave (BAW) technologies, which are often subject to higher spurious effect limit. In order to meet this demand, the recently proposed Lamb wave structure, which mainly adopts the plate wave mode and has a higher sound speed, shows application advantages in sub-6GHz and millimeter wave mobile communications. In Lamb wave resonators, the main mode is Lamb wave, and modes such as Rayleigh wave are spurious modes. The presence of spurious modes can affect the performance of the resonator, such as reducing the Q value (quality factor). How to improve ...

AI Technical Summary

Problems solved by technology

[0002] The development of 5G mobile phone filters requires lower loss, higher frequency and larger bandwidth, which poses serious challenges to the existing surface acoustic wave (SAW) and bulk acoustic wave (BAW) technologies, which are usually affected by more stray effect limitation

The presence of spurious modes can affect the performance of the resonator, such as reducing the Q value (quality factor)

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