Surface acoustic wave resonator and filter

Abstract

The embodiment of the invention discloses a surface acoustic wave resonator and a filter. The resonator comprises a supporting layer, an energy trap layer, a temperature compensation layer, a piezoelectric layer and an interdigital transducer layer which are sequentially stacked, the interdigital transducer layer comprises a plurality of interdigital transducers, the material of the piezoelectric layer comprises X-40Y lithium niobate, the acoustic bulk wave propagation velocity of the support layer is greater than the acoustic surface wave propagation velocity of the piezoelectric layer, and the energy trap layer is used for capturing parasitic charges on the surface of the support layer to improve the Q value of the acoustic surface wave resonator. According to the embodiment of the invention, the piezoelectric layer and the supporting layer of the resonator are improved, and the speed of transmitting sound waves by X-40Y lithium niobate is relatively high, so that the working frequency of the resonator is greatly improved and reaches 5G and more than 5G; the acoustic bulk wave propagation speed of the supporting layer is greater than that of the surface acoustic wave propagation speed of the piezoelectric layer, energy is limited on the surface, and bulk wave leakage is avoided, so that the device loss is reduced; the energy trap layer can improve the Q value to enhance the stability of the surface acoustic wave resonator.

Description

technical field [0001] Embodiments of the present invention relate to the technical field of surface acoustic waves, and in particular, to a surface acoustic wave resonator and filter. Background technique [0002] With the development of communication technology from 2G to 5G, the number of communication frequency bands has gradually increased (from 4 frequency bands in 2G to more than 50 frequency bands in 5G). In order to improve the compatibility of smartphones with different communication systems, the amount of filters required by 5G smartphones will increase significantly, driving the large-scale growth of the filter market. At present, the radio frequency filter widely used in wireless communication terminals is the surface acoustic wave filter, which is responsible for receiving and transmitting the radio frequency signal of the channel, and outputs the signal of a specific frequency among the various input radio frequency signals. Due to the advent of 5G communicat...

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Problems solved by technology

[0003] At present, the operating frequency of surface acoustic wave devices is generally below 3GHz. Even if the super high performance (Incredible High Performance, IHP) surface acoustic wave structure is used, the frequency can reach up to about 3.5GHz, and it cannot be used at higher frequencies (such as 5GHz). Work

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