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CN-122001333-A - High-performance acoustic wave filter and acoustic wave resonator

CN122001333ACN 122001333 ACN122001333 ACN 122001333ACN-122001333-A

Abstract

The invention relates to the technical field of filter design, in particular to a high-performance acoustic wave filter, which comprises at least two series resonators connected in series in sequence, wherein the middle node of each two series resonators is connected with a parallel resonator, the series resonators and the parallel resonators at least comprise four layers of structures of an acoustic mirror, an upper electrode, a piezoelectric layer and a lower electrode, the overlapping area of the four layers of structures in the vertical direction is an effective area of the resonator, and the roundness of patterns of the effective areas of the series resonators or the parallel resonators is set according to the classification condition of the filter. According to the technical scheme, no additional process is needed, the Rp values of the resonators are adjusted by setting the shape of the effective area of the resonator, and therefore the performance of different types of filters is improved.

Inventors

  • HUANG YUANQING
  • GAO YIFEI
  • ZHANG WEI
  • Chai Zhuqing
  • JIANG XINGYONG

Assignees

  • 诺思(天津)微系统有限责任公司

Dates

Publication Date
20260508
Application Date
20260116

Claims (10)

  1. 1. A high performance acoustic wave filter, comprising: the intermediate node of each two series resonators is connected with the parallel resonator; The series resonator and the parallel resonator at least comprise four layers of structures of an acoustic mirror, an upper electrode, a piezoelectric layer and a lower electrode, and the overlapping area of the four layers of structures in the vertical direction is an effective area of the resonator; The roundness of the effective area pattern of the series resonator or the parallel resonator is set according to the classification condition of the filter.
  2. 2. The high performance acoustic wave filter according to claim 1 wherein, If the filter is classified as a band-pass filter; The roundness of the pattern of the effective area of at least one parallel resonator in the filter is larger than a preset threshold value, and the roundness of the pattern of the effective area of at least one series resonator in the filter is smaller than the roundness of the pattern of the effective area of the parallel resonator; Each series resonator in the filter is not provided with a mass-loading layer, or the mass-loading layer thickness of each series resonator is smaller than that of any parallel resonator.
  3. 3. The high performance acoustic wave filter according to claim 1 wherein, If the filter is classified as a high pass band rejection filter, and the performance of the resonator in the frequency band on the right side of the pass band is required to reach the preset requirement; The roundness of the pattern of the effective area of at least one parallel resonator in the filter is larger than a preset threshold value, and the roundness of the pattern of the effective area of at least one series resonator in the filter is smaller than the roundness of the pattern of the effective area of the parallel resonator; each parallel resonator in the filter is not provided with a mass-loading layer, or the mass-loading layer thickness of each parallel resonator is smaller than that of any series resonator.
  4. 4. The high performance acoustic wave filter according to claim 1 wherein, If the filter is classified as a high pass band rejection filter, and the performance of the resonator in the frequency band at the left side of the pass band is required to reach the preset requirement; the roundness of the pattern of the effective area of at least one series resonator in the filter is larger than a preset threshold value, and the roundness of the pattern of the effective area of at least one parallel resonator in the filter is smaller than the roundness of the pattern of the effective area of the series resonator; each parallel resonator in the filter is not provided with a mass-loading layer, or the mass-loading layer thickness of each parallel resonator is smaller than that of any series resonator.
  5. 5. The high performance acoustic wave filter according to claim 1 wherein, If the filter is classified as a low pass band reject filter; The roundness of the pattern of the effective area of at least one parallel resonator in the filter is larger than a preset threshold value, and the roundness of the pattern of the effective area of at least one series resonator in the filter is smaller than the roundness of the pattern of the effective area of the parallel resonator; each parallel resonator in the filter is not provided with a mass-loading layer, or the mass-loading layer thickness of each parallel resonator is smaller than that of any series resonator.
  6. 6. The high performance acoustic wave filter according to claim 1 wherein, The calculation formula of the roundness of the effective area pattern of the series resonator or the parallel resonator is as follows: Roundness = Where S is the area of the active area of the resonator and Perimeter is the Perimeter of the active area of the resonator.
  7. 7. The high performance acoustic wave filter according to claim 1 wherein, The high-performance acoustic wave filter is a T-shaped filter, and the number of stages of the high-performance acoustic wave filter is more than or equal to 2.
  8. 8. An acoustic wave resonator comprising at least: The area of the four layers of structures overlapped in the vertical direction is an effective area of the resonator; The roundness of the effective area pattern of the resonator is larger than a preset threshold value.
  9. 9. The acoustic wave resonator according to claim 8, characterized by comprising: the shape of the effective area of the resonator is a closed shape or a polygon composed of a circle, an ellipse and a multi-order Bezier curve.
  10. 10. The acoustic wave resonator according to claim 8, characterized by comprising: The preset threshold value of the roundness of the effective area pattern of the resonator is 0.8.

Description

High-performance acoustic wave filter and acoustic wave resonator Technical Field The invention relates to the technical field of filter design, in particular to a high-performance acoustic wave filter and an acoustic wave resonator. Background In the current background of rapid development of communication technology, the filter is used as a core device of signal gating, and the requirements of key performance such as Insertion Loss (IL) and the like are increasingly strict. The resonator is used as a core component unit of the filter, the height of parallel resonance impedance (Rp) of the resonator directly affects the overall performance of the filter, and the improvement of the Rp value of a specific resonator is one of key ways for optimizing the performance of the filter. In the prior art, in order to raise the Rp value of the resonator, a mode of adding special structures such as an air wing, an air bridge, a recess or a bulge is generally adopted, and the Rp is raised by optimizing the mechanical vibration characteristic of the resonator. Firstly, the method needs to add additional process steps and structural design in the preparation process of the resonator, so that the process complexity is remarkably improved, the production and manufacturing cost of the filter is increased, and the mass production and cost control are not facilitated. In addition, as the communication technology is developed towards high frequency and high bandwidth, the Rp requirement of the filter is further improved, and the existing lifting mode relying on an additional structure has difficulty in meeting the practical application requirement of lifting the Rp value and combining process simplification and cost control. In addition, in a scene with a lower requirement on Rp, the prior art cannot reduce the cost by simplifying the structure, and has the problem of insufficient performance and cost adaptability. Therefore, a technical solution is needed that does not require additional process and does not increase the complexity of the process, so as to effectively increase the Rp value of the resonator and optimize the filter performance. Disclosure of Invention Therefore, the present invention is directed to a high performance acoustic wave filter and an acoustic wave resonator, so as to solve the problems of the prior art that an additional process is required and the complexity of the process is increased by the technical means of increasing the value of the resonator Rp. According to a first aspect of the present invention, there is provided a high performance acoustic wave filter comprising: At least two series resonators which are sequentially connected in series in sequence, wherein the middle node of each two series resonators is connected with the parallel resonator; the resonator at least comprises a four-layer structure of an acoustic mirror, an upper electrode, a piezoelectric layer and a lower electrode, and the area where the four-layer structure is overlapped in the vertical direction is an effective area of the resonator; The roundness of the effective area pattern of the series resonator or the parallel resonator is set according to the classification condition of the filter. Preferably, in the high-performance acoustic wave filter, if the filter is classified as a band-pass filter, the roundness of the pattern of the effective area of at least one parallel resonator in the filter is greater than a preset threshold, the roundness of the pattern of the effective area of at least one series resonator in the filter is smaller than the roundness of the pattern of the effective area of the parallel resonator, and each series resonator in the filter is not provided with a mass load layer, or the thickness of the mass load layer of each series resonator is smaller than the thickness of the mass load layer of any parallel resonator. Preferably, in the high-performance acoustic wave filter, if the filter is classified as a high-pass band rejection filter, and the performance of the resonator in the band on the right side of the pass band is required to reach a preset requirement; The roundness of the pattern of the effective area of at least one parallel resonator in the filter is larger than a preset threshold value, and the roundness of the pattern of the effective area of at least one series resonator in the filter is smaller than the roundness of the pattern of the effective area of the parallel resonator; each parallel resonator in the filter is not provided with a mass-loading layer, or the mass-loading layer thickness of each parallel resonator is smaller than that of any series resonator. Preferably, in the high-performance acoustic wave filter, if the filter is classified as a high-pass band rejection filter, and the performance of the resonator in the left frequency band of the pass band is required to reach a preset requirement; the roundness of the pattern of the effective area of at least one series re