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CN-121984473-A - Multimode coupling acoustic wave resonator, filter and radio frequency equipment

CN121984473ACN 121984473 ACN121984473 ACN 121984473ACN-121984473-A

Abstract

The invention provides a multimode coupling acoustic wave resonator, a filter and radio frequency equipment, and relates to the technical field of acoustic wave resonators. The multimode coupled acoustic wave resonator is characterized in that the piezoelectric coefficient of the piezoelectric layer comprises an e 11 component, an e 13 component and an e 34 component in a piezoelectric coefficient matrix by selecting the material of the piezoelectric layer and setting the value range of an in-plane Euler angle, a transverse electric field and a longitudinal electric field exist in the piezoelectric layer simultaneously when voltage is applied to the interdigital electrode by designing the ratio of the thickness of the piezoelectric layer to the periodical wavelength of the interdigital electrode, and the integral of the dot product of the electric field and the alternating stress field in the piezoelectric layer in the thickness direction of the piezoelectric layer is not zero by designing the ratio of the thickness of the interdigital electrode to the thickness of the piezoelectric layer, so that the transverse electric field and the longitudinal electric field simultaneously excite a multimode coupled acoustic wave resonator with ultrahigh working frequency and large electromechanical coupling coefficient can meet the large bandwidth requirement of a centimeter wave communication frequency band.

Inventors

  • ZUO CHENGJIE
  • DONG JIAXIN
  • DAI ZHONGBIN

Assignees

  • 中国科学技术大学

Dates

Publication Date
20260505
Application Date
20260130

Claims (10)

  1. 1. A multi-modal coupled acoustic wave resonator, the multi-modal coupled acoustic wave resonator comprising: A substrate; the piezoelectric layer is positioned on one side of the substrate, and the material of the piezoelectric layer is anisotropic piezoelectric material; An interdigital electrode positioned on one side of the piezoelectric layer away from the substrate; The method comprises the steps of taking an included angle between a positive direction of an X axis and a first direction of a global coordinate system of a piezoelectric material as an in-plane Euler angle of the piezoelectric material in a plane where the piezoelectric layer is located, wherein the value range of the in-plane Euler angle is a first preset range, so that the piezoelectric coefficient of the piezoelectric layer comprises an e 11 component, an e 13 component and an e 34 component in a piezoelectric coefficient matrix, and the first direction is perpendicular to the length extending direction of an interdigital electrode; the range of the ratio of the thickness of the piezoelectric layer to the periodic wavelength of the interdigital electrode is a second preset range, so that when a voltage is applied to the interdigital electrode, a transverse electric field and a longitudinal electric field exist in the piezoelectric layer at the same time; The ratio of the thickness of the interdigital electrode to the thickness of the piezoelectric layer is in a third preset range so that the integral of the dot product of the electric field and the alternating stress field in the piezoelectric layer in the thickness direction of the piezoelectric layer is not zero.
  2. 2. The multi-modal coupled acoustic wave resonator of claim 1, wherein the piezoelectric layer is a lithium niobate layer or a lithium tantalate layer.
  3. 3. The multi-modal-coupled acoustic wave resonator of claim 2 wherein, when the piezoelectric layer is an X-tangential lithium niobate layer, The first preset range is-10 DEG to 62 DEG, or-190 DEG to-118 DEG, inclusive; when the piezoelectric layer is an X-tangential lithium tantalate layer, The first preset range is-8 ° to 56 °, or-188 ° to-124 °, inclusive.
  4. 4. The multi-modal-coupled acoustic wave resonator of claim 1, wherein the second predetermined range is 0.3-0.6, inclusive.
  5. 5. The multimode coupled acoustic wave resonator of claim 1 wherein the third predetermined range is 0.3-0.7, inclusive.
  6. 6. The multi-modal-coupled acoustic wave resonator of claim 1, wherein the substrate is a silicon carbide substrate, a sapphire substrate, a diamond substrate, a gallium nitride substrate, or a silicon substrate.
  7. 7. The multi-modal coupled acoustic wave resonator of claim 1, wherein the interdigital electrode is a single metal layer or a multi-layered stack of metal layers; The interdigital electrode is made of aluminum material, nickel material, copper material, platinum material, gold material, silver material, tungsten material, molybdenum material, chromium material, titanium material or iron material.
  8. 8. The multi-modal coupled acoustic wave resonator of claim 1, wherein the number of interdigital electrodes ranges from 2 to 500, inclusive; the width of the interdigital electrode in the first direction ranges from 0.001 mu m to 5 mu m, and the end point value is included; The length of the interdigital electrode ranges from 1 μm to 500 μm, inclusive.
  9. 9. A filter comprising the multi-modal-coupled acoustic wave resonator of any one of claims 1-8.
  10. 10. A radio frequency device comprising the multi-modal-coupled acoustic wave resonator of any one of claims 1-8; or, the radio frequency device comprises the filter of claim 9.

Description

Multimode coupling acoustic wave resonator, filter and radio frequency equipment Technical Field The application relates to the technical field of acoustic wave resonators, in particular to a multimode coupling acoustic wave resonator, a filter and radio frequency equipment. Background The large-scale deployment of the fifth generation mobile communication technology and the research and development exploration of the sixth generation technology are oriented, and the wireless communication spectrum resource is continuously driven to expand to a higher frequency band. The centimeter wave band (usually, 7GHz to 24 GHz) is a core carrier for realizing the key scenarios such as extremely high rate (Enhanced Mobile Broadband, eMBB for short), high reliability and Low delay (uRLLC for short), and large-scale connection (MASSIVE MACHINE TYPE Communications, mMTC for short) because of its capability of providing a large bandwidth continuous spectrum. However, the upgrading of the spectrum places unprecedented performance demands on the rf front-end module, and in particular its "spectrum portal" filter. Acoustic wave technology is considered to be an ideal path for achieving high performance micro filters due to its high quality factor and miniaturization advantages. In particular, to the centimeter wave band, the demands for acoustic wave resonators and filters are mainly focused on ultra-high frequency and large bandwidth, and to support high-speed data transmission, the filters must achieve a high absolute bandwidth, for example, a relative bandwidth of 5% at a center frequency of 6GHz, requiring an absolute bandwidth of 300 MHz. The Bandwidth (BW) is proportional to the electromechanical coupling coefficient of the resonator, so the essence of achieving a large Bandwidth is to seek and excite acoustic resonant modes with high k 2. The current mainstream acoustic wave filtering technology presents fundamental limitations when facing the above dual requirements of ultra-high frequency and large bandwidth. For example, conventional surface acoustic wave resonators, which typically operate at a frequency band below 3GHz due to their low acoustic speed, while bulk acoustic wave technology can operate at higher frequencies, whose resonant frequency depends on the thickness of the piezoelectric film, pursuing ultra-high frequencies (> 8 GHz) necessarily requires the use of extremely thin piezoelectric films, which not only presents serious process reliability challenges, but more importantly, its inherently limited electromechanical coupling coefficient of conventional longitudinal bulk wave modes, fundamentally limiting the maximum bandwidth achievable. Therefore, the architecture in the prior art has difficulty in synchronously realizing the cooperation of high frequency, large bandwidth and high performance in the centimeter wave high frequency band, and becomes a key obstacle for restricting the development of the next-generation radio frequency front end, and a brand new acoustic mode capable of breaking through the limitation of the existing acoustic mode is needed. Disclosure of Invention In view of the above problems, the application provides a multimode coupling acoustic wave resonator, a filter and a radio frequency device, which break through the constraint relation between the modal order of the traditional acoustic wave and the electromechanical coupling coefficient, greatly increase the electromechanical coupling coefficient of the acoustic wave resonator and can meet the ultrahigh frequency and large bandwidth requirements of the centimeter wave communication frequency band. The specific scheme is as follows: a first aspect of the present application provides a multimode coupled acoustic wave resonator comprising: A substrate; the piezoelectric layer is positioned on one side of the substrate, and the material of the piezoelectric layer is anisotropic piezoelectric material; An interdigital electrode positioned on one side of the piezoelectric layer away from the substrate; The method comprises the steps of taking an included angle between a positive direction of an X axis and a first direction of a global coordinate system of a piezoelectric material as an in-plane Euler angle of the piezoelectric material in a plane where the piezoelectric layer is located, wherein the value range of the in-plane Euler angle is a first preset range, so that the piezoelectric coefficient of the piezoelectric layer comprises an e 11 component, an e 13 component and an e 34 component in a piezoelectric coefficient matrix, and the first direction is perpendicular to the length extending direction of an interdigital electrode; the range of the ratio of the thickness of the piezoelectric layer to the periodic wavelength of the interdigital electrode is a second preset range, so that when a voltage is applied to the interdigital electrode, a transverse electric field and a longitudinal electric field exist in the piezoelectr