Surface Acoustic Wave Resonator with Lattice Structure

Abstract

The invention discloses a surface-acoustic-wave resonator with a lattice structure. The surface-acoustic-wave resonator comprises a piezoelectric substrate. A metal interdigital transducer and metal grating arrays are arranged on the piezoelectric substrate by means of sputtering, and the metal grating arrays are arranged on two sides of the metal interdigital transducer. The metal grating arrays include open gratings which are arranged on the left side and the right side of the metal interdigital transducer and respectively called the first open grating and the second open grating, and the first open grating and the second open grating are symmetrically distributed on the left side and the right side of the metal interdigital transducer. The metal grating array consisting of the first open grating and the second open grating is arranged along the y direction parallelly, arranged along the x direction vertically and distributed in the x direction periodically. Photonic crystals are arranged on the metal interdigital transducer and are distributed in the x direction periodically and distributed in the y direction randomly. The surface-acoustic-wave resonator with the lattice structure has the advantages that affection of a high-order transverse-wave mode to frequency characteristics of the resonator is eliminated and frequency response performance of the surface-acoustic-wave resonator is improved.

Description

technical field [0001] The invention relates to a surface acoustic wave resonator capable of eliminating high-order shear wave mode interference to realize optimized frequency response, and belongs to the field of signal and information processing. Background technique [0002] Resonator-type surface acoustic wave (SAW) filters are widely used in the field of telecommunications due to their good performance, small size, low cost, and easy mass production. [0003] A general SAW resonator is a sputtered metal interdigital transducer (Interdigital Transducer, IDT) and a metal grid array on the surface of a piezoelectric substrate. However, in the SAW resonator structure, the interdigital transducer has a finite acoustic aperture, which will produce various acoustic diffraction effects. [0004] The literature "Analysis of general planar waveguides with n segments," (IEEEUltrason. Symp., pp.137–141, 2000.) points out that the surface of a surface acoustic wave resonator can be...

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Problems solved by technology

[0006] (1) As reported in the literature "GHz SAW resonators" (IEEE Ultrason. Symp., pp. 815–823, 1979), the use of apodization weighting or a sawtooth design for the bus bar can be used to smooth the peaks caused by high-order shear wave modes, But this increases the device size and does not eliminate the presence of higher order shear wave modes

[0007] (2) The document "Low resistance quartz resonators for automotive applications without spurious modes" (IEEE Ultrason. Symp., pp. 1326–1329, 2004.) reports that the first-order asymmetric fundamental wave mode is used to carry acoustic signals, which can be used in a certain frequency range suppress the influence of high-order shear wave modes internally, but this method is only limited to the case where there are relatively few high-order shear wave modes, and it will cause a certain frequency shift

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