Surface acoustic wave resonator having photonic crystal reflector

Abstract

The invention belongs to the technical field of radio frequency micro electro mechanical systems, and particularly provides a surface acoustic wave resonator with a photonic crystal reflector, which is used for remarkably improving the quality factor of the resonator. The resonator comprises a substrate 1, a piezoelectric layer 2 arranged on the substrate, an input electrode 3 arranged on the piezoelectric layer 2, an output electrode 4, a ground electrode 6 and a photonic crystal reflector 5, wherein the input electrode 3 and the output electrode 4 jointly form an interdigital transducer, thephononic crystal reflector 5 is composed of two phononic crystal arrays symmetrically arranged on the two sides of the interdigital transducer, and the ground electrode 6 is arranged around the interdigital transducer and the phononic crystal reflector. According to the invention, the phononic crystal reflector is adopted to replace a traditional electrode reflector, so that the quality factor ofthe resonator can be effectively improved; meanwhile, compared with the traditional electrode reflector design, the photonic crystal reflector has a wider acoustic band gap, and can inhibit sound wave propagation in the whole band gap frequency range, so that the inhibition of sound energy loss is more effective.

Description

technical field [0001] The invention belongs to the technical field of radio frequency micro-electromechanical systems, and specifically provides a surface acoustic wave resonator with a phonon crystal reflector and a preparation method thereof. Background technique [0002] Filters are an essential element in modern wireless communication systems, providing frequency selection for the system. At present, filters based on acoustic resonators are used in most portable wireless communication systems (such as smartphones), because compared with traditional electrical resonators (such as LC resonant circuits, microwave resonators), due to the propagation of sound waves The speed is much smaller than the wave speed of electromagnetic waves. For example, the speed of sound waves in air is 340m / s, while the wave speed of electromagnetic waves in air is approximately 3×10 8 m / s, and the size of the circuit is proportional to the wavelength of the signal, so for the same frequency o...

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Problems solved by technology

[0006] The purpose of the present invention is to address the deficiencies in the above-mentioned prior art, and propose a surface acoustic wave resonator with a phononic crystal reflector, which can effectively reduce the energy loss of the surface acoustic wave resonator, improve the quality factor of the device, and then solve the problem of The problem of low quality factor existing in the prior art

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