Application Of Phononic Crystal Technology In Radio Frequency Microacoustic Resonator

In order to meet the growing demand for radio frequency filter applications,highperformance and miniaturized acoustic resonator has become an industry trend.At present,phononic crystal has become a research hotspot in the field of piezoelectric acoustic devices because of its regulation of acoustic waves.Therefore,this thesis will focus on the application of phononic crystal in acoustic wave resonator,focusing on the influence of phononic crystal technology on the performance of surface acoustic wave resonator and contour mode resonator.And the research of this thesis is mainly divided into three parts.Firstly,the basic theories of surface acoustic wave resonator,contour mode resonator and phononic crystal are introduced,which lays a foundation for the subsequent application of phononic crystal in surface acoustic wave resonator and contour mode resonator.Secondly,the influence of phononic crystal on the surface acoustic wave resonator is studied,and the working frequency of the surface acoustic wave resonator is determined by designing parameters and structure.By comparing and analyzing the effects of traditional metal reflector and phononic crystal reflector on the quality factor and resonator size of the resonator,the phononic crystal structure is finally selected as the reflector gate of the resonator.In view of the successful application of phononic crystal in surface acoustic wave resonator,the influence of phononic crystal on contour mode resonator is then further studied.Through the analysis of the energy loss mechanism of the contour mode resonator,the main factor leading to its low quality factor is the anchor loss,in order to reduce the anchor loss,a four-leaf clover shaped phononic crystal structure is designed,through the analysis of the position of phononic crystal in the resonator and the number of arrays,the best scheme is determined,and the results show that placing the phononic crystal in the support structure of the resonator can not only effectively increase the quality factor of the resonator,but also does not increase the size of the device.In summary,the phononic crystal structure applied to surface acoustic wave resonator and contour mode resonator is mainly studied,and the experimental results show that phononic crystal technology can effectively reduce the energy loss and improve the quality factor of the resonator.