Research On Bulk Acoustic Wave Filter Chip For Mobile Communications Based On FBARs

Filters are used to retain signals in a specific frequency band and filter out-of-band interference and noise.They are an important component of the radio frequency front end and an important part of the mobile communication system.With the rapid development of mobile communication system,higher requirements are placed on the basic units in the radio frequency modules of mobile terminals.As a device used for frequency selection and attenuation of other spectrum resources in a radio system,the performance of filter components will often play a decisive role in the overall performance of the system.Film Bulk Acoustic Resonator(FBAR)can work at higher frequencies and has the characteristics of high Q,small size,and high-power capacity.A series of high-performance filter components formed by FBAR is the basic guarantee for ensuring spectrum efficiency in communication system at present and in the future.Therefore,the research on the Bulk Acoustic Wave(BAW)composed of FBAR has obviously become an important subject with both theoretical significance and practical value.This thesis designs high-performance BAW filters based on FBARs.The main research contents include the following aspects:1.Based on the improved Mason model of FBAR,a complete set of BAW filter design methods and design processes are proposed,including design spec formulation,circuit structure design,circuit simulation optimization,Layout design and Chip Die simulation,Laminate design,EM simulation,and power capacity analysis.2.According to the proposed filter design method and design process,design a flip-chip BAW filter of N41₁20 MHz(2535 MHz-2655 MHz)frequency band,and compare the designed filter with circuit simulation and EM simulation analysis.3.According to the proposed filter design method and design process,design a wire bonding 2.4 GHz Wi-Fi(2402.5 MHz-2481.5 MHz)frequency band BAW filter.Fabrication,measurementt and comparative analysis of actual measured and designed filter.