Research On Multi-mode Diplexer And Filtenna

The filter,diplexer and duplex-filtenna,functioning as the RF front-end components,are widely used in station-base,radar and other communication systems.With the development of the wireless communication system,it should have the characteristics of miniaturization,broadband,high integration and so on.Then,the multi-mode technology and integration of filter and antenna have been widely utilized to improve the miniaturization and broadbanding of radio-frequency front-end module.In this paper,the major research area is the multi-mode filter,diplexer and filtenna,which is researched by following three aspects:(Ⅰ)Multi-mode resonator technology is used to improve the miniaturization and broader operational bandwidth.Firstly,realizing the multi-mode technology on the suspended stripline filter and introducing the mixed-coupling into the multi-mode cavity filter.A multi-mode rectangular cavity filter and diplexer with slot coupling is proposed in this paper,which is of the wideband,high selectivity and low-profile characteristics.In detail,the traditional higher mode of rectangular cavity is utilized to construct the multi-mode resonator while the mixed coupling structure is used to generate transmission zeros.Next,the multi-mode technology is used for broadband filter design.A quintuple-mode wideband filter based on a single cavity is proposed,which make the relative bandwidth reach 70% and has an excellent filtering performance.(Ⅱ)Utilizing the elliptical triple-mode resonator to design the diplexer integrating of three-state operational states.In this paper,there is an analysis for the resonant modes of planar elliptical resonator,and a planar component based on planar elliptical resonator and fed by three micro-strips is proposed for three-state diplexers,which is of small-size,high-integration,and multi-function characteristics.(Ⅲ)Integration of filter and antenna can reduce the matching network between components and improve the miniaturization of module.Firstly,the method of cavity filtenna and duplex-filtenna design is proposed in this paper,and the co-design of filtering circuit and cavity-backed antenna achieve a filtenna and duplex-filtenna with broadband,high-selectivity,unidirectional radiation and compactness.Next,the PCB-stacked technology is proposed for cavity filter and filtenna packaging,and an X-band filter and filtenna based on PCB-stacked structure is proposed,which is of lightness,easy-processing and low-cost.