Study Of Ultra-wideband And Multichannel Filtering Power Divider

In recent years,with the continuous development of communication systems,people have become more and more demanding for the system intelligence and portability.Therefore,miniaturization and high-performance microwave devices have become the focus of research in the entire industry.Filters,diplexers,and power dividers are common microwave passive devices.Their performance and size are critical to the overall system.Traditional design methods are usually designed independently and then cascaded.The entire device usually occupies a relatively large space and has a high insertion loss.Therefore,the most effective method is to adopt a comprehensive integrated design of the filter and the diplexer and the power divider so that it can simultaneously perform multiple functions such as power splitting,filtering,and frequency selection.In this way,the whole system size can be reduced effectively,the design cost of the system is reduced to a certain extent,and the insertion loss of the whole system can be reduced as much as possible.The scheme of integrating multiple microwave devices proposed in this thesis has great significance and application prospects in wireless communication systems.After understanding the background and research significance of the filtering power divider,duplexer and ultra wideband filter,this thesis completed the design of two different performance filter dividers:1.Design of ultra wideband filtering power divider: Firstly,an ultra wideband filter is designed based on the theory of multi-mode resonators,its structural characteristics are analyzed in detail,which lays a foundation for the performance of ultra wideband achieved by the filtering power divider.Second,the characteristics of the microstrip/slotline coupling structure are briefly introduced,which provides a theoretical basis for the proposed feeding structure of the power unit.In addition,combined with the traditional Wilkinson power divider to improve the isolation method,the two placement modes of the isolation resistor in the structure is compared and analyzed,so that the isolation of the ultrawide band filtering power splitter meets the requirements of the system.Finally,according to the analysis method and implementation method provided in the previous,the design of the ultrawide band filtering power divider is completed.The ultrawide band filtering power splitter adopts a double-layer microstrip structure and uses a microstrip/slotline coupling structure to combine the filtering unit located in the upper layer and the power dividing unit located in the lower layer compactly,and realizes filtering power divider in the ultrawide band.In addition,the ultrawide band filtering power divider is processed and tested,and it is found that the ultrawide band filtering power splitter has good performance in the working frequency band.2.Design of multi-channel filtering power divider: Firstly,the characteristics of multichannel and the requirements of multi-channel filtering power divider and the design theory of duplexer are introduced.Second,using step impedance resonator to design two filters that work in different frequency bands,they are combined into a duplexer through a T-shaped structure,which lays the foundation for the multi-channel filtering performance of the multichannel filtering power divider.Finally,combining the combination of the filter and power divider described in Chapter 3,the duplexer and the power splitters working in different frequency bands are tightly combined by the microstrip/slotline coupling structure,making it possible to be different.The power distribution performance is achieved in the operating frequency band.In addition,the multi-channel filtering power divider was processed and tested.It is found that the multi-channel filtering power divider can meet the design requirements in the working frequency band.