Research And Realization Of Tunable Filter-antenna

Now wireless communication is developing rapidly,a heterogeneous network coexisting wireless communication environment has gradually formed.Multi-mode and multi-protocol reconfigurable RF transceivers have gradually become mainstream,and tunable filter-antennas are becoming more and more important as key passive devices for reconfigurable RF front-ends.In this dissertation,the joint design method of fixed frequency filter-antenna is first studied.Based on this,the joint design method of tunable filter-antenna is expanded,and the realization of tunableble bandwidth and the calculation analysis of external coupling are studied.A dual-mode dual-passband filter-antenna based on the T-SIR structure is designed in this dissertation,which verifies the feasibility of T-SIR application filter-antenna design.By adding a set of varactor diode tuning circuits to the fixed T-SIR structure,the center frequency of the voltage-controlled filter-antenna can be continuously tuned,and the processing test verification is performed.Based on QSIW filter and microstrip antenna,a tunable filter-antenna with mixed structure is designed.The bandwidth of the filter-antenna is tuned by tuning the electrical coupling between the resonant cavities in the filter structure integrated in the antenna feed structure.The bandwidth of the tested filter-antenna can be continuously tuned within 60-130MHz;after improved optimization,the designed fully tunable QSIW filter-antenna can continuously tune the center frequency in the range of 133 MHz in the 55 MHz bandwidth state,and the radiation pattern remains stable during the process.The multiple tunable filter-antennas designed by the author have achieved better agreement with the test results and simulation results,verified the correctness of the design.Compared with similar literature at home and abroad,it can be seen that the performance of the tunable filter-antenna designed in this dissertation has reached the same level as that in similar literature,moreover,this dissertation first proposed and implemented a filter-antenna that can be continuously tuned in frequency and bandwidth,which is of great significance to the development of tunable filter-antennas.