短路枝节加载微带传输线滤波器设计方法研究OA北大核心CSTPCD

For transmission-line filters such as the microstrip filters,it is key to fast determine their topologies and structural parameters when the technical specifications are given.However,the design of transmission-line filters becomes very challenging due to the distributed-element effect.A kind of the shorted-circuited stubs loaded microstrip transmission-line filters was investigated,the physical mechanism was discussed,and the design method was developed.At first,the transmission matrix of the filter was derived.The cot transformation was applied,and then the ideal transmission matrix was synthesized theoretically and compared with the former.So the structural parameters of the filter could be calculated.In order to verify the proposed design method,a third-order bandpass filter example was designed,fabricated and measured.The center frequency of it is 3.0 GHz,the bandwidth is 2.0 GHz,and the in-band return loss is lower than-20 dB.The measured results show that the theory,simulation and test results are consistent,so that the proposed design method is verified.