Research on Electrically Tuned Filter

In this paper, an electrically tuned cavity filter is designed based on the coupling matrix. A pair of zeros are generated on both sides of the passband by using the coupling mode of source load. The out-of-band suppression is below -40dB, Insertion loss less than 0.3db, The return loss is greater than 17dB and the tunable range is 172MHz-630MHz. It has certain scientific research value.