Design of multistage ferrite microwave loop filters

An algorithm is presented for the computerized design of a multistage ferrite microwave bandpass filter with coupling loops. A mathematical model in the linear approximation has the following characteristics. The total magnetic flux in the coil coupling elements which is conditioned by the coil current as well as by the radiation field of the ferrite resonator was calculated. The resistance matrix of the four-pole network was obtained, and the transmission matrix of the i-th stage of the loop filter was computed. The block diagram of the algorithm is provided, and curves depicting the amplitude-frequency characteristics of the filter and the frequency dependence of resonant losses and of the pass bands are presented.