MICROWAVE FILTER WITH MOUNTED PLANAR CIRCUIT IN WAVEGUIDE.

A filter which employs the evanescent resonator is described. A sheet of conductor with slots is placed in the middle of the waveguide. The resonance system of the slots (evanescent mode resonator) allows the conductor sheet to function as a cut-off region in non-resonance frequency and provides it with pass characteristics in the vicinity of the resonance frequency. The design of a single-stage and N-stage bandpass filter is presented. Experimental results on single-stage and two-stage filters are also included.