A Modified Equal-Element Band-Pass Filter

A method is presented whereby considerable improvement in the frequency response of a five-stage, equal-element waveguide filter can be realized while preserving nearly all the structural simplicity of this realization. It is shown that by increasing the loaded Q of the center resonant element of a five-stage, equal-element filter, the pass band ripple can be appreciably reduced and the skirt selectivity improved. The modified design also provides a simple means of bandwidth adjustment.