Design Procedure for Waveguide Combline Filters Based on Flat Metallic Strips

Abstract

Abstract —In this work, we discuss the complete design procedure for a new topology of waveguide combline filters based on flat metallic strip resonators. The main advantages of the new topology that we propose are the ability to implement transmission zeros (TZ), compactness and low-cost practical realization. Furthermore, the position of the TZs can be controlled using offset resonators, thus achieving more selective filter responses. The design of several bandpass filter examples with finite-frequency TZs is also discussed. The correct operation of the filters is verified using commercial software packages, thus validating both the topology that we propose and the design procedure.