Hexagonal bandpass filter using open end step impedance stub perturbation

Abstract

A novel dual-mode hexagonal loop resonator bandpass filter with a step impedance open-end stub perturbation is proposed along with possible applications. It is shown that different responses can be realized using only a single dual-mode resonator by changing the parameters of the perturbation. As compared to rectangle and square counterparts the interior angles are large in hexagonal geometry which promises better confinement in the microstrip circuits. The structure is very simple, easy to fabricate and useful for communication system.