SIMPLE WIDEBAND MICROSTRIP RING BANDPASS FILTER BY UTILIZING FORCED HARMONIC SUPPRESSION AND DIRECT FEED LINE COUPLING

摘要

A compact wideband microstrip ring bandpass filter is demonstrated in this article by means of forced harmonic suppression of a single square ring resonator with the absence of the feed line coupling gaps. Via-hole and slit-gap are incorporated as the forced boundary conditions of the resonator in the filter design. Both simulation and measurement results are provided and shown in good agreement.