Design of microwave filters using a ground-through-hole structure

摘要

In this report, a novel high pass filter and band pass filter using a ground-through-hole (GTH) structure is presented. The GTH structure is a ring resonator or a section of microstrip line with a cylindrical via hole in a microstrip substrate ground plane. This uniplanar compact GTH structure realizes an electric resonator in the high pass filter and band pass filter. The Resonant frequency of the GTH depends on the through hole diameter, so we can easily control the filter characteristics. In the conventional microwave filter design method, we cannot control the filter's cut-off frequency, bandwidth and midband frequency by just one design parameter. However, using our novel GTH structure microwave filter design method, we can easily control these characteristics by the through hole diameter