Miniaturized Reconfigurable Band Pass Filters

Abstract

A mechanical tuning technique is proposed to design two compact reconfigurable filters in SIW technology. Cylindrical dielectric rods are loaded at the cavities of the filters and their dielectric material is changed to show tunability in the center frequency of the filters. A reconfigurable SIW cavity resonator is designed first to study the effect of change in relative permittivity of rods. Based on that, a reconfigurable cross coupled filter, and a Half Mode SIW (HMSIW) iris window coupled band pass filter are designed using full wave EM simulation software. Then they are fabricated and experimentally verified with measarements. The preliminary experiment shows wide range of tunability with low insertion loss $(\lt 2\mathrm{~dB})$ and good return loss $\gt 10 \mathrm{dB}$) for all tunable cases.