Ceramic Waveguide Filters With Wide Spurious-Free Stopband Response

Abstract

This work proposes new filter design techniques to improve the out of band spurious performance of integrated ceramic waveguide filters and ceramic loaded filters. Various resonators of different types like non-uniform width, TEM and half ridge were used. The proposed filter designs offer a considerable miniaturization and significantly improved spurious performance up to 85% without compromising the figure of merits of the filters like Q-factor, return loss, etc. Two sixth order filters with best in-band and out-band performance have been fabricated. Measured results of the fabricated filters are in good agreement with the computer simulations, which confirm the validity and accuracy of designs.