Substrate integrated waveguide dual-mode filters for broadband wireless systems

Abstract

A planar dual-mode filter on the basis of the substrate integrated waveguide (SIW) technique has been proposed and developed. Microstrip probes are used to excite two modes in an SIW cavity. These modes cancel each other at one frequency to create a transmission zero. Parametric influences in the filter design have been studied. A 26 GHz dual-mode filter has been designed, fabricated and measured. The insertion loss of 0.5 dB is obtained at the center frequency. The return loss is lower than 15 dB.