A new class of SIW filters based on periodically perforated dielectric substrate

A novel class of substrate integrated waveguide (SIW) filters based on perforations of the dielectric substrate is presented in this paper. The air-hole perforations allow the local modification of the characteristic impedance of the SIW as well as its cutoff frequency, thus permitting the easy design of filtering structures. Four-pole filters operating at 3.6 GHz, based on conventional and half-mode SIW, have been designed, experimentally validated, and discussed. The proposed approach provides high flexibility, low sensitivity to fabrication inaccuracy, and simple design rules.