Broadband phase shifter using air holes in Substrate Integrated Waveguide

This paper presents a novel configuration of broadband phase shifter designed with Substrate Integrated Waveguide (SIW) technique. The phase shift mechanism is based on the synthesis of a low dielectric slab in the middle of the SIW using an array of air holes. A simple design technique is proposed where unit cells are simply cascaded, which leads to the summation of their phase shift. The number of holes, their diameter and their spacing can be adjusted in order to obtain the required phase shift, thus giving a very flexible structure. Two different phase shifters, both giving a phase shift of 30° are designed and simulated. Finally, an experimental validation in the Ka band (26.5 to 40 GHz) is presented for both circuits.