Design of substrate integrated gap waveguide

To miniaturize the conventional air gap waveguide (GW), a substrate integrated gap waveguide (SIGW) is proposed. Moreover, SIGW makes up the defects in the microstrip-ridge air GW, such as inconstant gap height, holes in strip, as well as strip electroless nickel immersion gold (ENIG) coating. To verify the proposed SIGW, a prototype was designed and manufactured using the multi-layer printed circuit board (PCB) technology. It contains a very simple transition between SIGW and microstrip lines for measurements. Further, the experimental results show that the measured performance agrees well with the simulated.