design, simulation and fabrication of 2x2 microstrip patch antenna array fed by substrate integrated waveguide at x band

this paper describes the design of a 2x2 micro strip patch antenna array in the frequency of 9.5ghz for radar applications, using substrate integrated waveguide, siw, for feeding network. the micro strip patches are aperture-coupled with the feeding network of siw. the feeding network consisting of a perpendicular coax-to-siw transition and two y-junction power dividers. the antenna is simulated in full wave software of cst and the prototype is fabricated. the measurement results good agreement with the simulation results. a fabricated prototype has a gain of 11.6db and a side lobe level below -14.5db in the e-plane and –18db in the h-plane.