Dielectricless Floating-Patch Antenna at 28 GHz Fed With an Empty Substrate Integrated Waveguide

This paper presents a novel dielectricless floating patch antenna structure fed with an empty substrate integrated waveguide (ESIW). The main premise is to eliminate the dielectric from the patch design, which is equivalent to have an air-dielectric and leads to the necessity of a proper 3D printed plastic support to fasten the patch in the air above the ESIW, which is used as the feeding waveguide through a slot under the aperture-coupled approximation. A single-element antenna prototype has been studied, designed, optimized and manufactured in order to achieve excellent bandwidth, directivity, gain and beamwidth performance at 28 GHz. The main advantages of this prototype are a low fabrication cost, low losses, a low profile, high integration capability and removal of bulky dielectric material. On the whole, this prototype is a new suitable solution to be used in millimeter-wave 5G applications and beyond compared to the state-of-the-art.