A wideband strip-slot-air-inverted patch antenna array using resonant aperture

In this paper, a SSFIP array antenna is considered. Roger RO4003 with 0.508 mm thickness is used as the feed layer substrate and also the cover layer. Coupling between feed layer and patch layer is enhanced employing an optimized dog-bone shaped aperture in the ground. The antenna can be named SSAIP (strip-slot-air-inverted patch) as it used air instead of foam. To minimize the cost and substrate losses, 3 mm air is used as an upper layer above the ground. The use of air is more low-priced than using low loss foam material. In addition, the porous nature of foams makes it sensitive to moisture. Using this idea, the patch can´t be placed on the foam layer and close it up by a piece of plastic. Therefore, another inverted thin covering the Roger RO4003 layer above the air holds the inverted square patch in its position and covers the antenna. Furthermore, four holders at the corners of the structure guarantee the mechanical stability of the antenna