Low-profile double-frequency Fabry-Perot (F-P) cavity antenna

A new electromagnetic metamaterial unit cell of multiband frequency selective surface (FSS) is proposed in this paper. The new unit cell consists of meander line on one side of a substrate. It is shown that the structure exhibits a negative reflection phase property and Strong reflection characteristic at 1.9GHz and 2.44GHz. A 6×8 array of these unit cells (FSS screen) is used as a superstrate at a distance λ/24(center frequency) over a multiband patch antenna. Gain improvement of 5 dBi at 1.9GHz and 4.1dBi at 2.44GHz respectively, as the patch antenna with FSS superstrate compared to the patch antenna without superstrate.