MM-Wave Beam-Steering Slot Antenna using Gradient Relative-Permittivity FSS Superstrate

This paper presents a novel beam-steering technique for planar antennas with gain enhancement utilizing gradient relative-permittivity of frequency selective surface (FSS) unit-cells for fifth-generation (5G) applications. A dual- used at the above a slot antenna. The slot antenna using the ridge gap waveguide (RGW) technology, which is composed of printed parallel-plate waveguide surrounded by the mushrooms unit cells, is used to excite an FSS superstrate. Simulated results show that the proposed beam-steering antenna has a wide impedance bandwidth (S11 <; -10 dB) from 31 to 35.8 GHz (14 %). A maximum gain of 11.8 dB is achieved by adding FSS.