Wideband metasurface-based antenna with enhanced gain

A low profile, wideband and high gain metasurface (MS) based antenna is investigated in this paper. The MS consists of 4×4 metallic patch cells and it is fed by two parallel microstrip-coupled slots. A substrate with lower relative permittivity is used to fabricate the MS, which enhances the average gain from previous 9 dBi to 9.9 dBi. On the other hand, the two coupling slots perturb current distributions on the MS, and also shift its resonant modes up to higher frequency band which effectively enlarges overall area of the radiating MS. As a result, the average gain is further enhanced from 9.9 dBi (using single-slot) to 12.4 dBi. Compared to the gain of original design, an increment of 3.4 dB is achieved. The proposed MS-based antenna still maintains a low profile of ‼0.06μ0 and has a wide bandwidth of 20%.