A bandwidth enhanced metasurface antenna for wireless applications

Abstract

This article presents a two layer metasurface antenna in which the top layer is metasurface and the bottom layer is patch antenna. The metasurface enhances the bandwidth and gain of the patch antenna. The metasurface is composed of an array of radiating element which is arranged in 5 × 6 layout. Complementary split ring resonator is used as radiating element. The substrate used for metasurface and patch antenna is Rogers RO4350B having loss tangent of 0.0037, relative permittivity of 3.48 and thickness of 1.524 mm.The overall length and width of the total structure is 0.72λo × 0.95λo (38 × 50 mm2). The metasurface is acting as Double Negative material in which permeability and permittivity both are negative so as a result refractive index will also be negative. The waves coming out of the patch antenna is affected by the array of radiating element on the metasurface, which is above the patch antenna due to which equivalent relative permittivity and permeability of the structure changes and therefore there is change in the performance of the patch antenna. The proposed antenna resonates at 5.7 GHz with bandwidth enhancement from 150 to 260 MHz with gain of 5.8 dBi. The return loss bandwidth is found to be 2.83% (5.64–5.8 GHz) under simulation and 4.64% (5.62–5.78 GHz) under measurement at the resonating frequency when metasurface is used with patch antenna. Overall 39% increase in return loss bandwidth is achieved. The fractional bandwidth of 55.22% is achieved. The proposed antenna is useful for WiFi application.