High performance terahertz slotted waveguide antenna based on electrically split ring resonator metasurface employing low epsilon medium for E‐plane beam focusing

Abstract

In this article, a high performance terahertz slotted waveguide antenna incorporated with three dimension anisotropic low epsilon medium (LEM) is proposed, designed and theoretically investigated. The LEM is constructed from multilayer two dimension structure of electrically split ring resonator (eSRR) metasurface which exhibits anisotropic LEM medium in direction of propagation when it is placed in front of the slotted waveguide antenna at optimum distance. As a result, the E‐plane radiation beam of the slotted waveguide antenna is focused, and hence the directivity and the gain are improved, while the beam area is reduced. The proposed antenna as well as the LEM structure operating at 303 GHz are designed, optimized, and numerically simulated by using CST software. The effective parameters of the eSRR structure are extracted by Nicolson Ross Weir algorithm from the S‐parameters. The simulated results showed that, the E‐plane gain of the proposed slotted waveguide antenna is improved from 6.7 to 10.1 dB compared with the conventional slotted waveguide antenna. In addition, the E‐plane beam width is reduced from 94.1° to about 47°. The antenna return loss and the bandwidth are slightly changed. Furthermore, the proposed THz antenna offered easier fabrication processes with a high gain if it is compared with the horn antenna of the same size.