Gain enhancement of conformal wideband antenna with parasitic elements and low index metamaterial for WiMAX application

摘要

In this paper, novel techniques are presented for gain enhancement of a wideband directional conformal antenna. Initially a wideband conformal antenna is proposed as a basic antenna which consists of an array of three fork shaped elements. To achieve the gain enhancement of the basic conformal antenna, three triangular shaped parasitic elements and an array of 3 x 6 number of low index metamaterial unit cells are integrated on both side of the substrate. The phase velocity in the metamaterial region is higher than the other region due to low refractive index as compared with other region. So, the proposed meta material can be considered as a beam focusing lens. As a result, the proposed antenna is more directive with narrow beamwidth and the half power beamwidth is reduced by 24 degrees in the H-plane. The gain of the proposed conformal antenna which is integrated with parasitic elements and metamaterial unit cells is enhanced by 1.8 dBi compared to basic conformal antenna. The impedance bandwidth of the proposed conformal antenna achieves a bandwidth of 22.3% from 3.1 to 3.88 GHz which is suitable for WiMAX application. (C) 2019 Elsevier GmbH. All rights reserved.