Low-profile Broadband and Compact Metasurface Antenna for Imaging Applications

In this paper, a low-profile broadband and compact metasurface(MS)-based antenna is proposed for C-band imaging radar application. The proposed structure consists of three metallic layers and two dielectric spacers including an array of modified 4 x 4 squares. The MS radiator is fed by a microstrip line at its bottom through a slot centered on a ground plane. A prototype with a dimension of 1.3 lambda(0) x 0.85 lambda(0) x 0.04 lambda(0) operating at the center frequency 6.5 GHz (f(0)) has been fabricated and measured. The reflection coefficient characteristic, radiation patterns and realized gain of the proposed antenna are presented. The measured results show that the proposed antenna achieves a wide bandwidth of 26.6% (5.80 - 7.58 GHz) with an average gain of 6.62 dBi.