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
$4\times 4$
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
$1.3\lambda_{0}\times 0.85\lambda_{0}\times 0.04\lambda_{0}$
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.