Compact Dual-Band Dual-Polarized Microstrip Patch Antenna for Synthetic Aperture Radar

Abstract

A dual frequency-band (L and S) dual linearly-polarized microstrip patch antenna is proposed for synthetic aperture radar (SAR) system and communications applications. The proposed square patch antenna is printed on a roger TMM4 substrate. The proposed antenna has four L-shaped slots cut at the patch corners and four axial slots cut at the middle of each edge and perpendicular to it. The antenna has two ports; applying the feeding at one of them gives one of two orthogonal polarizations. The antenna is relatively compact, with an input impedance of 50Ω at each port. The antenna has been designed to work at 1.25 GHz and 3.3 GHz. The high isolation between the two feeding ports is −35 dB at 1.25GHz and −30 dB at 3.2GHz. The radiation patterns for the two polarizations are almost the same. The maximum gain of the antenna is about 4 dBi and 9 dBi at 1.25GHz and 3.3GHz, respectively. The CST commercial package has been used to analyze such antenna, and the HFSS package is used for confirmation of the produced results. The simulation results have proved the practicability of this antenna for dual polarized applications.