Low RCS Patch Antenna based on Meander Line Checkerboard

The design, simulation, and fabrication results of a microstrip patch antenna using meander line unit cells based on Polarization Conversion Metasurface (PCM) and Artificial Magnetic Conductor (AMC) on a checkerboard metasurface for reducing the Radar Cross Section (RCS) are presented in this paper. The double meander line structure acts as a PCM and a single meander line structure rotated at 75 ◦ acts as AMC. These unit cells achieve unity amplitude and (180±37)◦ reflection phase difference in a frequency band of 4.5 GHz to 6.5 GHz. The proposed antenna is a checkerboard metasurface formed by setting the patch antenna at the middle of unit cells, which reduces RCS for normal incidence. The microstrip patch antenna without unit cells is considered as a reference antenna. Simulation and experimental analysis are carried out for a frequency range of 4.5 GHz to 6.5 GHz to demonstrate the efficacy of the proposed structure. The proposed antenna has a gain enhancement of 3 dB and more than 20 dB RCS reduction in both x- and y polarization at the resonance frequency of 5.5 GHz. The proposed design significantly reduces size and mutual coupling compared to other structures in reported works.