Design of Circularly Polarized SIW Slot Array with broadband RCS Reduction

In this paper, a novel circularly polarized (CP) substrate integrated waveguide (SIW) slot array at 14.2 GHz is proposed with broadband low radar cross section (RCS) performance. A chessboard arranged metasurface with polarization conversion metasurface (PCM) unit is used for broadband RCS reduction. However, the PCM cells deteriorate the CP radiation performance of the antenna elements. A novel PCM-integrated CP element is designed by inserting a corner-cut patch into PCM unit and radiated slot-pair. By adjusting the cutting size of patch, the element CP performance is improved. Therefore, broadband RCS reduction is realized with without deteriorating the circularly polarized radiation. A 4 × 4 antenna array is designed, and the monostatic RCS reduction is achieved over a wideband of 5-17.5 GHz for normal incidence of x- polarized wave. A gain of 16.6 dBic with good axial ratio(AR) is obtained.