Radar Cross Section Reduction of Conformal Patch Antenna Using Mantle Cloak

Abstract

In this paper out-of-band radar cross section (RCS) reduction of conformal patch antenna without affecting the antenna characteristics is investigated by mantle cloaking. First, a conformal microstrip antenna with inset feed is considered on dielectric substrate with ε r = 10 grounded by a perfect electric conductor (PEC) cylinder. The working frequency and bandwidth of the patch antenna are 5 GHz and 80 MHz, respectively. Then, a patch frequency selective surface (FSS) is placed on top of the substrate layer except the regions covered by the patch and feed line of the antenna. The FSS, substrate and ground make a mantle cloak decreasing the monostatic and bistatic RCS of the antenna structure from 8.5 GHz to 10.5 GHz. The propagation characteristics of the new antenna are compared with the first one and it is shown that mantle cloaking has negligible effect on impedance bandwidth, gain and pattern of the antenna.