Out-of-band RCS Reduction of a Dipole Antenna Based on Frequency-Selective Metasurface

This paper presents an approach to design a dipole antenna with low out-of-band radar cross section (RCS) and relatively high gain while without absorptive material using. A reflective metasurface (also called “Meta-mirror”) with frequency dependent diffusive scattering property is used as the ground plane of the dipole antenna to effectively reduce the out-of-band RCS and maintain high gain at the in-band frequencies. The metasurface structures is realized by random distribution of 1-bit meta-mirror elements and the two elements are composed with same metallic pattern with different orientations. Compared with the reference antenna with normal PEC ground plane, the radiation characteristics of the proposed array is maintained with a measured peak gain of 6.5 dBi. Meanwhile, more than 10 dB two-sided out-of-band RCS reduction is achieved from 7.6 GHz to 8 GHz and 11.5 GHz to 15 GHz.