Metamaterial Structure Integrated With a Dielectric Absorber for Wideband Reduction of Antennas Radar Cross Section

This paper presents the design, synthesis, and testing of a novel wide band electromagnetic hybrid absorber (HA) for the radar cross section (RCS) reduction of antennas. The proposed HA is based on the design of a metamaterial structure coated with the synthesized dielectric absorber material. The dielectric filler based composite absorber is fabricated by optimizing weight percentage of graphite and glass microballoon powders mixed into an epoxy medium. The proposed HA shows minimum -10 dB reflection loss (RL) in the 6-12 GHz frequency region having maximum absorption of 99.56% (-20 dB RL) at 9.26 GHz. The proposed HA is ultimately loaded onto a wide band antenna in order to reduce the in-band RCS of the antenna. The simulated and the experimental results show remarkable RCS reduction of the antenna over the full operating frequency range. It is also observed that the antenna characteristics, e.g., the gain and the radiation pattern remain almost preserved after loading the antenna with HA. The significant RCS reduction capability of the proposed HA shows that it has the potential applications for RF stealth technology.