Design, fabrication and evaluation of low density, broadband microwave absorbing composite for X & Ku band

Microwave absorbing materials are of vital importance in solving the increasing menace of electromagnetic interference problems, caused due to the proliferation of electronic devices & systems. They have potential applications in the stealth technology for radar cross section reduction. In this paper, a radar absorber structural (RAS) composite has been proposed for frequency region 8.2-18 GHz. Proposed RAS composite is based on sandwich structure where indigenously developed syntactic foam has been used as care material. RAS is designed with impedance gradation for attenuation of microwave energy and shows better than 10 dB reflection loss in X (8.2-12.4 GHz) & Ku (12.4-18 GHz) band frequency region. The measurement results of fabricated RAS composite are in good concurrence to the simulated results. The proposed RAS is compact with less weight penalty, environmental resistance, and good mechanical strength.