Investigation and performance evaluation of carbon black- and carbon fibers-based wideband dielectric absorbers for X-band stealth applications

Abstract

This paper presents the design, preparation, and electromagnetic testing of wideband dielectric absorbers based on carbon fibers and carbon black powders for stealth applications. The specially prepared absorbers are characterized using the partially filled waveguide technique for the complex permittivity, and the return loss of the sample is measured using the free-space system in the X-band frequency region. A maximum return loss of 29 dB i.e. absorption of 99% at 10.3 GHz is achieved with minimum 97% absorption throughout the X-band frequency region. The fabricated absorber having density of 0.28 gm/cc and thickness of 2 mm makes it a potential candidate for stealth applications especially for the defense targets. A multilevel fast multipole method-based electromagnetic simulation is carried out on the artillery shell model, and on the leading edge model of the aircraft using the measured electromagnetic properties of designed absorber for the radar cross-section (RCS) reduction. The maximum RCS reduction of 27 and 20 dB has been observed for the artillery shell model, and for the leading edge of stealthy aircraft model, respectively, as compared to that of the PEC structure at 10.3 GHz frequency.

Keywords:

• dielectric materials
• permittivity
• reflection loss
• radar cross-section