Ultra-Broadband and Wide Angularly Stable Electromagnetic Wave Absorber Based on Multilayer Resistive Films for RCS Reduction

In this article, an ultrabroadband electromagnetic wave absorber with wide angular stability is proposed. The absorber matrix is formed by multilayers of foams and resistive films with different patterns, and two dielectric matching layers are superimposed on the surface of the absorber to improve the absorption effect of the absorber in the case of oblique incidences. Simulations show that the absorptivity of the proposed design reaches more than 90% in the frequency range of 4.0–50.9 GHz, with a relative absorption bandwidth of 171%. In addition, when the incidence angle reaches 60°, the absorber absorbs more than 90% within the frequency band of 15.3–47.3 GHz and 11.3–52 GHz when transverse electric (TE-) and tra nsverse magnetic TM-polarized waves are incident, respectively. The broadband absorption mechanism of the absorber and the role of the dielectric matching layers on the stability of oblique incidence are analyzed, and samples are prepared and tested to validate the design. The ultra-broadband absorbing bandwidth and wide angular stability make the absorber potentially useful for energy absorption and radar scattering cross section reduction applications.