Ultra‐broadband metamaterial absorbers based on spoof surface plasmon polaritons structure

Inspired by the dispersion engineering of spoof surface plasmon polaritons, in this paper, a comprehensive scheme is proposed, which firstly develops a plasmonic absorbing structure (PAS) with wide absorption band and high angular stability. The PAS unit cell is composed of a graded metallic strip array printed on a dielectric grid and backed with a metal ground. It realizes wideband absorption in the frequency range of 18–37 GHz. Moreover, a commercial absorbing film is further integrated with the proposed PAS to expand the overall absorption bandwidth covering around 5.5–55 GHz without increasing the thickness of the whole structure excessively. Simulated and experimental results show that the proposed hybrid metamaterial absorber can provide ultra‐broadband absorption with simple design procedure and light weight, allowing potential applications such as RCS reduction of antennas, electromagnetic shielding, and so on.