Wideband surface-wave absorber with dual adjustability of bandwidth and amplitude

Abstract In this paper, a wideband surface-wave absorber with adjustable bandwidth and amplitude is proposed by employing multi-mode resonance theory to achieve wideband absorption, different from traditional surface-wave absorbers. The resonance generation principles are elucidated using characteristic mode theory and parameter analysis. The absorber demonstrates absorption of 90% within 3.44–5.43 GHz, and relative bandwidth of 44.9%. Additionally, it features dual adjustability in both relative bandwidth and absorption amplitude. The relative bandwidth can be modulated from 23.5%–44.9% by integrating the PIN diode and varying the applied voltage. The absorption amplitude can be adjusted from 0% to 90.2% by changing the unit’s operating state via the circuit control module. The surface-wave absorber was fabricated and measured, and the experimental results were almost identical with the simulations. This surface wave absorber shows great potential applications in electromagnetic pulse interference mitigation.