A Novel Energy-Adaptive Wideband Absorber: Design, Simulation, and Experiment

This paper presents a wideband absorber with energy-selective characteristics, composed of three independent layers, suitable for high-power electromagnetic protection. To achieve a nonlinear response to incident wave power, periodic metallic structures were designed with PIN diodes loaded in the energy-selective layer. Simultaneously, effective absorption of high-power electromagnetic waves was realized in the top layer by combining resonant structures with resistor loading. After completing full-wave simulations, the designed structure was fabricated and measured, showing good consistency between simulation and experimental results. The proposed energy-selective absorber achieves an absorption bandwidth of 3.9 GHz (5.3–9.2 GHz) for high-power signals, while maintaining an insertion loss below 3 dB for low-power signals in the 5.5–5.9 GHz frequency range, with an insertion loss of only 2.6 dB at 5.8 GHz. The integrated transmission and absorption functionality of this energy-selective absorber makes it promising for applications in high-power electromagnetic protection.