Design and preparation of square ring electromagnetic energy conversion absorber based on lumped resistance

Absorbing metamaterials loaded with lumped elements exhibit high absorptivity across a wide absorption band, effectively addressing electromagnetic interference and other problems. However, conventional absorbing metamaterials often dissipate electromagnetic energy directly, leading to energy wastage. In this paper, three square-ring absorbers based on lumped resistance are designed, which consist of a metal ground, a F4B dielectric layer, and a surface metal layer with loaded lumped resistors. The load of lumped resistors is intended to enhance the impedance matching performance. In order to enhance the electromagnetic wave absorption, an equivalent circuit model of the metamaterial absorber is established to optimize the circuit parameters. The surface resistors are adjusted to 30–240 Ω, resulting in resonance peaks at 2, 4, and 6 GHz, respectively, and the absorptivity is greater than 90% at different resonant peaks. The simulation and experimental results demonstrate that the metamaterial absorber mainly absorbs electromagnetic waves through ohmic loss. Finally, the absorption performance of the metamaterial is verified by calculating the electromagnetic energy conversion efficiency, and the experimental results agree well with the simulated results.