A Compact Ultra-Wideband Polarization-Insensitive Metamaterial Absorber at 5G Millimeter Wave Band

Aiming at the problem of electromagnetic interference (EMI) in the 5G millimeter wave band, an ultra-wideband metamaterial absorber (MMA) operating at 23GHz-47GHz is proposed. The ultra-wideband characteristics are realized by staggered arrangement of metal strips and loaded lumped resistance. At the same time, the inner ring is symmetrically slotted in the direction of ± 45 ° to increase the equivalent capacitance so as to control the resonant frequency. The size of the structural unit is 5mm×5mm×1.38mm. Due to its symmetry, the polarization angle is insensitive and wide-angle incidence is realized. At the same time, the S-parameter inversion method is used to study the absorption mechanism of the MMA unit, and the equivalent impedance and absorption rate curves mutually confirm the occurrence of high absorption rate. The influence of the lumped resistance and structural parameters loaded on the surface of the MMA on the absorptivity is analyzed to achieve impedance matching. The incident electromagnetic wave is completely absorbed by the dielectric layer and the resistance layer. In addition, the measurement results validate the performance of MMA.