Design and Performance of a Dual-Layer ITO-Based Ultra-Wideband Metamaterial Absorber for Enhanced Polarization Insensitivity and Wide-Angle Stability

A two-layer ultra-thin and ultra-wideband planar metamaterial absorber with the top layer unit cell made of a square ring and a spider-web-shaped resistance patch is presented in this study. Ohmic losses along with powerful local electromagnetic resonance, are enhancing this absorber's performance. The unit cell is small, with dimensions of 10.0 mm by 10.0 mm by 3.0 mm. According to numerical studies, the absorber attains an outstanding absorption rate of almost 99.0% at normal incidence in the frequency range of 15.8 GHz to 81 GHz with a total bandwidth of 65.2 GHz. Furthermore, the bandwidth for relative absorption reaches 134.7%. These results provide important information for creating effective wideband absorbers in metamaterial designs. Even at high incidence angles, the absorber shows efficacy for both transverse magnetic (TM) and transverse electric (TE) polarizations. This demonstrates its strong performance throughout a broad range of incidence angles and complete polarization states, further validating its adaptability in several real-world applications.