Wide-Angle Absorption with Broadband Response by Composite Meta-Atoms

Advances in antenna technology require controlled electromagnetic environments for precise radar cross-section (RCS) measurements and reduced parasitic scattering, highlighting the need for multifunctional absorbers. Traditional single-mechanism designs inherently compromise between bandwidth expansion, low-frequency absorption, and angular robustness. Addressing this trilemma, composite multilayer architecture is proposed through tactical fusion of resistive interfaces and reconfigurable metasurfaces. The proposed resistive surface absorber achieves high-efficiency absorption (>90%) across a broad angular range (0°-60°) for both TE and TM polarizations, demonstrating robust angular stability and polarization insensitivity. Numerical results demonstrate over 0.9 absorptivity across 2.6-20 GHz through active-passive co-design, with an active tuning range of 2.2 GHz (2.59-4.8 GHz). The structure achieves a sub-wavelength thickness of 0.099λ₀(11.5 mm) at the fundamental frequency. This hybrid architecture unlocks transformative potential for intelligent electromagnetic absorbers, particularly in adaptive wideband scattering suppression and contrast-enhanced RCS measurements.