S-band application: Ultra-slim metamaterial absorber unit cell with dual-negative characteristics and polarization neutrality

The current work offers an electromagnetic metamaterial absorber that uses the double-a1Qnegative property and is designed for operation in the 1 to 4 GHz frequency range, with a peak absorption at 3.31 GHz, emphasizing S-band applications. The suggested structure is very thin, having a total absorber thickness of 0.0184 λ. It was constructed using CST software and simulated with a frequency domain solver. The unit cell`s performance is studied at different polarization angles (φ) and incidence angles (θ). The results show good design, insensitivity to polarization angles up to 90°, and a wide incidence angle range of up to 50°. The investigation comprises an analysis of the electric field (E field) and surface current to supplement the absorption analysis. The suggested design is developed by parameter studies, which include changes to the split gap, loss tangent, and testing alternative substrate materials and thicknesses. The resonance frequencies vary somewhat according to array arrangements, resulting in double-negative characteristics. The fractional bandwidth is 5.4 %, with a central frequency of 3.31 GHz. The suggested design is validated using advanced design system (ADS) software, and the comparable circuit is shown to correspond very well with the CST simulation findings. The absorber is constructed on a FR-4 substrate in a 10 x 10 array format. Comparative analysis with existing literature indicates acceptable results, highlighting the potential utility of this metamaterial absorber design in S-band applications.