A Design of Ultra-Wideband and Wide Angle Rasorber Based on ITO-FSR for RCS Reduction

In this paper, an Indium Tin Oxides (ITO) resistive film and Frequency Selective Rasorber (FSR) composite structure is proposed for radar cross section (RCS) reduction. The proposed rasorber achieves an impressive bandwidth of 184.8% with absorption rate more than 85% (RCS reduction 8.2dB) under the incidence of electromagnetic waves with different polarizations, spanning from 0.94 GHz to 23.2 GHz. When EM waves are incident obliquely, the rasorber maintains performance over an angle of ± 45° (TE polarization) and ± 60° (TM polarization). Additionally, the physical dimensions of the rasorber cell are $5 \mathrm{~cm} \times 5 \mathrm{~cm} \times 3 \mathrm{~cm}$, corresponding to an electrical size of $0.15 \lambda \times 0.15 \lambda \times 0.09 \lambda$, where $\lambda$ is the wavelength of the lowest working frequency 0.94 GHz. It demonstrates the characteristics of ultra-wideband, polarization-insensitive, miniaturization and wide angle, provides a technical solution for research and application in related fields.