An Ultra-wideband Transparent Radar-Infrared Bi-Stealth Absorber

This paper presents a radar-infrared bi-stealth metamaterial absorber (MA), which consists of an infrared shielding layer (IRSL), two microwave-absorption layers (MAL) and a ground layer. The IRSL achieves infrared stealth by increasing the duty cycle of low emissivity materials. The two MALs create multiple resonances, thereby broadening the bandwidth. The absorber exhibits a wide absorption bandwidth of 10 dB from 2.75 to 18.07 GHz, covering S, C, X and Ku bands. Additionally, it demonstrates a low infrared emissivity of 0.252 from 3 to 5 and 8 to 14 mm by formula calculation. Moreover, the absorber's microwave absorption capability shows good angular stability, with a stable performance of 45 degrees for TE polarization and 60 degrees for TM polarization.