Liquid reconfigurable stealth window constructed by a metamaterial absorber

• DOI: 10.1364/josab.438914
• Publication Date: 2021-09-17T12:01:41Z
• Authors: Xiangkun Kong; Weihao Lin; Xuemeng Wang; Lei Xing; Shunliu Jiang; Lingqi Kong; Meilin Liu
• Keywords: 0202 electrical engineering, electronic engineering, information engineering; 02 engineering and technology; 7. Clean energy

In this paper, a liquid reconfigurable stealth window constructed by a metamaterial absorber at the microwave band is proposed. The stealth window consists of an anti-reflection glass with indium tin oxide (ITO) as resistive film and a liquid container made of polymethyl methacrylate (PMMA). Since the materials constituting the window are all optically transparent, the metamaterials that can be switched through the liquid control system can always maintain high light transmission. The proposal can obtain a transmission passband from 2.3 GHz to 5 GHz with low insertion loss, especially at 2.45 GHz and 5 GHz with the insertion loss of the passband reaching 0.51 dB and 0.99 dB, by water with 75% ethanol drainage. It can also reflect electromagnetic waves at 2.45 GHz and absorb them from 4.5 GHz to 10.5 GHz with a strong absorptivity over 90% by ethanol injection, exhibiting the reconfigurable electromagnetic characteristic of switching between the transmission state and absorption state. Furthermore, the proposed absorber shows its good transmission/absorption performance. Under the condition of ethanol filling, when electromagnetic waves are incident obliquely at 50°, the absorption rate still exceeds 80%. Finally, the prototype window has been fabricated to demonstrate the validity of the proposed structure, which indicates that the proposal presents significant implications for smart stealth systems and wireless local area network (WLAN) communication that require switching of working states in a complex electromagnetic environment.