Liquid Reconfigurable Stealth Window Constructed by Metamaterial Absorber

TL;DR

This paper introduces a liquid-reconfigurable metamaterial-based stealth window that can switch between high transmission and strong absorption states in the microwave band, enabling adaptable electromagnetic stealth and communication functions.

Contribution

It presents a novel transparent metamaterial absorber with liquid control for reconfigurable microwave stealth windows, combining high transparency with switchable transmission and absorption capabilities.

Findings

Achieves a transmission passband from 2.3 GHz to 5 GHz with low insertion loss.

Can reflect at 2.45 GHz and absorb from 4.5 GHz to 10.5 GHz with over 90% absorptivity.

Maintains performance under different polarizations and oblique incidence angles.

Abstract

In this paper, a liquid reconfigurable stealth window constructed by metamaterial absorber at 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 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 reach 0.51 and 0.99 , by alcohol 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 alcohol injection, exhibiting the reconfigurable electromagnetic characteristic of switching between transmission state and absorption state. Furthermore, the proposed absorber shows its good transmission/absorption performance under different polarizations and obtains absorptivity over 90% when alcohol injection in an oblique incidence of 50{\deg}. 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 WLAN communication that require switching of working states in a complex electromagnetic environment.