Transparent transmission-selective radar-infrared bi-stealth structure

Abstract

We report a multifunctional metamaterial composite structure that not only provides the broadband radar and thermal infrared bi-stealth function but also possesses an in-band microwave transmission window and high optical transparency. It is composed of four metasurface layers made of indium tin oxide (ITO) films with different surface resistances, which are specifically designed to sequentially control the infrared emission, microwave absorption and transmission. The fabricated sample exhibits a low reflectivity less than 10% in 1.5-9 GHz and a transmission peak of 50% around 3.8 GHz up to the incident angle of 30 degrees. In the infrared atmosphere window, a low thermal emissivity of about 0.52 is achieved. Meanwhile, it keeps good optical transparency by the use of the ITO films. The optically transparent, low-infrared-emissivity, radar-reflectionless and frequency-selective-transmission properties will enable the promising application of communication-compatible multispectral stealth technology.

Flexible and Transparent Microwave–Infrared Bistealth Structure

“…Recently, several metamaterial structures have been proposed to achieve multiple-spectral stealth performances. [31] However, these metamaterial-based stealth structures are typically rigid, which cannot be used for the applications on nonplanar surface. [30], a dual-layer metasurface was adopted to realize microwave-IR bistealth performance, which can absorb the radar wave between 3 and 8 GHz and simultaneously realize a low IR emission of 0.2.…”

“…Specifically, the emissivity ε FSS of the FSS can be calculated as [29][30][31] (1 ) Here, the ISL is implemented by using capacitive frequency selective surface (FSS) due to the low-pass filtering characteristic.…”

“…It can be observed from Figure 1b that the reflectance is about 91%, while the transmittance is close to zero from 6 to 15 µm. [31] By combining the designed ISL with a broadband microwave absorber, the prototype of the microwave-IR bi-stealth metamaterial is shown in Figure 3a, which is composed of three layers of ITO films spaced by two PVC substrates. Besides, the EM responses of the ITO film in microwave band are also calculated.…”

“…[14][15][16][17][18][19][20][21][22][23][24][25][26][27][28] Many intriguing devices based on metamaterial have been proposed in the stealth field, such as perfect absorber, [17][18][19][20] invisible cloak, [21][22][23][24][25] and low-scattering material. [31] However, these metamaterial-based stealth structures are typically rigid, which cannot be used for the applications on nonplanar surface. Recently, several metamaterial structures have been proposed to achieve multiple-spectral stealth performances.…”

“…[31] However, these metamaterial-based stealth structures are typically rigid, which cannot be used for the applications on nonplanar surface. Afterward, microwave transmission window and optical transparency have been integrated in single metamaterial.…”