A transparent broadband flexible metamaterial absorber for radar infrared-compatible stealth

Abstract

The iterative upgrading of the means of warfare has promoted the development of detection technology, and military activities are increasingly demanding target stealth. In this paper, a multifunctional metamaterial absorber is recommended, which simultaneously realizes the integrated stealth functions of ultra-wideband radar wave absorption, low infrared emission, and optically transparent. The structure is composed of an infrared shield (IRSL), a radar-absorbing layer (RAL), and a reflective layer (RL). Simulation results indicate that the absorption bandwidth in the radar band (1.81-20.4 GHz) is more than 90%, and the infrared emissivity is as low as 0.271 in the IR band (3-14 μm). Moreover, it has the features of flexibility, angle stability (0-45°), polarization insensitivity (0-90°), and so on. Furthermore, the electric field current distribution and equivalent circuit model of the structure are analyzed, and a 180 mm*180 mm sample is built and tested; the results show that the simulated and actual measurements are in agreement, and it is expected that such absorbers will be used in areas such as aircraft.

Broadband optically transparent microwave absorber made of interdigital metasurfaces in rotational symmetry with a single air spacer

“…Table 1 compares this work with several other broadband MMAs [8][9][10][13][14][15][16][17][18][19][20][21][22] in recent years. With regard to a single spacer (the spacer number is 1), this work shows its unique absorbing ability in the 4-octave bandwidth, which is much broader than the precedent works in [8,9,[13][14][15][16][17].…”

“…The MMAs can be further designed optically transparent (OT) [11][12][13][14][15][16][17][18][19][20][21][22] adapted for applications of airplane windscreen, vehicle glasses, etc. It demands the metals and dielectrics in the MMAs to both allow good transmission for light.…”

“…The PDMS and PMMA work as the dielectric spacer between these different ITO/PET layers. In a practical OT MMA, there may be a single [13][14][15][16][17] or more such transparent dielectric spacers [18][19][20][21][22]. Generally, an OT MMA based on the single spacer in current works [13][14][15][16][17] is relatively easy to fabricate with its absorbing bandwidth limited at the order of 3octave.…”

“…Generally, an OT MMA based on the single spacer in current works [13][14][15][16][17] is relatively easy to fabricate with its absorbing bandwidth limited at the order of 3octave. By including multiple dielectric spacers [18][19][20][21][22], the MMA's absorbing bandwidth can be further improved, which are nevertheless at the cost of increasing the absorber's vertical profile and difficulties in the fabrication and assembling processes.…”

“…Considering the difficulties of multiple dielectric spacers [18][19][20][21][22], we focus on the single dielectric spacer architecture in this paper, for its advantages to actualize a practical OT MMA. However, compared with the existing single spacer MMAs [13][14][15][16][17], the proposal in this work has a much broader absorbing bandwidth by concerting techniques of unique interdigital metasurfaces in rotational symmetry and an air spacer.…”