Ultra-wideband microwave absorber via an integrated metasurface and impedance-matching lattice design

Abstract

In this letter, we propose a method of extending the bandwidth of radar absorbing materials (RAMs) by integrating the metasurface and an impedance-matching lattice. The metasurface operates at lower frequencies and is sandwiched as an interlayer between a RAM sheet and an impedance-matching lattice. Absorption at lower frequencies will be enhanced due to the strong resonance of the metasurface, which extends the bandwidth to lower frequencies.To enhance absorption at higher frequencies, a square lattice of RAM patches, rather than a complete sheet, is placed on top of the metasurface to improve the impedance matching. As well as the dissipation of the RAM patches themselves, a high absorption at higher frequencies can also be achieved, which extends the bandwidth towards higher frequencies. Therefore, through such an integrated design, a high absorption of radar waves can be achieved in an ultra-wide band. To verify this method, we designed, fabricated and measured a prototype based on a commercial magnetic rubber RAM. Both the simulated and measured results show that the prototype can achieve an absorption rate of over 90% on average in 2.5-18.0 GHz. Moreover, such a design not only maintains the softness of rubber RAMs, but also reduces the total aerial density, which will facilitate practical applications. This work provides an alternative method for designing microwave absorbers for ultra-wideband applications.

Review of Broadband Metamaterial Absorbers: From Principles, Design Strategies, and Tunable Properties to Functional Applications

“…[ 212 ] To extend the bandwidth of radar absorber materials, Fu et al. designed and fabricated a device by integrating a hypersurface and an impedance matched lattice, [ 213 ] allowing an average of more than 90% absorption in 2.5–18.0 GHz.…”

“…The transmittance of MAs in most BMAs is frequently negligible due to the presence of a continuous metal plate at the bottom, allowing us to focus only on the reflectance of MAs. Actually, in addition to MAs, [70,[211][212][213][214] impedance matching theory is widely used in various fields, such as thermoelectric devices, [215] sensors, [216] nanodevices, [217] and electrochromic devices. [218] According to Fresnel reflection formula, the reflectance (R) of metamaterials could be obtained as: [128] R r n…”

“…It has been additionally shown that periodic impedance matched metallic dielectric metamaterials and the advantage of embossing moth-eye surfaces on them enable the construction of ideal BMAs from which devices can achieve perfect absorption over an extremely wide frequency range of 400 nm to 6 µm. [212] To extend the bandwidth of radar absorber materials, Fu et al designed and fabricated a device by integrating a hypersurface and an impedance matched lattice, [213] allowing an average of more than 90% absorption in 2.5-18.0 GHz.…”

A review of graphene-based broad bandwidth microwave absorbing textile-based composites in the low-frequency range

“…With complicated modern battlefield conditions, radar detection systems are simultaneously exposed to EMW interference. Besides, the civilian and military applications suffer from the booming EMW interference as well, such as R.F., 1 radar stealth technology, 2 national defense security, 3 portable transmission, 4 and electronic devices. 5 Therefore, military and civilians suffer from the booming EMW interference due to upgrading continuous communication technology.…”

Structural design and optimization of double-cross shape broadband absorption metamaterial based on CB-ABS

“…Electromagnetic metamaterials have received extensive attention from researchers due to their tunable electromagnetic properties (Fu et al, 2019;. Different from traditional materials, the unique electromagnetic properties of metamaterials are mainly derived from the periodic structural units and the variation in arrangement (Chen et al, 2022;Mei et al, 2019;Xiong et al, 2022;Zhang et al, 2020a).…”