Multi-functional tunable ultra-broadband water-based metasurface absorber with high reconfigurability

Abstract

Promising microwave ultra-broadband water-based metasurface absorbers have attracted increasing attention due to their novel applications in EM radiation prevention, stealth technology, and energy harvesting. In this paper, the proposed water-based metasurface absorber, composed of mushroom-shaped and layer-shaped water with resin shell, can reach over 90% polarization-insensitive and wide-angle absorption from 7.2 to 100 GHz with a relative bandwidth of 173%. Moreover, the proposed absorber is reconfigurable to control the water content, salinity, and type of inside liquid for tunable absorption and infrared radiation with thermally tunable absorption. Since the experimental and simulated ultra-broadband absorption originates from multiple resonances concentrated on the top, the ground-free all-dielectric design is achieved. Furthermore, the proposed curved absorber is fabricated and demonstrated for omnidirectional absorption. The water-based metasurface absorber shows great potential in achieving both microwave and infrared radiation camouflage for practical shaped structures in both civil and military domains.

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

“…Therefore, this section first presents the dynamic modulation of VO 2 ‐based BMAs and then discusses BMAs with thermally tunable properties based on GST, [ 481–489 ] indium antimonide (InSb), [ 490,491 ] strontium titanate (STO), [ 492,493 ] nanocomposites, [ 494 ] and water. [ 452,495–499 ]…”

“…Comparable work was available for a multifunctional tunable ultra‐broadband water‐based absorber that achieves 90% in the 7.2 to 100 GHz. [ 497 ] The moisture content, salinity, and type of internal liquid are controlled to perform tunable absorption and IR radiation with thermally tunable absorption. Besides, a 3D structured BMA based on water substrate and metallic metamaterials was designed, [ 498 ] which absorbs more than 90% in the range of 8.3–21.0 GHz and possesses thermally tunable performance due to the presence of water.…”

“…Therefore, this section first presents the dynamic modulation of VO 2 -based BMAs and then discusses BMAs with thermally tunable properties based on GST, [481][482][483][484][485][486][487][488][489] indium antimonide (InSb), [490,491] strontium titanate (STO), [492,493] nanocomposites, [494] and water. [452,[495][496][497][498][499] A thermally tuned BMA based on the phase transition properties of VO 2 was developed. [93] The critical phase transition temperature of VO 2 is set to 68 °C.…”

“…Therefore, BMAs containing both broadband absorption response and near-perfect absorption are rightly applied to energy harvesting applications, which are currently the most widely used in solar energy harvesting [261,[563][564][565][566][567][568][569][570][571][572][573] and microwave energy harvesting. [278,309,[399][400]497,[574][575][576]…”

“…The absorption bandwidth of four asymmetric sectional resonators is about 16.2 times that of single resonators or four identical resonators. Besides, a multifunctional microwave BMA with tunable resonance responses was experimentally reported, [ 497 ] which is based on the mushroom‐shaped and laminated water having resin shells, an ultra‐broadband high absorption (over 90%) having polarization insensitive and wide angle tolerance from 7.2 to 100 GHz with relative absorption bandwidth of 173% is realized. Its absorption could be adjusted by controlling the water content, salinity, and type of internal liquid, which has enormous potential for microwave energy harvesting.…”