Abstract-Topological flexible metamaterials with isotropic dual-frequency terahertz-band absorption

Jianli Cui, Binzhen Zhang, Hong Cheng Xu, Huixia Sun, Guirong Shao



https://www.sciencedirect.com/science/article/abs/pii/S0030401819301439

This study demonstrates an isotropic flexible absorptive metamaterial structure for terahertz wave bands based on topological-optimization design. One rotationally symmetric absorbing element consists of a polarization-sensitive metamaterial cell arranged with a counterclockwise topology. A flexible topological metamaterial absorber is formed from crystalline elements through an infinite periodic arrangement using Floquet’s theorem. This artificial material achieves dual-frequency absorption with peak absorptions of 94% and 99.9% at 0.136 and 0.143 THz, respectively. The independent polarization angle of the two absorption peaks exceeds 45°under an oblique incident-wave process operation and in bending measurement, which indicate polarization isotropy. The equivalent electrical thickness corresponding to the minimum resonance point is close to one-ninth. The proposed ultra-thin flexible artificial material not only possesses perfect conformity with complex surfaces but also achieves larger angle electromagneticabsorption. The study results can present this material a potential candidate for polarized manipulation in electromagnetic stealth and electromagnetic control in the terahertz technology.

Abstract-Investigating flexible band-stop metamaterial filter over THz

Yuhua Yang, Yongqing Xu, Binzhen Zhang, Junping Duan, Li Yan, Hongcheng Xu, Yunpeng Liu, Yanan Shi,


https://www.sciencedirect.com/science/article/abs/pii/S003040181930029X

Metamaterial filter is a novel type of photoelectric device. In this study, a triple-band band-stop filter for terahertz is fabricated by magnetron sputtering of periodic metamaterial resonators on flexible polyimide substrates. The band-stop resonant points of the filter are 107.3, 167.45, and 209.9 GHz, and the 3 dB bandwidths are 14.13, 14.03, and 22.44 GHz. S21 parameters at the resonance point reach $-$30.217, $-$30.432, and $-$38.618 dB, thereby possibly achieving an excellent frequency blocking performance. Simultaneously, the stop-band can be adjusted by controlling the length of the metamaterial unit size, thus modifying the frequency of the filter.

Abstract-A micromechanical tunable 3D metamaterial based on periodic rotatable double split resonant rings

Zeng Qu, Yong Zhang, Binzhen Zhang,

https://www.sciencedirect.com/science/article/pii/S0030402618309616

The electromagnetic response of the reported metamaterial is usually fixed, which greatly limits practical applications. Microstructural reconfiguration produces a drastic and dynamic controllability in metamaterials response that typically depend on shape, size, and distribution of metaatoms. Periodic rotatable double split resonant rings (DSRRs) structured on an ultrathin dielectric are adopted to design a micromechanical tunable 3 dimensional metamaterial (MT3DM). The powerful tunability quantified by transmissivity is conveniently achieved by mechanically changing location of gap in inner split ring. Modulation of transmissivity amplitude, resonance frequency, and band width reaches 54.41 dB, 0.31 THz, and 0.08 THz, respectively. The microstructure, equivalent circuit model, and reconfiguration mechanism of the proposed MT3DM are deeply discussed. The adjustable resonance can be easily scaled to the entire spectrum by geometrically regulating. Based on the powerful controllability, the proposed MT3DM can by widely applied in biochemical sensing, function materials, and electromagnetic devices including antenna, switch, absorber, and detector.

Abstract-A flexible metamaterial absorber with four bands and two resonators

• Yong Zhang^a, b, 
• Junping Duan^a, b, 
• Binzhen Zhang^a, b,, 
• Wendong Zhang^a, b, 
• Wanjun Wang^c

• ^a Science and Technology on Electronic Test & Measurement Laboratory, North University of China, Taiyuan, Shanxi, 030051, China
• ^b School of Instrument and Electronics, North University of China, Taiyuan, Shanxi, 030051, China
• ^c Department of Mechanical Engineering, Louisiana State University, Baton Rouge, LA 70803, USA
• 
  

http://www.sciencedirect.com/science/article/pii/S0925838817305030

An efficient approach for achieving more resonance bands with fewer resonators is proposed in this paper. We investigate the theory, design, simulation, fabrication, and performance of a flexible metamaterial perfect absorber (MPA) with two resonators and four resonances located in GHz and THz ranges. The sandwich microstructure of the MPA consists of periodic “回” shaped metal patches on a metasurface, a dielectric of FR4 board on the interlayer, and a continuous copper film on the substrate. The four peaks of absorptivity owing to the coupling effect of the strong LC and surface resonance of the outer ring resonator as well as the strong LC and surface resonance of the inner ring resonator are 93.887%, 99.479%, 98.296%, and 93.035% at 38.165 GHz, 155.48 GHz, 231.71 GHz, and 275.27 GHz, respectively. The influences on absorptivity produced by angles, dimensions, and materials are also studied. The proposed MPA, equipped with strong flexibility, ultrathin thickness, light weight, strong absorption, sparks inspirations in designing the MPA with more resonances and fewer resonators.