An efficient resolution for ultrathin metamaterial perfect absorber (MPA) is proposed and demonstrated in the VHF radio band (30-300 MHz). By adjusting the lumped capacitors and the through vertical interconnects, the absorber is miniaturized to be only λ/816 and λ/84 for its thickness and periodicity with respect to the operating wavelength (at 102 MHz), respectively. The detailed simulation and calculation show that the MPA can maintain an absorption rate over 90% in a certain range of incident angle and with a wide variation of capacitance. Additionally, we utilized the advantages of the initial single-band structure to realize a nearly perfect dual-band absorber in the same range. The results were confirmed by both simulation and experiment at oblique incidence angles up to 50°. Our work is expected to contribute to the actualization of future metamaterial-based devices working at radio frequency.
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http://dx.doi.org/10.1038/srep45151 | DOI Listing |
Microsyst Nanoeng
January 2025
Sichuan University, 610207, Chengdu, China.
In conventional nondispersive infrared (NDIR) gas sensors, a wide-spectrum IR source or detector must be combined with a narrowband filter to eliminate the interference of nontarget gases. Therefore, the multiplexed NDIR gas sensor requires multiple pairs of narrowband filters, which is not conducive to miniaturization and integration. Although plasmonic metamaterials or multilayer thin-film structures are widely applied in spectral absorption filters, realizing high-performance, large-area, multiband, and compact filters is rather challenging.
View Article and Find Full Text PDFLangmuir
January 2025
Catalysts and Organic Synthesis Research Laboratory, Department of Chemistry, Iran University of Science and Technology, 16846-13114 Tehran, Iran.
Carbon microspheres (CMSs) are recognized as highly effective microwave absorbers due to their exceptional wave absorption properties. In this study, 5,10,15,20-tetrakis(4-aminophenyl)porphyrin, a metamaterial, was chemically bonded to CMSs─considered a conjugated carbon structure─using a 1,3-dibromopropane linker to explore the synergistic properties and microwave absorption capabilities of the synthesized composite. The synthesized structures were characterized by using X-ray diffraction, FE-SEM, Fourier transform infrared, diffuse reflectance spectroscopy, and VNA analyses.
View Article and Find Full Text PDFSci Rep
January 2025
Electrical Engineering Department, Kuwait University, 13060, Kuwait City, Kuwait.
Nano Lett
January 2025
School of Physics and Astronomy, Faculty of Science, Monash University, Melbourne, Victoria 3800, Australia.
Ultrathin and low-loss phase-change materials (PCMs) are highly valued for their fast and effective phase transitions and applications in reconfigurable photonic chips, metasurfaces, optical modulators, sensors, photonic memories, and neuromorphic computing. However, conventional PCMs mostly suffer from high intrinsic losses in the near-infrared (NIR) region, limiting their potential for high quality factor (-factor) resonant metasurfaces. Here we present the design and fabrication of tunable bound states in the continuum (BIC) metasurfaces using the ultra-low-loss PCM SbSe.
View Article and Find Full Text PDFNanoscale
December 2024
National Key Laboratory of Advanced Micro and Nano Fabrication Technology, Shanghai Jiao Tong University, Shanghai, 200240, China.
Broadband metamaterial absorbers in the long wavelength infrared region are promising in applications including thermal imaging, cloaking, radiative cooling and IR signature suppression. Although high absorption over the long wavelength infrared region has been extensively achieved, the challenge is to shrink both the thickness and lateral footprint of unit absorbing structures. Here, a compact broadband long wavelength infrared metamaterial absorber consisting of multilayered Ge/Ti/Ge/SiO hybrid cylindrical structures, whose period and thickness are only ∼1.
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