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- 实验方案
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Tunable Terahertz Metamaterials Based on Anapole Excitation with Graphene for Reconfigurable Sensors
摘要： Anapole mode is excited by the destructive interference between the toroidal and electric dipoles moments, resulting in a high quality (Q)-factor. In this paper, we designed a high Q-factor metamaterial which shows anapole behaviors in terahertz region. Through introducing graphene, the destructive interference condition is disturbed and tunability can be realized. This pattern reflects brilliant tunability performance that frequency movements above 250 GHz per 0.1eV can be verified. Ingenious adjustment by the position of graphene offers the possibility of diversified tuning capabilities. Such a tunable terahertz metamaterial has great potential in reconfigurable sensors.
关键词： tunable,terahertz,metamaterial,graphene,anapole
更新于2025-09-19 17:13:59
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Graphene assisted terahertz metamaterials for sensitive bio-sensing
摘要： We report that single-stranded deoxyribonucleic acids (ssDNAs) at very low concentrations can be detected using graphene-combined nano-slot-based terahertz (THz) resonance. A combination of the resonant structure and tuned electro-optical properties of graphene can provide unprecedentedly sensitive biomolecule sensing even using very low energy THz photons, overcoming the huge scale di?erence of 10,000:1 between the wavelength and the size of the ssDNAs. Ultrahigh sensitivity is obtained by the signi?cant increase in the absorption cross-section of the graphene sheet with the targeted biomolecules, induced by strong THz ?eld enhancement at the resonance frequency inside the slots. Clearly distinguishable THz optical signals were observed between di?erent species of ssDNAs even at the nano-mole level and analyzed quantitatively in terms of the electro-optical properties of the suspended graphene layer modi?ed by the attached ssDNAs without any molecular-speci?c labeling for the THz regime. Quantitative analysis of ssDNA molecule adsorption was carried based on the change in conductivity using a theoretical THz transmission model.
关键词： Terahertz,Graphene,Metamaterial,Biosensor
更新于2025-09-19 17:13:59
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[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Multispectral Photodetectors Based on PbS Colloidal Quantum Dots
摘要： It is demonstrated numerically that a metamaterial-inspired, low profile (height approximately λ/80), electrically small (ka = 0.45) Huygens source antenna can be designed to radiate at 300 MHz in its broadside direction with a high radiation efficiency and a large front-to-back ratio. Two electrically small, near-field resonant parasitic (NFRP) antennas are first designed. Both are based on a coax-fed dipole antenna. An electric dipole response is obtained by combining it with a tunable Egyptian axe dipole (EAD) NFRP element. A magnetic dipole response is obtained by spatially loading the driven dipole with tunable, extruded capacitively loaded loop (CLL) NFRP elements. The driven dipole and the EAD and CLL NFRP elements are combined together and retuned to achieve a broadside radiating Huygens source antenna. Two different designs, one with two CLL elements and one with four, are obtained, and their performance characteristics are compared.
关键词： Huygens source,Directivity,metamaterial-inspired antennas,electrically small antennas
更新于2025-09-19 17:13:59
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Actively tunable toroidal excitations in graphene based terahertz metamaterials
摘要： Toroidal dipoles, unlike electric and magnetic dipoles, are formed due to currents flowing on the surface of a torus along its meridians. We investigate the toroidal dipole response in a graphene based infinite 2D array of terahertz (THz) meta-material (MM) and report the active tuning of the toroidal resonances. Each metamolecule in our proposed MM configuration consists of two joint split ring resonators (SRRs) made up of graphene material with two gaps in each resonator. We examine actively tunable response of the toroidal excitations with respect to a change in the Fermi energy of graphene material. The toroidal effect is elaborated using surface current and magnetic field profiles at the resonance frequency of the metamolecule structure. The modulation of the metamaterial toroidal response and effect on Q factor is further examined by changing the relaxation time of graphene. The excitation of toroidal resonances at terahertz frequencies and their dynamic control could be significant in designing efficient tunable modulators, filters and sensors.
关键词： terahertz,toroidal resonance,metamaterial,graphene
更新于2025-09-16 10:30:52
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HIGH GAIN SLOTTED WAVEGUIDE ANTENNA BASED ON BEAM FOCUSING USING ELECTRICALLY SPLIT RING RESONATOR METASURFACE EMPLOYING NEGATIVE REFRACTIVE INDEX MEDIUM
摘要： In this paper, a new high performance slotted waveguide antenna incorporated with negative refractive index metamaterial structure is proposed, designed and experimentally demonstrated. The metamaterial structure is constructed from a multilayer two-directional structure of electrically split ring resonator which exhibits negative refractive index in direction of the radiated wave propagation when it is placed in front of the slotted waveguide antenna. As a result, the radiation beams of the slotted waveguide antenna are focused in both E and H planes, and hence the directivity and the gain are improved, while the beam area is reduced. The proposed antenna and the metamaterial structure operating at 10 GHz are designed, optimized and numerically simulated by using CST software. The e?ective parameters of the eSRR structure are extracted by Nicolson Ross Weir (NRW) algorithm from the s-parameters. For experimental veri?cation, a proposed antenna operating at 10 GHz is fabricated using both wet etching microwave integrated circuit technique (for the metamaterial structure) and milling technique (for the slotted waveguide antenna). The measurements are carried out in an anechoic chamber. The measured results show that the E plane gain of the proposed slotted waveguide antenna is improved from 6.5 dB to 11 dB as compared to the conventional slotted waveguide antenna. Also, the E plane beamwidth is reduced from 94.1 degrees to about 50 degrees. The antenna return loss and bandwidth are slightly changed. Furthermore, the proposed antenna o?ered easier fabrication processes with a high gain than the horn antenna, particularly if the proposed antenna is scaled down in dimensionality to work in the THz regime.
关键词： negative refractive index,slotted waveguide antenna,metamaterial,beam focusing,high gain,electrically split ring resonator
更新于2025-09-16 10:30:52
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[IEEE 2019 Thirteenth International Congress on Artificial Materials for Novel Wave Phenomena (Metamaterials) - Rome, Italy (2019.9.16-2019.9.21)] 2019 Thirteenth International Congress on Artificial Materials for Novel Wave Phenomena (Metamaterials) - Frequency Tunable Monopole Patch Antenna Using Broadside Coupled Split Ring Resonator for Wireless Communication Applications
摘要： This paper presents metamaterial based monopole patch antenna capable of tuning the radiating frequency over a wide bandwidth. The proposed novel antenna structure makes use of the metamaterial properties of Broadside Coupled Split Ring Resonator (BCSRR) for frequency tuning. The magnetic resonant frequency of the proposed antenna can be tuned by slightly adjusting the interplanar distance between the rings of the BCSRR so that the coupling due to effective capacitance and inductance between them can be changed. The desired range of frequency tuning for potential applications like Global System for Mobiles (GSM), Bluetooth, Wi-Fi, Wi-Max, WLAN etc. is achieved by proper designing of the geometrical parameters of BCSRR. The different antennas for different applications in a single device can be replaced with the proposed novel metamaterial based antenna structure.
关键词： monopole patch antenna,wireless communication,frequency tuning,metamaterial,Broadside Coupled Split Ring Resonator
更新于2025-09-16 10:30:52
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Transmission control by asymmetric electromagnetically induced transparency-like metamaterials in transverse electromagnetic waveguide
摘要： We numerically and experimentally present passive and active electromagnetically induced transparency-like metamaterials in a TEM waveguide under normal excitation. Asymmetry of the metamaterial unit cell leads to the splitting of the radiative resonance. Surface current distributions are analyzed to account for each resonance. Moreover, by implementing a varactor diode to one of the gaps of the double-split ring resonator, electromagnetically induced transmission-like band is shifted in frequency and the corresponding bandwidth is modulated. A modulation ratio of 29.5 dB in transmission is experimentally demonstrated by only increasing the bias voltage 4 volts.
关键词： Surface current distributions,Radiative resonance,Electromagnetically induced transparency,Metamaterial,Modulation ratio
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Design of Metamaterial Microstrip Array Antenna
摘要： In this paper, a new type of metamaterial structure based on open resonant ring is proposed. On this basis, a microstrip array antenna based on metamaterial is designed and simulated by HFSS.
关键词： Open resonant ring,Metamaterial,Microstrip array antenna
更新于2025-09-16 10:30:52
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Near-infrared multi-narrowband absorber based on plasmonic nanopillar metamaterial
摘要： A multi-narrowband absorber composed of gold nanopillar metamaterial is numerically designed and investigated in this paper. Full-wave simulations indicate that five distinctive narrow-band absorption peaks with the maximum absorption rate up to 99.3% and the lowest above 80% can be achieved in the near-infrared regime at normal incidence. Polarization dependence over a incident angular range of ± 30° is also researched. We demonstrate the spectroscopic tunability of our absorber by adjusting the structural parameters of the gold nanopillar array. Physical mechanism of the multi-narrowband absorption is construed as the vertical Fabry-Perot-like gap plasmonic resonances induced by electric and magnetic dipolar polaritons. Compared to the previous researches on multi-band absorbers, we realize no less than five near-infrared narrow absorption bands by utilizing just simple configuration with single pattern, which makes considerable application potential in the fields of absorption filtering and spectroscopic sensing.
关键词： Metamaterial,Multi-band absorber,Near-infrared,Gap plasmonic resonance
更新于2025-09-16 10:30:52
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[IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Ultra-broadband Reflector based on Subwavelength All-dielectric Grating
摘要： It is demonstrated numerically that a metamaterial-inspired, low profile (height approximately λ/80), electrically small (ka = 0.45) Huygens source antenna can be designed to radiate at 300 MHz in its broadside direction with a high radiation efficiency and a large front-to-back ratio. Two electrically small, near-field resonant parasitic (NFRP) antennas are first designed. Both are based on a coax-fed dipole antenna. An electric dipole response is obtained by combining it with a tunable Egyptian axe dipole (EAD) NFRP element. A magnetic dipole response is obtained by spatially loading the driven dipole with tunable, extruded capacitively loaded loop (CLL) NFRP elements. The driven dipole and the EAD and CLL NFRP elements are combined together and retuned to achieve a broadside radiating Huygens source antenna. Two different designs, one with two CLL elements and one with four, are obtained, and their performance characteristics are compared.
关键词： Huygens source,Directivity,metamaterial-inspired antennas,electrically small antennas
更新于2025-09-16 10:30:52