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Compact and efficient
摘要： Using light to manipulate small particles has proven an indispensable tool for ‘tweezing’, sorting and force measurements. To achieve effective optical traps with high ‘stiffness’, researchers often go to great lengths to tailor light fields, for example by using holographic elements. Now, Aliaksandra Ivinskaya and colleagues from Russia, the USA, the UK and Israel predict that small particles can be manipulated using a plane wave of light and a simple flat surface of an anisotropic media supporting hyperbolic modes. Their hyperbolic metamaterial is composed of metal and dielectric layers and is potentially less affected by losses and offers more broadband capability than purely plasmonic approaches. In their theoretical study a small dielectric sphere near a hyperbolic metamaterial is considered. The particle is sufficiently small to provide the required momentum to excite both surface plasmon and bulk hyperbolic waves from incident plane waves. Strong optical pulling forces were predicted over the 400–800 nm wavelength range thanks to the broadband high density of states of hyperbolic modes.
关键词： hyperbolic modes,nano-optics,optical manipulation,metasurface,plasmon
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - Auckland, New Zealand (2018.8.5-2018.8.8)] 2018 IEEE Asia-Pacific Conference on Antennas and Propagation (APCAP) - A Metasurfaced Pyramidal Horn Antenna for Circularly-Polarized Applications
摘要： A high-gain circularly-polarized pyramidal horn antenna is developed by loading a thin metasurface linear-to-circular polarization (LP-CP) converter on the aperture of a standard pyramidal horn. The LP-CP converter is composed of two identical dielectric slabs, sandwiched by three subwavelength metallic element arrays. By placing the metasurface LP-CP converter on the aperture of a standard horn antenna, the linearly-polarized wave emitted by the horn can be converted to be circularly-polarized, without changing much other radiation performance. An example is given of a metasurface LP-CP converter and horn (metahorn) antenna that exhibits high gain and circular polarization. The measurement of this metahorn shows a 3-dB axial ratio bandwidth of 8.7%, with a maximum gain reduction of 2 dB, compared with that of the original air-filled standard pyramidal horn.
关键词： pyramidal horn,polarization converter,circularly-polarized,metasurface
更新于2025-09-09 09:28:46
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ANISOTROPIC ZERO INDEX MATERIAL: A METHOD OF REDUCING THE FOOTPRINT OF VIVALDI ANTENNAS IN THE UHF RANGE
摘要： In this work, an anisotropic zero index material is designed for use in Vivaldi antennas. The metasurface structures are placed within the aperture of a Vivaldi antenna to improve the directivity and gain of the emitted radiation. The range of operation is in the ultrahigh frequency (UHF) range, between 300 MHz and 3 GHz. Two approaches are presented: a type of resonant metallic metamaterial that belongs to the larger class of anisotropic zero index metamaterials and a non-resonant material. A technique for lowering the dimensions of the resonant metamaterial unit cell is presented and applied. The work presented consists of simulation results obtained with HFSS modelling software from ANSYS.
关键词： metasurface structures,gain,UHF range,Vivaldi antennas,anisotropic zero index material,directivity
更新于2025-09-04 15:30:14
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PHASE QUANTIZED METASURFACE SUPERCELLS FOR WAVE MANIPULATION AND RCS REDUCTION
摘要： Recently, the introduction of surface phase in Snell’s law and Huygens’ phenomena leads to ultrathin phased surfaces which can tailor the transmission and scattering of the incident wavefront in many ways. In this article, a remodeled Jerusalem cross used as the meta-element whose geometrical parameters are varied to obtain 360? phase variation and a 3-bit quantization is presented to design phase coded surfaces to manipulate (focusing and splitting) normally incident beam. Further, two 3-bit phase quantized supercells of approximately 2λ length and width are proposed and simulated (3 × 3 matrix arrangement) to test and compare the scattering properties with traditional chessboard type supercell. Obtained simulated results show di?used re?ections for both the models and reduced intensity of four corner lobes in comparison to chessboard supercells (at θ = 30? and φ = 45?). Experimentally recorded monostatic RCS of model-2 prototype has a close agreement with the simulated results and more than 10 dBsm RCS reduction observed from 9 GHz–11 GHz.
关键词： wave manipulation,metasurface,RCS reduction,phase quantization,Jerusalem cross
更新于2025-09-04 15:30:14
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[Institution of Engineering and Technology 12th European Conference on Antennas and Propagation (EuCAP 2018) - London, UK (9-13 April 2018)] 12th European Conference on Antennas and Propagation (EuCAP 2018) - Dual Polarized Metasurface for Microwave Energy Harvesting and Wireless Power Transfer
摘要： We introduce the design of a dual polarized metasurface collector based on the metamaterial full absorption concept for electromagnetic energy harvesting. Different from previous metamaterial absorber designs, here the power absorbed is mostly dissipated across a resistive load rather than in the dielectric substrate. This is achieved by channeling the absorbed power to an optimal resistive load through a via hole. The simulation results show that power absorption efficiency of 98% is achieved at an operating frequency of 2.5 GHz for a single unit cell. A super unit cell consisting of 4 cells with alternating vias was also designed to produce a dual polarized metasurface. The simulation results yielded a radiation to AC efficiency of around 90% for each polarization.
关键词： metamaterial,dual polarized,wireless power transfer,metasurface,microwave energy harvesting
更新于2025-09-04 15:30:14
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Chirality‐Assisted High‐Efficiency Metasurfaces with Independent Control of Phase, Amplitude, and Polarization
摘要： Simultaneously independent control of phase, amplitude, and polarization is pivotal yet challenging for manipulating electromagnetic waves by transmissive metasurfaces. Huygens’ metasurface affords a high-efficiency recipe primarily by engineering phase-only meta-atoms, restricting itself from realizing unprecedentedly complex functions of the transmission beam. Here, a 3D chirality-assisted metasurface concept relying on integrated magnetoelectric meta-atoms is proposed. It empowers the completely decoupled and arbitrary control of phase and amplitude at large incident angles and arbitrary polarizations. This strategy thus facilitates very sophisticated beam manipulations at close-to-unity cross-polarized efficiency via trilayer integrated resonators with mutual twist. The prescribed phase coverage can be determined by geometrical footprints of the unit cell, while the global azimuthal twist unlocks the capability of tuning amplitudes without affecting the phase. The concept and significance of it are validated to implement several proof-of-prototype demanding functionalities by thin metasurfaces of λo/12, which generate self-accelerating diffraction-free Airy beams, lateral and axial dual focusing, and even specific multiplexed beam shaping, respectively. This finding opens up an alternative way in very fine control of light with minimalist complexity and advanced performance. It can stimulate novel and high-performance versatile photonic metadevices, thanks to the fully independent control of phase, amplitude, and polarization.
关键词： decoupling,self-accelerating beams,wavefront control,chirality-assisted metasurface
更新于2025-09-04 15:30:14
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Analysis and design of a multi-function metasurface
摘要： In this paper, based on phase gradient principle, a multi-function dual-layer reflective metasurface is proposed for linear-to-circular (LTC) polarization conversion, beam control and gain improvement. The rotation of reflected circularly polarized wave is switched by the electric field direction of incident linearly polarized waves. At the same time, the reflective circularly polarized wave emerges anomalous refraction (45.6°). The maximum gain of the reflected wave is increased by 3.6dB (70%). The measured results and simulation results are in a reasonable agreement. The presented multi-function metasurface may offer unprecedented potentials for real-time, fast polarization conversion and beam control.
关键词： switch,phase gradient,metasurface,anomalous reflection
更新于2025-09-04 15:30:14
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Generation of Broadband Multiple OAM Modes Using Pancharatnam-Berry Metasurface
摘要： Vortex beams carrying orbital angular momentum (OAM) have been extensively realized using different approaches. Here, we present a Pancharatnam-Berry (PB) metasurface to generate broadband multiple vortex beams, which can carry different OAM modes towards different directions. The proposed PB metasurface could control the circularly polarized incident waves by attaching geometric phase to the orientation angle of the anisotropic meta-atoms. This design is numerically demonstrated at Ku band (12-18 GHz) and can be further exploited for OAM multiplexing in the communication systems.
关键词： vortex beam,Pancharatnam-Berry (PB) phase,Metasurface,orbital angular momentum (OAM)
更新于2025-09-04 15:30:14
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[IEEE 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Chengdu, China (2018.5.7-2018.5.11)] 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - A Reconfigurable Electromagnetic Metasurface with Bifunctional Illusions
摘要： A planar dynamically bifunctional metasurface is proposed to rebuild its scattering field as a convex or a concave mirror illusion. Generalized Snell’s law and phase compensation principle are used to analyze the proposed metasurface. A novel unit cell, with controlled reflection phase, is used to design the metasurface and transform electromagnetic illusion. The illusion performance of the presented metasurface is verified with simulation results. With the advantages of reconfigurability, low profile, and easy integration, the proposed metasurface can be widely used in the fields of electromagnetic metamaterials and scattering regulation.
关键词： phase gradient,electromagnetic illusion,scattering regulation,metasurface,reconfigurable
更新于2025-09-04 15:30:14
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Heat Resisting Metallic Meta-Skin for Simultaneous Microwave Broadband Scattering and Infrared Invisibility Based on Catenary Optical Field
摘要： Metallic skins are widely used in practical engineering owing to their inherent advantages in mechanical and physical characteristics. In this paper, a metasurface skin composed of subwavelength metallic gratings with space-variant orientations has been proposed to realize exotic electromagnetic properties in microwave and infrared regimes. Equivalent circuit theory and transfer matrix method have been adopted to quantitatively describe the optical fields and dispersion with high accuracy in a catenary form. Based on these analyses, broadband and wide-angle radar cross-section (RCS) reduction for microwave has been simulated and experimentally demonstrated. Additional characteristics such as high temperature resistance and low infrared thermal emission are also verified. It is believed that these results may provide a new platform to achieve multifunctional electromagnetic devices and are promising for many applications.
关键词： scattering,catenary optics,metasurface,thermal emission,all-metal metasurfaces
更新于2025-09-04 15:30:14