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[IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Radiation Patterns of Monopole Nano-Antenna Placed on Finite Size Metal Screen
摘要： Directive properties of monopole nano-antenna formed by carbon nanotube placed perpendicularly to metal rectangular screen are investigated. On the base of the method of the uniform geometric diffraction theory the asymptotic solution of the 3D vector problem of diffraction of the field of impedance monopole with radius r and length l placed on the ideally conducting rectangular screen is obtained. The fast-active algorithms and software for calculating 3-D patterns of this radiating system are developed. Analysis of the radiation patterns and directivity versus the screen sizes is carried out.
关键词： ellipticity,directivity,carbon nanotube antenna,square screen,radiation pattern,impedance monopole
更新于2025-09-19 17:13:59
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Metasurface-enabled interference mitigation in visible light communication architectures
摘要： Light can be used for wireless information transmission apart from illumination; that is the key idea behind visible-light communication (VLC), one of the disruptive technologies of our days. It combines remarkably high data rates due to ultrashort wavelengths with huge reliability and security due to small distances; nevertheless, it substantially suffers from interference of neighboring light sources in multiple-link configurations. In this manuscript, we investigate a pair of light emitting diodes interfering each other and propose a simple nanoslit metasurface that radically increases the directivity of the transmitting beams. As a result, enhancement of the signal-to-interference ratio by several orders of magnitude is reported. The considered generic setup retains its beneficial features in the presence of realistic design defects and, accordingly, may inspire standardization efforts towards the adoption of VLC in next-generation heterogeneous communication networks.
关键词： directivity,metasurface,visible-light communications,radiation pattern,indoor environment
更新于2025-09-19 17:13:59
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[IEEE 2019 TEQIP III Sponsored International Conference on Microwave Integrated Circuits, Photonics and Wireless Networks (IMICPW) - Tiruchirappalli, India (2019.5.22-2019.5.24)] 2019 TEQIP III Sponsored International Conference on Microwave Integrated Circuits, Photonics and Wireless Networks (IMICPW) - Metasurface Loaded Patch Antenna For Wi-Fi Applications
摘要： Design of rectangular patch antenna with hexagonal shaped metasurfaces for Wi-Fi applications. In this paper, the corners of the rectangular patch are replaced by means of circular structures. This will remove the sharp transition and the desired frequency is achieved with smaller dimension in comparison with normal rectangular patch. A layer of metasurface elements is added with the antenna to improve the return loss. The proposed antenna is radiating at resonant frequency of 2.4 GHz with the gain value of 6.8 dB. The bandwidth is achieved from 2.37 GHz to 2.43 GHz around the resonant frequency of 2.4 GHz.
关键词： metasurface,antenna gain,radiation pattern,Wi-Fi
更新于2025-09-16 10:30:52
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[IEEE 2019 IEEE 2nd Ukraine Conference on Electrical and Computer Engineering (UKRCON) - Lviv, Ukraine (2019.7.2-2019.7.6)] 2019 IEEE 2nd Ukraine Conference on Electrical and Computer Engineering (UKRCON) - Radiating Unit Based on Inverted Dielectric Waveguide
摘要： The results of the experimental research of the radiating structure, based on inverted dielectric waveguide with metal plane and periodic sequence of auxiliary partially-metallized dielectric rods, are presented. The attenuation and VSWR measurements have been carried out in a wide frequency range. The near field amplitude has been measured through the moving probe method. The radiation energy characteristics have been measured.
关键词： VSWR,radiation pattern,inverted isolated dielectric waveguide,attenuation
更新于2025-09-16 10:30:52
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[IEEE 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA) - Granada, Spain (2019.9.9-2019.9.13)] 2019 International Conference on Electromagnetics in Advanced Applications (ICEAA) - Radiation of Electromagnetic Waves from a Nonsymmetric Antenna Located on the Surface of an Open Gyrotropic Cylindrical Waveguide
摘要： Radiation characteristics of an antenna with the nonsymmetric current specified on the surface of an open gyrotropic cylindrical waveguide is studied. As the filling medium of the waveguide, a cold magnetoplasma is considered. The radiation pattern of such a source is calculated using an approach based on an expansion of the total field in terms of the discrete- and continuous-spectrum waves of the waveguide. Conditions are found under which the presence of a gyrotropic guiding structure significantly affects the radiation pattern of the antenna.
关键词： helical antennas,magnetoplasma,radiation pattern
更新于2025-09-16 10:30:52
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Holey metasurface prism for the reduction of the dispersion of gap waveguide leaky-wave antennas
摘要： Leaky-wave antennas (LWA) are dispersive, meaning that the direction of maximum radiation is a function of frequency. This behavior, called “beam squinting effect” can be reduced by introducing a dispersive metamaterial prism. In this paper a holey metasurface prism is combined with a leaky-wave antenna in gap waveguide technology. The dispersion characteristics of the hole unit cell are studied in order to achieve the reduction of the main beam steering aiming to ±1o or less variation. A prototype designed at the Ka band is measured and compared with the simulation results.
关键词： groove gap waveguide,leaky-wave antenna,metasurface prism,dispersive radiation pattern
更新于2025-09-12 10:27:22
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[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Simulations of LED Patterned with IP-DIP Woodpile Structure
摘要： In this paper, we present simulations of three-dimensional (3D) photonic crystal structure (PhC) in IP-Dip polymer. We investigated woodpile structure and LED patterned by woodpile structure by various simulation methods. Structure was designed by the computer aided design (CAD) and optical properties were simulated by finite-difference time-domain (FDTD) and rigorous coupled-wave analyses (RCWA) simulation methods. We are focused on diffraction of optical radiation by woodpile structure and possibility of influencing extraction ratio and radiation patterns of LED with patterned woodpile structure. There is improving a significant percentage of transmittance of the radiation. It results in the influence of the radiation from the LED and it has positive impact on the LED parameters.
关键词： photonic crystal,simulations,3D woodpile structure,light extraction,photonic band gap,radiation pattern
更新于2025-09-11 14:15:04
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High-Performance Smooth-Walled Horn Antennas for THz Frequency Range: Design and Evaluation
摘要： Traditionally, corrugated conical horn antennas have been the main choice for use in astronomical receivers in the range of millimeter and submillimeter waves. They present low cross-polar level and high coupling efficiency into the fundamental Gaussian mode. However, this type of antenna is difficult to manufacture, inevitably increasing its price and extending the production process. In this work, we present two kinds of feed horn antennas, aimed for use in a frequency range equivalent to ALMA Band 6 (211-275 GHz), which can be fabricated in a much simpler way with conventional machining tools. Specifically, we present the design and performance comparison of smooth-walled spline-profile horns in two geometries, diagonal and conical. Optimization of the designs has been made by means of an algorithm that allowed us to obtain models whose electrical and mechanical characteristics make them competitive when compared with corrugated horns. In particular, they are 40% shorter than conventional corrugated horns suited for this band, representing an advantage given the stringent space constraints of most astronomical receivers. We also demonstrate that they can be coupled efficiently to an astronomical-grade optical system, using ALMA Band-6 receiver as an example. Furthermore, we have constructed the diagonal horn and characterized it thoroughly. Experimental results of the radiation pattern at room temperature show a good cross-polar performance with levels below ?20 dB and gaussicity above 96%. Our calculations show a good antenna-efficiency level with losses less than 1%. All these properties demonstrate the feasibility of this type of horns to become the main option at the time of choosing a feed system for cutting-edge astronomical applications.
关键词： diagonal horn,spline-profile,conical horn,ALMA,optical train calculation,radiation pattern measurements,profile optimization,millimeter/submillimeter wave,split-block
更新于2025-09-11 14:15:04
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Electronically Beam-Steering Antenna with Active Frequency Selective Surface
摘要： A beam-sweeping antenna utilizing a novel active frequency selective surface (FSS) is developed in this letter. It is comprised of a simple dipole and a cylindrical FSS formed by six columns of unit cells. The dipole used as a radiating source is situated at the center of the cylindrical FSS. The radiation pattern of the antenna could be reconfigured by controlling the states of the PIN diodes in the FSS. The dimension of the whole antenna is 0.75 λg × 0.75 λg × 1.57 λg (λg is the guided wavelength at its resonant frequency). Experimental results demonstrate that the presented beam-steering antenna can operate at 2.45 GHz and the main beam can be swept across the whole azimuth plane with a peak gain of 8.15 dBi.
关键词： beam-sweeping,frequency selective surface,Radiation pattern,beam-switching
更新于2025-09-10 09:29:36
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[IEEE 2018 12th International Congress on Artificial Materials for Novel Wave Phenomena (Metamaterials) - Espoo, Finland (2018.8.27-2018.9.1)] 2018 12th International Congress on Artificial Materials for Novel Wave Phenomena (Metamaterials) - Design of a Patch Antenna with a Sector Radiation Pattern by Exploiting Topological Properties of Vortex Fields
摘要： Topological properties of vortex fields have witnessed an increasing attention due to a wide spread of possible applications at both microwave and optical frequencies. In particular, we have recently shown that composite vortices, i.e. superposition of vortex fields with different topological charges, can be exploited to manipulate the radiation pattern of a microwave patch antenna. In this contribution, we further explore the generation and manipulation of composite vortices in order to design a single patch antenna that exhibits a sector radiation pattern and emulates the radiation properties of a dipole placed at a quarter of wavelength from a reflector.
关键词： vortex fields,dipole,topological properties,patch antenna,sector radiation pattern
更新于2025-09-10 09:29:36