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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • Signal-to-Noise Ratio (SNR)
  • Infinite Gain Multiple Feedback (IGMF)
  • Visible Light Communications (VLC)
  • LED
  • Trans-Impedance Amplifier (TIA)
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • University of Northumbria
  • University of Huddersfield
233 条数据
?? 中文（中国） ▾

  • ANFIS Based Voltage Determination for Photovoltaic Systems According to the Specific Cell Parameters, and a Simulation for the Non-Isolated High Gain DCa??DC Boost Converter Control Regard to Voltage Fluctuations

    摘要： In this study, a solar panel is modeled and parametric simulation studies are performed with Ansys-Electronics 2019 R2 software according to atmospheric and temperature coefficient parameters that affect the efficiency of electrical energy produced in photovoltaic (PV) systems. Based on parametric simulation studies, 482 data of the voltage value of the electrical energy produced were obtained. Then a certain part of this data was used for training in Adaptive Network Fuzzy Inference System (ANFIS) algorithms and the system was tested with the estimated values produced. Thus, in the generation of solar and electrical energy, the duty ratio controller performance designed with an uninsulated DC–DC converter circuit proposed to generate a 400 V constant value DC bus voltage at the output due to voltage changes at the input is reported.

    关键词： Non-Isolated High Gain converter,photovoltaic (PV) systems,parametric simulation,Adaptive Network Fuzzy Inference System (ANFIS)

    更新于2025-09-23 15:19:57

  • Gain characteristics of the hybrid slot waveguide amplifiers integrated with NaYF <sub/>4</sub> :Er <sup>3+</sup> NPs-PMMA covalently linked nanocomposites

    摘要： Waveguide amplifiers based on slot waveguide have enormous capacity due to their ability to confine light strongly to a narrow slot waveguide. NaYF4:Er3+ nanoparticles-polymeric methyl methacrylate covalently linked nanocomposites were synthesized and filled into the slot. The stability and the Er3+ concentration doped in this novel material were improved. The slot waveguide was designed accurately. The rigorous numerical method, full-vector finite difference method, was used to analyze the modal characteristics and optimize the slot combined with the maximum power confinement in the slot and the minimum effective mode area of the slot. A four-level spectroscopic model pumped at 1480 nm was presented. The rate equations and propagation equations were solved and the gain characteristics of the slot waveguide amplifier were numerically simulated. The primary parameters were optimized. A net gain of 5.78 dB was achieved when the signal power was 0.001 mW at 1530 nm, pump power was 20 mW, Er3+ concentration was 1.3 (cid:1) 1027 m(cid:3)3, and the waveguide length was 1.5 cm.

    关键词： NaYF4:Er3+ NPs-PMMA,slot waveguide,erbium-doped polymer waveguide amplifier,full-vector finite difference method,gain characteristics

    更新于2025-09-23 15:19:57

  • Observation of edge solitons in photonic graphene

    摘要： Edge states emerge in diverse areas of science, offering promising opportunities for the development of future electronic or optoelectronic devices, sound and light propagation control in acoustics and photonics. Previous experiments on edge states in photonics were carried out mostly in linear regimes, but the current belief is that nonlinearity introduces more striking features into physics of edge states, leading to the formation of edge solitons, optical isolation, making possible stable lasing in such states, to name a few. Here we report the observation of edge solitons at the zigzag edge of a reconfigurable photonic graphene lattice created via the effect of electromagnetically induced transparency in an atomic vapor cell with controllable nonlinearity. To obtain edge solitons, Raman gain is introduced to compensate strong absorption experienced by the edge state during propagation. Our observations may open the way for future experimental exploration of topological photonics on this nonlinear, reconfigurable platform.

    关键词： topological photonics,nonlinearity,Raman gain,edge solitons,photonic graphene

    更新于2025-09-23 15:19:57

  • Fractal Analysis - Applications in Physics, Engineering and Technology || Fractals in Antennas and Metamaterials Applications

    摘要： Recently, telecommunications systems have been requiring more advanced features in the design and operation. Among others a smaller size of devices, which can be integrated for multiple mobile communications systems, applied in one user's device board, such as PDA or smartphone. Moreover, the cost of mass production should be minimized as much as possible. To meet part of that request, the antennas of these devices should have small size, lower weight, operating in multiple frequency bands and/or be broadband. There are many research methods to achieve this goal, one of which is using the fractal geometries for the shape of antenna elements. In recent years, there are many fractal shapes that have been proposed for such applications, and the designed antennas have significantly improved antenna features such as smaller size, operating in multi-frequency bands, with improved power gain and efficiency. In recent years, the new approach for modern antenna the metamaterials, MTM, is adopted, and sometimes that based on the fractal geometry is adopted.

    关键词： fractal geometries,fractal antenna,antenna array,efficiency,fractal dimension,IFS,metamaterials,power gain,MTM,multiband,antenna elements,compact size

    更新于2025-09-19 17:15:36

  • Modeling degraded performance metrics of optical amplifiers under radiation

    摘要： Gain, noise figure (NF), and output power are considered the common performance metrics of an optical fiber amplifier. With an increasing interest of space industry in developing technologies for satellite-ground and intersatellite communication in the optical band, the EDFA (erbium doped fiber amplifier) is needed as power amplifier in space to compensate attenuation and insertion losses between the building blocks of the architecture. There is very little research on modeling the degradation mechanisms of typical commercial fibers, specifically on the NF and output power metrics, that requires knownledge of the insertion losses at the entrance of the fiber for both the pump and the signal wavelengths λp and λs. In this brief report we propose that the noise figure and output power trends can be extrapolated from a semi-empirical model for the insertion losses proved at high and low dose rates at two different temperatures. The results show reasonable trends that a common off-the shelf EDFA can present in co-propagating configuration on the NF and output power under several doses at low and high rates. The radiation losses using non-hardened fiber show sustainable attenuation levels in dB that can possibly allow employing this off-the shelf fibers in CubeSats or small satellites without the need of special radiation insulation. It is further supported with theoretical data that the temperature factor can affect more the EDFA degradation in space than the radiation itself, imposing limits on the temperature control of commercial satellites using this photonics.

    关键词： Noise,Figure,Gain,Radiation,Power,EDFA

    更新于2025-09-19 17:15:36

  • [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) - Design of a High-Gain Millimeter-Wave Antenna Using Characteristic Modes

    摘要： This paper proposes the use of the Theory of Characteristic Modes to aid the design of high-gain antennas for mm-wave applications. A new lens antenna operating in the 19 to 22 GHz band is proposed. The lens consists of two metallic rings distributed in two layers and illuminated by a square aperture. The Theory of Characteristic Modes is used to analyze the proposed antenna in order to provide insight into the radiation characteristics of the structure. The proposed antenna has been optimized, obtaining a large bandwidth and a maximum directivity of 11.19 dBi at 22 GHz.

    关键词： propagation,characteristic modes,high gain,Lens antenna

    更新于2025-09-19 17:15:36

  • [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) - V-Band High-Gain Slot Antenna Using Single Layer Partially Reflective Surface

    摘要： In this paper, a novel design of a high-gain and wideband slot antenna operating at V-band is presented. The gain and bandwidth enhancements are achieved by feeding a simple radiating slot with a ridge-gap waveguide and placing a single layer superstrate above the antenna. The superstrate is based on a complementary frequency selective surface which provides positive phase gradient over the frequency range 47 to 65 GHz. Numerical simulations of the proposed design demonstrate a gain enhancement of 8.3 dB at 63 GHz when compared with the antenna without the superstrate, and 3-dB gain bandwidth of about 5 GHz. Moreover, the antenna is matched to the feeding ridge-gap waveguide over the frequency range of 56.0 to 66.7 GHz.

    关键词： ridge-gap waveguide,high-gain,V-band

    更新于2025-09-19 17:15:36

  • [IEEE IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society - D.C., DC, USA (2018.10.21-2018.10.23)] IECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society - An Exact Time Domain Analysis of DCM Boost Mode LLC Resonant Converter for PV applications

    摘要： The search for a cost feasible, optimal design of LLC converter for wide input voltage range conditions is inhibited by errors in steady state values of peak gain, tank current, tank voltage, active power etc., due to various approximations in the analysis. This leads to erroneous selection of circuit parameters. The present work provides an exact, approximation free time domain mathematical model of LLC converter operating in transformer secondary current discontinuous mode (DCM) below resonance in boost mode. The proposed approach defines voltage gain as a function of relative switching frequency (ω) and td, which represents the rectifier diode to switch conduction ratio for DCM operation. Existing works have defined voltage gain as an explicit function of quality factor (Q) and ω. The current approach leads to accurate derivation of converter voltage gain, tank RMS current, tank capacitor voltage, zero voltage switching (ZVS) angle etc. Analytical expressions are validated with simulation studies using PSIM for various inductor ratio values. A final design is verified on an experimental prototype of 320W output LLC converter designed for an input range of 20-40V for solar PV applications.

    关键词： LLC,peak gain,DCM,time domain

    更新于2025-09-19 17:15:36

  • A Compact Wideband High-Gain Metasurface-Lens-Corrected Conical Horn Antenna

    摘要： In this paper, a compact wideband high-gain metasurface-lens-corrected conical horn (meta-horn) antenna is developed. A metasurface lens that has a thickness of less than 0.1λ is developed to provide wideband transmission phase compensation, with high transmission efficiency. The ultra-thin lens is then used to develop a wideband high-gain horn antenna that has a shorter horn length and a large flare angle, resulting in a compact horn structure that is easy to be fabricated and mounted, and at a low cost. Simulations and experiments were conducted to demonstrate the effectiveness of the design. Measured results show that the meta-horn has a peak gain of 24.2 dBi and a 3-dB gain bandwidth of over 26%.

    关键词： horn antenna,flare angle,metasurface lens,high-gain

    更新于2025-09-19 17:15:36

  • Fast and accurate model for a coax-fed rectangular patch antenna with varying aspect ratio, feed location and substrate electrical parameters

    摘要： An improved closed-form model based on cavity model and single resonant parallel R-L-C circuit analysis is proposed to predict the resonant frequency, quality factor, bandwidth, gain and input impedance of a coax-fed rectangular patch antenna as a function of aspect ratio, feed location and substrate electrical parameters. The computed values employing the present model are compared with our experimental results and experimental results available in open literature. We have also employed electromagnetic high-frequency structure simulator (HFSS) software to validate the model. The present model shows very close agreements with the experimental and simulation results compared to the other models. This model is very simple, fast and accurate. The present model can be directly applied to CAD program.

    关键词： Improved closed-form model,microstrip antennas,gain,bandwidth,input impedance,resonant frequency,quality factors

    更新于2025-09-19 17:15:36