- 标题
- 摘要
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- 实验方案
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Beam steering characteristics of highly directive photoconductive dipole phased array antenna for terahertz imaging application
摘要： In this paper, the beam-steering characteristics of photoconductive dipole phased array antenna configuration at 1.95 THz is presented. The proposed array antenna configuration with frequency selective surface favourably improves its gain and directivity which is useful to upsurge the imaging capabilities to address the deliberations such as limited depth-of-field (DoF) and size-weight-and-power of the THz source for imaging applications. These are important considerations for applications like stand-off imaging and surveillance of moving targets where the high angular resolution as well as extended DoF are the important parameters for successful detection of concealed explosives. The projected planar profile and compact highly directive (2 × 2) small-gap photoconductive dipole phased array antenna can be castoff for the exposure of concealed explosives such as RDX, TNT, and HMX which illustrate their substantial spectral absorption fingerprints in terahertz (1.4–2.2 THz) regime of the spectrum. A simple method of beam-steering has been explored based on phase controlled optical excitation of highly directive small-gap photoconductive dipole array antenna. Further, the effects of uniform progressive phase shift on the beam-steering of uniform linear array (along x-axis) as well as planar array (x-axis and y-axis) is investigated.
关键词： Terahertz frequency,Uniform current distribution,Photoconductive dipole antenna,Phased array,Frequency selective surface
更新于2025-09-23 15:23:52
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A robust and versatile platform for image scanning microscopy enabling super-resolution FLIM
摘要： Image scanning microscopy (ISM) can improve the effective spatial resolution of confocal microscopy to its theoretical limit. However, current implementations are not robust or versatile, and are incompatible with fluorescence lifetime imaging (FLIM). We describe an implementation of ISM based on a single-photon detector array that enables super-resolution FLIM and improves multicolor, live-cell and in-depth imaging, thereby paving the way for a massive transition from confocal microscopy to ISM.
关键词： super-resolution,SPAD array,fluorescence lifetime imaging,confocal microscopy,image scanning microscopy
更新于2025-09-23 15:23:52
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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) - A Novel mm-Wave Phased Array for 180° coverage for 5G Smartphone Applications
摘要： A one-dimensional array configuration capable of providing 1800 coverage for future mm-Wave 5G communications is presented. The proposed antenna array consists of 16 antenna elements located at the bottom edge of the mobile phone chassis of which 8 antenna elements are dual-polarized, broadband, broadside capacitive loaded patch antennas and the other 8 elements are broadband end-fire modified Yagi-Uda antennas placed alternately. The array configuration and its performance are discussed. The antenna element and its working principle are also presented. The proposed antenna elements exhibit wide bandwidth, low-cost fabrication uniform radiation pattern and use technique. The antenna array achieves a minimum realized gain of 12.1 dBi throughout the 1800 sector making it suitable for implementation for 5G smartphone applications.
关键词： Yagi Uda,phased array,smartphone,patch antenna,mm-Wave,5G,antenna
更新于2025-09-23 15:23:52
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[IEEE 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - Waterloo, ON (2018.8.19-2018.8.22)] 2018 18th International Symposium on Antenna Technology and Applied Electromagnetics (ANTEM) - A Log-Periodic Monopole Array with Uniform Spacing
摘要： This paper presents a log-periodic monopole array antenna with end-fire radiation and vertical polarization. It consists of 13 monopole elements and a meandering microstrip line on the bottom as the feeding line. The adjacent monopoles are of uniform spacing instead of conventional logarithmic spacing. A prototype is fabricated and tested. Measured results show that an impedance bandwidth from 2 to 6 GHz (3:1) for VSWR < 2 and a realized gain better than 7.6 dBi over the same operating frequency band are obtained.
关键词： log-periodic antenna,End-fire radiation,monopole array,uniform spacing
更新于2025-09-23 15:23:52
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[IEEE 2017 5th International Conference on Mechanical, Automotive and Materials Engineering (CMAME) - Guangzhou (2017.8.1-2017.8.3)] 2017 5th International Conference on Mechanical, Automotive and Materials Engineering (CMAME) - Modeling and Application of Output Current of the Solar Array for Satellite in Sun Synchronous Orbit
摘要： The output current of the solar array for satellite in sun synchronous orbit is a critical parameter for performance in-orbit analyzing. In order to analysis the rules of the solar array output current accurately, some influential factors, such as the incidence angle of the sun, the temperature of the solar array, the earth-sun distance factor and the fixed offset angle to the sun of solar wing, are comprehensively researched. Then a model of output current is established. Results in-orbit show that the model has high accuracy, which can provide a reference for optimization design of satellite solar array.
关键词： the solar array,modeling,output current,sun synchronous orbit,satellite
更新于2025-09-23 15:23:52
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[IEEE 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Paris (2018.7.8-2018.7.13)] 2018 Conference on Precision Electromagnetic Measurements (CPEM 2018) - Open-Source Package for PJVS Testing and Calibration
摘要： This paper describes a software package for PJVS automated measurements written in Python, an interpreted programming language widely used in scientific applications. The code is modular and expandable with the support of many libraries allowing easy reconfiguration for different calibration and testing purposes.
关键词： Python,measurement software,programmable Josephson array,Voltage standards,open source
更新于2025-09-23 15:23:52
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[IEEE 2018 IEEE Industry Applications Society Annual Meeting (IAS) - Portland, OR, USA (2018.9.23-2018.9.27)] 2018 IEEE Industry Applications Society Annual Meeting (IAS) - Performance Based Design of IMD for Single Stage PV Fed Water Pumping
摘要： This paper presents an improved designed induction motor, used for photovoltaic (PV) array fed water pumping system. The overall system is designed without a mechanical sensor to reduce both cost and complexity with simultaneous assurance of optimum power utilization of a PV array. The proposed system consists of an induction motor operated water pump, controlled by field-oriented control (FOC) with artificial neural network (ANN) current control technique. The MPPT (Maximum Power Point Tracking) as well as DC link voltage, is regulated by three-phase voltage source inverter (VSI). The estimation of motor speed eliminates the use of mechanical sensor and makes the system cheaper and robust. A new robust speed adaptive algorithm is presented, which is less dependent on parameters. A detailed study of various factors affecting the efficiency of the motor, is given to improve the behavior of the induction motor drive (IMD) for water pumping. The designed motor is tested on the developed prototype in the laboratory and its suitability is judged through various results under steady state and dynamic conditions of insolation variations.
关键词： Field-Oriented Control (FOC),Speed Adaptation,Finite Element Method,ANN Based Current Control,IMD (Induction Motor Drive),Water pump,PV Array,P&O Based MPPT Algorithm
更新于2025-09-23 15:23:52
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Dual-Linear Polarized Phased Array with 9:1 Bandwidth and 60° Scanning off Broadside
摘要： We present for the first time a novel dual-linear polarized tightly coupled dipole array (TCDA) with integrated balun operating across a 9:1 bandwidth, from 2GHz to 18GHz. This dual-linear polarized array employs a tightly coupled dipole topology and scans down to 60° from boresight. The overall geometry consists of cross-located tightly coupled dipoles integrated with a folded Marchand balun that serves as an impedance transformer to achieve a wideband feeding network. Notably, the traditional dielectric superstrate is replaced with double layers of frequency selective surfaces (FSS) to enable scanning down to 60° in both E-, H-, and diagonal (D-) planes across the entire band. The design achieves VSWR<3 across 2 to 18GHz at broadside. This dual-polarized array is also demonstrated to have a good polarization isolation of -20dB for most of the band. The array’s total height is less than 12mm (λlow/10). The design is validated through fabrication and testing of an 11×11 prototype. Measurements of this prototype are presented and are in good agreement with simulations.
关键词： tightly coupled dipole array,low profile array,ultra-wideband,wide-angle scanning
更新于2025-09-23 15:22:29
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[IEEE 2018 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC) - Xuzhou (2018.7.21-2018.7.24)] 2018 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC) - Three Methods to Generate Orbital Angular Momentum Beams in Microwaves
摘要： This paper reviews three methods to generate orbital angular momentum (OAM) beams in microwave region. Circular patch array, Vivaldi connecting array and microstrip ring antenna are the potential candidates. The first two utilizes phased array technique, which needs complex feeding network, while the later method uses the higher modes of microstrip ring. Vortex OAM beams can be observed in all the methods.
关键词： Orbital angular momentum,microstrip ring antenna,patch antenna array,Vivaldi connecting array
更新于2025-09-23 15:22:29
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[IEEE 2018 International Conference on Current Trends towards Converging Technologies (ICCTCT) - Coimbatore (2018.3.1-2018.3.3)] 2018 International Conference on Current Trends towards Converging Technologies (ICCTCT) - Implementation of Differential Power Processing to Optimize the Solar Power Generation
摘要： The objective of this paper is to harvest the optimum power from solar panel using different MPPT techniques for low power application under non-uniform irradiance conditions. The overall power output of photovoltaic system is reduced due to partial shading. A new differential power converter along with INC control algorithm is introduced to reduce the partial shading effect and oscillations of output power.
关键词： Differential power processing,Maximum Power Point Tracking (MPPT) techniques,Photo-Voltaic (PV) array,Maximum Power Point (MPP),Partial Shading Condition (PSC)
更新于2025-09-23 15:22:29