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An Inclusive Survey on array Antenna Design for Millimeter-Wave Communications

IEEE ACCESS 2019年 7卷 83137-83161页

作者： Ghosh, Saswati Sen, Debarati IIT Kharagpur GS Sanyal Sch Telecommun Kharagpur 721302 W Bengal India

The enormous growth of wireless data traffic in recent years has made the millimeter-wave (mm-wave) technology as a good fit for high-speed communication systems. Extensive works are continuing from the device to system, to the radio architecture, to the network to support the communication in mm-wave frequency ranges. To support this extensive high data rate, beam forming is found to be the key-enabling technology. Hence, an array antenna design is an extremely important issue. The beam-forming arrays are chosen to achieve the desired link capacity considering the high path loss and atmospheric loss at mm-wave frequencies and also to increase the coverage of the mm-wave communication system. There are diverse design challenges of the array due to the small size, use of large numbers of antennas in close vicinity, integration with radio-frequency (RF) front ends, hardware constraints, and so on. This paper focuses on the evolution and development of mm-wave array antenna and its implementation for wireless communication and numerous other related areas. The scope of the discussion is extended on the reported works in every sphere of mm-wave antenna array design, including the selection of antenna elements, array configurations, feed mechanism, integration with front-end circuitry to understand the effects on system performance, and the underlying reason of it. The new design aspects and research directions are unfolded as a result of this discussion.

关键词： Mm-wave communication antenna array design array configuration feed mechanism RF circuit

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Flume investigation of landslide debris-resisting baffles

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CANADIAN GEOTECHNICAL JOURNAL 2014年第5期51卷 540-553页

作者： Choi, C. E. Ng, C. W. W. Song, D. Kwan, J. H. S. Shiu, H. Y. K. Ho, K. K. S. Koo, R. C. H. Hong Kong Univ Sci & Technol Dept Civil & Environm Engn Kowloon Hong Kong Peoples R China HKSAR Civil Engn & Dev Dept Geotech Engn Off Hong Kong Hong Kong Peoples R China

Landslide debris is a common occurrence in mountainous regions around the world that can potentially result in disastrous consequences to downstream facilities. Flow-impeding structures are often constructed along the flow path to impede this hazardous phenomenon. Baffles are a type of flow-impeding structure regularly installed using empirical and prescriptive design methods as the interaction mechanism and the influence of baffle configuration on flow impedance is not well understood. A series of flume experiments were carried out to investigate flows characterizing landslide debris impacting an array of baffles using dry uniform sand. The influence of baffle height, row number, and spacing between successive rows was examined. Photoconductive sensors were used to estimate flow velocity, laser sensors were installed to measure flow depth profiles, and high-speed cameras were used to capture flow kinematics. Experimental results reveal that baffles can be categorized relative to the approach flow depth (h) and increasing the baffle height from 0.75h to 1.5h leads to a 40% increase in upstream flow depths from backwater effects, more effective development of subcritical conditions, and additional energy losses of up to 9%. Increasing the number of rows of 1.5h baffles from a single row to a three-row staggered array results in up to 72% additional energy loss. The energy loss is attributed to the deflection of granular jets and additional backwater effects. Increasing the row spacing from 50 to 100 mm results in up to a 14% increase in energy loss.

关键词： landslide debris flume modelling baffles array configuration flow impedance

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Measurements of the wake characteristics of co- and counter-rotating twin H-rotor vertical axis wind turbines

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ENERGY 2017年 131卷 13-26页

作者： Lam, H. F. Peng, H. Y. City Univ Hong Kong Dept Architecture & Civil Engn Hong Kong Hong Kong Peoples R China

Increasing the efficiency of individual vertical-axis wind turbines (VAWTs) has been the subject of much research. However, wind farms that comprise individual VAWTs are not necessarily the most efficient configuration in accordance with VAWTs' signature wake pattern. This study aims to identify efficient array configurations and thereby increase the packing density and power output by grouping individual VAWTs as a unit. Systematic measurements of wake aerodynamics of co-rotating and counter-rotating (forward- and backward-rotating) twin VAWTs were taken in a wind tunnel. The wake was measured both along the blade mid-span plane up to 10 turbine diameters (10D) and along the vertical plane. The wake of co-rotating twin VAWTs showed great asymmetry, similar to that of a single VAWT. Interestingly, the wake of counter-rotating twin VAWTs demonstrated elegant symmetric patterns. Two pairs of stationary counter-rotating vortices were found to evolve in the wake. The turbulence intensity down-stream was observed to experience drastic changes and slow recovery compared with its velocity counterpart. Finally, two types of array units are proposed for applications in wind farms in accordance with the measurements. (C) 2017 Elsevier Ltd. All rights reserved.

关键词： Twin VAWTs array configuration Wake aerodynamics Wind tunnel Co-rotating Counter-rotating

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MATLAB-based modeling to study the effects of partial shading on PV array characteristics

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IEEE TRANSACTIONS ON ENERGY CONVERSION 2008年第1期23卷 302-310页

作者： Patel, Hiren Agarwal, Vivek Indian Inst Technol Dept Elect Engn Bombay 400076 Maharashtra India Sarvajanik Coll Engn & Technol Surat 395001 India

The performance of a photovoltaic (PV) array is affected by temperature, solar insolation, shading, and array configuration. Often, the PV arrays get shadowed, completely or partially, by the passing clouds, neighboring buildings and towers, trees, and utility and telephone poles. The situation is of particular interest in case of large PV installations such as those used in distributed power generation schemes. Under partially shaded conditions, the PV characteristics get more complex with multiple peaks. Yet, it is very important to understand and predict them in order to extract the maximum possible power. This paper presents a MATLAB-based modeling and simulation scheme suitable for studying the I-V and P-V characteristics of a PV array under a nonuniform insolation due to partial shading. It can also be used for developing and evaluating new maximum power point tracking techniques, especially for partially shaded conditions. The proposed models conveniently interface with the models of power electronic converters, which is a very useful feature. It can also be used as a tool to study the effects of shading patterns on PV panels having different configurations. It is observed that, for a given number of PV modules, the array configuration (how many modules in series and how many in parallel) significantly affects the maximum available power under partially shaded conditions. This is another aspect to which the developed tool can be applied. The model has been experimentally validated and the usefulness of this research is highlighted with the help of several illustrations. The MATLAB code of the developed model is freely available for download.

关键词： array configuration maximum power point tracking (MPPT) partial shading photovoltaic (PV) characteristics

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Clutter Rank Analysis in Airborne FDA-MIMO Radar With Range Ambiguity

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IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS 2022年第2期58卷 1416-1430页

作者： Wang, Keyi Liao, Guisheng Xu, Jingwei Zhang, Yuhong Huang, Lei Xidian Univ Natl Lab Radar Signal Proc Xian 710071 Peoples R China Xidian Univ Sch Elect Engn Xian 710071 Peoples R China Shenzhen Univ Coll Informat Engn Shenzhen 518060 Peoples R China

Frequency diverse array (FDA), which employs a small frequency increment across its array elements to generate controllable degrees-of-freedom (DOFs) in range dimension, has attracted extensive attentions in recent years. In order to extract and exploit the DOFs in range and angle dimensions, FDA has been combined with multiple-input multiple-output (MIMO) technique, which shows sufficient performance improvement in clutter suppression in scenarios with range ambiguities. Therefore, clutter rank evaluation is an important issue for FDA-MIMO radar mounted on a moving platform. In this article, a clutter rank evaluation criterion is developed with respect to different transmit/receive array configurations and different number of range ambiguities. It is based on a subspace transformation matrix that decouples the clutter subspace and allows a direct determination of clutter rank. With the proposed clutter rank evaluation criterion, the maximum resolvable number of range ambiguities can be determined, which is bounded by the system's DOFs. Three cases according to different relationships between uniform array element spacings are studied. Then, the aforementioned clutter rank evaluation method is extended to nonuniform array configurations. Moreover, the robustness of the method is studied in the presence of gain-phase errors. Several simulation results are provided to verify the effectiveness of the proposed method.

关键词： Clutter Radar Radar clutter MIMO radar Airborne radar MIMO communication Frequency diversity array configuration clutter rank frequency diverse array (FDA) multiple-input multiple-output (MIMO) range ambiguity

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60GHz wideband LTCC microstrip patch antenna array with parasitic surrounding stacked patches

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IET MICROWAVES ANTENNAS & PROPAGATION 2019年第1期13卷 35-41页

作者： Lee, Hua-Juan Li, Eric S. Jin, Huayan Li, Chung-Yi Chin, Kuo-Sheng Chang Gung Univ Dept Elect Engn Taoyuan Taiwan Natl Taipei Univ Technol Dept Elect Engn Taipei Taiwan Hangzhou Dianzi Univ Sch Elect & Informat Hangzhou Zhejiang Peoples R China

This work presents a wideband 60GHz microstrip patch antenna (MPA) array based on low-temperature co-fired ceramic (LTCC) multilayer technology. Four parasitic patches are stacked above the driven MPA. An additional resonant mode is excited by the proposed parasitic surrounding stacked patches (PSSPs) to enhance the bandwidth of the MPA. The structure of the PSSPs increases the gain of the MPA due to its array configuration. The proposed PSSP structure can find many applications in designs for large-scale antenna arrays because the PSSPs and the driven microstrip patch are distributed at different layers. This arrangement allows a direct feed network to the MPA without the blockage caused by the PSSPs. A 2x2 antenna array was designed and fabricated with the PSSPs to further increase its gain. The proposed array can achieve a gain of 10.5dBi and a wide bandwidth of 27.3% at 60GHz.

关键词： millimetre wave antenna arrays microstrip antenna arrays antenna feeds ceramics wideband LTCC microstrip patch antenna array parasitic surrounding stacked patches low-temperature co-fired ceramic multilayer technology LTCC multilayer technology MPA PSSP array configuration large-scale antenna arrays direct feed network frequency 60 GHz

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Analysis of electrical behaviour of PV arrays covered with non-uniform snow

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ELECTRONICS LETTERS 2020年第4期56卷 192-194页

作者： Hosseini, S. Taheri, S. Pouresmaeil, E. Taheri, H. Univ Quebec Outaouais Dept Comp Sci & Engn Gatineau PQ Canada Aalto Univ Dept Elect Engn & Automat Helsinki Finland LED Lighting Powered GE Montreal PQ Canada

Snowfall during cold months impacts the performance of photovoltaic (PV) installations. In real field operations, different ambient conditions often cause non-uniform snow accretion on PV panels. This can have a considerable effect on PV power production depending on array configuration, the pattern of snow coverage, and bypass diodes included in a PV system. The electrical behaviour of snow-covered PV cells is experimentally characterised. Then, the true impact of non-uniform snow accretion on PV system performance is investigated. Effect of employing bypass diodes on a PV string power generation is also verified. Different PV array layouts are studied to improve the PV harvest efficiency in cold climate regions. This research may be regarded as a practical tool for the design and selection of PV modules subjected to snowfall.

关键词： solar cells photovoltaic power systems snow electrical behaviour PV arrays snowfall cold months photovoltaic installations different ambient conditions nonuniform snow accretion PV panels PV power production array configuration snow coverage diodes snow-covered PV cells PV system performance PV string power generation different PV array layouts PV harvest efficiency PV modules

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THE NOBEYAMA RADIOHELIOGRAPH

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PROCEEDINGS OF THE IEEE 1994年第5期82卷 705-713页

作者： NAKAJIMA, H NISHIO, M ENOME, S SHIBASAKI, K TAKANO, T HANAOKA, Y TORII, C SEKIGUCHI, H BUSHIMATA, T KAWASHIMA, S SHINOHARA, N IRIMAJIRI, Y KOSHIISHI, H KOSUGI, T SHIOMI, Y SAWA, M KAI, K COMMUN RES LABS KOGANEITOKYO 184JAPAN UNIV TOKYO SCH SCIDEPT ASTRONBUNKYO KUTOKYO 113JAPAN

A new 17-GHz radio interferometer dedicated for solar observations was constructed in 2 years at Nobeyama, Nagano. It consists of eighty-four 80-cm-diameter antennas arranged in a Tee-shaped array extending 490 m in east-west and 220 m in north-south directions. Since late June of 1992, radio full-disk images of the Sun have been observed for 8 h every day. The spatial resolution is 10'' and the temporal resolution is 1 s and also 50 ms for selected events. Every 10 s, correlator data are synthesized into images in real time and displayed on a monitor screen. The array configuration is optimized to observe the whole Sun with high spatial and temporal resolution and a high dynamic range of images. Image quality of better than 20 dB is realized by incorporation of technical advances in hardware and software, such as 1) low-loss phase-stable optical-fiber cables for local reference signal and IF signals, 2) newly developed phase-stable local oscillators, 3) custom CMOS gate-array LSI's of 1-b quadra-phase correlators for 4 x 4 combinations, and 4) new image processing techniques to suppress large sidelobe effects due to the solar disk and extended sources.

关键词： 0.8 m 17 GHz 17-GHz radio interferometer 1b quadraphase correlators 4×4 combination Nobeyama radioheliograph SHF Sun array configuration calibration correlator data custom CMOS gate-array LST image processing techniques image quality image reconstruction low-loss phase-stable optical-fiber cables microwave antenna arrays phase-stable local oscillators radio receivers radioastronomical techniques radiotelescopes radiowave interferometers reflector antennas resolution sidelobe effects solar observations tee-shaped array

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array-Level Inverse Design of Beam Steering Active Metasurfaces

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ACS NANO 2020年第11期14卷 15042-15055页

作者： Thureja, Prachi Shirmanesh, Ghazaleh Kafaie Fountaine, Katherine T. Sokhoyan, Ruzan Grajower, Meir Atwater, Harry A. CALTECH Thomas J Watson Lab Appl Phys Pasadena CA 91125 USA Northrop Grumman Corp NG Next Redondo Beach CA 90278 USA

We report an array-level inverse design approach to optimize the beam steering performance of active metasurfaces, thus overcoming the limitations posed by nonideal metasurface phase and amplitude tuning. In contrast to device-level topology optimization of passive metasurfaces, the outlined system-level optimization framework relies on the electrical tunability of geometrically identical nanoantennas, enabling the design of active antenna arrays with variable spatial phase and amplitude profiles. Based on this method, we demonstrate high-directivity, continuous beam steering up to 70 degrees for phased arrays with realistic tunable antenna designs, despite nonidealities such as strong covariation of scattered light amplitude with phase. Nonintuitive array phase and amplitude profiles further facilitate beam steering with a phase modulation range as low as 180 degrees. Furthermore, we use the device geometries presented in this work for experimental validation of the system-level inverse design approach of active beam steering metasurfaces. The proposed method offers a framework to optimize nanophotonic structures at the array level that is potentially applicable to a wide variety of objective functions and actively tunable metasurface antenna array platforms.

关键词： inverse design active metasurface phased array beam steering array configuration genetic algorithm wavefront engineering

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Integration of wireless flexible sensor and virtual internal impedance model for blood leakage detection during haemodialysis

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IET SCIENCE MEASUREMENT & TECHNOLOGY 2018年第5期12卷 617-625页

作者： Huang, Ping-Tzan Wu, Jian-Xing Li, Chien-Ming Lin, Chia-Hung Natl Tsing Hua Univ Dept Elect Engn Hsinchu 30013 Taiwan Univ Calif Los Angeles Calif NanoSyst Inst Dept Niche Biomed LLC Los Angeles CA 90095 USA Chi Mei Med Ctr Dept Med Div Infect Dis Tainan 710 Taiwan Natl Chin Yi Univ Technol Dept Elect Engn Taichung 41170 Taiwan

Blood leakage and resultant loss during haemodialysis therapy are life-threatening complications. As the venous needles (at arterial/venous sites) disconnect from blood lines, little reaction time is left to stop the blood loss. The authors integrate the wireless flexible sensor with a virtual internal impedance model to design a warning tool to early detect blood leakage and further lower the mortality rate it causes. This flexible sensor is fabricated via a screen-printing technique by printing electronic circuits on a soft substrate in an array configuration. The virtual internal impedance model employed is advantageous for both detecting if any short-circuit branch resistance develops and estimating the virtual internal impedances of the sensor. Once the metering nodal voltage changes, the estimated quantity resistances and near infinite resistances are employed to separate a short circuit from an open circuit. The algorithm developed can be implemented in an embedded system via a wireless fidelity wireless network through cloud computing. The experimental results show feasibility and potential of specifications for commercial design.

关键词： wireless sensor networks electric impedance measurement haemodynamics blood patient treatment biomedical transducers biomedical measurement printing electric resistance measurement wireless flexible sensor virtual internal impedance estimation model blood leakage detection haemodialysis therapy screen-printing technique electronic circuit soft substrate array configuration short-circuit branch resistance nodal voltage metering embedded system wireless fidelity wireless network cloud computing

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