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Ground-based deformation measurement radar configured with multiple-input multiple-output antennas

JOURNAL OF ENGINEERING-JOE 2019年第20期2019卷 7030-7033页

作者： Wang, Haofei Li, Jiandong Mao, Erke Yang, Jian Tsinghua Univ Dept Elect Engn Beijing Peoples R China Beijing Inst Technol Sch Informat & Elect Radar Res Lab Beijing Peoples R China Minist Educ Beijing Inst Technol Key Lab Elect & Informat Technol Satellite Nav Beijing Peoples R China Southwest China Inst Elect Technol Chengdu Sichuan Peoples R China

The application of ground-based radar to monitor the terrain displacement has attracted more and more attentions recently. Most of the existing ground-based radars utilise a linear horizontal rail where the antennas move to generate the image of the test site. Here, the authors present a topology of antenna array with which the digital elevation model of the observed scene can also be generated besides the 2-D image. Several field experiments have been carried out to evaluate the performance of authors' developed ground-based differential interferometry radar (GB-DInR) configured with this multiple-input multiple-output (MIMO) antenna array. The results demonstrate that authors' developed MIMO GB-DInR is able to achieve a sub-millimetre precision of displacement measurement and derive the elevation information of target with an error of <0.1 m at a distance of around 100 m.

关键词： terrain mapping remote sensing by radar displacement measurement interferometry antenna arrays MIMO communication synthetic aperture radar digital elevation models geophysical techniques radar interferometry antennas authors displacement measurement ground-based deformation measurement radar multiple-input multiple-output antennas ground-based radar terrain displacement existing ground-based radars linear horizontal rail test site digital elevation model multiple-input multiple-output antenna array size 0.1 m size 100.0 m

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A Broadband MIMO Antenna Array for WiFi-6E/7 in Laptop Computer Applications

A Broadband MIMO Antenna Array for WiFi-6E/7 in Laptop Compu...

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IEEE International Workshop on Electromagnetics - Applications and Student Innovation Competition (IWEM)

作者： Yang, Jun-Hong Su, Hsin-Lung Natl Pingtung Univ Dept Comp Sci & Informat Engn Pingtung Taiwan Natl Pingtung Univ Dept Comp & Commun Pingtung Taiwan

ISBN: (纸本)9798350366983;9798350366976

This paper proposed a broadband 2x2 MIMO antenna array for a WiFi-6E/7 mobile communication system in laptop computer applications. The structure of the single antenna element is composed of a compact loop antenna with a straight parasitic metal line structure. The operating frequency band covers the WiFi-6E/7 band and the future possible WiFi-7 frequency band (similar to 9 GHz). The single antenna size is 20 mm x 4.0 mm x 4.0 mm. The 2x2 MIMO antenna array is on the edge of the top of a laptop screen. The overall size of the 2x2 MIMO antenna array is 44 mm x 4.0 mm x 4.0 mm. The antenna design does not use extra passive components for impedance matching or isolation technology to improve isolation. The isolation is more than 16.5 dB, the measured efficiency of the antenna is between 65-90%, and the value of gain is between 4.2-8.5 dBi.

关键词： Laptop computer antennas multiple-input multiple-output antennas broadband antennas miniaturized antennas

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Sub-6 GHz Highly Isolated Wideband MIMO Antenna Arrays

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IEEE ACCESS 2022年 10卷 19875-19889页

作者： Megahed, Amany A. Abdelazim, Mohamed Abdelhay, Ehab H. Soliman, Heba Y. M. Higher Inst Engn & Technol New Damietta 41525 Egypt Mansoura Univ Elect & Commun Dept Mansoura 35516 Egypt Port Said Univ Elect & Commun Dept Port Fuad 42526 Egypt

This study proposes a compact four-port multiple-input multiple-output (MIMO) antenna system to operate within a frequency range of 3.2-5.75 GHz to serve in 5G new radio (NR) sub-6 GHz n77/n78/n79 and 5 GHz WLAN with good impedance matching. To increase the isolation between the MIMO antenna elements with low complexity and cost, the antenna elements are orthogonally oriented to each other with distance spacing of 0.3) between elements, including electromagnetic bandgap (EBG) structure, defected ground structure (DGS), capacitive elements (CE), and neutralization line (NL). The simulation results show that the measured mutual coupling between the array elements is improved from -20 to -45 dB. The envelope correlation coefficient is enhanced. In addition, the diversity gain, mean effective gain, and total active reflection coefficient are improved simultaneously. The suggested structure has been designed on CST Microwave Studio 2019. The antennas' overall dimensions for all methods are the same as they approach 46 mm x 46 mm x 1.6 mm. The measured gain of the proposed designs ranges from 6 to 9 dBi, and the radiation efficiency approaches 90%. The antennas are fabricated and tested, where better experimental results are noticed compared to the simulation results. Our antennas are designed over FR-4 substrate with a noticeable cost reduction. Each antenna element has a dimension of 15 mm x 23 mm x 1.6 mm. An "EL" slot into the radiating element and two identical stubs coupled to the partial ground are used to improve the impedance matching and radiation characteristics across the bands of interest. The isolation decreases by 22 dB using the EBG method, reaching the value of -65 dB. Meanwhile, the isolation decreases by 19 dB using the DGS method, reaching -60 dB. Due to gaps between adjacent unit cells and the capacitance generated from the dielectric gap between the top metallic patch and ground plane, the EBG method gives the best results. However, in the CE method,

关键词： 5G multiple-input multiple-output antennas ECC DG MEG TARC DGS NL

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Survey of CSI fingerprinting-based indoor positioning and mobility tracking systems

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IET SIGNAL PROCESSING 2020年第7期14卷 407-419页

作者： Rocamora, Josyl Mariela Wang-Hei Ho, Ivan Mak, Wan-Mai Lau, Alan Pak-Tao Hong Kong Polytech Univ Dept Elect & Informat Engn Kowloon Hong Kong Peoples R China Univ Santo Tomas Dept Elect Engn Manila Philippines Hong Kong Polytech Univ Dept Elect Engn Kowloon Hong Kong Peoples R China

Techniques for indoor positioning systems (IPSs) can be categorised as range-based or range-free. Range-based methods rely on geometric mappings to approximate a location given the calculated distances or angles from multiple reference points. In contrast, range-free strategies utilise fingerprinting, wherein an acquired fingerprint data is compared to a pre-collected dataset to identify the best position estimate. Among these, fingerprinting of channel state information (CSI) is preferred over other information such as received signal strength indicator as the former can exploit the effect of multipath propagation and is robust against non-line-of-sight channels. CSI has the potential to achieve cm-level positioning accuracy with a single reference point only. In this study, the authors survey CSI fingerprinting-based indoor positioning and mobility tracking systems. The process of fingerprinting that includes site surveying and signal preprocessing is discussed in detail. They determine the potential challenges of such systems and propose remedies to improve positioning accuracy. In general, spatial diversity, such as multiple-input multiple-output antennas and wireless sensor networks, or frequency diversity (e.g. high subcarrier count, frequency hopping mechanism) are exploited to achieve high positioning resolution. Such IPS can also be enhanced via additional sensors or spatial graphs for motion detection and tracking.

关键词： indoor communication MIMO communication indoor radio fingerprint identification tracking wireless sensor networks indoor positioning systems range-based methods calculated distances multiple reference points range-free strategies acquired fingerprint data position estimate channel state information CSI received signal strength indicator nonline-of-sight channels cm-level positioning accuracy single reference point mobility tracking systems site surveying signal preprocessing multiple-input multiple-output antennas high positioning resolution

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Decoupling using diamond-shaped patterned ground resonator for small MIMO antennas

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IET MICROWAVES antennas & PROPAGATION 2017年第2期11卷 177-183页

作者： Wu, Di Cheung, Sing Wai Li, Qin Long Yuk, Tung Ip Univ Hong Kong Dept Elect & Elect Engn Hong Kong Hong Kong Peoples R China

A decoupling technique using a patterned ground structure for small multiple-input multiple-output (MIMO) antennas is proposed in this study. The MIMO antenna consists of two symmetrical L-shaped inverted-F antenna (IFA) elements designed to operate in the wireless-local-area-network band and installed on a compact printed-circuit board (PCB) with a size of 72.4 x 20 mm(2) serving as ground. The two IFA elements have a very short separating distance of only 16.2 mm (0.13). To reduce strong mutual coupling, a diamond-shaped patterned ground resonator (DSPGR) with a compact size of 16.2 x 10.13 mm(2) is printed on the PCB between the two IFA elements. The effect of the DSPGR on reducing mutual coupling is studied using computer simulation. The impedance bandwidth, mutual coupling, peak gain, radiation pattern and efficiency, envelope-correlation coefficient and multiplexing efficiency of the MIMO antenna are studied using simulation and measurement. Results show that the DSPGR can dramatically reduce mutual coupling between the two IFA elements to below -20 dB within the operating frequency range of 2.18-2.65 GHz (19.5%).

关键词： planar inverted-F antennas antenna radiation patterns printed circuits correlation methods diamond-shaped patterned ground resonator decoupling technique patterned ground structure small MIMO antennas multiple-input multiple-output antennas symmetrical L-shaped inverted-F antenna elements IFA elements wireless-local-area-network band compact printed-circuit board PCB DSPGR mutual coupling reduction antenna radiation pattern antenna efficiency envelope-correlation coefficient multiplexing efficiency frequency 2 18 GHz to 2 65 GHz

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Isolation enhancement of small-size WLAN MIMO antenna array for laptop computer application

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JOURNAL OF ELECTROMAGNETIC WAVES AND APPLICATIONS 2017年第3期31卷 323-334页

作者： Chen, Shu-Chuan Sze, Jia-Yi Chuang, Kai-Jen Natl Def Univ Chung Cheng Inst Technol Dept Elect & Elect Engn Taoyuan Taiwan

This paper proposes a multiple-input multiple-output (MIMO) antenna array comprising two compact wireless local-area network (WLAN) antennas with high isolation in between. The two operating frequency bands are designed to completely enclose the 2.4/5.2/5.8 GHz WLAN bands. The MIMO antenna array having a small size, a low height, and a small thickness is especially suitable to be installed in ultra-thin notebook computers. The size of the designed antenna array has been reduced to about 40% than those of the MIMO arrays appearing in the recent literature. The designed isolation element between the two radiating antennas consists of two resonant slots, the lengths of which are individually a quarter-wavelength at 2.45 and 5.5 GHz. The isolation elements block the horizontal surface currents on the system ground plane, leading to mutualcoupling reduction between the two source antennas and hence excellent isolation between them. Results indicate that the proposed MIMO antenna array has good characteristics of antenna radiation efficiency, and impedance matching in the two bands of interest.

关键词： WLAN antenna laptop computer antenna MIMO antenna antenna isolation multiple-input multiple-output antennas

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Physical modelling of multiple-input multiple-output antennas and channels by means of the spherical vector wave expansion

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IET MICROWAVES antennas & PROPAGATION 2010年第6期4卷 778-791页

作者： Glazunov, A. A. Gustafsson, M. Molisch, A. F. Tufvesson, F. Univ Bedfordshire Ctr Wireless Network Design Luton LU1 3JU Beds England Univ So Calif Dept Elect Engn Los Angeles CA 90089 USA Lund Univ Dept Elect & Informat Technol SE-22100 Lund Sweden Mitsubishi Elect Res Labs Cambridge MA USA Lund Univ Dept Elect & Informat Theory SE-22100 Lund Sweden

The authors propose a new physically motivated model that allows the study of the interaction between the antennas and the propagation channel for multiple-input multiple-output (MIMO) systems. The key tools employed in the model are the expansion coefficients of the electromagnetic field in spherical vector waves and the scattering matrix representation of the properties of the antenna. The authors derive the expansion of the MIMO channel matrix, H, in spherical vector wave modes of the electromagnetic field of the antennas as well as the propagation channel. The authors also introduce the channel scattering dyadic, C, with a corresponding correlation model for co-polarised and cross-polarised elements and introduce the concept of mode-to-mode channel mapping, the M-matrix, between the receive and transmit antenna modes. The M-matrix maps the modes excited by the transmitting antenna to the modes exciting the receive antennas and vice versa. The covariance statistics of this M-matrix are expressed as a function of the double-directional power-angular spectrum (PAS) of co-polarised and cross-polarised components of the electromagnetic field. Their approach aims at gaining insights into the physics governing the interaction between antennas and channels and it is useful for studying the performance of different antenna designs in a specified propagation channel as well as for modelling the propagation channel. It can furthermore be used to quantify the optimal properties of antennas in a given propagation channel. The authors illustrate the developed methodology by analysing the interaction of a 2 x 2 system of slant polarised half-wavelength dipole antennas with some basic propagation channel models.

关键词： electromagnetic field M-matrix maps multiple-input multiple-output channels dipole antennas Radio links and equipment correlation model half- wavelength dipole antennas physical modelling power-angular spectrum Single antennas multiple-input multiple-output antennas channel scattering spherical vector wave expansion MIMO communication propagation channel

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8-antenna and 16-antenna arrays using the quad-antenna linear array as a building block for the 3.5-GHz LTE MIMO operation in the smartphone

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2016年第1期58卷 174-181页

作者： Wong, Kin-Lu Lu, Jun-Yu Chen, Li-Yu Li, Wei-Yu Ban, Yong-Ling Natl Sun Yat Sen Univ Dept Elect Engn Kaohsiung 80424 Taiwan Ind Technol Res Inst Informat & Commun Res Labs Hsinchu 31040 Taiwan Univ Elect Sci & Technol China Inst Electromagnet & Sch Elect Engn Chengdu 611731 Peoples R China

Using the quad-antenna linear (QAL) array as a building block, the 8-antenna and 16-antenna arrays for the 3.5-GHz long term evolution multiple-input multiple-output (MIMO) operation in the smartphone are demonstrated. The QAL array has a planar structure of narrow width 3 mm (0.035) and short length 50 mm (0.58), with being the wavelength at 3.5 GHz. For the 8-antenna array, two QAL arrays are disposed along two opposite side edges (denoted as Array A) or the same side edge (denoted as Array B) of the system circuit board of the smartphone. The obtained envelope correlation coefficient values of the antennas in Array A and B are shown. The calculated channel capacities for Array A and B applied in an 8 x 8 MIMO system are also analyzed. The 16-antenna array formed by four QAL arrays disposed along two opposite side edges (denoted as Array C) is then studied. For operating in a 16 x 16 MIMO system, the calculated channel capacity of Array C can reach about 66-70 bps/Hz with a 20-dB signal-to-noise ratio. The obtained channel capacity is about 5.7-6.1 times that (11.5 bps/Hz) of the upper limit of an ideal 2 x 2 MIMO system with 100% antenna efficiency for the antennas therein. Details of the proposed Array A, B, and C are described, and the obtained results are presented. (c) 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:174-181, 2016

关键词： mobile antennas multiple-input multiple-output antennas 8-antenna array 16-antenna array quad-antenna linear array smartphone antennas slot antennas

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Automatic Modulation Classification in Cognitive Radio using multiple antennas and Maximum-Likelihood Techniques 15

Automatic Modulation Classification in Cognitive Radio using...

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IEEE International Conference on Computer and Information

作者： Salam, Ahmed O. Abdul Sheriff, Ray E. Al-Araji, Saleh R. Mezher, Kahtan Nasir, Qassim Univ Bradford Sch Elect Engn & Comp Sci Bradford BD7 1DP W Yorkshire England Khalifa Univ Sci Technol & Res Abu Dhabi U Arab Emirates Sharjah Univ Sharjah U Arab Emirates

ISBN: (纸本)9781509001545

The automatic modulation classification (AMC) is linked to the accurate identification of a received signal modulation. The AMC represents an important part of cognitive radio (CR) systems recently envisioned to be an appropriate platform to adjust against changing work conditions. The two main distinguished streams of AMC are either by using the likelihood based (LB) statistical tests or featured based (FB) recognitions. The LB is viewed to be optimum providing that all statistical signal descriptions are available to a receiver, while the FB usually viewed as suboptimal. In some practical situations, especially when the AMC process is carried out blindly, a signal enhancement is viewed necessary to boost the detection accuracy. The multiple-input multiple-output (MIMO) antennas configuration is widely accepted as key enhancer to signal and system performance. This paper is intended to explore opportunities of the AMC detection accuracy improvements using MIMO and diversity combining settings. The probability of error detection is reformulated using diagonalized MIMO channel through singular value decomposition (SVD) realization. Simulation results show that classification performance is improved by adopting multiple antennas with appropriate signal combining configuration.

关键词： cognitive radio automatic modulation classification likelihood algorithms multiple-input multiple-output antennas diversity combining support vector decomposition

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Planar four-element frequency agile MIMO antenna system with chassis mode reconfigurability

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MICROWAVE AND OPTICAL TECHNOLOGY LETTERS 2015年第8期57卷 1933-1938页

作者： Hussain, Rifaqat Sharawi, Mohammad S. King Fahd Univ Petr & Minerals Dept Elect Engn Dhahran 31261 Saudi Arabia

In this work, a novel multiband, four-element, meandered-line reconfigurable planar F-shaped multiple-input-multiple-output antenna is presented. The proposed design includes chassis mode reconfigurability option as well. A combination of PIN and varactor diodes is used to achieve the frequency tuning over a wide-band. The proposed design covers several well-known frequency bands between 0.7 and 3 GHz. The design is compact and realized on a single commercial substrate board with dimensions 65 x 120 x 1.56 mm(3) that can be used in small wireless handheld devices for cognitive radio applications. (c) 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1933-1938, 2015

关键词： multiple-input multiple-output antennas reconfigurable antenna chassis mode reconfigurability cognitive radio

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