Articles de revues sur le sujet « Antenna processing »
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1
Vinothkanna, R. « A Survey – Wearable Antenna Techniques and its Applications ». December 2022 1, no 1 (15 décembre 2022) : 87–98. http://dx.doi.org/10.36548/rrrj.2022.1.008.
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Smart Antenna is an array of antennas which uses the smart signal processing algorithms to track and locate the client device using the direction of arrival of a signal. Smart Wearable Antennas are designed to function while being worn. Wearable antennas are used within the context of Wireless Body Area Networks. The wearable antenna is high in efficiency, miniature in size, and simple in structure, and is implemented with electrical performance and polarization effects, which helps in healthcare, medical and military applications, smart glasses, sensor devices in sports, etc. This research study reviews different wearable antenna technologies such as wearable textile antenna, microstrip antenna and wearable antenna array. Furthermore, the integrated different next generation antennas are also discussed.
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Vinothkanna, R. « A Survey – Wearable Antenna Techniques and its Applications ». December 2022 1, no 1 (15 décembre 2022) : 87–98. http://dx.doi.org/10.36548/rrrj.2023.1.008.
Texte intégralRésumé :
Smart Antenna is an array of antennas which uses the smart signal processing algorithms to track and locate the client device using the direction of arrival of a signal. Smart Wearable Antennas are designed to function while being worn. Wearable antennas are used within the context of Wireless Body Area Networks. The wearable antenna is high in efficiency, miniature in size, and simple in structure, and is implemented with electrical performance and polarization effects, which helps in healthcare, medical and military applications, smart glasses, sensor devices in sports, etc. This research study reviews different wearable antenna technologies such as wearable textile antenna, microstrip antenna and wearable antenna array. Furthermore, the integrated different next generation antennas are also discussed.
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Dawidowicz, Karol, et Radosław Baryła. « GNSS Antenna Caused Near-Field Interference Effect in Precise Point Positioning Results ». Artificial Satellites 52, no 2 (1 juin 2017) : 27–40. http://dx.doi.org/10.1515/arsa-2017-0004.
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Abstract Results of long-term static GNSS observation processing adjustment prove that the often assumed “averaging multipath effect due to extended observation periods” does not actually apply. It is instead visible a bias that falsifies the coordinate estimation. The comparisons between the height difference measured with a geometrical precise leveling and the height difference provided by GNSS clearly verify the impact of the near-field multipath effect. The aim of this paper is analysis the near-field interference effect with respect to the coordinate domain. We demonstrate that the way of antennas mounting during observation campaign (distance from nearest antennas) can cause visible changes in pseudo-kinematic precise point positioning results. GNSS measured height differences comparison revealed that bias of up to 3 mm can be noticed in Up component when some object (additional GNSS antenna) was placed in radiating near-field region of measuring antenna. Additionally, for both processing scenario (GPS and GPS/GLONASS) the scattering of results clearly increased when additional antenna crosses radiating near-field region of measuring antenna. It is especially true for big choke ring antennas. In short session (15, 30 min.) the standard deviation was about twice bigger in comparison to scenario without additional antenna. When we used typical surveying antennas (short near-field region radius) the effect is almost invisible. In this case it can be observed the standard deviation increase of about 20%. On the other hand we found that surveying antennas are generally characterized by lower accuracy than choke ring antennas. The standard deviation obtained on point with this type of antenna was bigger in all processing scenarios (in comparison to standard deviation obtained on point with choke ring antenna).
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Chougule, Rutuja. « Smart Antenna Systems ». International Journal for Research in Applied Science and Engineering Technology 10, no 6 (30 juin 2022) : 1182–86. http://dx.doi.org/10.22214/ijraset.2022.43988.
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Abstract: Smart antennas have received increasing interest for improving the performance of wireless radio systems. These systems of antennas include a large number of techniques that attempt to enhance the received signal, suppress all interfering signals, and increase capacity, in general. The main purpose of this article is to provide an overview of the current state of research in the area of smart antennas, and to describe how they can be used in wireless systems. A smart antenna takes advantage of diversity effect at the source (transmitter), the destination (receiver), or both. Diversity effect involves the transmission and/or reception of multiple radio frequency (RF) waves to increase data speed and reduce the error rate. Thus, this article provides a basic model for determining the angle of arrival for incoming signals, the appropriate antenna beamforming, and the adaptive algorithms that are currently used for array processing. Moreover, it is shown how smart antennas, with spatial processing, can provide substantial additional improvement when used with TDMA and CDMA digitalcommunication systems.
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Miawarni, Herti, M. Mahaputra Hidayat, Surya Sumpeno et Eko Setijadi. « Tracking System for Indoor TV Antenna Based on CVBS Signal Processing ». Jurnal Elektronika dan Telekomunikasi 17, no 2 (31 décembre 2017) : 48. http://dx.doi.org/10.14203/jet.v17.48-55.
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Analog terrestrial TV is still a popular choice for urban societies although the migration to digital system has already begun. Video quality of analog TV was heavily influenced by performance of the antenna. Most users prefer to use indoor antenna due to its simplicity. The disadvantage of this type of antenna is the users may need to change the antenna direction repeatedly when they change to different TV channel. In this research, we designed and developed tracking system that enable indoor TV antenna to adjust its direction automatically to get optimum video clarity. This system is built by several servo motors and telescopic antennas. Composite Video Baseband Signal (CVBS) processing is used to obtain reference information regarding video clarity level conditions on TV screen. The results show that CVBS signal processing has performance in describing video clarity level. System performance has been verified from trial results on some UHF channels. Minimum tracking time is reach 23.4 second and the maximum reach 24.6 second.
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Kuz'kin, Venedikt M., Sergey A. Pereselkov, Yuri V. Matvienko, Vladimir I. Grachev, Sergey A. Tkachenko et Nadezhda P. Stadnaya. « Holographic processing of hydroacoustic information using linear antennas ». Radioelectronics. Nanosystems. Information Technologies. 15, no 2 (29 juin 2023) : 169–78. http://dx.doi.org/10.17725/rensit.2023.15.169.
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The formation of an interferogram and a hologram of a moving underwater noise source using linear antennas is considered. The relationship between the spectral density of the hologram and the aperture and the angular dependence of the received field is derived. Antenna gain has been estimated. The issue of the limiting signal-to-noise ratio at which the holographic processing remains operational is discussed. An analytical expression is obtained that establishes a relationship between the signal/noise ratios at the output and input of the antenna. Conditions are formulated under which the interferogram of the source is not distorted.
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Basu, Sukla. « A Novel Shaped Four Port MIMO Antenna for Wireless Communication ». Asian Journal of Electrical Sciences 12, no 1 (14 juin 2023) : 17–22. http://dx.doi.org/10.51983/ajes-2023.12.1.3667.
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This paper presents a compact novel shaped micro strip line fed four element Multiple Input Multiple Output (MIMO) antenna for wireless application at 2.4 GHz. Four vertically oriented identical rectangular patch antennas are used to form a hollow cylinder of rectangular cross section. The direction of radiation of each antenna is thus oriented at 900 with respect to its two adjacent antennas providing good isolation between adjacent antennas in this compact MIMO system. Each antenna element has the dimensions of 0.30λx0.38λx0.012λ. The whole MIMO antenna has the outer dimensions of 0.38λx0.38λx0.30λ. The uniqueness of the proposed MIMO antenna is that the inner space of the hollow cylindrical structure can be used for hosting the associated signal processing unit of the whole system. Performance parameters of the proposed MIMO antenna are investigated using Computer Simulation Technology (CST). Envelope Correlation Coefficient (ECC) less than 0.033 and almost 10dB Diversity Gain (DG) are obtained at 2.4 GHz for this simple and compact antenna system. Ratio of Mean Effective Gain (MEG) of any two antennas is less than 0.02dB. Performance parameters of the proposed MIMO antenna system are compared with similar types of antennas found in recent literature.
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Lu, Zukun, Feiqiang Chen, Yuchen Xie, Yifan Sun et Hongliang Cai. « High Precision Pseudo-Range Measurement in GNSS Anti-Jamming Antenna Array Processing ». Electronics 9, no 3 (29 février 2020) : 412. http://dx.doi.org/10.3390/electronics9030412.
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Radio frequency interference has become a rising problem to the signal of the Global Navigation Satellite System (GNSS). An effective way to achieve anti-jamming is by using an antenna array in GNSS signal processing. However, antenna array processing will cause a decline in the accuracy of pseudo-range measurements because of the channel mismatch and some other non-ideal factors. To solve this problem, space–time or space–frequency adaptive array processing is widely used for interference cancellation while constraining the delay of each antenna at the same time. In this paper, an anti-jamming algorithm with a time-delay constraint is proposed, where one antenna is chosen as the reference and data from other antennas is corrected based on the signal received from it. The deduction and simulation results show that the proposed algorithm can effectively improve the accuracy of pseudo-range measurements without degradation of anti-jamming performance.
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KOCZ, J., L. J. GREENHILL, B. R. BARSDELL, G. BERNARDI, A. JAMESON, M. A. CLARK, J. CRAIG et al. « A SCALABLE HYBRID FPGA/GPU FX CORRELATOR ». Journal of Astronomical Instrumentation 03, no 01 (mars 2014) : 1450002. http://dx.doi.org/10.1142/s2251171714500020.
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Radio astronomical imaging arrays comprising large numbers of antennas, O(102–103), have posed a signal processing challenge because of the required O (N2) cross correlation of signals from each antenna and requisite signal routing. This motivated the implementation of a Packetized Correlator architecture that applies Field Programmable Gate Arrays (FPGAs) to the O (N) "F-stage" transforming time domain to frequency domain data, and Graphics Processing Units (GPUs) to the O (N2) "X-stage" performing an outer product among spectra for each antenna. The design is readily scalable to at least O(103) antennas. Fringes, visibility amplitudes and sky image results obtained during field testing are presented.
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Tserne, Eduard, Anatoliy Popov, Oleksandr Pidlisnyi, Danyil Kovalchuk et Oleksandr Sereda. « Four-antenna amplitude direction finder : statistical synthesis and experimental research of signal processing algorithm ». Radioelectronic and Computer Systems, no 4 (6 décembre 2023) : 88–99. http://dx.doi.org/10.32620/reks.2023.4.08.
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The subject of this study is the algorithms for measuring the angular positions of radio emission sources. The goal of this study is to develop an improved algorithm for signal processing in amplitude direction finders that will provide several unambiguous measurement angles at high steepness of the discrimination characteristic by combining measurements of systems with different widths of antenna patterns. The task: to develop an optimal signal processing algorithm for a four-antenna amplitude direction finding system, two antennas of which have a wide radiation pattern and the other two have a narrow one; to test the overall performance of the resulting algorithm by simulating the direction finder; to develop and conduct a study of an experimental model of a four-antenna direction finder, which includes two antennas with wide radiation patterns, two antennas with narrow radiation patterns, radio frequency paths, and a signal processing unit that implements the developed algorithm; to analyze the effectiveness and features of the application of the developed algorithm, and to compare the results of simulation modeling and experimental research. The methods used are statistical methods and optimal solutions for solving problems of statistical synthesis of signal processing algorithms in passive radio systems, computer simulation modeling methods, and experimental research methods. The following results were obtained. The algorithm for signal processing in a four-antenna direction finding system was synthesized using the maximum likelihood method. By simulation modeling, the overall effectiveness of measurement integration in multi-antenna amplitude direction finders was confirmed, and the peculiarities of the synthesized algorithm application were revealed, namely, the need to introduce additional proportionality coefficients into the measurement channels. During the experimental studies of the developed model of the direction finder, the results of the simulation modeling were confirmed. Conclusions. To determine the direction of radiation sources by amplitude direction finders, it is advisable to simultaneously use systems with wide and narrow antenna patterns, the measurements of which are combined by the proposed algorithm. This makes it possible to simultaneously expand the range of unambiguous measurement angles and increase the accuracy of measurements within the equal-signal zone. The disadvantage of using the algorithm is the nonlinear form of the obtained discrimination characteristics and the need to determine additional proportionality coefficients heuristically.
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Zheng, Hanwen. « Lossy and Loss Free Material Research Taking Microstrip Patch Antenna Operating on the Band n261 as the Case ». Highlights in Science, Engineering and Technology 27 (27 décembre 2022) : 639–50. http://dx.doi.org/10.54097/hset.v27i.3827.
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The focus of this paper is to discuss the loss mechanism of the antenna and its effect on the antenna performance. This paper will follow the order of design basis, design idea, design content, and design results. Based on an antenna design for an n261 band, experiments are conducted in CST studio using different materials under lossy and lossless conditions. It includes 8 different sets of experiments. The lossy material will perform worse than the lossless material by processing the data through the program. When designing antennas, the performance of lossy materials will be worse. The material has a low tangential loss, and the loss of the antenna will be reduced. When designing an antenna, the antenna’s performance should be measured comprehensively by S11, Z11, as well as radiation efficiency and electric field results, instead of looking at only one parameter. Meanwhile, microstrip antenna design can be used to design antenna arrays or multi-band antennas.
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Xie, Yuchen, Zhengrong Li, Feiqiang Chen, Huaming Chen et Feixue Wang. « The Unbiased Characteristic of Doppler Frequency in GNSS Antenna Array Processing ». International Journal of Antennas and Propagation 2019 (24 avril 2019) : 1–10. http://dx.doi.org/10.1155/2019/5302401.
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The antenna array technology, especially the spaced-time array processing (STAP), is one of the effective methods used in Global Navigation Satellite System (GNSS) receivers to refrain the power of jamming and enhance the performance of receivers in the circumstance of interference. However, biases induced to the receiver because of many reasons, including characteristic of antennas, front-end channel electronics, and space-time filtering, are extremely harmful to the high precise positioning of receivers. Although plenty of works have been done to calibrate the antenna and to mitigate these biases, achieving a good performance of antijamming, high accuracy, and low complexity at the same time still remains challenging. Different from existing works, this paper leverages the characteristic of GNSS signal’s Doppler frequency in STAP, which is proven to remain unbiased to solve the problem, even when the nonideal antennas are used and the interference circumstance changes. Since the integration of frequency is carrier phase, the unbiased Doppler frequency leads to an accurate estimation of carrier phase which can be used to calibrate the antenna array without extra apparatus or complicating algorithms. Therefore, a simple Doppler-aid strategy may be developed in the future to solve the difficulty of STAP bias mitigation.
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Tsay, Tain-Sou. « Small Loop Antenna System Design for Radio Direction Finding ». WSEAS TRANSACTIONS ON COMMUNICATIONS 20 (16 décembre 2021) : 172–76. http://dx.doi.org/10.37394/23204.2021.20.22.
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In this literature, a low-cost small loop antenna is developed for radio direction finding. It consists of two coupled rectangular counter-wiring loop antennas. A signal-processing circuit is developed also for demodulated outputs. A single rectangular loop antenna is discussed first for illustrating the receiving characteristics and then the proposed two coupled rectangular counter-wiring loop antennas are designed for radio direction finding. Measurements give a large linear detecting range. It is ready for Omni-directional application using another two coupled loop antennas and can be used as a tracking control device.
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Sanjivani Munot. « Microwave Antenna Optimization for Low Latency and High Throughput Communication Systems ». Journal of Electrical Systems 20, no 6s (2 mai 2024) : 2410–16. http://dx.doi.org/10.52783/jes.3223.
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This paper presents a comprehensive exploration of microwave antenna optimization strategies aimed at achieving low latency and high throughput in modern communication systems. With the escalating demand for real-time applications and data-intensive services, the optimization of microwave antennas has become imperative to meet the stringent requirements of responsiveness and efficiency. The abstract delves into various facets of antenna optimization, including design parameters, signal processing techniques, and deployment considerations, all geared towards minimizing latency and maximizing throughput. Through a thorough review of existing literature and practical insights from real-world deployments, this research aims to provide valuable guidance for engineers and researchers in designing and implementing optimized microwave antennas for next-generation communication networks. By examining the intricate interplay between antenna design, signal processing algorithms, and deployment strategies, this paper elucidates the challenges and opportunities in achieving low latency and high throughput in microwave communication systems. Furthermore, it highlights the significance of factors such as gain, beamwidth, polarization, frequency band selection, multiple-input multiple-output (MIMO) systems, beamforming, adaptive coding and modulation (ACM), antenna placement, tower height, and line-of-sight considerations in optimizing antenna performance. The findings presented in this paper contribute to advancing the understanding of microwave antenna optimization and offer practical insights into enhancing the responsiveness, efficiency, and reliability of modern communication networks.
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Martinez-Ramon, Manel, Jose Luis Rojo-Alvarez, Gustavo Camps-Valls et Christos G. Christodoulou. « Kernel Antenna Array Processing ». IEEE Transactions on Antennas and Propagation 55, no 3 (mars 2007) : 642–50. http://dx.doi.org/10.1109/tap.2007.891550.
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Rigosi, Elisa, Albrecht Haase, Lisa Rath, Gianfranco Anfora, Giorgio Vallortigara et Paul Szyszka. « Asymmetric neural coding revealed by in vivo calcium imaging in the honey bee brain ». Proceedings of the Royal Society B : Biological Sciences 282, no 1803 (22 mars 2015) : 20142571. http://dx.doi.org/10.1098/rspb.2014.2571.
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Left–right asymmetries are common properties of nervous systems. Although lateralized sensory processing has been well studied, information is lacking about how asymmetries are represented at the level of neural coding. Using in vivo functional imaging, we identified a population-level left–right asymmetry in the honey bee's primary olfactory centre, the antennal lobe (AL). When both antennae were stimulated via a frontal odour source, the inter-odour distances between neural response patterns were higher in the right than in the left AL. Behavioural data correlated with the brain imaging results: bees with only their right antenna were better in discriminating a target odour in a cross-adaptation paradigm. We hypothesize that the differences in neural odour representations in the two brain sides serve to increase coding capacity by parallel processing.
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Kirtania, Sharadindu Gopal, Alan Wesley Elger, Md Rabiul Hasan, Anna Wisniewska, Karthik Sekhar, Tutku Karacolak et Praveen Kumar Sekhar. « Flexible Antennas : A Review ». Micromachines 11, no 9 (11 septembre 2020) : 847. http://dx.doi.org/10.3390/mi11090847.
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The field of flexible antennas is witnessing an exponential growth due to the demand for wearable devices, Internet of Things (IoT) framework, point of care devices, personalized medicine platform, 5G technology, wireless sensor networks, and communication devices with a smaller form factor to name a few. The choice of non-rigid antennas is application specific and depends on the type of substrate, materials used, processing techniques, antenna performance, and the surrounding environment. There are numerous design innovations, new materials and material properties, intriguing fabrication methods, and niche applications. This review article focuses on the need for flexible antennas, materials, and processes used for fabricating the antennas, various material properties influencing antenna performance, and specific biomedical applications accompanied by the design considerations. After a comprehensive treatment of the above-mentioned topics, the article will focus on inherent challenges and future prospects of flexible antennas. Finally, an insight into the application of flexible antenna on future wireless solutions is discussed.
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Shevchenko, M. E., A. B. Gorovoy, V. M. Balashov et S. N. Solovyov. « Features of application of ESPRIT method for different configurations of antenna arrays ». Issues of radio electronics, no 12 (3 février 2021) : 30–37. http://dx.doi.org/10.21778/2218-5453-2020-12-30-37.
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The paper discusses the features of the application of the ESPRIT method, which provides direction finding of a variety of radio sources with minimal computational costs, including in real time. To be able to use ESPRIT, antenna arrays are required that have the property of shift invariance, and for practical implementation, antenna arrays are required that allow you to form estimates of the directions of arrival of the largest number of signals that overlap in the spectrum, with a minimum number of antennas and reception channels. The aim of the work is to analyze the influence of the antenna array configuration on the features of ESPRIT application for different antenna array with the same number of antennas. A comparative qualitative analysis of the properties and features compared to the MUSIC method is presented. The algorithms developed by the authors for processing multichannel data received by angle and square antenna arrays are presented. It is shown analytically that when using a corner antenna array, it is necessary to take into account the possible presence of signals from indistinguishable-mirror directions of arrival. With a square antenna array, there are no mirror directions of arrival of different signals, which simplifies the implementation of the algorithm. It is shown analytically and by simulation modeling that the configuration of a square antenna array allows to increase the number of simultaneously tracked signals that overlap in the spectrum, compared to a corner antenna array with the same number of antennas.
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Qian, Kun, Wen-Qin Wang et Huaizong Shao. « Low-Complexity Transmit Antenna Selection and Beamforming for Large-Scale MIMO Communications ». International Journal of Antennas and Propagation 2014 (2014) : 1–11. http://dx.doi.org/10.1155/2014/159375.
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Transmit antenna selection plays an important role in large-scale multiple-input multiple-output (MIMO) communications, but optimal large-scale MIMO antenna selection is a technical challenge. Exhaustive search is often employed in antenna selection, but it cannot be efficiently implemented in large-scale MIMO communication systems due to its prohibitive high computation complexity. This paper proposes a low-complexity interactive multiple-parameter optimization method for joint transmit antenna selection and beamforming in large-scale MIMO communication systems. The objective is to jointly maximize the channel outrage capacity and signal-to-noise (SNR) performance and minimize the mean square error in transmit antenna selection and minimum variance distortionless response (MVDR) beamforming without exhaustive search. The effectiveness of all the proposed methods is verified by extensive simulation results. It is shown that the required antenna selection processing time of the proposed method does not increase along with the increase of selected antennas, but the computation complexity of conventional exhaustive search method will significantly increase when large-scale antennas are employed in the system. This is particularly useful in antenna selection for large-scale MIMO communication systems.
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Bansal, Preeti, et Nidhi Chahal. « Smart Antennas for Various Applications ». CGC International Journal of Contemporary Technology and Research 4, no 2 (5 août 2022) : 316–18. http://dx.doi.org/10.46860/cgcijctr.2022.07.31.316.
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The paper presents about smart antennas for advancement in wireless and mobile communication. Smart antennas also called adaptive array antennas with better signal processing & can be used to calculate beam forming vectors which helps in tracking & locating antenna beam of target. Smart antennas are helpful in health monitoring in covid-19 pandemic and provides better service quality. Smart antenna is one of the rising innovations which can satisfy the prerequisites. Smart antennas are being used for controlling, monitoring and analyzing real time systems for various applications In smart antennas spatial division of the signal is used as compared to spectrum division, it can be beneficial for improving the performance of wireless communication. This paper describes how switched beam & adaptive array antennas differ from basic antennas.
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Shcherbyna, Olga, Maksym Zaliskyi, Olena Kozhokhina et Felix Yanovsky. « Prospect for Using Low-Element Adaptive Antenna Systems for Radio Monitoring Stations ». International Journal of Computer Network and Information Security 13, no 5 (8 octobre 2021) : 1–17. http://dx.doi.org/10.5815/ijcnis.2021.05.01.
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This article is devoted to the analysis of prospect to apply multifunctional adaptive antenna systems for radio monitoring stations. The review of publications done demonstrates that current antennas that are developed and used in radio monitoring systems to control and measure the parameters of electromagnetic radiation should be applicable to conduct accurate measurements in wide frequency range under the condition of interferences. The analysis shows that modern adaptive antenna systems are mostly developed for radar and telecommunications applications. In this context we consider possible ways to solve the problem of adapting radio monitoring devices to a complex electromagnetic environment using antenna systems with primary processing of received signals . It was found that the developers of the antennas, which are based on adaptive interference suppression methods, focus basically on the development and implementation of adaptation processes, limiting themselves only to solving electromagnetic compatibility problems. In such approach, the functions of direction finding and measurement of radiation field parameters important exactly for radio monitoring systems are mostly ignored. Therefore, this research area opens up a wide field for identifying new possibilities for constructing multifunctional antenna systems. Focusing on this direction of research, we consider as an example the constraction of a simple two-element adaptive antenna system, which can be used to measure the parameters of the electromagnetic field in radio monitoring systems. The main relations for the error of determining the direction of arrival of the interference signal with a simple two-element antenna are investigated. The influence of the stability of the antenna array parameters and functional units of signal processing onto the errors is estimated.
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Vedenkin, Denis Andreevich, Yuri Evgenevich Sedelnikov et Aydar Revkatovich Nasybullin. « Antenna Arrays Focused on Broadband Signals ». Journal of Telecommunications and Information Technology, no 2 (30 juin 2016) : 95–102. http://dx.doi.org/10.26636/jtit.2016.2.726.
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Broadband and ultra-wideband signals are increasingly used in modern radio systems. Traditional performance of evaluation antennas operating with narrowband signals are not always adequately reflect the characteristics of broadband antennas, at least in view of the frequency dependence of the antenna pattern. Accounting for broadband signals the antennas becomes important in the low-frequency range of the spectrum. Systems using these types of signals may include control of the atmosphere and measuring its frequency-selective properties in the range meter and decameter wavelengths. Possibility of spatial selection based on focusing of broadband signals in this case promises to implement a number of additional features. Therefore, it is important to evaluate the properties of antennas based on the spectral content of the signal, as well as taking into account the ways of its processing in the receiving equipment. Consideration features of functioning the antenna array, focused on broadband signal is devoted to this article.
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Olivová, Jana, Miroslav Popela, Marie Richterová et Eduard Štefl. « Use of 3D Printing for Horn Antenna Manufacturing ». Electronics 11, no 10 (11 mai 2022) : 1539. http://dx.doi.org/10.3390/electronics11101539.
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This article describes the manufacturing of a horn antenna using a 3D commercial printer. The horn antenna was chosen for its simplicity and practical versatility. The standardised horn antenna is one of the most widely used antennas in microwave technology. A standardised horn antenna can be connected to standardised waveguides. The horn antenna has been selected so that this antenna can be fabricated by 3D printing and thus obtain the equivalent of a standardised horn antenna. This 3D horn antenna can then be excited by a standardised waveguide. The 3Dprinted horn antenna with metallic layers has very good impedance characteristics, standing wave ratio and radiation patterns that are close to those of a standardised horn antenna. The 3D-based horn antenna is suitable for applications where low antenna weight is required, such as aerospace and satellite technologies. The article also describes a manufacturing procedure for a horn antenna (E-sector horn antenna) that is plated with galvanic layers of silver and gold. The design of the plated horn antenna in the Matlab application using the Antenna Toolbox extension is also described, including 3D printing procedures, post-processing procedures (plating) and practical testing of its functionality. The measured results are compared to simulations of the standardised horn antenna and then analysed.
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Shen, Lingrong, Wei Luo, Youming Miao et Gui Liu. « Combined Shark-Fin Rooftop Antenna for LTE, WLAN and BeiDou Applications ». Electronics 13, no 7 (1 avril 2024) : 1324. http://dx.doi.org/10.3390/electronics13071324.
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This paper presents rooftop automobile antennas designed for Long-Term Evolution (LTE), Wireless Local Area Network (WLAN) and navigation system applications. The proposed antennas are housed within a shark-fin structure on the car’s roof, and comprise a main antenna and a diversity antenna. The main antenna and diversity antenna combine for spatial diversity, receiving and processing the same signal to optimize signal quality. To accommodate the limited space within the shark-fin housing, various miniaturization and multiband techniques are utilized. The hexagonal substrate is more closely fitted to the shape of the shark fin, thus making full use of the space of the shark-fin shell. The main antenna and the diversity antenna are perpendicular to each other, which saves the space of the overall antenna and improves the utilization rate of the overall antenna space. The proposed main antenna, compactly sized at 50 mm × 20 mm × 1.59 mm, maintains a VSWR value below 2 across the frequency range of 1.19–2.8 GHz, enabling support for LTE bands 1, 2, 3, 4, 7, 11, 15, 16, 34, 39, 40, and 41, as well as WLAN 2400 bands. The diversity antenna maintains a VSWR value below 2 across the frequency range of 1.5–2.6 GHz, which can cover BeiDou B1-1, LTE 1, 2, 3, 4, 7, 11, 15, 16, 34, 39, and 40, and WLAN 2400 bands. The main antenna and the diversity antenna both demonstrate favorable radiation patterns on the azimuth plane. Simulation and measurement results exhibit a high level of agreement.
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Thompson, J. S. « Editorial : Antenna array processing techniques ». IEE Proceedings - Radar, Sonar and Navigation 145, no 1 (1998) : 1. http://dx.doi.org/10.1049/ip-rsn:19981818.
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Chang, Z., P. Lyu et B. Peng. « Differentiated Reception Modes Based Multiple Access ». Wireless Communications and Mobile Computing 2022 (11 octobre 2022) : 1–9. http://dx.doi.org/10.1155/2022/5328007.
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In recent years, the continuous increase in wireless data services and users’ traffic demand has been imposing great challenges on traditional multiple access control (MAC) methods. Some existing MAC techniques improve the communication system’s spectral efficiency (SE) via signal processing based cochannel interference (CCI) management. However, no interference management (IM) is free, i.e., its realization is based on the consumption of some communication resources, such as power and degree-of-freedom (DoF), which can also be used for the user’s desired data transmission. To lessen the resource cost for IM-based MAC, we exploit interactions among multiple wireless signals to propose a new MAC method, namely, Differentiated Reception Modes based Multiple Access (DRM-MA), in this paper. Under DRM-MA, a central control unit (CCU) is adopted to manage and pair multiple transmitting antennas with their serving receivers (Rxs). The CCU first calculates the phase difference of signals sent from each candidate antenna and perceived by the two receiving antennas of an Rx based on the locations of the transmitting antenna and Rx. Then, the CCU selects and pairs a proper transmitting antenna with each Rx, so that various Rxs can adopt either additive or subtractive reception mode to postprocess the signals received by its two antennas to realize in-phase desired signal construction and inverse-phase interference destruction. DRM-MA can avoid transmission performance loss incurred by signal processing-based IM. Our theoretical analysis and simulation results have shown that DRM-MA can enable concurrent data transmissions of multiple antenna-receiver pairs and output a high system’s SE.
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Dawidowicz, Karol, Rafal Kazmierczak et Krzysztof Swiatek. « SHORT STATIC GPS/GLONASS OBSERVATION PROCESSING IN THE CONTEXT OF ANTENNA PHASE CENTER VARIATION PROBLEM ». Boletim de Ciências Geodésicas 21, no 1 (mars 2015) : 213–30. http://dx.doi.org/10.1590/s1982-217020150001000014.
Texte intégralRésumé :
So far, three methods have been developed to determine GNSS antenna phase center variations (PCV). For this reason, and because of some problems in introducing absolute models, there are presently three models of PCV receiver antennas (relative, absolute converted and absolute) and two satellite antennas (standard and absolute). Additionally, when simultaneously processing observations from different positioning systems (e.g. GPS and GLONASS), we can expect a further complication resulting from the different structure of signals and differences in satellite constellations. This paper aims at studying the height differences in short static GPS/GLONASS observation processing when different calibration models are used. The analysis was done using 3 days of GNSS data, collected with three different receivers and antennas, divided by half hour observation sessions. The results show that switching between relative and absolute PCV models may have a visible effect on height determination, particularly in high accuracy applications. The problem is especially important when mixed GPS/GLONASS observations are processed. The update of receiver antenna calibrations model from relative to absolute in our study (using LEIAT504GG, JAV_GRANT-G3T and TPSHIPER_PLUS antennas) induces a jump (depending on the measurement session) in the vertical component within to 1.3 cm (GPS-only solutions) or within 1.9 cm (GPS/GLONASS solutions).
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Hult, Tommy, et Abbas Mohammed. « Power Constrained Space-Time Processing for Suppression of Electromagnetic Fields ». Journal of Communications Software and Systems 1, no 1 (6 avril 2017) : 71. http://dx.doi.org/10.24138/jcomss.v1i1.319.
Texte intégralRésumé :
Active suppression of noise and vibrations is a well established field of research with many applications in acoustic and mechanical industries. In this paper we investigate the possibility of applying these adaptive active control methods with the aim of lowering the electromagnetic power density at a specific volume in space using the superposition principle and space-time processing employing the full MIMO (Multiple Input Multiple Output) antenna system setup. The application that we evaluated is a model of a mobile phone equipped with one ordinary transmitting antenna and two actuator-antennas whichpurpose is to cancel out the electromagnetic field at the human head while maintaining a predefined level of the overall output power of the system. This power control is achieved through the use of a quadratic constraint on the active control algorithm. Simulation results show the promise of using the adaptive control algorithms and MIMO system to attenuate the electromagnetic field power density.
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Milivojčević, Marko, Nenad Tolić et Mijat Štimac. « Potential to use microstrip patch instead of dipole antennas in 2.4 GHz wireless sensor networks ». Telfor Journal 14, no 1 (2022) : 44–48. http://dx.doi.org/10.5937/telfor2201044m.
Texte intégralRésumé :
This paper describes the process of designing, simulating and measuring antenna parameters in order to perform a comparative analysis of the performance of microstrip patch antennas and dipole antennas intended for use in wireless sensor networks. The implemented antennas are designed for the unlicensed ISM band of 2.402-2.480 GHz as one of the most widely used bands for this type of network. The patch antenna was created based on calculation and tested in simulation software, and then adjusted with appropriate measurements to suit the intended purpose. Measurements in real conditions were made to compare the patch and dipole antennas in the same frequency range. The patch antenna was further tested, due to the specificity of the implementation within the WSN, in an enclosed and open enclosure made of a conductive material that simulates the enclosure of wireless sensor network nodes in certain applications. The aim of this paper is to show the possibility of using patch antennas instead of dipole antennas in the enclosures of wireless sensor networks nodes.
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Mikki, Said. « The antenna spacetime system theory of wireless communications ». Proceedings of the Royal Society A : Mathematical, Physical and Engineering Sciences 475, no 2224 (avril 2019) : 20180699. http://dx.doi.org/10.1098/rspa.2018.0699.
Texte intégralRésumé :
A general deterministic spacetime system theory of antennas suitable for the analysis and design of wireless communication links is rigorously developed using the recently introduced antenna current Green's function formalism. We provide the first complete derivation of the antenna spatio-temporal response to a delta source using only electromagnetic Green's functions, effectively eliminating all field and current distributions in the final expressions. While the theory works well in both space and time, it puts into sharper focus how the spatio-temporal structure of electromagnetic processes imposes restrictions on the signal processing capabilities of antenna systems by constraining the allowable mathematical form of the effective impulse response of the global wireless communication link. It is shown that the antenna current Green's functions of both the receive and transmit terminals, plus the propagation environment Green's functions, are the only quantities needed to obtain the single input–single output link response function in closed form. One of the results deduced from the theory is that an exact impulse response cannot be ascribed to an arbitrary antenna in general, but may be approximated for many applications. The theory can be deployed for future antenna systems research to boost up spectral efficiency (without increasing physical bandwidth) by directly incorporating electromagnetic knowledge into the design of the communication system's signal processing functions.
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Wang, Wen-Qin. « Virtual Antenna Array Analysis for MIMO Synthetic Aperture Radars ». International Journal of Antennas and Propagation 2012 (2012) : 1–10. http://dx.doi.org/10.1155/2012/587276.
Texte intégralRésumé :
Multiple-input multiple-output (MIMO) synthetic aperture radar (SAR) that employs multiple antennas to transmit orthogonal waveforms and multiple antennas to receive radar echoes is a recently proposed remote sensing concept. It has been shown that MIMO SAR can be used to improve remote sensing system performance. Most of the MIMO SAR research so far focused on signal/data models and corresponding signal processing algorithm. Little work related to MIMO SAR antenna analysis can be found. One of the main advantages of MIMO SAR is that the degrees of freedom can be greatly increased by the concept of virtual antenna array. In this paper, we analyze the virtual antenna array for MIMO SAR high-resolution wide-swath remote sensing applications. The one-dimensional uniform and nonuniform linear antenna arrays are investigated and their application potentials in high-resolution wide-swath remote sensing are introduced. The impacts of nonuniform spatial sampling in the virtual antenna array are analyzed, along with a multichannel filtering-based reconstruction algorithm. Conceptual system and discussions are provided. It is shown that high operation flexibility and reconfigurability can be obtained by utilizing the virtual antenna arrays provided by the MIMO SAR systems, thus enabling a satisfactory remote sensing performance.
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Wang, Xinhai, Liqiong Wu, Hua Chen, Wei Wang et Zhaoping Liu. « Frequency-Reconfigurable Microstrip Patch Antenna Based on Graphene Film ». Electronics 12, no 10 (19 mai 2023) : 2307. http://dx.doi.org/10.3390/electronics12102307.
Texte intégralRésumé :
Fifth-generation mobile communication systems must connect to multiple wireless networks. In order to enable a single device to match the frequency bands of multiple wireless networks, it is usually necessary to use multiple single-band or multi-band antennas, which occupy a large amount of space inside a given device. Using frequency-reconfigurable antennas to replace multiple single-function antennas is an effective way to solve this problem. In this paper, we propose a frequency-reconfigurable microstrip patch antenna based on graphene film, which fills the slot of the radiating patch with graphene film. It was found that the surface current of the antenna can be changed by changing the conductivity of graphene through bias voltage, which allows the operating mode of the antenna to switch between a nearly slotted antenna and a nearly unslotted antenna to achieve frequency reconfigurability. By changing the bias voltage from 0 V to 9 V, the resonant frequency of the antenna can be switched from 29.6 GHz to 40 GHz, and the center frequency can by altered by 10.4 GHz, corresponding to the reflection coefficients of −26 dB and −20.8 dB, respectively. The antenna achieves good matching in both operating modes.
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Fortes, Jana, Michal Švingál, Tamás Porteleky, Patrik Jurík et Miloš Drutarovský. « Positioning and Tracking of Multiple Humans Moving in Small Rooms Based on a One-Transmitter–Two-Receiver UWB Radar Configuration ». Sensors 22, no 14 (13 juillet 2022) : 5228. http://dx.doi.org/10.3390/s22145228.
Texte intégralRésumé :
The paper aims to propose a sequence of steps that will allow multi-person tracking with a single UWB radar equipped with the minimal antenna array needed for trilateration. Its localization accuracy is admittedly limited, but on the other hand, thoughtfully chosen placement of antennas can increase the detectability of several humans moving in their immediate vicinity and additionally decrease the computational complexity of the signal processing methods. It is shown that the UWB radar measuring with high rate and fine range resolution in conjunction with properly tuned processing parameters can continually track people even in the case when their radar echoes are crossing or merging. Emphasis is given to the simplified method of the time-of-arrival (TOA) estimation and association and the novel method needed for antenna height compensation. The performance of the proposed human tracking framework is evaluated for the experimental scenario with three people moving closely in a small room. A quantitative analysis of the estimated target tracks confirms the benefits of suggested high antenna placement and application of new signal processing methods in the form of decreasing the mean localization error and increasing the frequency of correct target position estimations.
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Srikar, D., Anveshkumar Nella, Ranjith Mamidi, Ashok Babu, Sudipta Das, Sunil Lavadiya, Abeer D. Algarni et Walid El-Shafai. « A Novel Integrated UWB Sensing and 8-Element MIMO Communication Cognitive Radio Antenna System ». Electronics 12, no 2 (8 janvier 2023) : 330. http://dx.doi.org/10.3390/electronics12020330.
Texte intégralRésumé :
In this article, a cognitive radio (CR) integrated antenna system, which has 1 sensing and 24 communication antennas, is proposed for better spectrum utilization efficiency. In the 24 communication antennas, 3 different operating band antennas are realized with an 8-element MIMO configuration. The sensing antenna linked to port 1 is able to sense the spectrum that ranges from 2 to 12 GHz, whereas the communication 8-element MIMO antennas linked with ports 2 to 9, ports 10 to 17 and ports 18 to 25 perform operations in the 2.17–4.74 GHz, 4.57–8.62 GHz and 8.62–12 GHz bands, respectively. Mutual coupling is found to be less than −12 dB between the antenna elements. Peak gain and radiation efficiency of the sensing antenna are better than 2.25 dBi and 82%, respectively, whereas the peak gains and radiation efficiencies of all communication antennas are more than 2.5 dBi and 90%, respectively. Moreover, diversity characteristics of the MIMO antenna are assessed by parameters such as DG, ECC and CCL. It is found that ECC and CCL are less than 0.42 and 0.46 bits/s/Hz, respectively, and also DG is more than 9.1 dB.
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Bin Abdullah, Muhammad Azfar, Mohamad Kamal A. Rahim, Noor Asmawati Samsuri, Mohd Fairus, Mohd Khairul Hisham Ismail et Huda A. Majid. « On human body transmission wearable diamond dipole antennas above engineered jackets ». Indonesian Journal of Electrical Engineering and Computer Science 22, no 3 (1 juin 2021) : 1513. http://dx.doi.org/10.11591/ijeecs.v22.i3.pp1513-1519.
Texte intégralRésumé :
This paper presents the propagation of dual-band diamond dipole antenna on three various jackets. The jackets are purely fleece fabric with Shieldit fabric patches on top of it. The network analyzers with the flexible lossless coaxial cable are used to measure the communication of the antennas. The experiment involves a man with ideal body mass index (BMI) wearing the jackets by placing the flexible antennas on top of it. It is observed that the best on-body communication is by wearing the engineered jacket. The 10 dB improvements are observed when the antenna is positioned on top of engineered jacket contrast to the regular jacket. In other words, the performance of the antenna is also be determined by antenna placement. High transmission lossesses cause the antenna mismatch when the antennas are positioned above the full conductive jacket.
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Chang, Haowei, Chunlei Pang, Liang Zhang et Zehui Guo. « Rotating Single-Antenna Spoofing Signal Detection Method Based on IPNN ». Sensors 22, no 19 (21 septembre 2022) : 7141. http://dx.doi.org/10.3390/s22197141.
Texte intégralRésumé :
The traditional carrier-phase differential detection technology mainly relies on the spatial processing method, which uses antenna arrays or moving antennas to detect spoofing signals, but it cannot be applied to static single-antenna receivers. Aiming at this problem, this paper proposes a rotating single-antenna spoofing signal detection method based on the improved probabilistic neural network (IPNN). When the receiver antenna rotates at a constant speed, the carrier-phase double difference of the real signal will change with the incident angle of the satellite. According to this feature, the classification and detection of spoofing signals can be realized. Firstly, the rotating single-antenna receiver collects carrier-phase values and performs double-difference processing. Then, we construct an IPNN model, whose smoothing factor can be adaptively adjusted according to the type of failure mode. Finally, we use the IPNN model to realize the classification and processing of the carrier-phase double-difference observations and obtain the deception detection results. In addition, in order to reflect that the method has a certain practical value, we simulate the spoofing scenario of satellite signals and effectively identify abnormal satellite signals according to the detection results of the inter-satellite differential combination. Actual experiments indicate that the detection accuracy of the proposed method for spoofing signals reaches 98.84%, which is significantly better than the classical probabilistic neural network (PNN) and back-propagation neural network (BPNN), and the method can be implemented in fixed base station receivers for the real-time detection of forwarding spoofing.
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M. Africa, Aaron Don, Rica Rizabel M. Tagabuhin et Jan Jayson S. D. Tirados. « Design and simulation of an adaptive beam smart antenna using MATLAB ». Indonesian Journal of Electrical Engineering and Computer Science 21, no 3 (10 mars 2021) : 1584. http://dx.doi.org/10.11591/ijeecs.v21.i3.pp1584-1593.
Texte intégralRésumé :
<span id="docs-internal-guid-ad3b6b0d-7fff-2d92-685e-3d423ac2713f"><span>Signals transmitted over a long range of distance may pass through several obstacles and scatter, taking multiple paths to reach the receiver. Beamforming antennas are controlled electronically to adjust the radiation pattern following the first received signal. This allows the antenna to maximize the received signal and consequently, suppress the interfering signals received. A smart antenna should be able to diminish noise, increase the signal to noise ratio, and have better system competence. The adaptive beam makes use of the spacing of the several antennas and the phase of the signal of each antenna array to control the shape and direction of the signal beam. This paper focuses on the use of smart antennas using an adaptive beam method as a better system for the transmission of signals. A simulation between the existing Omnidirectional antenna system and the smart antenna system will be made and compared. The paper will discuss the corresponding advantages that a smart antenna system has compared to the Omnidirectional antenna system.</span></span>
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Nurhayati, Nurhayati, Eko Setijadi, Alexandre Maniçoba de Oliveira, Dayat Kurniawan et Mohd Najib Mohd Yasin. « Design of 1 × 2 MIMO Palm Tree Coplanar Vivaldi Antenna in the E-Plane with Different Patch Structure ». Electronics 12, no 1 (30 décembre 2022) : 177. http://dx.doi.org/10.3390/electronics12010177.
Texte intégralRésumé :
In this paper, 1 × 2 MIMO of Palm Tree Coplanar Vivaldi Antenna is presented that simulated at 0.5–4.5 GHz. Some GPR applications require wideband antennas starting from a frequency below 1 GHz to overcome high material loss and achieve deeper penetration. However, to boost the gain, antennas are set up in MIMO and this is costly due to the large size of the antenna. When configuring MIMO antenna in the E-plane, there is occasionally uncertainty over which antenna model may provide the optimum performance in terms of return loss, mutual coupling, directivity, beam squint, beam width, and surface current using a given substrate size. However, the configuration of E-plane antenna in MIMO has an issue of mutual coupling if the distance between elements is less than 0.5λ. Furthermore, it produces grating lobes at high frequencies.We implement several types of patch structures by incorporating the truncated, tilt shape, Hlbert and Koch Fractal, Exponential slot, Wave slot, the lens with elips, and metamaterial slot to the radiator by keeping the width of the substrate and the shape of the feeder. The return loss, mutual coupling, directivity, beam squint, beamwidth, and surface current of the antenna are compared for 1 × 2 MIMO CVA. A continuous patch MIMO has a spacing of 0.458λ at 0.5 GHz, which is equivalent to its element width. From the simulation, we found that Back Cut Palm Tree (BCPT) and Horizontale Wave Structure Palm Tree (HWSPT) got the best performance of return loss and mutual scattering at low-end frequency respectively. The improvement of directivity got for Metamaterial Lens Palm Tree (MLPT) of 4.453 dBi if compared with Regular Palm Tree-Coplanar Vivaldi Antena (RPT) at 4 GHz. Elips Lens Palm Tree (ELPT) has the best beam squint performance across all frequencies of 0°. It also gots the best beamwidth at 4.5 GHz of 3.320. In addition, we incorporate the MLPT into the radar application.
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Alabed, Samer, Amer Alsaraira, Nour Mostafa, Mohammad Al-Rabayah, Ahmed Shdefat, Chamseddine Zaki, Omar A. Saraereh et Zakwan Al-Arnaout. « Two-way differential strategy for wireless sensor networks ». Bulletin of Electrical Engineering and Informatics 12, no 6 (1 décembre 2023) : 3499–508. http://dx.doi.org/10.11591/eei.v12i6.6121.
Texte intégralRésumé :
In this paper, a novel optimal two-way amplify and forward (AF) differential beamforming method for wireless sensor network is proposed. The proposed method is an advanced signal processing technique used to enhance the performance and reliability of the communication link by exploiting the diversity provided by multiple antennas. Unlike current state-of-the-art methods which require the knowledge of channel state information (CSI) at both transmitting and receiving antennas or at least at the receiving antennas, the suggested method does not need CSI at any transmitting or receiving antenna. Moreover, the proposed method enjoys high error performance with high diversity and coding gain and has a very low encoding and decoding complexity. Through our simulations, the proposed method is proved to outperform the best known non-coherent multi-antenna methods.
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Sohel Rana, Md, Sifat Hossain, Shuvashis Biswas Rana et Md Mostafizur Rahman. « Microstrip patch antennas for various applications : a review ». Indonesian Journal of Electrical Engineering and Computer Science 29, no 3 (1 mars 2023) : 1511. http://dx.doi.org/10.11591/ijeecs.v29.i3.pp1511-1519.
Texte intégralRésumé :
<span lang="EN-US">This paper aims to review microstrip antennas for various applications. The design of microstrip patch antennas is a new research field developed for use in 5th generation communication applications. An antenna is a collection of multiple devices connected together that function as a single antenna to send or receive radio waves. Antennas can be of different shapes and sizes. The microstrip patch is an antenna pattern that is light in weight, low profile, and focuses on producing results. In the future, microstrip patch antennas may be used for some 6G communication systems applications. In addition, 6G communication applications can be created on other devices, including biomedical, autonomous vehicles, vehicle-to-vehicle (V2V) communication, internet of things (IoT), machine learning, Artificial Neural Network Algorithms, radar, and wireless communication. In the past, the multiple input, multiple output (MIMO) pattern was a standard geometry used in 4G wireless applications. This paper discusses the geometric structures of antennas, various analysis methods for antenna characteristics, antenna dimensions, and many different types of antennas. Also, it will discuss the previous papers' substrate materials, loss tangent, thickness, return loss, bandwidth, voltage-standing-wave-ratio (VSWR), gain, and directivity.</span>
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Zeng, Lingqi, Chengxin Wang, Haibo Liu, Ning Liu, Jinxin Wang, Lanlan Zhou, Yong Wang et Yongqing Wang. « Influence of Antenna Element Position Deviation on Radiation Performance of Helical Antenna Array ». Sensors 23, no 10 (17 mai 2023) : 4827. http://dx.doi.org/10.3390/s23104827.
Texte intégralRésumé :
The electrical performance of the feed array is degraded because of the position deviation of the array elements caused by manufacturing and processing, which cannot meet the high performance feeding requirements of large feed arrays. In this paper, a radiation field model of the helical antenna array considering the position deviation of array elements is proposed to investigate the influence law of position deviation on the electrical performance of the feed array. With the established model, the rectangular planar array and the circular array of the helical antenna with a radiating cup are discussed and the relationship between electrical performance index and position deviation is established by numerical analysis and curve fitting method. The research results show that the position deviation of the antenna array elements will lead to the rise of the sidelobe level, the deviation of the beam pointing, and the increase of the return loss. The valuable simulation results provided by this work can be used in antenna engineering, guiding antenna designers to set optimal parameters when fabricating antennae.
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Zheng, Zi Wei. « Iterative Channel Estimation Scheme for the WLAN Systems with the Multiple-Antenna Receivers ». Advanced Engineering Forum 6-7 (septembre 2012) : 871–75. http://dx.doi.org/10.4028/www.scientific.net/aef.6-7.871.
Texte intégralRésumé :
Alleviate the multipath delay spread and suitable for broadband transmission efficiency, orthogonal frequency division multiplexing wireless local area network (WLAN) is widely used to assist inverse fast Fourier transform and fast Fourier transform operation domain. Orthogonal frequency division multiplexing is a blow to the broadcast channel multipath fading and high data throughput, transmission, wireless fading channel method, which is widely used to support high performance bandwidth-efficient wireless multimedia services. Several times in the transmitter and receiver antenna technology allows data transfer rate and spectrum efficiency and the use of multiple transmit antennas and multiple receive antennas through spatial processing. High-precision channel estimation scheme is very important wideband multi-carrier orthogonal frequency complex WLAN systems use multiple antenna receiver based division of labor and the overall multi-carrier orthogonal frequency multiplexing division of performance-based WLAN system is to crucial antenna to receive the symbol error rate. In this article, the iterative channel estimation scheme proposed multi-carrier orthogonal frequency division multiplexed using multiple antennas receiver-based WLAN system.
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Chung, Ming-An, Cheng-Wei Hsiao, Chih-Wei Yang et Bing-Ruei Chuang. « 4 × 4 MIMO Antenna System for Smart Eyewear in Wi-Fi 5G and Wi-Fi 6e Wireless Communication Applications ». Electronics 10, no 23 (26 novembre 2021) : 2936. http://dx.doi.org/10.3390/electronics10232936.
Texte intégralRésumé :
This paper proposes a small-slot antenna system (50 mm × 9 mm × 2.7 mm) for 4 × 4 multiple-input multiple-output (MIMO) on smart glasses devices. The antenna is set on the plastic temple, and the inverted F antenna radiates through the slot in the ground plane of the sputtered copper layer outside the temple. Two symmetrical antennas and slots on the same temple and series capacitive elements enhance the isolation between the two antenna ports. When both temples are equipped with the proposed antennas, 4 × 4 MIMO transmission can be achieved. The antenna substrate is made of polycarbonate (PC), and its thickness is 2.7 mm εr=2.85, tanδ=0.0092. According to the actual measurement results, this antenna has two working frequency bands when the reflection coefficient is lower than −10dB, its working frequency bandwidth at 4.58–5.72 GHz and 6.38–7.0 GHz. The proposed antenna has a peak gain of 4.3 dBi and antenna efficiency of 85.69% at 5.14 GHz. In addition, it also can obtain a peak gain of 3.3 dBi and antenna efficiency of 82.78% at 6.8 GHz. The measurement results show that this antenna has good performance, allowing future smart eyewear devices to be applied to Wi-Fi 5G (5.18–5.85 GHz) and Wi-Fi 6e (5.925–7.125 GHz).
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Chen, Yi, Jiang Lu, Qing Guo et Lei Wan. « 3D printing of CF/nylon composite mold for CF/epoxy parabolic antenna ». Journal of Engineered Fibers and Fabrics 15 (janvier 2020) : 155892502096948. http://dx.doi.org/10.1177/1558925020969484.
Texte intégralRésumé :
Parabolic antennas, which are wildly used as high-gain antennas for point-to-point communications, need many iterations of design-fabrication-test in parabolic antenna development. However, traditional molding via mechanical processing takes a long manufacturing cycle and high cost. In this paper, a 3D-printed CF/nylon composite parabolic mold for CF/epoxy parabolic antenna is studied. It’s found that the coefficient of thermal expansion (CTE) of 3D-printed CF/nylon composite is usually anisotropic due to the low adhesion between printed layers and the aligned short carbon fiber along the printing trace. Here an inclined mode of 3D printing could uniform the CTE of the antenna mold and solve the problems of large printing steps and the separation of supports and mold occurred in horizontal and vertical modes, respectively. The parabolic mold also reveals high profile precision with a low root mean square (RMS) deviation of 0.14 mm. Utilizing the 3D-printed CF/nylon composite mold, parabolic antenna skin with low surface RMS deviation of 0.16 mm was successfully fabricated by laying CF/epoxy prepreg and curing in autoclave. This research about isotropic and smooth 3D-printed CF/nylon mold may support the low-cost and rapid mold development for microwaves relay links on ground and satellite communication antennas.
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Wang, Zihang, Xiaodong Du, Changrui Wang, Wei Tian, Chao Deng, Ke Li, Yifan Ding et Wenhe Liao. « Design and Research of Intelligent Assembly and Welding Equipment for Three-Dimensional Circuit ». Applied Sciences 13, no 16 (17 août 2023) : 9359. http://dx.doi.org/10.3390/app13169359.
Texte intégralRésumé :
The processing of the three-dimensional circuit on the surface of conformal antennas is mainly performed via manual processing. At present, there is no automatic intelligent equipment for the processing of a similar small-sized circuit with variable curvature in China. Therefore, a high-precision, automated, full-process manufacturing method for three-dimensional circuits with flexible surfaces on conformal antennas of radar equipment has been proposed to improve processing quality and manufacturing efficiency. The processing relationship between solder paste spraying, resistor mounting, and laser welding in the flexible three-dimensional circuit manufacturing process was analyzed. The structure of the new conformal antenna three-dimensional circuit intelligent manufacturing equipment was determined, and simulation verification of the three-dimensional circuit processing was performed using Vericut. The optimal processing parameters were selected based on solid experiments. This method meets the electronic assembly requirements of radar equipment and fills the domestic gap.
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Zhao, Fan, Luhong Mao, Weilian Guo, Sheng Xie et Clarence Augustine T. H. Tee. « On-Chip Terahertz Detector Designed with Inset-Feed Rectangular Patch Antenna and Catadioptric Lens ». Electronics 9, no 6 (24 juin 2020) : 1049. http://dx.doi.org/10.3390/electronics9061049.
Texte intégralRésumé :
This study proposes an on-chip terahertz (THz) detector designed with on-chip inset-feed rectangular patch antenna and catadioptric lens. The detector incorporates a dual antenna and dual NMOSFET structure. Radiation efficiency of the antenna reached 89.4% with 6.89 dB gain by optimizing the antenna inset-feed and micro-strip line sizes. Simulated impedance was 85.55 − j19.81 Ω, and the impedance of the antenna with the ZEONEX horn-like catadioptric lens was 117.03 − j20.28 Ω. Maximum analyzed gain of two on-chip antennas with catadioptric lens was 17.14 dB resonating at 267 GHz. Maximum experimental gain of two on-chip patch antennas was 4.5 dB at 260 GHz, increasing to 10.67 dB at 250 GHz with the catadioptric lens. The proposed on-chip rectangular inset-feed patch antenna has a simple structure, compatible with CMOS processing and easily implemented. The horn-like catadioptric lens was integrated into the front end of the detector chip and hence is easily molded and manufactured, and it effectively reduced terahertz power absorption by the chip substrate. This greatly improved the detector responsivity and provided very high gain. Corresponding detector voltage responsivity with and without the lens was 95.67 kV/W with NEP = 12.8 pW/Hz0.5 at 250 GHz, and 19.2 kV/W with NEP = 67.2 pW/Hz0.5 at 260 GHz, respectively.
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Hashim, Fatimah Fawzi, Wan Nor Liza Binti Mahadi, Tariq Bin Abdul Latef et Mohamadariff Bin Othman. « Key Factors in the Implementation of Wearable Antennas for WBNs and ISM Applications : A Review WBNs and ISM Applications : A Review ». Electronics 11, no 15 (8 août 2022) : 2470. http://dx.doi.org/10.3390/electronics11152470.
Texte intégralRésumé :
The increasing usage of wireless technology has prompted the development of a new generation antenna compatible with the latest devices, with on-body antennas (wearable antennas) being one of the revolutionary applications. This modern design is relevant in technologies that require close human body contact, such as telemedicine and identification systems, due to its superior performance compared to normal antennas. Some of its finer characteristics include flexibility, reflection coefficient, bandwidth, directivity, gain, radiation, specific absorption rate (SAR), and efficiency that are anticipated to be influenced by the coupling and absorption by the human body tissues. Furthermore, improvements like band-gap structure and artificial magnetic conductors (AMC) and (DGS) are included in the wearable antenna that offers a high degree of isolation from the human body and significantly reduces SAR. In this paper, the development of on-body antennas and how they are affected by the human body were reviewed. Additionally, parameters that affect the performance of this new antenna model, such as materials and common technologies, are included as an auxiliary study for researchers to determine the factors affecting the performance of the wearable antenna and the access to a highly efficient antenna.
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Palanisamy, Satheeshkumar, Balakumaran Thangaraju, Osamah Ibrahim Khalaf, Youseef Alotaibi, Saleh Alghamdi et Fawaz Alassery. « A Novel Approach of Design and Analysis of a Hexagonal Fractal Antenna Array (HFAA) for Next-Generation Wireless Communication ». Energies 14, no 19 (28 septembre 2021) : 6204. http://dx.doi.org/10.3390/en14196204.
Texte intégralRésumé :
The study and exploration of massive multiple-input multiple-output (MMIMO) and millimeter-wave wireless access technology has been spurred by a shortage of bandwidth in the wireless communication sector. Massive MIMO, which combines antennas at the transmitter and receiver, is a key enabler technology for next-generation networks to enable exceptional spectrum and energy efficiency with simple processing techniques. For massive MIMOs, the lower band microwave or millimeter-wave band and the antenna are impeccably combined with RF transceivers. As a result, the 5G wireless communication antenna differs from traditional antennas in many ways. A new concept of the MIMO tri-band hexagonal antenna array is being introduced for next-generation cellular networks. With a total scaling dimension of 150 × 75 mm2, the structure consists of multiple hexagonal fractal antenna components at different corners of the patch. The radiating patch resonates at 2.55–2.75, 3.45–3.7, and 5.65–6.05 GHz (FR1 band) for better return loss (S11) of more than 15 dB in all three operating bands. The coplanar waveguide (CPW) feeding technique and defective ground structure in the ground plane have been employed for effective impedance matching. The deviation of the main lobe of the radiation pattern is achieved using a two-element microstrip Taylor antenna array with series feeding, which also boosts the antenna array’s bandwidth and minimizes sidelobe. The proposed antenna is designed, simulated, and tested in far-field radiating conditions and generates tri-band S-parameters with sufficient separation and high-quality double-polarized radiation. The fabrication and testing of MIMO antennas were completed, where the measurement results matched the simulation results. In addition, the 5G smartphone antenna system requires a new, lightweight phased microwave antenna (μ-wave) with wide bandwidth and a fire extender. Because of its decent performance and compact architectures, the proposed smartphone antenna array architecture is a better entrant for upcoming 5G cellular implementations.
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Crocker, Dylan A., et Waymond R. Scott. « Compensation of Dispersion in Sinuous Antennas for Polarimetric Ground Penetrating Radar Applications ». Remote Sensing 11, no 16 (19 août 2019) : 1937. http://dx.doi.org/10.3390/rs11161937.
Texte intégralRésumé :
In order to improve the accuracy of subsurface target classification with ground penetrating radar (GPR) systems, it is desired to transmit and receive ultra-wide band pulses with varying combinations of polarization (a technique referred to as polarimetry). The sinuous antenna exhibits such desirable properties as ultra-wide bandwidth, polarization diversity, and low-profile form factor, making it an excellent candidate for the radiating element of such systems. However, sinuous antennas are dispersive since the active region moves with frequency along the structure, resulting in the distortion of radiated pulses. This distortion may be compensated in signal processing with accurately simulated or measured antenna phase information. However, in a practical GPR, the antenna performance may deviate from that simulated, accurate measurements may be impractical, and/or the dielectric loading of the environment may cause deviations. In such cases, it may be desirable to employ a simple dispersion model based on antenna design parameters which may be optimized in situ. This paper explores the dispersive properties of the sinuous antenna and presents a simple, adjustable, model that may be used to correct dispersed pulses. The dispersion model is successfully applied to both simulated and measured scenarios, thereby enabling the use of sinuous antennas in polarimetric GPR applications.
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Krietemeyer, Andreas, Hans van der Marel, Nick van de Giesen et Marie-Claire ten Veldhuis. « A Field Calibration Solution to Achieve High-Grade-Level Performance for Low-Cost Dual-Frequency GNSS Receiver and Antennas ». Sensors 22, no 6 (15 mars 2022) : 2267. http://dx.doi.org/10.3390/s22062267.
Texte intégralRésumé :
Low-cost dual-frequency receivers and antennas have created opportunities for a wide range of new applications, in regions and disciplines where traditional GNSS equipment is unaffordable. However, the major drawback of using low-cost antenna equipment is that antenna phase patterns are typically poorly defined. Therefore, the noise in tropospheric zenith delay and coordinate time series is increased and systematic errors may occur. Here, we present a field calibration method that fully relies on low-cost solutions. It does not require costly software, uses low-cost equipment (~500 Euros), requires limited specialist expertise, and takes complex processing steps into the cloud. The application is more than just a relative antenna calibration: it is also a means to assess the quality and performance of the antenna, whether this is at a calibration site or directly in the field. We cover PCV calibrations, important for deformation monitoring, GNSS meteorology and positioning, and the computation of PCOs when the absolute position is of interest. The method is made available as an online web service. The performance of the calibration method is presented for a range of antennas of different quality and price in combination with a low-cost dual-frequency receiver. Carrier phase residuals of the low-cost antennas are reduced by 11–34% on L1 and 19–39% on L2, depending on the antenna type and ground plane used. For the cheapest antenna, when using a circular ground plane, the L1 residual is reduced from 3.85 mm before to 3.41 mm after calibration, and for L2 from 5.34 mm to 4.3 mm. The calibration reduces the Median Absolute Deviations (MADs) of the low-cost antennas in the vertical direction using Post Processed Kinematic (PPK) by 20–24%. For the cheapest antenna, the MAD is reduced from 5.6 to 3.8 mm, comparable to a geodetic-grade antenna (3.5 mm MAD). The calibration also has a positive impact on the Precise Point Positioning (PPP) results, delivering more precise results and reducing height biases.