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Hamizah Muhamad Mokhtar, Nur, Norun Abdul Malek, Ahmad Zamani Jusoh, Khamis Ali, Farah Nadia Mohd Isa, and Farah Diyana Abdul Rahman. "Design and comparison of printed antennas using meander line technique." Bulletin of Electrical Engineering and Informatics 8, no. 2 (June 1, 2019): 596–603. http://dx.doi.org/10.11591/eei.v8i2.1499.
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The interest for compact antennas in wireless communication increase due to the portability and mobility of the communication devices. Generally, an antenna at low frequency exhibits in large physical size. This project investigates the design of an antenna at 400 MHz. The simulation of the antenna has been performed using CST MWS. Since medical applications are dealing with low frequency, it will lead to large size of antenna which brings a challenge for wireless personal area network (WPAN). It is well known that the antenna performance decreases (according to Chu’s equation) as the size of antenna decreases. Therefore, antenna miniaturization using Meander Line (ML) will be taking place to overcome the challenges. Thus, this paper presents a comparison between i) printed dipole antenna without meander line technique, ii) printed dipole with meander line technique and iii) printed monopole antenna with meander line technique. The results show that an estimation of reduction size by 50% can be achieved using Meander Line technique.
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Kozieł, Sławomir, and Adrian Bekasiewicz. "Rapid Design Optimization of Multi-Band Antennas by Means of Response Features." Metrology and Measurement Systems 24, no. 2 (June 27, 2017): 337–46. http://dx.doi.org/10.1515/mms-2017-0030.
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AbstractThis work examines the reduced-cost design optimization of dual- and multi-band antennas. The primary challenge is independent yet simultaneous control of the antenna responses at two or more frequency bands. In order to handle this task, a feature-based optimization approach is adopted where the design objectives are formulated on the basis of the coordinates of so-called characteristic points (or response features) of the antenna response. Due to only slightly nonlinear dependence of the feature points on antenna geometry parameters, optimization can be attained at a low computational cost. Our approach is demonstrated using two antenna structures with the optimum designs obtained in just a few dozen of EM simulations of the respective structure.
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Taam, Hussein Abou, Georges Zakka El Nashef, Eric Arnaud, Nicolas Chevalier, Bertrand Lenoir, Bernard Jecko, and Mohamed Rammal. "Design development and experimental validation of an EBG matrix antenna for tracking application." International Journal of Microwave and Wireless Technologies 9, no. 1 (September 3, 2015): 231–39. http://dx.doi.org/10.1017/s1759078715001245.
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Today's increase of functions, improvement of performances, and cost reductions required on an agile electronically scanned antenna, drive researchers to develop an innovative antennas’ concept in order to deal with the proposed challenge. In this context, this article describes and demonstrates an experimental prototype to show the reliability and efficiency of the electromagnetic band gap(EBG)matrix antenna theoretical aspect, for beam forming and beam steering applications. The originality of this work is the antenna itself which constitutes the subject of an accepted national and international patent. In fact, the proposed antenna is based on the equivalent radiating surface approach and used special EBG antennas called “pixels” to overcome some of the array approach defects. The antenna has demonstrated different electromagnetic behaviors, such as low mutual coupling, high gain preservation for high scanning angles values, etc.
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Casula, Giovanni, and Giorgio Montisci. "A Design Rule to Reduce the Human Body Effect on Wearable PIFA Antennas." Electronics 8, no. 2 (February 21, 2019): 244. http://dx.doi.org/10.3390/electronics8020244.
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The robustness of wearable Ultra-High Frequency (UHF)-band planar inverted-F Antennas (PIFAs) with respect to coupling with the human body is an extremely difficult challenge for the designer. In this work a design strategy is presented to help the designer to adequately shape and extend the antenna ground plane, which has been derived by accurately analyzing the distribution of the electric and magnetic energy densities of the antenna in a region around the antenna borders. The optimal extension of the ground plane will be discussed for three different grounded antennas, both in terms of free space wavelength, and in terms of electric energy density magnitude. Following these rules, the antenna robustness with respect to the coupling with the human body can be significantly improved, but with a minimal impact on the antenna size. The antenna robustness has been successfully tested considering several models for the human phantom in the simulation environment. The numerical simulations, performed using Computer Simulation Technology (CST) Microwave Studio, have been confirmed by experimental data measured for one of the analyzed grounded antenna configurations.
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Skrivervik, A. K., J. F. Zurcher, O. Staub, and J. R. Mosig. "PCS antenna design: the challenge of miniaturization." IEEE Antennas and Propagation Magazine 43, no. 4 (2001): 12–27. http://dx.doi.org/10.1109/74.951556.
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Tamrakar, Shweta, and Rahul Shrivastava. "Overview of Microstrip Patch Antenna for GNSS communication System." International Journal on Recent and Innovation Trends in Computing and Communication 7, no. 5 (June 1, 2019): 22–25. http://dx.doi.org/10.17762/ijritcc.v7i5.5306.
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Microstrip patch antenna are playing very important role in all wireless global navigation satellite communication system. It uses L band, X band, C band, Ku band, Ka band for global navigation satellite system (GNSS) communication application. L band frequency range is 1-2GHz so it can be used in lower frequency range communication. With the increasing need for communication and the emergence of many other systems, it is important to design compact size antennas to cover a wide frequency range. The design of an efficient wideband small size antenna, for recent wireless applications, is a major challenge. Patch antennas have found extensive applications in wireless communication system. In this paper microstrip patch antenna discussed and detail studied of GNSS system application.
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Giri, Kali Krishna, Raj Kumar Singh, Kumari Mamata, and Ajeet Kumar Shrivastava. "A Theoretical Survey on Patch Antenna for Wideband Communication." International Journal of Research in Engineering, Science and Management 3, no. 11 (November 20, 2020): 69–73. http://dx.doi.org/10.47607/ijresm.2020.376.
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Modern communication system is based on wideband communication. A wideband antenna is designed in such a way that it will receive a wide range of frequencies. Microwave frequency spectrum is classified as ranging from 1GHz to 100GHz and this range is divided into a number of frequency bands. These bands are defined as L Band, S Band, C Band, X Band etc. To fulfil the demands of many users patch antenna is designed in these bands. Among different types of antenna, Microstrip Patch Antenna is most popular in wireless communication system. Microstrip patch Antennas have many advantages over other familiar antennas because microstrip patch antennas are of low profile, low cost, low volume, light weight. Low efficiency, low gain and narrow bandwidth of patch antenna create major challenge to a designer. Slots are created on patch for preparing antenna forwideband applications. In this paper, we have surveyed upon various types of Microstrip Patch Antenna, feeding techniques, design equation Substrate Characteristics, Simulation tools etc.
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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 (March 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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Adam, I., M. N. M. Yasin, M. E. A. Aziz, and Sulaiman M.I. "Rectifier for RF energy harvesting using stub matching." Indonesian Journal of Electrical Engineering and Computer Science 13, no. 3 (March 1, 2019): 1007. http://dx.doi.org/10.11591/ijeecs.v13.i3.pp1007-1013.
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One of challenge in rectenna design is the impedance matching of the antenna to the rectifier load. Rectifier exhibits complex impedance while antennas are normally designed to match either 50 Ω or 75 Ω loads. For the optimum power transfer between antenna and the rectifier circuit, both impedances should be matched. This paper presents the design and development of the 7-stages Dickson multiplier in energy harvesting. The objective of this paper is to analyze the performance of the designed multiplier together with matching circuit. An improvement of 60% output voltage is achieved by feeding -30dBm of low input power at the multiplier circuit.
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Fernandes, Filipa S. S., Christian Rom, António Rodrigues, Simon Svendsen, and Ole Jagielski. "Two-Step Method for Millimeter-Wave Antenna Performance Assessment in 5G Smartphones." International Journal of Antennas and Propagation 2021 (June 10, 2021): 1–18. http://dx.doi.org/10.1155/2021/6641501.
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A critical challenge for 5G is transitioning to the mm-Wave spectrum. Despite providing unprecedented data rates, mm-Waves also suffer high path loss, atmospheric absorption, and higher fluctuating channel conditions, sparking numerous paradigm shifts in the smartphone industry. Extending mm-Wave communications to smartphones requires first a comprehensive study to identify the antenna design/smartphone implementation challenges that impact the quality of communications. This work proposes a two-step assessment metric, the mmWAESI, to evaluate mm-Wave antennas’ potential and limitations regarding their impact on system performance. First, it analyzes the spatial distribution of the smartphone-integrated beam steering array’s radiated power. Then, it evaluates the antenna’s influence on the MIMO performance, using a discrete, time-variant geometrical MIMO channel simulator to recreate any mm-Wave propagation scenario. For enhanced accuracy, mmWAESI accounts simultaneously for several communication aspects: antenna type, realistic radiation patterns, mobile phone form factor constraints, phone orientation, and user influence. The method is illustrated for two different 4-element linear arrays at 39 GHz, based on patch or monopole elements, integrated into smartphones. Their performance is compared under similar conditions, revealing that, unless array switching is employed, the smartphone’s form factor and user influence will mask any potential advantage of the unperturbed array characteristics.
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He, Ming Lu, Yan Bing Xue, and Jing Zhang. "A Novel RFID Tag Dipole Antenna." Applied Mechanics and Materials 513-517 (February 2014): 2808–11. http://dx.doi.org/10.4028/www.scientific.net/amm.513-517.2808.
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There is a problem in normal meander line antenna (MLA) that it is difficult to get performances of miniaturization, high efficiency and high inductance at the same time. A simple novel antenna design for this challenge is described. Two capacitive loads are added at the end of MLA to adjust the impendence. For saving material, holes are digged on the loads. Simulation by HFSS shows that, comparing with the regular MLA, the proposed antennas impedance enhances from 10-12j to 23+150j, and the maximum gain enhances from 1.31dB to 1.67dB, with a read range of 10.1m. Meanwhile the return loss at 915MHz is-34dB, with a wide-10dB bandwidth of 860 ~ 985 MHz.
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Meneses González, Ricardo, R. Linares y Miranda, and R. Leyva Hernández. "Spiral Slotted Microstrip Antenna Design for 700 MHz Band Application." International Journal of Antennas and Propagation 2016 (2016): 1–7. http://dx.doi.org/10.1155/2016/1879287.
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This work describes the design and implementation of spiral slotted microstrip antenna. Recently, just like other countries, in Mexico, terrestrial digital television has been implemented (analogic shutdown); as a consequence, the 700 MHz UFH Band (698–806 MHz) has been opened to new telecommunications services, particularly wireless mobile communication. This technological advance represents a radio mobile antenna design challenge because it is necessary to design an antenna whose dimensions must be small enough, which satisfies gain, resonance frequency, and bandwidth requirements and is of low cost.
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Ali, Syed Muhammad. "Design of Compact Dual Band Circular Polarized Micro-strip Antenna for High Efficiency WLAN 802.11ax-2019." International Journal of Informatics and Communication Technology (IJ-ICT) 7, no. 3 (December 1, 2018): 135. http://dx.doi.org/10.11591/ijict.v7i3.pp135-140.
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Design of antennas for the latest upcoming standards of WLANs is considered as a key challenge in the science of Mobile Communication Engineering. Micro strip antennas are supposed to have some quality features in mobile and wireless network systems. Their weight and size are reduced and they are capable of having low power capacity. All these interesting features enabled these type of antennas suitable for the communication of IEEE 802.11ax-2019 high speed WLANs. Shape of these antennas can be designed in an efficient manner to achieve required gain and bandwidth. In this paper the concept of circular polarization has been introduced along with compact design of antennas in order to achieve return loss and axial ratio of less than -10 dB and 3dB respectively. Antenna has been designed and simulated on CST MW studio software and usage of dual bands 2.4 and 5.2GHz having circular polarization is properly elucidated for 802.11ax-2019.
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Zhang, Jie, Jin Huang, Pengbing Zhao, Wei Liang, and Congsi Wang. "Antenna control systems for flexible structure under a wind load." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 9 (September 18, 2018): 3050–59. http://dx.doi.org/10.1177/0954406218802322.
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Higher levels of pointing (directional) accuracy are required with the increase of diameter of large reflector antennae. The influence of wind disturbance on the level of pointing error has become a serious problem with the increased size of antenna. Newer, larger antenna designs have to combine increased control and more accurate pointing mechanisms that challenge existing technology. With reference to the typical Cassegrain antenna, this paper aims to improve the accuracy of antenna pointing mechanisms under a variety of wind conditions. This is based on the pointing model derived from combining both structural dynamics and electromechanics such that the pointing error caused by wind can be estimated efficiently. Using different controller design methods, which present the flexible pointing error as a combination of rotation angle error, torque disturbance, and state disturbance, the pointing error is compensated effectively. Tests and analysis of a 7.3 m antenna have been conducted. The results show that the linear-quadratic-Gaussian controller can reduce the maximum pointing errors by 79.3%, and the sliding mode controller is found to significantly outperform other controllers as it has the smallest root mean square of pointing error.
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Dala, Aliyu, and Tughrul Arslan. "Design, Implementation, and Measurement Procedure of Underwater and Water Surface Antenna for LoRa Communication." Sensors 21, no. 4 (February 13, 2021): 1337. http://dx.doi.org/10.3390/s21041337.
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There is an increasing interest in water bodies, which make up more that seventy percent of our planet. It is thus imperative that the water environment should be remotely monitored. Radio frequency (RF) signals have higher bandwidth and lower latency compared to acoustic signals. However, water has high permittivity and conductivity which presents a challenge for the implementation of RF technology. In this work, we undertook a novel design, fabrication, measurement and implementation of an antenna for a sensor node with dual ability of underwater and water surface long range (LoRa) communication at 868 MHz. It was observed that the antenna’s performance deteriorated underwater without −10 dB effective bandwidth between 668 MHz and 1068 MHz. The introduction of an oil-impregnated paper buffer around the antenna resulted in an effective 400 MHz bandwidth within the same frequency span. The sensor node with the buffered antenna was able to achieve a distance of 6 m underwater and 160 m over water surface communication to a data gateway node. The sensor node without the buffered antenna was only able to achieve 80 m over water surface communication. These experimental results show the feasibility of using the LoRa 868 MHz frequency in underwater and water surface communication.
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Bien, Duong Xuan, Pham Quoc Hoang, Le Xuan Hung, Do Manh Tung, Nguyen Tai-Hoai Thanh, Nguyen Hong Phong, Vuong Tien Trung, and Pham Van Tuan. "Kinematics modeling analysis of the geostationary satellite monitoring antenna system." Science & Technology Development Journal - Engineering and Technology 4, no. 1 (March 14, 2021): first. http://dx.doi.org/10.32508/stdjet.v4i1.770.
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The trend of scientific development in the future cannot fail to mention the great influence of the space field, but in the immediate future, the observational satellite systems are related to communication technology. In fact, in some countries with strong development of communication technology and space technology, the mechanical system of geostationary satellite monitoring antennas has certainly been thoroughly resolved. However, because of a specific technology, the sharing and transferring of design and manufacturing technology to developing countries is a great challenge. It is almost difficult to find published works related to mechanical design calculation and manufacture of geostationary satellite monitoring antenna systems. The problem of proactive grasping of technology, step by step autonomy in manufacturing technology of telecommunications equipment related to space technology has always been the goal of developing countries like Vietnam to limit technology dependence, minimizing technology transfer costs, ensuring national security. The first step in these problems is the autonomous construction of terrestrial transceivers such as geostationary satellite monitoring antennas. This paper presents the kinematics modeling analysis of the mechanical system of the geostationary satellite monitoring antenna. Each component of the antenna system is assumed a rigid body. The mathematical model is built based on multi-bodies kinematics and dynamics theory. The DENAVIT-HARTENBERG (D-H) homogeneous matrix method was used to construct the kinematics equations. The forward kinematics problem is analyzed to determine the position, velocity, acceleration, and workspace of the antenna system with given system motion limits. The inverse kinematics problem is mentioned to determine the kinematics behaviors of the antenna system with a given motion path in the workspace. The numerical simulation results kinematics were successfully applied in practice, especially for dynamics and control system analysis of geostationary satellite antenna systems.
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Tesarik, Jan, Tomas Pokorny, and Jan Vrba. "Dielectric sensitivity of different antennas types for microwave-based head imaging: numerical study and experimental verification." International Journal of Microwave and Wireless Technologies 12, no. 10 (July 16, 2020): 982–95. http://dx.doi.org/10.1017/s1759078720000835.
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AbstractThe design of proper antenna element (AE) for microwave-based head imaging or brain stroke detection is a crucial challenge in the development process of microwave imaging (MWI) systems. The main purpose of this paper was to design, fabricate, and experimentally verify the compact and dimensions-reduced H-slot antenna suitable for the new generation of multichannel MWI system for brain stroke detection. The slot antenna type was chosen based on the numerical study of three AEs available in the literature, i.e. bow tie, slot, and waveguide-based. The study was focused on the sensitivity of the antennae (change of magnitude and phase of S21) due to dielectric parameters change or type and diameter of inclusion in a head phantom representing a hemorrhagic (HEM) or ischemic (ISCH) stroke phantom, respectively. Further, the analysis of antenna radiation to lossy medium/air and its immunity against plane wave exposure was carried out. The H-slot antenna was fabricated and experimentally verified (measurements of reflection as well as transmission coefficients) using a liquid head phantom with inserted HEM stroke phantom (both prepared as a mixture of propylene glycol, water, and salt). The phantoms were filled inside the designed two-port test system. Numerical models were validated by comparing calculated and measured S-parameters. The sensitivity of the H-slot antenna to the presence of the HEM stroke phenomenon within the phantom of the head was also demonstrated. The main advantage of the proposed H-slot antenna is its small dimensions, easy, inexpensive, and repeatable fabrication as well as mechanical stability.
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Ramos, Amélia, Tiago Varum, and João N. Matos. "Compact N-Band Tree-Shaped Multiplexer-Based Antenna Structures for 5G/IoT Mobile Devices." Sensors 20, no. 21 (November 8, 2020): 6366. http://dx.doi.org/10.3390/s20216366.
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This paper presents a simple, compact and low-cost design method that allows one to obtain low-profile multi-band antennas for the overcrowded future generation networks, which are widely versatile and very heterogeneous in the K/Ka bands. The proposed antennas comprise n radiating monopoles, one for each of the desired operating frequencies, along with a frequency selective feeding network fed at a single point. This concept enables a single antenna to be shared with different radio-frequency (RF) frontends, potentially saving space. Typically, with n-band structures the biggest challenge is to make them highly efficient and here this is assured by multiplexing the frequency, and thus isolating each of the monopoles, allowing the design of scalable structures which fit the 5G applications. Based on the vision proposed here, a dual-band and a tri-band structures were built and characterized by their main parameters. Both prototypes achieved peak efficiencies around 80%, with adequate bandwidths and gains, as well as great compactness.
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Uthansakul, Peerapong, Danai Assanuk, and Monthippa Uthansakul. "An Optimal Design of Multiple Antenna Positions on Mobile Devices Based on Mutual Coupling Analysis." International Journal of Antennas and Propagation 2011 (2011): 1–10. http://dx.doi.org/10.1155/2011/791697.
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The topic of practical implementation of multiple antenna systems for mobile communications has recently gained a lot of attention. Due to the area constraint on a mobile device, the problem of how to design such a system in order to achieve the best benefit is still a huge challenge. In this paper, genetic algorithm (GA) is used to find the optimal antenna positions on a mobile device. Two cases of3×3and4×4MIMO systems are undertaken. The effect of mutual coupling based onZ-parameter is the main factor to determine the MIMO capacity concerning the objective function of GA search. The results confirm the success of the proposed method to design MIMO antenna positions on a mobile device. Moreover, this paper introduces the method to design the antenna positions for the condition of nondeterministic channel. The concern of channel variation has been included in the process of finding optimal MIMO antenna positions. The results suggest that the averaging position from all GA solutions according to all channel conditions provides the most acceptable benefit.
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Et. al., Jyothsna Undrakonda,. "Comparative Analysis of Microstrip Patch Antenna of Wearable IOT Devices for Health Care." Turkish Journal of Computer and Mathematics Education (TURCOMAT) 12, no. 2 (April 11, 2021): 1364–82. http://dx.doi.org/10.17762/turcomat.v12i2.1347.
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The Advances in the biomedical applications demands an antenna having highefficiency and gain, low return losses and Specific Absorption Ratio (SAR) to beassociated with the wearable and implantable devices for the accurate data transferwithout any data drift. For this, multi-band MIMO (multi-input multi output)applications, the antenna design with the target parameters is a challenging task toestablish a rich and reliable wireless communication setup with the monitoring systemin SHM of both biomedical and industrial sectors. Higher SAR will create the hazardsto the human body. The gain of the antenna and return loss figures depends on thesignal loss in the human tissues. Another important design challenge is the antennasize, which should be convenient to carry. Usually, Micro strip patch antenna is usingfor such type of applications as it satisfies most of the design parameters. But thebandwidth and gain of MSP are very limited. Hence there is huge scope to enhancethe gain and bandwidth of the micro strip patch antenna to fit for the biomedicalinvasive applications. Artificial materials having negative permittivity andpermeability will yield a negative refractive index will do better than the existingmaterials in the antenna design for the ISM band(2.45-5.8GHz) and satellites (11-13GHz).
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Pietrenko-Dabrowska, Anna, and Slawomir Koziel. "Nested Kriging with Variable Domain Thickness for Rapid Surrogate Modeling and Design Optimization of Antennas." Electronics 9, no. 10 (October 2, 2020): 1621. http://dx.doi.org/10.3390/electronics9101621.
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Design of modern antennas faces numerous difficulties, partially rooted in stringent specifications imposed on both electrical and field characteristics, demands concerning various functionalities (circular polarization, pattern diversity, band-notch operation), but also constraints imposed upon the physical size of the radiators. Conducting the design process at the level of full-wave electromagnetic (EM) simulations, otherwise dictated by reliability, entails considerable computational expenses, which is another and a serious challenge. It is especially pronounced for the procedures involving repetitive EM analyses, e.g., parametric optimization. Utilization of fast surrogate models as a way of mitigating this issue has been fostered in the recent literature. Unfortunately, construction of reliable surrogates for antenna structures is hindered by their highly nonlinear responses and even more by the utility requirements: design-ready models are to be valid over wide ranges of operating conditions and geometry parameters. Recently proposed performance-driven modeling, especially the nested kriging framework, addresses these difficulties by confining the surrogate model domain to a region that encapsulates the designs being optimum with respect to the relevant figures of interest. The result is a dramatic reduction of the number of training samples needed to render a usable model. This paper introduces a variable-thickness domain, which is an important advancement over the basic nested kriging. The major benefit demonstrated using two antenna examples is a further and significant (up to seventy percent) reduction of the training data acquisition cost. It is achieved while ensuring that the model domain covers the regions containing optimum designs for various sets of performance specifications.
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Alam, Touhidul, Mohammad Tariqul Islam, Md Amanath Ullah, and Mengu Cho. "A Solar Panel-Integrated Modified Planner Inverted F Antenna for Low Earth Orbit Remote Sensing Nanosatellite Communication System." Sensors 18, no. 8 (July 31, 2018): 2480. http://dx.doi.org/10.3390/s18082480.
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One of the most efficient methods to observe the impact of geographical, environmental, and geological changes is remote sensing. Nowadays, nanosatellites are being used to observe climate change using remote sensing technology. Communication between a remote sensing nanosatellite and Earth significantly depends upon antenna systems. Body-mounted solar panels are the main source of satellite operating power unless deployable solar panels are used. Lower ultra-high frequency (UHF) nanosatellite antenna design is a crucial challenge due to the physical size constraint and the need for solar panel integration. Moreover, nanosatellite space missions are vulnerable because of antenna and solar panel deployment complexity. This paper proposes a solar panel-integrated modified planner inverted F antenna (PIFA) to mitigate these crucial limitations. The antenna consists of a slotted rectangular radiating patch with coaxial probe feeding and a rectangular ground plane. The proposed antenna has achieved a −10 dB impedance bandwidth of 6.0 MHz (447.5 MHz–453.5 MHz) with a small-sized (80 mm× 90 mm× 0.5 mm) radiating element. In addition, the antenna achieved a maximum realized gain of 0.6 dB and a total efficiency of 67.45% with the nanosatellite structure and a solar panel. The challenges addressed by the proposed antenna are to ensure solar panel placement between the radiating element and the ground plane, and provide approximately 55% open space to allow solar irradiance into the solar panel.
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Dias, Maurício Henrique Costa, Bruno Roberto Franciscatto, Hans Adel, and Tan-Phu Vuong. "Dual-Band Compact Planar Antenna for a Low-Cost WLAN USB Dongle." International Journal of Antennas and Propagation 2014 (2014): 1–10. http://dx.doi.org/10.1155/2014/793191.
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Among the present technologies for WLAN devices, USB dongles still play a noticeable role. One major design challenge regards the antenna, which unavoidably has to comply with a very small volume available and sometimes should also allow multiband operation. In this scope, the present work discusses a dual-band WiFi compact planar IFA-based antenna design for a low-cost USB dongle application. Like most of the related published solutions, the methodology for deriving the present proposition was assisted by the use of an antenna analysis software. A prototype was assembled and tested in order to qualify the radiator design. Practical operation conditions were considered in the tests, such as the influence of the dongle case and the effect of the notebook itself. The results complied with the design constraints, presenting an impedance match quite stable regardless of the stick position alongside a laptop base.
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Rama Sanjeeva Reddy, B., and D. Vakula. "Tri-band dual circularly polarized planar antenna with defective ground structure for wireless applications." International Journal of Microwave and Wireless Technologies 8, no. 7 (April 13, 2015): 1121–28. http://dx.doi.org/10.1017/s1759078715000628.
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A novel tri-band asymmetric slot with defective ground structure (DGS) microstrip antenna for dual circular polarization (CP) is proposed. By placing a slot with 45° across diagonally at the center of the patch, excites resonant bands with narrow bandwidth and dual CP operation. The main design challenge is to introduce optimized defected element of circular dumbbell shape to enhance the impedance bandwidth with frequency shift operation at all bands. DGS enabled antenna is practically fabricated and simulated. Antenna is compact in size and shows a good quality of CP at two resonant bands and linearly polarized at one band. Structure displays the impedance bandwidth of 8% (2.26–2.45 GHz), 5.45% (3.41–3.6 GHz) and 3.07% (5.12–5.28 GHz). The design also shows 40 and 11 MHz, 3-dB axial ratio bandwidth at lower and middle bands, respectively. Simulated gain for each band is 4.72, 6.2 and 4 dB. Performance of antenna with and without DGS is also studied and compared. This single probe feed proposed antenna remains consistent with good radiation patterns and sufficient antenna gain over the operating bands. Excellent agreement was obtained between measurements and simulations.
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Diet, Antoine M., Nicolas Ribière-Tharaud, Martine Villegas, and Geneviève Baudoin. "Front-end HPA/antenna for multi-radio." International Journal of Microwave and Wireless Technologies 4, no. 5 (May 1, 2012): 483–93. http://dx.doi.org/10.1017/s1759078712000372.
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This paper focuses on multi-radio front-end transmitter, a function implied by cognitive radio (0.5–6 GHz). S and C bands standards (wireless local and metropolitan area networks) present a challenge, due to the signal modulation schemes (orthogonal frequency division multiplex (OFDM)/WCDMA, wideband code division multiple access) dynamic (tens of dBs), driving us to a mandatory transmitter linearization. The idea is to provide frequency, flexibility, and average power control of a multi-radio high-efficiency front end for such signals (polar/envelope elimination and restoration (EER) structure). The study implies antennas design and average power control demonstration. Based on a switched mode power amplifier (PA), a discrete detuning is possible to adapt the PA at both “WiMAX” and “Wifi5” frequencies. This architecture amplifies signals with amplitude information. This is coded here by the ΣΔ/PWM (pulse width modulation) technique, to present a constant envelope signal. The amplitude information is restored by a pass-band radio frequency (RF) filter. The antenna can be designed with a notch, to reduce the filtering constraints (selectivity and standards coexistences) and to help in the restoration of amplitude information. Average power control is illustrated by voltage supply variation and results are a possible dynamic of 9.5 dB. To complete the analysis, the simulation of the propagation channel, including antennas, with CST (free space, line of sight) is imported under AGILENT-ADS.
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Tiwari, Pritesh, and Lalita Gupta. "An Analytical Model Verification for high Gain H- Slot RPA Using Discontinuities of Radiator." International Journal of Engineering & Technology 7, no. 2.16 (April 12, 2018): 77. http://dx.doi.org/10.14419/ijet.v7i2.16.11420.
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Antenna plays an important role in most of the RF and microwave applications. Intensifying applications of wireless communications now a day’s persist to challenge RF or microwave Antenna with ever more meticulous requirements- smaller size, lighter weight, high performance, economical and easy for fabrication. The advancement in the modern materials fabrication technologies and different research on novel materials, including monolithic microwave integrated circuits (MMIC), low-temperature cofired ceramics (LTCC), high-temperature superconductors (HTS), micro electro mechanic system (MEMS), and micromachining technology, have encouraged the fast strengthening of latest microstrip and supplementary Antenna for RF and microwave applications. The manuscript presented here is a representation of the H shape patch antenna design and effect of coupling of parasitic patch and discontinuities in radiating structure in order to achieve high gain and better bandwidth (-10 dB). A mathematical model is presented which has been established on the basis of result obtained. The working frequency range of the manuscript is from 1 GHz to 20 GHz.
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Couraud, Benoit, Remy Vauche, Spyridon Nektarios Daskalakis, David Flynn, Thibaut Deleruyelle, Edith Kussener, and Stylianos Assimonis. "Internet of Things: A Review on Theory Based Impedance Matching Techniques for Energy Efficient RF Systems." Journal of Low Power Electronics and Applications 11, no. 2 (March 31, 2021): 16. http://dx.doi.org/10.3390/jlpea11020016.
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Within an increasingly connected world, the exponential growth in the deployment of Internet of Things (IoT) applications presents a significant challenge in power and data transfer optimisation. Currently, the maximization of Radio Frequency (RF) system power gain depends on the design of efficient, commercial chips, and on the integration of these chips by using complex RF simulations to verify bespoke configurations. However, even if a standard 50Ω transmitter’s chip has an efficiency of 90%, the overall power efficiency of the RF system can be reduced by 10% if coupled with a standard antenna of 72Ω. Hence, it is necessary for scalable IoT networks to have optimal RF system design for every transceiver: for example, impedance mismatching between a transmitter’s antenna and chip leads to a significant reduction of the corresponding RF system’s overall power efficiency. This work presents a versatile design framework, based on well-known theoretical methods (i.e., transducer gain, power wave approach, transmission line theory), for the optimal design in terms of power delivered to a load of a typical RF system, which consists of an antenna, a matching network, a load (e.g., integrated circuit) and transmission lines which connect all these parts. The aim of this design framework is not only to reduce the computational effort needed for the design and prototyping of power efficient RF systems, but also to increase the accuracy of the analysis, based on the explanatory analysis within our design framework. Simulated and measured results verify the accuracy of this proposed design framework over a 0–4 GHz spectrum. Finally, a case study based on the design of an RF system for Bluetooth applications demonstrates the benefits of this RF design framework.
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Reiche, Enrico, and Michael Schneider. "Challenges in the EM-based design of modern telecommunication satellite antennas." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 37, no. 4 (July 2, 2018): 1461–80. http://dx.doi.org/10.1108/compel-09-2017-0378.
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Purpose This paper aims to introduce design challenges of modern telecommunication satellite antennas. The antenna farms accommodated on a satellite are systems of high complexity. From the radio frequency (RF) point of view, the most important design issues, e.g. high power applications in space (vacuum) or typical antenna scenarios (single/multi beam antennas), and their solution are considered. Design/methodology/approach The paper presents the application of electro-magnetic (EM) field simulation in the design and optimisation process. The design of a telecommunications satellite antenna splits into several areas, for which different types of EM field solvers are used. Findings The use of EM field solvers enables an accurate and efficient design approach of modern geostationary telecommunications satellite antennas. Due to the use of EM field solvers, an excellent agreement between predictions and measurement results on feed as well as antenna system level is achieved. Originality/value This paper gives an overview of state-of-the-art telecommunications satellite antenna architectures and their efficient RF design due to the use of EM field solvers. Typical high power effects and other design issues are explained. RF engineers are encouraged to work on this exciting topic to further improve the design process and to develop new satellite antenna and feed products.
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Patil, Kasturi Sudam, and Elizabeth Rufus. "A review on antennas for biomedical implants used for IoT based health care." Sensor Review 40, no. 2 (August 19, 2019): 273–80. http://dx.doi.org/10.1108/sr-01-2019-0020.
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Purpose The paper aims to focus on implantable antenna sensors used for biomedical applications. Communication in implantable medical devices (IMDs) is beneficial for continuous monitoring of health. The ability to communicate with exterior equipment is an important aspect of IMD. Thus, the design of an implantable antenna for integration into IMD is important. Design/methodology/approach In this review, recent developments in IMDs, three types of antenna sensors, which are recommended by researchers for biomedical implants are considered. In this review, design requirements, different types of their antenna, parameters and characteristics in medical implants communication system (MICS) and industrial, scientific and medical (ISM) bands are summarized here. Also, overall current progress in development of implantable antenna sensor, its challenges and the importance of human body characteristics are described. Findings This article give information about the requirements of implantable antenna sensor designs, types of antennas useful to design implantable devices and their characteristics in MICS and ISM bands. Recent advancement in implantable devices has led to an improvement in human health. Originality/value The paper provides useful information on implantable antennas design for biomedical application. The designing of such antennas needs to meet requirements such as compact size, patients’ safety, communication ability and biocompatibility.
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Zichner, R., and R. R. Baumann. "Printed antennas: from theory to praxis, challenges and applications." Advances in Radio Science 11 (July 4, 2013): 271–76. http://dx.doi.org/10.5194/ars-11-271-2013.
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Abstract. Miniaturized, highly integrated wireless communication systems are used in many fields like logistics and mobile communications. Often multiple antenna structures are integrated in a single product. To achieve such a high level of integration the antenna structures are manufactured e.g. from flexible boards or via LDS (laser direct structuring) which allows the production of complex monopole or dipole antennas with three-dimensionally curved shapes. Main drawbacks are the sophisticated production process steps and their costs. The additive deposition of metallic inks or pastes by a printing process is an alternative manufacturing method with reduced cost. To implement such printed antennas we investigated in the fields of antenna design, simulation, printing technology and characterization. The chosen example of use was a customized dipole antenna for a Radio Frequency Identification application. The results prove the intended functionality of the printed dipole in regard to a highly cost efficient printing manufacturing.
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Mathur, Manisha, Jaynendra Kumar Rai, and Nilakantan Sridhar. "Microwave photonic network for active electronically scanned array radar." International Journal of Microwave and Wireless Technologies 9, no. 3 (March 3, 2016): 543–50. http://dx.doi.org/10.1017/s1759078716000295.
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Active electronically scanned array (AESA) radar has large number oftransmit/Receive (T/R) modules which require multiple microwave and digital signals. Distribution of these signals through conventional method such as coaxial cable, twisted pair, etc. not only introduces engineering complexities and signal loss but also have limitation of bandwidth, data rate, transmission distance, etc. This paper addresses design and implementation of microwave photonic network for distribution of microwave and digital signals over single optical fiber using wavelength division multiplexing for AESA radars. The design challenge is to limit the variation in output radio frequency power within ±1 dB over full operational band of radar from 2 to 4 GHz and functionality under hostile military environment. Optical amplifiers have been used in all channels to stabilize optical output independent of wavelength with automatic light control. The optical signal is split into 64 identical parts to feed multiplexed signal into different digital receivers physically spread across the antenna array. It is an additional challenge to normalize performance as all 64 receivers show variation in output in spite of identical electronic circuitry. Experimental results validate the feasibility of microwave photonic network for wide branching distribution of multiple microwave and digital signals for AESA radar.
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Ramos, Amélia, Tiago Varum, and João Matos. "Compact Multilayer Yagi-Uda Based Antenna for IoT/5G Sensors." Sensors 18, no. 9 (September 2, 2018): 2914. http://dx.doi.org/10.3390/s18092914.
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To increase the capacity and performance of communication systems, the new generation of mobile communications (5G) will use frequency bands in the mmWave region, where new challenges arise. These challenges can be partially overcome by using higher gain antennas, Multiple-Input Multiple-Output (MIMO), or beamforming techniques. Yagi-Uda antennas combine high gain with low cost and reduced size, and might result in compact and efficient antennas to be used in Internet of Thins (IoT) sensors. The design of a compact multilayer Yagi for IoT sensors is presented, operating at 24 GHz, and a comparative analysis with a planar printed version is shown. The stacked prototype reveals an improvement of the antenna’s main properties, achieving 10.9 dBi, 2 dBi more than the planar structure. In addition, the multilayer antenna shows larger bandwidth than the planar; 6.9 GHz compared with 4.42 GHz. The analysis conducted acknowledges the huge potential of these stacked structures for IoT applications, as an alternative to planar implementations.
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Soliman, Md Mohiuddin, Muhammad E. H. Chowdhury, Amith Khandakar, Mohammad Tariqul Islam, Yazan Qiblawey, Farayi Musharavati, and Erfan Zal Nezhad. "Review on Medical Implantable Antenna Technology and Imminent Research Challenges." Sensors 21, no. 9 (May 2, 2021): 3163. http://dx.doi.org/10.3390/s21093163.
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Implantable antennas are mandatory to transfer data from implants to the external world wirelessly. Smart implants can be used to monitor and diagnose the medical conditions of the patient. The dispersion of the dielectric constant of the tissues and variability of organ structures of the human body absorb most of the antenna radiation. Consequently, implanting an antenna inside the human body is a very challenging task. The design of the antenna is required to fulfill several conditions, such as miniaturization of the antenna dimension, biocompatibility, the satisfaction of the Specific Absorption Rate (SAR), and efficient radiation characteristics. The asymmetric hostile human body environment makes implant antenna technology even more challenging. This paper aims to summarize the recent implantable antenna technologies for medical applications and highlight the major research challenges. Also, it highlights the required technology and the frequency band, and the factors that can affect the radio frequency propagation through human body tissue. It includes a demonstration of a parametric literature investigation of the implantable antennas developed. Furthermore, fabrication and implantation methods of the antenna inside the human body are summarized elaborately. This extensive summary of the medical implantable antenna technology will help in understanding the prospects and challenges of this technology.
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Kirtania, Sharadindu Gopal, Alan Wesley Elger, Md Rabiul Hasan, Anna Wisniewska, Karthik Sekhar, Tutku Karacolak, and Praveen Kumar Sekhar. "Flexible Antennas: A Review." Micromachines 11, no. 9 (September 11, 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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Matin, M. A. "Review on Millimeter Wave Antennas- Potential Candidate for 5G Enabled Applications." Advanced Electromagnetics 5, no. 3 (December 19, 2016): 98. http://dx.doi.org/10.7716/aem.v5i3.448.
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The millimeter wave (mmWave) band is considered as the potential candidate for high speed communication services in 5G networks due to its huge bandwidth. Moreover, mmWave frequencies lead to miniaturization of RF front end including antennas. In this article, we provide an overview of recent research achievements of millimeter-wave antenna design along with the design considerations for compact antennas and antennas in package/on chip, mostly in the 60 GHz band is described along with their inherent benefits and challenges. A comparative analysis of various designs is also presented. The antennas with wide bandwidth, high-gain, compact size and low profile with easiness of integration in-package or on-chip with other components are required for 5G enabled applications.
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Sabban, Albert. "New Compact Wearable Metamaterials Circular Patch Antennas for IoT, Medical and 5G Applications." Applied System Innovation 3, no. 4 (October 8, 2020): 42. http://dx.doi.org/10.3390/asi3040042.
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The development of compact passive and active wearable circular patch metamaterials antennas for communication, Internet of Things (IoT) and biomedical systems is presented in this paper. Development of compact efficient low-cost wearable antennas are one of the most significant challenges in development of wearable communication, IoT and medical systems. Moreover, the advantage of an integrated compact low-cost feed network is attained by integrating the antenna feed network with the antennas on the same printed board. The efficiency of communication systems may be increased by using efficient passive and active antennas. The system dynamic range may be improved by connecting amplifiers to the printed antenna feed line. Design, design considerations, computed and measured results of wearable circular patch meta-materials antennas with high efficiency for 5G, IoT and biomedical applications are presented in this paper. The circular patch antennas electrical parameters on the human body were analyzed by using commercial full-wave software. The circular patch metamaterial wearable antennas are compact and flexible. The directivity and gain of the antennas with Circular Split-Ring Resonators (CSRR) is higher by 2.5dB to 3dB than the antennas without CSRR. The resonant frequency of the antennas without CSRR is higher by 6% to 9% than the antennas with CSRR. The computed and measured bandwidth of the stacked circular patch wearable antenna with CSRR for IoT and medical applications is around 12%, for S11 lover than −6dB. The gain of the circular patch wearable antenna with CSRR is around 8dBi.
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Farasat, Madiha, Dushmantha N. Thalakotuna, Zhonghao Hu, and Yang Yang. "A Review on 5G Sub-6 GHz Base Station Antenna Design Challenges." Electronics 10, no. 16 (August 19, 2021): 2000. http://dx.doi.org/10.3390/electronics10162000.
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Modern wireless networks such as 5G require multiband MIMO-supported Base Station Antennas. As a result, antennas have multiple ports to support a range of frequency bands leading to multiple arrays within one compact antenna enclosure. The close proximity of the arrays results in significant scattering degrading pattern performance of each band while coupling between arrays leads to degradation in return loss and port-to-port isolations. Different design techniques are adopted in the literature to overcome such challenges. This paper provides a classification of challenges in BSA design and a cohesive list of design techniques adopted in the literature to overcome such challenges.
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Wagih, Mahmoud, Alex S. Weddell, and Steve Beeby. "Overcoming the Efficiency Barrier of Textile Antennas: A Transmission Lines Approach." Proceedings 32, no. 1 (December 11, 2019): 18. http://dx.doi.org/10.3390/proceedings2019032018.
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Designing high-efficiency antennas on textiles is fundamental for the development of wirelessly-connected smart garments. Furthermore, large antenna arrays could be used to receive or harvest directional and ambient radio-frequency (RF) power from the environment, thus enabling battery-free e-textiles. The key challenges that are hindering the realisation of high efficiency antennas lie in the dielectric properties of fabrics, the conductivity of their traces, and their low textile thickness. This work numerically and experimentally analyses different RF transmission line structures to establish the limitations of widely utilised antenna designs, such as the microstrip patch, and proposes alternative wearable antenna design based on coplanar waveguide (CPW) structures. It is demonstrated that by using a CPW, insertion losses in a 20 mm line can be minimized by up to 40% for the same substrate, as compared to a microstrip, at 30 GHz. A CPW monopole antenna is demonstrated with more than 80% efficiency on a lossy, thin, poly-cotton substrate. Moreover, it is shown that the efficiency of the CPW monopole is independent of the substrate’s thickness and type of fabric.
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Abubakar, Idrissa, Jafri Bin Din, Lam Hong Yin, and Manhal Alhilali. "Rain attenuation in broadband satellite service and worst month analysis." Indonesian Journal of Electrical Engineering and Computer Science 15, no. 3 (September 1, 2019): 1443. http://dx.doi.org/10.11591/ijeecs.v15.i3.pp1443-1451.
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<span>Satellite link design, link margin and services at lower bands of satellite spectrum has been facing the challenges of meeting the demands for higher bandwidth requirements. Satellite operators and service providers are been compelled to migrate to the use of higher frequencies above 10 GHz. These higher frequencies were discovered to be vulnerable to atmospheric degradation creating the challenge of service availability especially for tropical rain zones with higher rainfall intensities and longer rain event durations. This study strive to evaluate the profile of rainfall and the monthly and annual variability to improve the design parameters of satellite propagation. Two yeas rainfall measurement campaign was conducted in Abuja at Nigcomsat-1R ground station with a view to understanding the characteristics of Abuja rain. The location of the site is on lat. 9.06o N and lon. 7.48o E. Tipping bucket rain gauge was used for point rain rate and 1.8 m VSAT antenna was installed to monitor the rain induced attenuation on satellite broadband signal. The results shows a huge variability between month to month as well as annual average between 2016 and 2017. The performance of broadband satellite service was found to largely to depend on the quality of the carrier power above the system noise rather than bandwidth capacity or the receive signal level while higher attenuations are associated with higher rain intensities and the slant path effects.</span>
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Nalanagula, Rajasekhar, Naresh K. Darimireddy, Runa Kumari, Chan-Wang Park, and R. Ramana Reddy. "Circularly Polarized Hybrid Dielectric Resonator Antennas: A Brief Review and Perspective Analysis." Sensors 21, no. 12 (June 15, 2021): 4100. http://dx.doi.org/10.3390/s21124100.
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Recently, it has been a feasible approach to build an antenna, in view of the potential advantages they offer. One of the recent trends in dielectric resonator antenna research is the use of compound and hybrid structures. Several considerable investigations have been already underway showing quite interesting and significant features in bandwidth, gain, and generation of circular polarization. A critical review on a journey of circularly polarized hybrid dielectric resonator antennas is presented in this article. A general discussion of circular polarization and DR antennas are provided at the forefront. Evolution, significant challenges, and future aspects with new ideas in designing hybrid dielectric resonator antennas are indicated at the end of the review. State-of-the-art advances and associated design challenges of circularly polarized hybrid DR antennas and related empirical formulas used to find resonance frequency of different hybrid modes produced are discussed in this paper.
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Kiourti, Asimina, and Konstantina S. Nikita. "Design of Implantable Antennas for Medical Telemetry." International Journal of Monitoring and Surveillance Technologies Research 1, no. 1 (January 2013): 16–33. http://dx.doi.org/10.4018/ijmstr.2013010102.
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Implantable Medical Devices (IMDs) with wireless telemetry functionalities in the radio-frequency (RF) range are recently attracting significant scientific interest for medical prevention, diagnosis, and therapy. One of the most crucial challenges for IMDs is the design of the integrated implantable antenna which enables bidirectional wireless communication between the IMD and exterior monitoring/control equipment. In this paper, a parametric model of a miniature implantable antenna is initially proposed, which can be adjusted to suit any antenna design and implantation scenario requirements in hand. Dependence of the resonance, radiation, and safety performance of implantable antennas upon (a) operation frequency, (b) tissue anatomy and dielectric properties, and (c) implantation site is further studied. Simulations are carried out: (a) at 402, 433, 868 and 915 MHz considering a 13-tissue anatomical head model, (b) at 402 MHz considering five head models (3- and 5-layer spherical, 6-, 10- and 13-tissue anatomical) and seven dielectric parameter scenarios (variations ±20% in the reference permittivity and conductivity values), and (c) at 402 MHz considering 3-layer canonical models of the human head, arm, and trunk. The study provides valuable insight into the design of implantable antennas. Finite Element and Finite Difference Time Domain numerical solvers are used.
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Bist, Sunil, and Dr Rajveer Singh Yaduvanshi. "Investigations into Hybrid Magneto-hydrodynamic (MHD) Antenna." INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY 4, no. 2 (October 30, 2005): 454–59. http://dx.doi.org/10.24297/ijct.v4i2b2.3306.
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Dielectric Resonator Antennas (DRAs) have received lots of attention in the last two decades due to several attractive characteristics such as high radiation efficiency, light weight, and low profile. There is also increasing challenges for the design of high bandwidth and multi-bands antennas which can be achieved using MHD Antennas for high speed and reconfigurable applications in wireless communication. In this work the objective is to design and develop a cylindrical MHD antenna with circular patch and two annular rings. Magneto-hydrodynamics (MHD) Antenna is a Fluid based Antenna in which the fluid resonator provides excellent coupling of RF energy into fluid. Fluid resonator volume, chemical properties, electric field and magnetic fields are the factors of resonant frequency, gain and return loss. The proposed antenna shall be tuned in the wide band of frequency range between 7.9 – 27 GHz. Simulations using HFSS and measurements have been carried out in respect of design prototype for ‘Air’ and BSTO (Barium Strontium Titanate Oxide) microwave fluid. The findings in this work that the Fluid Resonator based hybrid approach for antenna enhances the bandwidth by a large factor and annular rings with circular patch in proper geometry provides multiband operation. Variation in the volume of the fluid shifts the resonant frequency of the solid structure in the wideband. When magnetic field is applied, significant improvement has been noticed in return loss of the proposed antenna.
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Nyangwarimam Obadiah, Ali, Mohamad Rijal Hamid, Mohamad Kamal Abd Rahim, and Noor Asniza Murad. "A Review on Filter-Antennas." Applied Mechanics and Materials 735 (February 2015): 289–93. http://dx.doi.org/10.4028/www.scientific.net/amm.735.289.
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A review on the recent advancements made on filtennas are presented in this paper. RF fronts ends continue to generate a lot of research attention in communication systems due to the effect it has on the overall bit error rate and SNR. Issues such as compactness, interference and noise are addressed by embedding the bandpass filter into the antenna to form a filtenna. Designing a filtering antenna has its own challenges also. Various techniques (synthesis approach, T shaped resonator or slots.) are being used to design filtennas in order to achieve “weak coupling between the feed and the radiating structure” hence yielding better selectivity. The filter-antenna gain results compared to that of the conventional antennas show better rejection of the out of band gain. This helps reduce interference with adjacent frequency band. This paper presents a review of the techniques, challenges faced and potential research trend in filtering antennas.
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Haider, N., D. Caratelli, and A. G. Yarovoy. "Recent Developments in Reconfigurable and Multiband Antenna Technology." International Journal of Antennas and Propagation 2013 (2013): 1–14. http://dx.doi.org/10.1155/2013/869170.
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A comparative analysis of various reconfigurable and multiband antenna concepts is presented. In order to satisfy the requirements for the advanced systems used in modern wireless and radar applications, different multiband and reconfigurable antennas have been proposed and investigated in the past years. In this paper, these design concepts have been classified into three basic approaches: tunable/switchable antenna integration with radio-frequency switching devices, wideband or multiband antenna integration with tunable filters, and array architectures with the same aperture utilized for different operational modes. Examples of each design approach are discussed along with their inherent benefits and challenges.
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Tu, Yuxiang, Yasir I. A. Al-Yasir, Naser Ojaroudi Parchin, Ahmed M. Abdulkhaleq, and Raed A. Abd-Alhameed. "A Survey on Reconfigurable Microstrip Filter–Antenna Integration: Recent Developments and Challenges." Electronics 9, no. 8 (August 4, 2020): 1249. http://dx.doi.org/10.3390/electronics9081249.
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Reconfigurable and tunable radio frequency (RF) and microwave (MW) components have become exciting topics for many researchers and design engineers in recent years. Reconfigurable microstrip filter–antenna combinations have been studied in the literature to handle multifunctional tasks for wireless communication systems. Using such devices can reduce the need for many RF components and minimize the cost of the whole wireless system, since the changes in the performance of these applications are achieved using electronic tuning techniques. However, with the rapid development of current fourth-generation (4G) and fifth-generation (5G) applications, compact and reconfigurable structures with a wide tuning range are in high demand. However, meeting these requirements comes with some challenges, namely the increased design complexity and system size. Accordingly, this paper aims to discuss these challenges and review the recent developments in the design techniques used for reconfigurable filters and antennas, as well as their integration. Various designs for different applications are studied and investigated in terms of their geometrical structures and operational performance. This paper begins with an introduction to microstrip filters, antennas, and filtering antennas (filtennas). Then, performance comparisons between the key and essential structures for these aspects are presented and discussed. Furthermore, a comparison between several RF reconfiguration techniques, current challenges, and future developments is presented and discussed in this review. Among several reconfigurable structures, the most efficient designs with the best attractive features are addressed and highlighted in this paper to improve the performance of RF and MW front end systems.
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Lemon, Christopher M. "Optical oxygen sensing with quantum dot conjugates." Pure and Applied Chemistry 90, no. 9 (September 25, 2018): 1359–77. http://dx.doi.org/10.1515/pac-2018-0303.
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Abstract The ability to track and quantify changes in oxygen concentration as a function of disease progression or therapy is crucial to advance targeted chemotherapeutics. New non-invasive sensors must be developed that are small enough to penetrate into tissue and monitor dynamic changes with high resolution in real time. One way to address this challenge is with the use of nanoparticle-based sensors. This review details the design, synthesis, and characterization of optical oxygen sensors that combine a fluorescent semiconductor quantum dot (QD) with an oxygen-responsive phosphorescent molecule. The QD may have multifaceted roles in these constructs, serving as an internal standard for ratiometric sensing, as an antenna for multiphoton absorption, and as an energy transfer donor for the attendant phosphorescent molecule. Solid-state devices may be prepared by embedding the two components in a polymer matrix. Alternatively, solution-phase sensors can be synthesized by covalent conjugation, self-assembly in organic solvents, or micelle encapsulation in aqueous media. Several sensors have been used for biological imaging and oxygen sensing, demonstrating that these constructs can quantify oxygen in biological systems.
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Savić, Slobodan V., Milan M. Ilić, and Antonije R. Djordjević. "Design of Internal Wire-Based Impedance Matching of Helical Antennas Using an Equivalent Thin-Wire Model." International Journal of Antennas and Propagation 2017 (2017): 1–5. http://dx.doi.org/10.1155/2017/7365793.
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We propose a novel design of internal impedance matching networks for axial-mode helical antennas. This network comprises a single wire attached to the helix. One of the main challenges when designing an internal matching network is its strong electromagnetic coupling with the antenna. The matching network must hence be designed in the presence of the antenna, which slows down the design process. To overcome this problem, we formulate an equivalent thin-wire model of the complete helix, including the matching wire (matching network) and the dielectric support. This computationally low-demanding model can be analyzed extremely rapidly, yielding accurate results, which are in excellent agreement with alternative numerical solutions and measurements.
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Tomasson, Jon Atli, Anna Pietrenko-Dabrowska, and Slawomir Koziel. "Expedited Globalized Antenna Optimization by Principal Components and Variable-Fidelity EM Simulations: Application to Microstrip Antenna Design." Electronics 9, no. 4 (April 20, 2020): 673. http://dx.doi.org/10.3390/electronics9040673.
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Parameter optimization, also referred to as design closure, is imperative in the development of modern antennas. Theoretical considerations along with rough dimension adjustment through supervised parameter sweeping can only yield initial designs that need to be further tuned to boost the antenna performance. The major challenges include handling of multi-dimensional parameter spaces while accounting for several objectives and constraints. Due to complexity of modern antenna topologies, parameter interactions are often involved, leading to multiple local optima as well as difficulties in identifying decent initial designs that can be improved using local procedures. In such cases, global search is required, which is an expensive endeavor, especially if full-wave electromagnetic (EM) analysis is employed for antenna evaluation. This paper proposes a novel technique accommodating the search space exploration using local kriging surrogates and local improvement by means of trust-region gradient search. Computational efficiency of the process is achieved by constructing the metamodels over appropriately defined affine subspaces and incorporation of coarse-mesh EM simulations at the exploratory stages of the optimization process. The resulting framework enables nearly global search capabilities at the costs comparable to conventional gradient-based local optimization. This is demonstrated using two antenna examples and comparative studies involving multiple-start local tuning.
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U, Namrutha, Arun Raaza, and Ramesh S. "Conformal Antenna for Aerodynamic Drag Reduction in Airborne System." International Journal of Engineering & Technology 7, no. 3.1 (August 4, 2018): 66. http://dx.doi.org/10.14419/ijet.v7i3.1.16800.
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The conformal antenna receives more consideration towards the coverage augmentation of contemporary wireless communication systems. The foremost unprejudiced of conformal antenna is to reduce aerodynamic drag in aircraft. Consequently designing frequency reconfigurable conformal antenna has become a key concern in the airborne system. This article reviews the state-of-the-art conformal antenna design by considering the challenges of reducing the aerodynamic drag in the airborne applications. Microstrip patch antennas represent compact antenna that offer a conformal nature and capability of equipped integration with communication system. In this work, microstrip patch antenna is designed for airborne system for drag reduction. The hybrid particle swarm and cuckoo search optimization algorithm is utilized for the length and width. Then the algorithm values are used for the calculation of effective length. The performance of the proposed method is compared with hybrid artificial neural network and firefly, genetic algorithm and analyzed.
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Caimi, Frank. "Antenna design challenges for 4G." IEEE Wireless Communications 18, no. 6 (December 2011): 4–5. http://dx.doi.org/10.1109/mwc.2011.6108324.
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