Journal articles on the topic 'Antenna models'
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1
Warren, Craig, and Antonios Giannopoulos. "Creating finite-difference time-domain models of commercial ground-penetrating radar antennas using Taguchi’s optimization method." GEOPHYSICS 76, no. 2 (March 2011): G37—G47. http://dx.doi.org/10.1190/1.3548506.
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Very few researchers have developed numerical models of ground-penetrating radar (GPR) that include realistic descriptions of both the antennas and the subsurface. This is essential to be able to accurately predict responses from near-surface, near-field targets. We have developed a detailed 3D finite-difference time-domain models of two commercial GPR antennas — a Geophysical Survey Systems, Inc. (GSSI) 1.5-GHz antenna and a MALÅ Geoscience 1.2-GHz antenna — using simple analyses of the geometries and the main components of the antennas. Values for unknown parameters in the antenna models (due to commercial sensitivity) were estimated by using Taguchi’s optimization method, resulting in a good match between the real and modeled crosstalk responses in free space. Validation using a series of oil-in-water emulsions to simulate the electrical properties of real materials demonstrated that it was essential to accurately model the permittivity and dispersive conductivity. When accurate descriptions of the emulsions were combined with the antenna models, the simulated responses showed very good agreement with real data. This provides confidence for use of the antenna models in more advanced studies.
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Lampe, Bernhard, and Klaus Holliger. "Effects of fractal fluctuations in topographic relief, permittivity and conductivity on ground‐penetrating radar antenna radiation." GEOPHYSICS 68, no. 6 (November 2003): 1934–44. http://dx.doi.org/10.1190/1.1635047.
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Typical ground‐penetrating radar (GPR) transmitters and receivers are dipole antennas. These antennas have pronounced directivity properties and exhibit strong coupling to interfaces across which there are changes in electric material properties. Antenna coupling to the surface of idealized half‐space models has been the subject of intense research for several decades. In contrast, the behavior of antennas in the vicinity of interfaces with realistic topographic fluctuations and/or subsurface heterogeneities has been largely unexplored. To explore this issue, we simulate the responses of a typical surface GPR antenna system located on a suite of realistic fractal earth models using the finite‐difference time‐domain (FDTD) method. The models are characterized by topographic roughness of the air–soil interface and small‐scale heterogeneous distributions of permittivity and conductivity in the subsurface. Synthetic radiation patterns and input impedance values of the simulated GPR antenna system demonstrate that topographic roughness significantly affects the coupling of the antenna to the ground, whereas heterogeneities in the subsurface predominantly influence the antenna radiation through scattering and absorption along the propagation path.
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Koziel, Slawomir, and Anna Pietrenko-Dabrowska. "Fast Antenna Optimization Using Gradient Monitoring and Variable-Fidelity EM Models." Applied Computational Electromagnetics Society 35, no. 11 (February 5, 2021): 1348–49. http://dx.doi.org/10.47037/2020.aces.j.351143.
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Accelerated simulation-driven design optimization of antenna structures is proposed. Variable-fidelity electromagnetic (EM) analysis is used as well as the trust-region framework with limited sensitivity updates. The latter are controlled by monitoring the changes of the antenna response gradients. Our methodology is verified using three compact wideband antennas. Comprehensive benchmarking demonstrates its superiority over both conventional and surrogate-assisted algorithms.
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Mathur, Vinita, and Dr Manisha Gupta. "Morphology of Koch Fractal Antenna." INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY 13, no. 2 (April 4, 2014): 4157–63. http://dx.doi.org/10.24297/ijct.v13i2.2902.
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Antenna is paramount element for the radio communication entity using radio frequency and microwaves. In twenty-first century wireless communication systems, there is a demand for wider bandwidth, multiband and low profile antennas for both commercial and military purposes. This has initiated antenna analysis in various directions; one of them is using fractal shaped antenna elements. Fractal concepts have emerged and advanced as a unique technique for designing compact UWB antennas, because of the self-similarityand space-filling attributes. In a fractal antenna, the multiple frequencies of operation depend on the total dimensions of the design and the scale factor. There are varied fractal geometries that have been found to be favorable in developing novel and new models for antennas. In this paper we will be discussing one such type of fractal antennas i.e. the Koch structure. Koch antenna can be designed with a triangle, rectangle and pentagon as its initiator. Their geometry and parameters have been analyzed in this paper.Â
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Koziel, Slawomir, and Anna Pietrenko-Dabrowska. "Variable-Fidelity Simulation Models and Sparse Gradient Updates for Cost-Efficient Optimization of Compact Antenna Input Characteristics." Sensors 19, no. 8 (April 15, 2019): 1806. http://dx.doi.org/10.3390/s19081806.
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Design of antennas for the Internet of Things (IoT) applications requires taking into account several performance figures, both electrical (e.g., impedance matching) and field (gain, radiation pattern), but also physical constraints, primarily concerning size limitation. Fulfillment of stringent specifications necessitates the development of topologically complex structures described by a large number of geometry parameters that need tuning. Conventional optimization procedures are typically too expensive when the antenna is evaluated using high-fidelity electromagnetic (EM) analysis, otherwise required to ensure accuracy. This paper proposes a novel surrogate-assisted optimization algorithm for computationally efficient design optimization of antenna structures. In the paper, the optimization of antenna input characteristic is presented, specifically, minimization of the antenna reflection coefficient in a given bandwidth. Our methodology involves variable-fidelity EM simulations as well as a dedicated procedure to reduce the cost of estimating the antenna response gradients. The latter is based on monitoring the variations of the antenna response sensitivities along the optimization path. The procedure suppresses the finite-differentiation-based sensitivity updates for variables that exhibit stable gradient behavior. The proposed algorithm is validated using three compact wideband antennas and demonstrated to outperform both the conventional trust region algorithm and the pattern search procedure, as well as surrogate-based procedures while retaining acceptable design quality.
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Rajni, Rajni, Gursharan Kaur, and Anupma Marwaha. "Metamaterial Inspired Patch Antenna for ISM Band by Adding Single-Layer Complementary Split Ring Resonators." International Journal of Electrical and Computer Engineering (IJECE) 5, no. 6 (December 1, 2015): 1328. http://dx.doi.org/10.11591/ijece.v5i6.pp1328-1335.
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In this work, we propose the design of metamaterial inspired compact circular patch antennas loaded with complementary split-ring resonators (CSRRs) for ISM band operation. CSRRs have been incorporated horizontally inside the dielectric. The various models of CSRR loaded antennas with different patch radius are produced and are evaluated numerically with Ansoft HFSS software. The results of the suggested antenna designs are presented that reveal a comparable impedance match and radiation characteristics with those of a normal patch antenna without CSRR. The proposed antennas yield high levels of miniaturization and similar performance to the conventional patch antenna at the 2.45GHz.
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Czawka, Giennadij, and Marek Garbaruk. "Matrix Analysis and Pulse Transmission of Antenna Array for MIMO UWB Systems." International Journal of Electronics and Telecommunications 57, no. 1 (March 1, 2011): 91–96. http://dx.doi.org/10.2478/v10177-011-0013-z.
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Matrix Analysis and Pulse Transmission of Antenna Array for MIMO UWB Systems This paper presents a theoretical matrix analysis of antenna structure consisting of two double-element planar antennas for ultra-wideband (UWB) application in 2*2 MIMO indoor communication systems. The structure and characteristics of pla-nar two-element UWB antenna are presented. Two matrix models of MIMO antenna system are represented in the paper. A stan-dard MIMO signal transmission matrix without taking into con-sideration the coupling between antennas is described. A new ap-proach to a full electromagnetic analysis based on the scattering matrix of the MIMO spatial antenna array is proposed. Func-tional power parameters for the whole MIMO UWB transmit-receive antenna structure are introduced. Results of computer si-mulations of different matrices describing a MIMO antenna sys-tem and the transmission propagation pulses are presented.
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Labun, Ján, Pavol Kurdel, Alexey Nekrasov, Mária Gamcová, Marek Češkovič, and Colin Fidge. "Specific Resonant Properties of Non-Symmetrical Microwave Antennas." Sensors 21, no. 3 (January 31, 2021): 939. http://dx.doi.org/10.3390/s21030939.
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The aircraft avionics modernization process often requires optimization of the aircraft itself. Scale models of aircraft and their antennas are frequently used to solve this problem. Here we present interesting properties of the resonant antennas, which were discovered serendipitously during the measurement process of some microwave antennas’ models as part of an aircraft modernization project. Aircraft microwave antennas are often designed as non-symmetric flat microwave antennas. Due to their thin, low and longitudinally elongated outer profile, they are also called tail antennas. An analysis of the resonant properties of non-symmetric antennas was performed in the band from 1 GHz to 4 GHz. The length of the antenna models ranged from 2 cm to 7 cm. The width of the antennas, together with the thickness of the strip, was always a constant parameter for one measured set of six antennas. In the measurement and subsequent analysis, attention was focused on the first-series resonant frequency (λ/4) of each antenna. During the evaluation of the resonance parameters, the flat microwave antenna models showed specific resonant properties different from those of conventional cylindrical microwave antennas. This article aims to inform professionals about these unknown specific properties of non-symmetrical antennas. The results of experimental measurements are analyzed theoretically and then visually compared using graphs so that the reader can more easily understand the properties observed. These surprising observations open up some new possibilities for the design, implementation, and use of flat microwave antennas, as found in modern aircraft, automobiles, etc.
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Kumari, Bibha, and Nisha Gupta. "Multifrequency Oscillator-Type Active Printed Antenna Using Chaotic Colpitts Oscillator." International Journal of Microwave Science and Technology 2014 (November 30, 2014): 1–10. http://dx.doi.org/10.1155/2014/675891.
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This paper presents a new concept to realize a multifrequency Oscillator-type active printed monopole antenna. The concept of period doubling route to chaos is exploited to generate the multiple frequencies. The chaotic Colpitts oscillator is integrated with the printed monopole antenna (PMA) on the same side of the substrate to realize an Oscillator-type active antenna where the PMA acts as a load and radiator to the chaotic oscillator. By changing the bias voltage of the oscillator, the antenna can be made to operate at single or multiple frequencies. To test the characteristics of the antenna at single and multiple frequencies of operation, two similar prototype models of printed monopole broadband antennas are developed. One of these antennas used at transmit side is fed by the chaotic Colpitts oscillator while the other is used as the receive antenna. It is observed that the antenna receives single or multiple frequencies simultaneously for particular values of the bias voltage of the oscillator at the transmit end.
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Koshkid’ko, V. G., and M. M. Migalin. "Design of a Slotted Waveguide Antenna by Means of VBScript Scripting Language Macros in CAD Ansys HFSS." Journal of the Russian Universities. Radioelectronics 23, no. 1 (February 28, 2020): 6–17. http://dx.doi.org/10.32603/1993-8985-2020-23-1-6-17.
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Introduction. Modern antenna devices contain a large number of repeating elements. The process of development of CAD models of such devices requires repeatedly performed operations that is a routine task for an engineer. Therefore, the problem of repeating operations automation arises when constructing antenna models with periodic structures.Aim. To demonstrate the automation of slotted waveguide antennas design process in CAD Ansys HFSS.Materials and methods. In order to determine the dimensions of the slotted waveguide antenna the energy method was used. Automation procedure of the design of the slotted waveguide antennas in CAD Ansys HFSS using the Visual Basic Scripting Edition macros was presented.Results. In order to design and edit slotted waveguide antennas in CAD Ansys HFSS four macros in the VBScript language were established: for slot subtraction from a broad wall of a rectangular waveguide at given coordinates; for removing the original slots created using the previous macro; for drawing a polyline passing through the centers of the slots, in order to verify the antenna’s near field realized distribution; for inclined slot subtraction from a narrow wall of a rectangular waveguide at given coordinates. Results of the macros usage were presented.Conclusion. The above mentioned macros allow one to automate the routine steps during the process of creating and deleting objects while designing an antenna model with periodic structures in CAD Ansys HFSS. Specified procedures for creating macros could be extended to a wide class of tasks related to the studies of characteristics of electromagnetic structures including repeating objects (phased antenna arrays, reflective arrays, slotted waveguide antennas, fractal antennas, log-periodic antennas, multi-layer lens antennas, ladder-type microwave filters).
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RAHAYU, YUSNITA, MEILITA KURNIATI, and INESTI LAILATUL QODRIYAH. "Antena Mikrostrip Biosensor untuk Deteksi Virus pada Darah." ELKOMIKA: Jurnal Teknik Energi Elektrik, Teknik Telekomunikasi, & Teknik Elektronika 9, no. 3 (July 9, 2021): 604. http://dx.doi.org/10.26760/elkomika.v9i3.604.
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ABSTRAKKemajuan teknologi gelombang mikro memainkan peran penting dalam berbagai aplikasi diagnosa dan deteksi penyakit. Penelitian ini mengusulkan dua model antena untuk mendeteksi virus menggunakan Antena Mikrostrip Biosensor yang beroperasi pada ISM band (2,4-2,5 GHz). Antena yang diusulkan disimulasikan pada Software CST dengan material substrat Roger 3010. Hasil simulasi yang diperoleh antena pertama beroperasi pada 2,46 GHz, return loss -19,76 dB, bandwidth 401,2 MHz. Antena kedua pada 2,45 GHz, return loss -22,51 dB, bandwidth 227,4 MHz. Hasil simulasi pengujian menggunakan phantom darah menunjukkan pergeseran frekuensi semakin rendah dengan antena pertama 2,38 GHz dan antena kedua 2,43 GHz. Pengukuran antena pertama beroperasi pada 2,5 GHz dengan return loss -21,55 dB dan antena kedua beroperasi pada 2,47 GHz dengan return loss -28 dB. Pengukuran antena menggunakan VNA menunjukkan pergeseran frekuensi semakin meningkat diikuti return loss semakin rendah dibandingkan dengan hasil simulasi.Kata kunci: antena deteksi virus, ISM, proximity coupled, mikrostrip, phantom.ABSTRACTAdvances in microwave technology play an important role in a wide variety of disease diagnostic and detection applications. This study proposes two antenna models for virus detection using a Microstrip Biosensor antenna that operates on the ISM band (2.4-2.5 GHz). The proposed antenna is simulated in CST software with Roger 3010 substrate material. The simulation results obtained by the first antenna operate at 2.46 GHz, return loss of -19.76 dB, a bandwidth of 401.2 MHz. The second antenna at 2.45 GHz, return loss of -22.51 dB, a bandwidth of 227.4 MHz. The test simulation results using blood phantom show that the frequency shift is getting lower with the first antenna at 2.38 GHz and the second antenna at 2.43 GHz. The first antenna measurement operates at 2.5 GHz with a return loss of -21.55 dB and the second antenna operates at 2.47 GHz with a return loss of -28 dB. Antenna measurement using VNA shows that the frequency shift is increasing followed by lower return loss compared to the simulation results.Keywords: antena for virus detection, ISM, proximity coupled, microstrip, phantom.
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Zubinaitė, Vilma, and George Preiss. "A PROPOSED SIMPLIFIED TECHNIQUE FOR CONFIRMING HIGH PRECISION GNSS ANTENNA OFFSETS." Aviation 14, no. 3 (September 30, 2010): 83–89. http://dx.doi.org/10.3846/aviation.2010.13.
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The purpose of this research was to independently investigate and determine confirmatory calibration procedures for GNSS antennas. This paper focuses on the aspect of simplified techniques for confirming high precision GNSS antenna offsets. In the other words, the aim is to verify GNSS antenna offset parameters ‐ results, which will be used to find the consequences on ground positions of orbital distortions caused by solar activity. It is well known that the computation of GNSS observations using high precision GNSS antennas requires knowledge of the relevant antenna phase centre offsets. These offsets are the distance in three dimensions from the antenna's physical centre to the point in space at which the antenna ‘measures’ position. The calibration processes used by manufacturers appear to vary, and, where receivers of different models are to be used together, it is essential that the calibration parameters used are all produced using the same methods and by the same authoritative sources. Meanwhile, with the growth in the use of high precision GNSS systems, the likelihood of antennas being accidentally mishandled is possibly higher than previously. Finally, it is noted that it has long been the practise for surveyors to check their instruments to ensure that they are properly calibrated. In the modern electronic age, however, it seems that this practise has been allowed to lapse as far as GNSS instrumentation is concerned. With the above in mind, it has been decided to attempt to create a simplified procedure for calibrating high precision GNSS antennas. The aim is that it will be possible for the average surveyor to check his antenna without great effort or trouble. The objective can also be described as finding a simplified field procedure to determine whether a specific antenna's offset parameters are within reasonable agreement with published figures. Santrauka Straipsnyje analizuojamas supaprastintas metodas, kuriuo galima aprobuoti aukšto tikslumo globalines navigacines palydovines sistemos (GNPS) antenos nukrypimus. Siekiama patinkrinti GNPS antenos nukrypimo parametrus ‐ rezultatus, kurie bus naudojami nustatant GNPS palydovo orbitos iškraipymu padarinius. Nagrinejama procedūra, kai siekiama nustatyti, ar konkrečios GNPS antenos kalibravimo parametrai yra pagristi, palyginti su publikuotais duomenimis. Analizuojama problema yra aktuali, kai GNPS matavimams naudojamos aukšto tikslumo GNPS antenos ir reikalingos žinios, susijusios su antenos fazes centro nukrypimais.
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Kazemzadeh, R., W. John, and W. Mathis. "Automated parametrical antenna modelling for ambient assisted living applications." Advances in Radio Science 10 (September 18, 2012): 127–33. http://dx.doi.org/10.5194/ars-10-127-2012.
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Abstract. In this paper a parametric modeling technique for a fast polynomial extraction of the physically relevant parameters of inductively coupled RFID/NFC (radio frequency identification/near field communication) antennas is presented. The polynomial model equations are obtained by means of a three-step procedure: first, full Partial Element Equivalent Circuit (PEEC) antenna models are determined by means of a number of parametric simulations within the input parameter range of a certain antenna class. Based on these models, the RLC antenna parameters are extracted in a subsequent model reduction step. Employing these parameters, polynomial equations describing the antenna parameter with respect to (w.r.t.) the overall antenna input parameter range are extracted by means of polynomial interpolation and approximation of the change of the polynomials' coefficients. The described approach is compared to the results of a reference PEEC solver with regard to accuracy and computation effort.
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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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Buffi, Alice, Andrea Michel, Paolo Nepa, and Giuliano Manara. "Numerical analysis of wireless power transfer in near-field UHF-RFID systems." Wireless Power Transfer 5, no. 1 (November 27, 2017): 42–53. http://dx.doi.org/10.1017/wpt.2017.16.
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A preliminary numerical analysis of the power transfer efficiency (PTE) for the forward link of near-field (NF) ultra high frequency (UHF)-radio frequency identification (RFID) systems is addressed in this paper, by resorting to an impedance matrix approach where the matrix entries are determined through full-wave simulations. The paper is aimed to quantify the NF-coupling effects on the PTE, as a function of the distance between the reader and tag antennas. To allow for a PTE comparison between different reader and tag antenna pairs, a benchmarking tag-loading condition has been assumed, where the tag antenna is loaded with the impedance that maximizes the PTE. In a more realistic loading condition, the load impedance is assumed as equal to the conjugate of the tag antenna input impedance. Full-wave simulations use accurate antenna models of commercial UHF-RFID passive tags and reader antennas. Finally, a “shape-matched antenna” configuration has been selected, where the reader antenna is assumed as identical to the tag antenna. It is shown that the above configuration could be a valuable compact solution, at least for those systems where the relative orientation/position between the tag and reader antennas can be controlled, and their separation is of the order of a few centimeters or less.
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Alogla, A., M. A. H. Eleiwa, and H. Alshortan. "Design and Evaluation of Transmitting Antennas for Solar Power Satellite Systems." Engineering, Technology & Applied Science Research 11, no. 6 (December 11, 2021): 7950–56. http://dx.doi.org/10.48084/etasr.4607.
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This study attempts to identify, design, and evaluate transmitting antennas for Solar Power Satellite (SPS) systems. The design approach aimed at meeting the SPS operational requirements at ISM bands, namely 2.4-2.5GHz for the NASA and 5.725-5.875GHz for the JAXA models. The primary attributes of SPS antennas for transmitting Beamed High-Power Microwaves (BHPMs) are high power handling capability, efficiency, and directivity with narrow beamwidth and lower sidelobe levels. Using a planar end-fed 20×20 SWA module, the whole planar Slotted Waveguide Antenna Arrays (SWAAs) were designed for both the NASA and JAXA reference models having 1km diameter antenna aperture, peak power level over 1GW, directivity over 80dBi, Side Lobe Level (SLL) less than 20dB, and pencil beam with HPBW less than 0.01°. The proposed slotted waveguide transmitting antenna arrays fulfilled the operational requirements for both the NASA and JAXA SPS reference models. Due to the higher operating frequency, the results showed that the proposed planar SWA array performs better on the JAXA than on the NASA SPS model.
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Sultana, Sadia, and Rinku Basak. "Performance Evaluation of Meander Line Implantable Antenna integrated with EBG Based Ground for Anatomical Realistic Model." AIUB Journal of Science and Engineering (AJSE) 18, no. 1 (May 31, 2019): 1–10. http://dx.doi.org/10.53799/ajse.v18i1.16.
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A unique design and meander line implantable antenna is examined in this paper which satisfies the requirements of ultra-wide band. The designed antenna is integrated with the electromagnetic band gap (EBG) structure based ground plane to enhance the performance. Rectangular electromagnetic band gap (EBG) structures are represented here to evaluate the antenna performance. This compact and efficient MLA antenna is applied to improve the antenna performance for numerous implantable scenarios and biomedical applications. The proposed antenna with EGB ground plane is designed for both the simplified model and anatomical realistic models for the human body and executed the performance in bio-environment. To approve the results of implantable antennas more correctly, simulation is analyzed using anatomical realistic human models. The ultimate design has the whole dimension is 15.2 x 8.8 m2. The thickness of the antenna is about 0.8 mm. FR4 is chosen as the substrate material and Copper is chosen as the patch material. The antenna is enclosed biocompatible material with silicon inside the tissue in order to protect patient safety. Significant parameters such as S11 parameter, Far field (radiation pattern), VSWR, Efficiency, Directivity, Gain of the proposed antenna have calculated and measured the performance both the simplified and realistic human models. Comparison Analysis of S11 parameter for different substrate materials and patch materials have observed. The radiation mechanism and modified design of the implantable antenna reducing Specific Absorption Rate (SAR) for safety issues. All the simulation results and measurements are obtained from CST Microwave Studio to validate the design.
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Singh, Raghvendra, Dambarudhar Seth, Sanyog Rawat, and Kanad Ray. "In Body Communication." International Journal of Applied Evolutionary Computation 9, no. 1 (January 2018): 64–75. http://dx.doi.org/10.4018/ijaec.2018010104.
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This article makes an effort to assess the performance of a stacked meandered patch antenna in proximity of multiple homogeneous human tissue models. Nowadays, many smart wireless gadgets are being used around human vicinity, hence the performance investigation of these wireless gadgets is major concern. This article discloses the performance of meandered patch antenna for in-body communication in the MICS band. The human tissue is considerably effected by the exposure of electromagnetic radiation. Performance improvement of patch antennas used in wireless gadgets is the key solution of the problem. This article presents the estimation of parameters of stacked meandered patch antennas; reflection coefficient, radiation pattern, directive gain and VSWR in proximity of multiple homogeneous human tissue models.
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KARPOVA, LESIA, and ANITA BOIKO. "INFLUENCE OF LOCATION OF ONE AND MULTIPLE ANTENNAS ON CAPACITY OF C2C COMMUNICATION SYSTEMS." Herald of Khmelnytskyi National University 303, no. 6 (December 2021): 181–85. http://dx.doi.org/10.31891/2307-5732-2021-303-6-181-185.
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Due to the variety of existing and future wireless services, the number of antennas installed on a vehicle is constantly increasing. However, due to design limitations or the addition of more components of electrical equipment, the number of user-friendly antenna positions is reduced. To ensure stable data connections or even higher data rates with the remaining installation space, a possible solution is to use multiple antenna systems. This document discusses and evaluates 16 possible positions of antennas for communication between cars (C2C). The radiation pattern of all antennas is determined by the antenna synthesis maximization method, which takes into account real-world limitations such as space availability, transmission power, number and location of antennas. Channel bandwidth is used to compare different settings. This bandwidth is calculated using virtual disks based on typical application scenarios. The results of this study show which antenna positions and which combinations of antenna positions are most suitable for communication between C2C. Additional time and cost constraints, as well as an increase in the range of products for the automotive industry and a large number of degrees of freedom for the multi-purpose antenna necessitate the use of advanced modeling models and design strategies. Thus, this is the starting point for this work. Here is presented and used a technique that allows you to optimize single and multiple antenna systems. The main purpose of the proposed synthesis is to optimize the radiation profiles of antennas based on constraints specific to vehicles. For antenna design, this document identifies different scenarios based on typical C2C security scenarios. The simulation is carried out in a typical worst case in urban and rural areas or on highways.
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Lampe, Bernhard, and Klaus Holliger. "Resistively loaded antennas for ground-penetrating radar: A modeling approach." GEOPHYSICS 70, no. 3 (May 2005): K23—K32. http://dx.doi.org/10.1190/1.1926574.
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The design of surface ground-penetrating radar (GPR) antennas is inherently difficult, primarily because the presence of the air-soil interface greatly complicates both analytic and laboratory-based approaches aimed at characterizing the antennas. Versatile numerical simulation techniques capable of describing the key physical principles governing GPR antenna radiation offer new solutions to this problem. We use a finite-difference time-domain (FDTD) solution of Maxwell's equations in three dimensions to explore the radiation characteristics of various bow-tie antennas (including quasi-linear antennas) operating in different environments. The antenna panels are either modeled as having an infinite conductivity [i.e., a perfect electrical conductor (PEC)], a constant finite conductivity, or a Wu-King finite-conductivity profile. Finite conductivities are accommodated through a subcell extension of the classical FDTD approach, with the model space surrounded by highly efficient generalized perfectly matched layer (GPML) absorbing boundary conditions. Our results show that input impedances, radiated waveforms, and radiation patterns of bow-tie antennas with Wu-King conductivity profiles are largely invariant when placed in free space or above diverse half-space earth models. By comparison, antennas with PEC or constant finite-conductivity panels have variable characteristics that depend somewhat on their operating environment. Quasi-linear antenna designs tend to be less sensitive in this respect, and hence may be suitable for a somewhat larger variety of soil conditions than planar bow-tie antennas characterized by large flare angles. Antennas with constant finite-conductivity panels are considerably more robust (i.e., less sensitive to their environment) than their PEC analogs because the loss resistance is increased, and the range over which a significant amount of current flow occurs is decreased when the antenna panels are resistively loaded. For the extreme case of Wu-King conductivity profiles, the current in the antenna panels approaches that of a quasi-infinitesimal electric dipole. This is shown by the surface-charge distributions on the various antennas and by the corresponding energy radiation patterns. Unfortunately, the favorable characteristics of the latter antennas are counterbalanced by markedly lower radiation efficiency. For the antenna designs considered in this study, we found that the peak energy radiated into earth models from bow-tie antennas with Wu-King conductivity profiles is about one order of magnitude lower than for antennas with PEC terminals.
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Alwarafy, Abdulmalik, Ahmed Iyanda Sulyman, Abdulhameed Alsanie, Saleh A. Alshebeili, and Hatim M. Behairy. "Path-Loss Channel Models for Receiver Spatial Diversity Systems at 2.4 GHz." International Journal of Antennas and Propagation 2017 (2017): 1–12. http://dx.doi.org/10.1155/2017/6790504.
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This article proposes receiver spatial diversity propagation path-loss channel models based on real-field measurement campaigns that were conducted in a line-of-site (LOS) and non-LOS (NLOS) indoor laboratory environment at 2.4 GHz. We apply equal gain power combining (EGC), coherent and noncoherent techniques, on the received signal powers. Our empirical data is used to propose spatial diversity propagation path-loss channel models using the log-distance and the floating intercept path-loss models. The proposed models indicate logarithmic-like reduction in the path-loss values as the number of diversity antennas increases. In the proposed spatial diversity empirical path-loss models, the number of diversity antenna elements is directly accounted for, and it is shown that they can accurately estimate the path-loss for any generalized number of receiving antenna elements for a given measurement setup. In particular, the floating intercept-based diversity path-loss model is vital to the 3GPP and WINNER II standards since they are widely utilized in multi-antenna-based communication systems.
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Obukhovets, Victor. "Designing problems of antennas integrated with solar batteries." ITM Web of Conferences 30 (2019): 05009. http://dx.doi.org/10.1051/itmconf/20193005009.
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Designing problems of microstrip antennas placed on the solar battery surface and using it as a substrate are considered. Computational models taking into account the elements of its costruction and parameters of solar battery were performed by means of ANSYS HFSS. A number of numerical experiments for several antenna models were fulfilled. The aim of them is to design microstrip antenna integrated with solar battery without decreasing of solar elements effectiveness. The results of numerical experiments for several projects of microwave radiators with solid or mesh surface of the patch are presented
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Maxworth, Ashanthi. "Far-Field Radiation Characteristics of Folded Monopole Antennas over a Conducting Ground Plane." Eng 3, no. 1 (March 9, 2022): 142–60. http://dx.doi.org/10.3390/eng3010012.
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Folded monopole structures have been used for many applications, including low-frequency electromagnetic wave transmission and reception. However, the literature on these antenna types is quite limited. Folded monopole antennas are mathematically complex compared to conventional monopole or dipole antennas since every fold introduces a new set of design parameters. This work studied the far-field radiation characteristics of multi-folded monopole antennas operating at 75 MHz in terms of their radiated power concerning the frequency, the far-field directivity of the electric field, and the effect of each design parameter on the far-field radiation power. According to the results, folding a monopole antenna multiple times increases its effective length, making this antenna a suitable candidate for applications where the antenna height is restricted. Additionally, the ground-to-wire separation has the biggest effect on radiated power. In both single-fold and two-fold cases, doubling the ground-to-wire separation increased the radiated power by 0.2 W compared to the other models with the same number of folds. As for the challenges, the impedance mismatch between the source and antenna causes a significant amount of power reflection; hence, suitable impedance matching is required to reduce reflected power.
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Srilekha, G., P. Pardhasaradhi, B. T. P. Madhav, R. K. N. R. Manepalli, and M. C. Rao. "Design and analysis of 6CB nematic liquid crystal–based rectangular patch antenna for S-band and C-band applications." Zeitschrift für Naturforschung A 75, no. 10 (October 25, 2020): 863–75. http://dx.doi.org/10.1515/zna-2020-0144.
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AbstractThis article presents the design and analysis of 4-hexyl-4′-biphenylcarbonitrile (6CB) nematic liquid crystal (NLC)–based rectangular patch antenna for S-band and C-band communication applications. Two glass substrates with permittivity of 6.4, loss tangent of 0.01 and thickness of 1 mm each with 21 × 25 mm2 and 19 × 19 mm2 dimension has been used, and 0.005 mm air gap has been placed to fill 6CB NLC. A rectangular patch of 10 × 11 mm2 size has been considered over the top substrate to achieve the application specific bands. The designed antenna model-1 with air gap is resonating at 5 GHz (4.01–7.85 GHz) with minimum S11 of −24.2 dB. The proposed antenna model-2 is filled with 6CB NLC in the air gap between glass substrates is resonating at 3.3 GHz (2.61–4.45 GHz) with minimum S11 of −29.75 dB. Antennas of both air gaps filled, and liquid crystal material filled models are fabricated and tested through combinational analyser for validation. The correlation between transmitted and received signals of the antenna models are analysed with time domain analysis by taking the identical antennas in face to face and side by side condition. The simulated results from HFSS electromagnetic tool and fabricated antennas results in chamber are exhibiting good agreement with each other.
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Ahammed, Dr M. D. Javeed, and Dr G. Srinivasa Rao. "A Patch Antenna Design for Giga Frequency Unmanned Aerial Vehicles Application." Journal of Advanced Research in Dynamical and Control Systems 13, no. 1 (February 25, 2021): 01–07. http://dx.doi.org/10.5373/jardcs/v13i1/20211001.
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In this paper a present time developing application is used that is a UAV Antenna in aerospace technology. These antennas play a vital role in this WIMAX technology. A patch antenna is designed such that all the dimensions should be shrinked yet efficient in radiation in comb shape and this proposed antenna is used at 4.2GHz frequency range. A CST tool is used for designing and simulating our antenna all the dimensions taken for proposed antenna are comparatively less when compared to conventional models. Low return loss, gain, bandwidth and VSWR are optimized by using this design the efficiency is also enhanced by 95% which makes our antenna suitable to the UAV WIMAX applications. Surface current is also one of the major parameter which is reduced by our proposed model.
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Venu Madhav, P., and Dr M SivaGanga Prasad. "Topology Optimization of Dual Octagonal Array antenna for low frequency applications." International Journal of Engineering & Technology 7, no. 2.17 (April 15, 2018): 13. http://dx.doi.org/10.14419/ijet.v7i2.17.11552.
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Objectives: Efficient antenna design for use in communication systems is altering the face of the antenna modeling. The ever-increasing demand for portable and efficient antennas is making researchers to develop innovative models [1] using advanced antenna modeling tools that comply with industrial needs and standards. Methods/Statistical Analysis: Antennas with lower operating frequencies have the major constraints on its size, efficiency and gain. Study on matching techniques, feeding techniques was also to be considered.Findings: Micro strip patch antennas offers considerable amount of radiation, low cost when fabricated on FR4, light weight and are conformable to suite any application. This paper projects the design, simulation and testing of a dual octagonal patch, the topology algorithm [3] is used to optimize the size and shape of the patch where octagons are spaced in the form of an array to address optimization on size and fits into wireless applications. Application/Improvements: The proposed model is tested in the standard antenna test bench comprising of microwave integrated circuit analyzer receiver MIC10kit and found to operate at a resonant frequency of 1.8 GHz with good radiation characteristics.
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Irving, James D., and Rosemary J. Knight. "Numerical simulation of antenna transmission and reception for crosshole ground-penetrating radar." GEOPHYSICS 71, no. 2 (March 2006): K37—K45. http://dx.doi.org/10.1190/1.2187768.
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Numerical models that account for realistic transmitter and receiver antenna behavior are necessary to develop waveform-based inversion methods for crosshole ground-penetrating radar (GPR) data. A challenge in developing such models is simulating the antennae in a computationally efficient manner so that inversions can be performed in a reasonable amount of time. We present an approach to efficiently simulate crosshole GPR transmission and reception in heterogeneous media. The core of our approach is a finite-difference time-domain (FDTD) solution of Maxwell's equations in 2D cylindrical coordinates. First, we determine the behavior of the current on a realistic GPR antenna in a borehole through detailed FDTD modeling of the antenna and its immediate surroundings. To model transmission and reception, we then replicate this antenna current behavior on a much-coarser grid using a superposition of point-electric-dipole source and receiver responses. Results obtained with our technique agree with analytical results, with numerical modeling results where the transmitter antenna and borehole are explicitly accounted for using a fine discretization, and with crosshole GPR field data.
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Kumar, B. Ashok, P. Mallikarjuna Rao, and M. Satyanarayana. "Performance Analysis of 1x4 RMPA Array using Step Cut and DGS Techniques with Different Feed Techniques for LTE, Wi-Fi, WLAN and Military Communications." Review of Computer Engineering Research 9, no. 3 (September 30, 2022): 181–99. http://dx.doi.org/10.18488/76.v9i3.3146.
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This paper presents four different models of 1x4 antenna arrays excited by quarter wave transformer and mitered bend feeding techniques. These four antennae were designed and developed to examine the various radiation performance characteristics. The Ansys HFSS tool was used to simulate the four antenna models over the frequency range (1-5GHz). The simulation results were compared to identify the optimized design model. Both types of 1X4 arrays with mitered bend feed network showed better results than quarter wave transformer and were resonating at 2.4, 3.6, 4.5 and 4.7 GHz frequencies with a maximum gain of 13.118dB. The proposed antennae are suitable for Wi-Fi, Long Term Evolution (LTE), Wireless Local Area Network (WLAN) and military communication applications. The optimized four 1x4 array models were fabricated and tested using Vector Network Analyzer E507C. The measured results had good matching with the numerical values of the simulation results.
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Kuang, Ye, Aiping Yang, He Luan, Hailiang Mao, Wenwen Zhang, Lan Yao, and Yiping Qiu. "Effects of structural parameters of textile substrates on the novel textile conformal half-wave dipole antenna." Journal of Industrial Textiles 47, no. 2 (April 7, 2016): 269–80. http://dx.doi.org/10.1177/1528083716644288.
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In the smart textile area, textile antennas integrated into people’s clothing functioning as the wireless signal transmission devices have gained increasing attention in recent decades. In this study, a textile conformal dipole antenna was designed to work at the frequency of 915 MHz. The radiation elements of the antenna were adhered directly onto the stitched polyester fabric substrate to get the conformal effect. The measured results showed that the antenna had good performance with the return loss value and typical omnidirectional radiation patterns. To investigate the effect of textile substrate on the antenna performance, models for stitched and plain weave structures were built and the value of root mean square (RMS) surface error was calculated using integration methods. Then an acceptable range of operation frequencies versus RMS was marked out for estimating the reliability of textile substrate. The calculated RMS of our designed antenna was 0.25 mm, which was in the acceptable range area indicating the proper antenna design. Finally, the relationships between the critical frequencies and fabric parameters such as yarn thickness and density were studied, which gives the direct guideline for selecting the fabric as the substrate for textile antennas.
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Dawidowicz, Karol, Rafal Kazmierczak, and Krzysztof Swiatek. "SHORT STATIC GPS/GLONASS OBSERVATION PROCESSING IN THE CONTEXT OF ANTENNA PHASE CENTER VARIATION PROBLEM." Boletim de Ciências Geodésicas 21, no. 1 (March 2015): 213–30. http://dx.doi.org/10.1590/s1982-217020150001000014.
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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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Lifwarda, Lifwarda, and Firdaus Firdaus. "PEMBUATAN ANTENA MIKROSTRIP MODEL ANGKA 4 UNTUK PENERIMA SINYAL TELEVISA PADA JALUR UHF (ULTRA HIGH FREKUENSI)." Elektron : Jurnal Ilmiah 5, no. 2 (December 13, 2013): 75–80. http://dx.doi.org/10.30630/eji.5.2.57.
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Development of science and technology very rapidly in various fields brought great influence to all aspects of life one of this field of telecommunications. Development of telecommunication technology that bring due faster to hight public demand for telecommunications services users get an easy and fast service are used as medium convey information One of the device in question is antenna. Many type of antennas that have been developed for the reception of televisions signals and are generally made of wires, pipes or aluminium which has large size and weight. Needed for the antenna which has advantages in terms of shape light weight small volume from that can be easily adapted to the priimary device for on the fabrication and can be used for a wide band frequency. The antenna is microstrip antennas capable adjusted in assembly or in other words easily in a microstrip antenna placement. Microstrip antenna models 4 is designed to work in the range frequency 470 – 750 MHz. This antenna has a value of more than -10 dB returnloss to a predetermined range frequency. The measurement results of the antenna resonates at a frequency of 518 MHz gain value obtained by 1 dB, and has a wide bandwidth of 7 MHz, while for polaradiasi shaped bidirectional.
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Dhaliwal, Balwinder S., and Shyam S. Pattnaik. "Artificial Neural Network Analysis of Sierpinski Gasket Fractal Antenna: A Low Cost Alternative to Experimentation." Advances in Artificial Neural Systems 2013 (October 23, 2013): 1–7. http://dx.doi.org/10.1155/2013/560969.
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Artificial neural networks due to their general-purpose nature are used to solve problems in diverse fields. Artificial neural networks (ANNs) are very useful for fractal antenna analysis as the development of mathematical models of such antennas is very difficult due to complex shapes and geometries. As such empirical approach doing experiments is costly and time consuming, in this paper, application of artificial neural networks analysis is presented taking the Sierpinski gasket fractal antenna as an example. The performance of three different types of networks is evaluated and the best network for this type of applications has been proposed. The comparison of ANN results with experimental results validates that this technique is an alternative to experimental analysis. This low cost method of antenna analysis will be very useful to understand various aspects of fractal antennas.
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Altintas, Gulsah, Ibrahim Akduman, Aleksandar Janjic, and Tuba Yilmaz. "A Novel Approach on Microwave Hyperthermia." Diagnostics 11, no. 3 (March 10, 2021): 493. http://dx.doi.org/10.3390/diagnostics11030493.
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Microwave hyperthermia (MH) requires the selective focusing of microwave energy on the targeted region while minimally affecting the healthy tissue. Emerging from the simple nature of the linear antenna arrays, this work demonstrates focusing maps as an application guide for MH focusing by adjusting the antenna phase values. The focusing of the heating potential (HP) on different density breast models is performed via the proposed method using Vivaldi antennas. The effect of the tumor conductivity on the focusing is discussed. As a straightforward approach and utilizing the Vivaldi antennas, the system can be further combined with MH monitoring application.
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S. ALZAHRANI, AHMED, and ADNAN M. AFFANDI. "High Gain Microstrip Active Antenna Utilizes as Transmitter and Receiver with Linear and Circular Polarization." Academic Journal of Research and Scientific Publishing 3, no. 30 (October 5, 2021): 48–62. http://dx.doi.org/10.52132/ajrsp.e.2021.304.
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In this research paper, a high gain microstrip active antenna is operating as transmitter and receiver at the same time with linear and circular polarization operations. This proposed work contains five essential parts such as high gain and broadband applications. Firstly, mainly is dealing with passive patch antennas. These selected passive antennas enjoy both high gain and broadband applications. Part two intends to convert the selected passive patch antennas into an active antenna. Part three intended to improve the performances of the proposed active integrated antennas. Part four enhancement elements (which is known as parasitic elements) are utilized in order to increase the gain of selected antennas. Part five, this proposed active integrated antennas will be converted from linear polarization (LP) into circulation polarization (CP). All the selected antennas will simulate by using models of ADS Agilent.
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Januszkiewicz, Lukasz, Paolo Di Barba, and Slawomir Hausman. "Hierarchical paradigm for automated optimal design of dual-band wearable antenna with simplified human body models." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 37, no. 5 (September 3, 2018): 1597–608. http://dx.doi.org/10.1108/compel-01-2018-0048.
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Purpose The purpose of this study is to develop a method to reduce the computation time necessary for the automated optimal design of dual-band wearable antennas. In particular, the authors investigated if this can be achieved by the use of a hierarchical optimization paradigm combined with a simplified human body model. The geometry of the antenna under consideration is described via eight geometrical parameters which are automatically adjusted with the use of an evolutionary algorithm to improve the impedance matching of an antenna located in the proximity of a human body. Specifically, the antennas were designed to operate in the ISM band which covers two frequency ranges: 2.4-2.5 GHz and 5.7-5.9 GHz. Design/methodology/approach During the studies on the automated design of wearable antennas using evolutionary computing, the authors observed that not all design parameters exhibit equal influence on the objective function. Therefore, it was hypothesized that to reduce the computation effort, the design parameters can be activated sequentially based on their influence. Accordingly, the authors’ computer code has been modified to include this feature. Findings The authors’ novel hierarchical multi-parameter optimization method was able to converge to a better solution within a shorter time compared to an equivalent method not exploiting automatic activation of an increasing number of design parameters. Considering a significant computational cost involved in the calculation of the objective function, this exhibits a convincing advantage of their hierarchical approach, at least for the considered class of antennas. Research limitations/implications The described method has been developed for the design of single- or dual-band wearable antennas. Its application to other classes of antennas and antenna environments may require some adjustments of the objective functions or parameter values of the evolutionary algorithm. It follows from the well-recognized fact that all optimization methods are to some extent application-specific. Practical implications Computation load involved in the automated design and optimization can be significantly reduced compared to the non-hierarchical approach with a heterogeneous human body model. Originality/value To the best of the authors’ knowledge, the described application of hierarchical paradigm to the optimization of wearable antennas is fully original, as well as is its combination with simplified body models.
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Romey, William L., Magenta M. Miller, and Jose M. Vidal. "Collision avoidance during group evasive manoeuvres: a comparison of real versus simulated swarms with manipulated vision and surface wave detectors." Proceedings of the Royal Society B: Biological Sciences 281, no. 1788 (August 7, 2014): 20140812. http://dx.doi.org/10.1098/rspb.2014.0812.
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Coordinated group motion has been studied extensively both in real systems (flocks, swarms and schools) and in simulations (self-propelled particle (SPP) models using attraction and repulsion rules). Rarely are attraction and repulsion rules manipulated, and the resulting emergent behaviours of real and simulation systems are compared. We compare swarms of sensory-deprived whirligig beetles with matching simulation models. Whirligigs live at the water's surface and coordinate their grouping using their eyes and antennae. We filmed groups of beetles in which antennae or eyes had been unilaterally obstructed and measured individual and group behaviours. We then developed and compared eight SPP simulation models. Eye-less beetles formed larger diameter resting groups than antenna-less or control groups. Antenna-less groups collided more often with each other during evasive group movements than did eye-less or control groups. Simulations of antenna-less individuals produced no difference from a control (or a slight decrease) in group diameter. Simulations of eye-less individuals produced an increase in group diameter. Our study is important in (i) differentiating between group attraction and repulsion rules, (ii) directly comparing emergent properties of real and simulated groups, and (iii) exploring a new sensory modality (surface wave detection) to coordinate group movement.
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Koziel, Slawomir, and Adrian Bekasiewicz. "Rapid design optimization of antennas using variable-fidelity EM models and adjoint sensitivities." Engineering Computations 33, no. 7 (October 3, 2016): 2007–18. http://dx.doi.org/10.1108/ec-11-2015-0367.
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Purpose Development of techniques for expedited design optimization of complex and numerically expensive electromagnetic (EM) simulation models of antenna structures validated both numerically and experimentally. The paper aims to discuss these issues. Design/methodology/approach The optimization task is performed using a technique that combines gradient search with adjoint sensitivities, trust region framework, as well as EM simulation models with various levels of fidelity (coarse, medium and fine). Adaptive procedure for switching between the models of increasing accuracy in the course of the optimization process is implemented. Numerical and experimental case studies are provided to validate correctness of the design approach. Findings Appropriate combination of suitable design optimization algorithm embedded in a trust region framework, as well as model selection techniques, allows for considerable reduction of the antenna optimization cost compared to conventional methods. Research limitations/implications The study demonstrates feasibility of EM-simulation-driven design optimization of antennas at low computational cost. The presented techniques reach beyond the common design approaches based on direct optimization of EM models using conventional gradient-based or derivative-free methods, particularly in terms of reliability and reduction of the computational costs of the design processes. Originality/value Simulation-driven design optimization of contemporary antenna structures is very challenging when high-fidelity EM simulations are utilized for performance utilization of structure at hand. The proposed variable-fidelity optimization technique with adjoint sensitivity and trust regions permits rapid optimization of numerically demanding antenna designs (here, dielectric resonator antenna and compact monopole), which cannot be achieved when conventional methods are of use. The design cost of proposed strategy is up to 60 percent lower than direct optimization exploiting adjoint sensitivities. Experimental validation of the results is also provided.
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Pacini, Alex, Alessandra Costanzo, and Diego Masotti. "A theoretical and numerical approach for selecting miniaturized antenna topologies on magneto-dielectric substrates." International Journal of Microwave and Wireless Technologies 7, no. 3-4 (May 18, 2015): 369–77. http://dx.doi.org/10.1017/s1759078715000859.
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An increasing interest is arising in developing miniaturized antennas in the microwave range. However, even when the adopted antennas dimensions are small compared with the wavelength, radiation performances have to be preserved to keep the system-operating conditions. For this purpose, magneto-dielectric materials are currently exploited as promising substrates, which allows us to reduce antenna dimensions by exploiting both relative permittivity and permeability. In this paper, we address generic antennas in resonant conditions and we develop a general theoretical approach, not based on simplified equivalent models, to establish topologies most suitable for exploiting high permeability and/or high-permittivity substrates, for miniaturization purposes. A novel definition of the region pertaining to the antenna near-field and of the associated field strength is proposed. It is then showed that radiation efficiency and bandwidth can be preserved only by a selected combinations of antenna topologies and substrate characteristics. Indeed, by the proposed independent approach, we confirm that non-dispersive magneto-dielectric materials with relative permeability greater than unit, can be efficiently adopted only by antennas that are mainly represented by equivalent magnetic sources. Conversely, if equivalent electric sources are involved, the antenna performances are significantly degraded. The theoretical results are validated by full-wave numerical simulations of reference topologies.
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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.
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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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Eggleston, Michael S., Kevin Messer, Liming Zhang, Eli Yablonovitch, and Ming C. Wu. "Optical antenna enhanced spontaneous emission." Proceedings of the National Academy of Sciences 112, no. 6 (January 26, 2015): 1704–9. http://dx.doi.org/10.1073/pnas.1423294112.
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Atoms and molecules are too small to act as efficient antennas for their own emission wavelengths. By providing an external optical antenna, the balance can be shifted; spontaneous emission could become faster than stimulated emission, which is handicapped by practically achievable pump intensities. In our experiments, InGaAsP nanorods emitting at ∼200 THz optical frequency show a spontaneous emission intensity enhancement of 35× corresponding to a spontaneous emission rate speedup ∼115×, for antenna gap spacing, d = 40 nm. Classical antenna theory predicts ∼2,500× spontaneous emission speedup at d ∼ 10 nm, proportional to 1/d2. Unfortunately, at d < 10 nm, antenna efficiency drops below 50%, owing to optical spreading resistance, exacerbated by the anomalous skin effect (electron surface collisions). Quantum dipole oscillations in the emitter excited state produce an optical ac equivalent circuit current, Io = qω|xo|/d, feeding the antenna-enhanced spontaneous emission, where q|xo| is the dipole matrix element. Despite the quantum-mechanical origin of the drive current, antenna theory makes no reference to the Purcell effect nor to local density of states models. Moreover, plasmonic effects are minor at 200 THz, producing only a small shift of antenna resonance frequency.
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Dzul, M. C., C. B. Yackulic, and J. Korman. "Estimating disperser abundance using open population models that incorporate data from continuous detection passive integrated transponder arrays." Canadian Journal of Fisheries and Aquatic Sciences 75, no. 9 (September 2018): 1393–404. http://dx.doi.org/10.1139/cjfas-2017-0304.
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Autonomous passive integrated transponder (PIT) tag antenna systems continuously detect individually marked organisms at one or more fixed points over long time periods. Estimating abundance using data from autonomous antennas can be challenging because these systems do not detect unmarked individuals. Here we pair PIT antenna data from a tributary with mark–recapture sampling data in a mainstem river to estimate the number of fish moving from the mainstem to the tributary. We then use our model to estimate abundance of non-native rainbow trout (Oncorhynchus mykiss) that move from the Colorado River to the Little Colorado River, the latter of which is important spawning and rearing habitat for federally endangered humpback chub (Gila cypha). We estimate that 226 rainbow trout (95% confidence interval: 127–370) entered the Little Colorado River from October 2013 to April 2014. We discuss the challenges of incorporating detections from autonomous PIT antenna systems into mark–recapture population models, particularly in regards to using information about spatial location to estimate movement and detection probabilities.
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Muttair, Karrar Shakir, Ali Zuhair Ghazi Zahid, Oras Ahmed Shareef, Raed Hameed Chyad Alfilh, Ahmed Mohammed Qasim Kamil, and Mahmood Farhan Mosleh. "Design and analysis of wide and multi-bands multi-input multi-output antenna for 5G communications." Indonesian Journal of Electrical Engineering and Computer Science 26, no. 2 (May 1, 2022): 903. http://dx.doi.org/10.11591/ijeecs.v26.i2.pp903-914.
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A <span>good antenna design has played an essential role in the design of wireless communication systems, international companies are looking for the best design that suits their products in terms of size, bandwidth, gain, cost, and performance. In this paper, three antenna models are designed for fifth-generation (5G) communications, the first model is a single antenna, the second model is a two-ports multi-input multi-output (MIMO) antenna, and the third model is a four-ports MIMO antenna. The geometric dimensions of a single antenna are 20×37×1.6 mm<sup>3</sup>, the two-ports antenna dimensions are 44×37×1.6 mm<sup>3</sup>, while the four-ports antenna dimensions are 74×44×1.6 mm<sup>3</sup>. The design of these antennas was based on the latest strategies in terms of their small sizes and operating from 13.5 to 20 GHz in wide and multiple bands to be compatible with all advanced communication devices. Based on the results that emerged, it was noted that the reflection coefficient (S11) < -10 dB and has better isolation between the ports is < -26 dB. While the envelope correlation coefficient (ECC) value is < 1.036×10<sup>-9</sup>, and the diversity gain (DG) value is 10 dB. All antennas proposed operate in ultra-wideband (UWB) which is very necessary for 5G communications devices.</span>
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Bait-Suwailam, M. M., and O. M. Ramahi. "Mutual Coupling Reduction Between Axial-Mode Helical Antennas using Single-Negative (SNG) Magnetic Metamaterials." Journal of Engineering Research [TJER] 7, no. 2 (December 1, 2010): 59. http://dx.doi.org/10.24200/tjer.vol7iss2pp59-68.
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This paper investigates the mutual coupling effects between axial-mode helical antenna arrays. Single-negative (SNG) magnetic metamaterials are developed and used in this work in order to reduce mutual coupling between axial-mode helical antennas used in multiple-input multiple-output systems. The inclusions considered here are composed of broadside coupled split-ring resonators. The magnetic permeability of those SNG inclusions have complex effective magnetic permeability response over a frequency band with high negative real part above the resonance and positive real part below the resonance. The SNG resonators are inserted between closely-spaced axial-mode helical antenna elements. Effective responses of the constitutive parameters of the developed magnetic inclusions are incorporated within the numerical models. It is shown that mutual coupling between the antenna elements can be reduced significantly by incorporating such magnetic inclusions. The SNG magnetic resonators work as antenna decoupler, and thus can be applied in a variety of antenna applications.
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Ferdous, Nayla, Goh Chin Hock, Saidatul Hamidah A. Hamid, Mohamad Nazri Abdul Raman, Tiong Sieh Kiong, and Mahamod Ismail. "Different Structural Modification Methods of the Patch for Reducing the Size of An Microstrip Patch Antenna." International Journal of Engineering & Technology 7, no. 4.1 (September 12, 2018): 86. http://dx.doi.org/10.14419/ijet.v7i4.1.28231.
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The aim of this paper is to present a simulation and analysis of a rectangular microstrip patch antenna with three different structural modifications to reduce the size of the antenna. We have tried to decrease the size of the antenna by inducing three different shaped slits inside the patch of the antenna. All these models have been designed and analyzed using CST Microwave Studio software. For designing the antennas, Flame Retardant 4 (FR-4 lossy) has been used as the substrate material with a dielectric constant of Ԑr=4.3. The antenna works at the frequency of 2.4 GHz. Performance characteristics such as return loss S11 parameter<-10 dB, directivity, side lobe level, gain and bandwidth of each of the modified designs are obtained and compared with the original design. We were able to reduce the size by maximum 18% and minimum 7% by only inducing the slits, while maintain the performance.
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Lutfia, Paulen Aulia, Nurhayati Nurhayati, and Samuel Prasad Jones Christydass. "Umbrella Monopole Antenna for 5G Applications." INAJEEE Indonesian Journal of Electrical and Eletronics Engineering 4, no. 1 (May 14, 2021): 8. http://dx.doi.org/10.26740/inajeee.v4n1.p8-11.
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Umbrella Monopole Antenna (UMA) proposed in this paper for 5G application. We designed four models of UMA, i.e: UMA-A, UMA-B, UMA-C, and UMA-D. The antenna has a curvature in the patch as an umbrella shape with a feeding shape a microstrip feed line. Four variations of the patch antenna have been designed and get different performance in VSWR, surface current, and directivity. The proposed antenna has a wide bandwidth that operates 8 GHz – 30 GHz with VSWR <2 dB. The Increasing of directivity is reached for UMA-A, UMA-C, UMA-D, and UMA-B, i.e: 6.38 dBi, 7.97 dBi, 8,84dBi, and 9,15 dBi respectively at 24 GHz. The maximum gain has been reached for UMA-B of 9.15. The lowest frequency that has a return loss of 10 dB has resulted for UMA-D in the frequency around 5 GHz. All of the UMA antennas can be applied for 5G mmwave applications at 24 GHz and 28 GHz.
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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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Willis, T. M., and D. L. Sengupta. "Accuracy of standard patch antenna models." Electronics Letters 23, no. 25 (1987): 1376. http://dx.doi.org/10.1049/el:19870950.
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Poljak, Dragan, Khalil El Khamlichi Drissi, Sergey V. Tkachenko, and Andres Peratta. "Antenna Models for Electromagnetic Compatibility Applications." International Journal of Antennas and Propagation 2012 (2012): 1–2. http://dx.doi.org/10.1155/2012/591643.
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Li, Na, Baoyan Duan, and Fei Zheng. "Effect of the Random Error on the Radiation Characteristic of the Reflector Antenna Based on Two-Dimensional Fractal." International Journal of Antennas and Propagation 2012 (2012): 1–6. http://dx.doi.org/10.1155/2012/543462.
Full textAbstract:
Influence of the random error due to the distortion of the antenna reflector was discussed by using the two-dimensional fractal model. Firstly, a mathematical model of the random error was presented to investigate its impact on the radiation characteristic of the antenna, which was filtered from the two-dimensional fractal by using the wavelet analysis method. Based on the error model, a density formulation of the far field of the antenna with random error was deduced. Finally, a 3.7 m and a 3 m antennas were used to validate the proposed models, and a novel simulation method was put forward to remedy the deficiencies of existing software tools for the antenna with error. Results of the proposed methods showed a good agreement with the experimental data, and the existence of error broadened the beam width and raised the sidelobe level of the antenna, while it had little influence to the antenna gain. By comparison on results of the different scales error, the main influencing parameter of error was found out, which can provide the theoretical foundation for the control of the antenna surface working.
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Lampe, Bernhard, Klaus Holliger, and Alan G. Green. "A finite‐difference time‐domain simulation tool for ground‐penetrating radar antennas." GEOPHYSICS 68, no. 3 (May 2003): 971–87. http://dx.doi.org/10.1190/1.1581069.
Full textAbstract:
The generation and recording of electromagnetic waves by typical ground‐penetrating radar (GPR) systems are complex phenomena. To investigate the characteristics of typical GPR antennas operating in diverse environments, we have developed a versatile and efficient simulation tool. It is based on a finite‐difference time‐domain (FDTD) approximation of Maxwell's equations that lets one simulate the radiation characteristics of a wide variety of typical surface GPR antenna systems. The accuracy of the algorithm is benchmarked and validated with respect to laboratory measurements for comparable antenna systems. Computed radiation patterns demonstrate that the illumination of the subsurface in the near‐ to intermediate‐field range varies significantly according to how the antenna is designed. Our models show the effects of varying the shapes of the antennas, adding shielding (metal box with and without absorbing material and with and without resistive loading), adding a receiver antenna, and changing the soil conditions. Given the flexibility of this modeling software, we anticipate that it will be helpful in designing GPR surveys and new GPR systems with arbitrary planar structures. It will also be useful in interpreting certain GPR data sets.