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1
Revankar, U. K. "Three-Layer Electromagnetically Coupled Circular Microstrip Antennas." Thesis, Indian Institute of Science, 1995. http://hdl.handle.net/2005/241.
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Presented in this thesis are the following experimental and theoretical investigations carried out on the three-layer electromagnetically coupled (EMC) circular microstrip antennas and their arrays.
1.Three-Layer EMC Circular Microstrip Antenna
A three-layer EMC circular microstrip antenna consists of a probe-fed circular microstrip patch having two parasitically excited circular microstrip patches (without ground planes) stacked above it, with air gaps in between successive substrates. In the "inverted" configuration, the parasitic patches are on the lower (nearer to the driven substrate) surface of the substrate.
An exhaustive experimental study of the resonant frequencies, input impedance, impedance bandwidth and radiation characteristics of this antenna, has been carried out for both the "normal" and the "inverted" configurations. Based on this experimental study, the design and optimisation of the antenna have been discussed and experimentally tested. In the S-band, it is found that an impedance bandwidth as high as 20 percent coupled with good patterns, high gain and low cross-polarisation levels, have been obtained.
2.Three-Layer EMC Circular Microstrip Antenna Arrays
Experimental work has also been carried out on linear arrays of three-layer EMC circular microstrip antennas.
The design of a linear array both in the E- and H- planes, of the three-layer microstrip antennas in their "normal" as well as "inverted" configurations, has been discussed and realisation carried out. Impedance bandwidths of the arrays have been experimentally found to be the same as that of the three-layer antenna element High gain and good pattern shape with sidelobes as well as cross-polarisation levels better than -20 dB through a scan angle of 40°, have been realised.
A study of the mutual coupling between two-layer as well as three-layer EMC circular patch elements has also been carried out for the useful range of interelement spacings.
3.Theoretical Analysis of Resonant Frequencies of Multilayer Patch Structures
Theoretical investigations have been carried out on the resonance properties of single-layer and multilayer EMC patch structures employing the full-wave analysis based on spectral domain immittance approach. The impedance Green's functions for all these structures have been derived from the combination of equivalent transverse transmission lines concept Galerkin's method is employed in the spectral (Hankel) transform domain where two sets of disk current expansions are used for obtaining die characteristic equation. By solving the characteristic equation, the resonant frequencies are obtained for various values of the parameters of the layered antenna.
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Huysamen, Johan Herman. "Electrically small planar antenna for circular polarization /." Link to the online version, 2007. http://hdl.handle.net/10019/1047.
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Huysamen, Johan Herman. "Electrically small planar antenna for circular polarization." Thesis, Stellenbosch : Stellenbosch University, 2006. http://hdl.handle.net/10019.1/1572.
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Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2006.The design of an electrically small planar antenna for compact circular polarization is presented. After an in-depth study of the performance limitations on electrically small antennas and an investigation into the working of various existing electrically small antennas, the design, simulation and measurement of the proposed antenna element is presented in detail.
4
Edling, Thomas. "Design of circular polarized dual band patch antenna." Thesis, Uppsala universitet, Institutionen för teknikvetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-174672.
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At the moment Swedish Transport Administration uses a monitor system that candetect urgent errors as warm ball-bearings and flat wheels etc. with stationarydetectors. To avoid these errors Swedish Transport Administration, UPWIS AB andUppsala University work with a system that will continuously monitoring the train todetect the errors as fast as possible. This will save money in the future for SwedishTransport Administration and all other partners that use the rails.Swedish Transport Administration has already RFID readers beside the rail to detecttrains position. The new monitoring system will use these readers and send data fromthe monitoring system via these readers to a database.The aim of this thesis work is to design and build a RFID antenna to send data fromthe monitoring system to the RFID readers. The antenna should be a circularpolarized and it needs to manage the harsh environment on the train.This thesis work started with a theoretical study which investigated four commonantenna types (dipole, loop, PIFA and patch/microstrip) to evaluate which antennatype that is the best solution for this application. It was decided to design a patchantenna from the theoretical study since it fulfils all the requirements for the antenna.Simulations and tests shows that the antenna is circular polarized and have amaximum reading distance of 5 m for 868 MHz. For 2.45 GHz it is linear polarizedand has a reading distance of at least 10 m. With other hardware settings the antennawill have longer reading distance at 2.45 GHz.When all parts of the test bed was finished the test bed was mounted on themeasurement wagon. The final test shows that the antenna fulfils the task. Theantenna transmitted the data from the sensor boxes to the RFID readers.The report suggests future work to minimize the reading distance and size for theantenna. These are: transfer sensor data to RFID tag by “multi hop”, hardwareimprovement for instance antenna diversity and using another substrate (higherdielectric constant).
5
Lim, Eng G. "Circular polarised microstrip antenna design using segmental methods." Thesis, Northumbria University, 2002. http://nrl.northumbria.ac.uk/1330/.
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Research into the modelling and analysis of microstrip patch antenna have been reported in many studies. These include Transmission Line Modelling, Cavity Modelling, Coplanar Multiport Modelling and Full wave Modelling. Since the electromagnetic field elements are time harmonic, the phasor-form of the Maxwell field equations is used. In this thesis results are presented of the research that has been carried out into the segmental approach for the analysis of the microwave patch antennas. The segmental approach includes the "Segmentation" and the "Desegmentation" methods. In the segmentation method two distinct structural forms have been identified, cascade and shunt types. In the cascade type all consecutive segment elements share a common boundary, while for the shunt type, all appended segment elements have no common boundary. In the case of the shunt type structure a generalised input impedance matrix formula, for any number of appended segment elements, has been obtained. For the desegmentation method a generalised input impedance for any number of deleted segment elements, has been obtained. The above research studies have been applied in the design of a circular polarised two corner deleted square patch microstrip antenna with a single feed. For this structure the design involves both square and triangular patch geometries. The overall patch geometry for circular polarised is determined using perturbation analysis to determine the size of the deleted triangular segment elements. New computationally efficient impedance coupling expressions for the interconnecting port impedances on a rectangle, and, on a right angled isosceles triangle shaped antenna patch have been derived. In the determination of the input impedance of the overall antenna structure the coupling impedances constitute the elements of the individual segment coupling matrices. The matrices are used in a general multiport matrix circuit analysis to obtain the input impedance formula. It is established that, where applicable, the desegmentation method is computationally more efficient than the segmentation method. The new results obtained have been applied to the design of a corner deleted square patch antenna, and, the design procedure is fully described. The computer program implementation evaluates the perturbation quantity, and, the antenna input impedance. The structural properties of the coupling matrices, which are used for efficient computation, are described in detail. All the results from the above work show close agreement with full-wave software simulation and practical results. Significant research achievements: Both segmentation and desegmentation methods have been studied and it has been shown that the desegmentation approach, when applicable, is in general significantly more computationally efficient. In the segmentation method two structural forms, cascade and shunt have been identified. In the latter case a new generalised input impedance matrix formula has been obtained for any number of appended segment elements. A new generalised input impedance matrix formula has been obtained for any number of deleted segment elements in the desegmentation method. New computationally efficient expressions for the coupling impedances have been derived and used in test applications. New computationally efficient expressions for the offset input impedance of a linear polarised rectangular patch, and, an isosceles right-angled triangular patch have been derived and experimentally verified. A program implementing the design procedure for the corner-deleted truncated square patch circular polarised microstrip antenna has been constructed using MATHCAD programming.
6
Nelakonda, Nikitha. "Design of Robust Superdirective Receiving Antenna Array for Circular, Hexagonal and Elliptical Geometries." University of Akron / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=akron1460984746.
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Kirik, Mustafa Sancay. "Design, Analysis, And Implementation Of Circular Disk - Annular Ring (cdar) Antenna." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12609156/index.pdf.
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In satellite applications, a circularly polarized satellite antenna is desirable with a pattern that results in constant received power while the distance between the transmitter and the receiver is changing. The Circular Disk - Annular Ring (CDAR) antenna satisfies these requirements along with other requirements for the satellite antenna. The CDAR antenna is a combination of a Circular Disk and an Annular Ring patch antennas. In this thesis, a circularly polarized CDAR antenna that is fed from a single point is designed at the center frequency of 8.2 GHz. This antenna is investigated and optimized to ease the fabrication process. The design parameters are defined on this report and optimized by using an Electromagnetic Simulation software program. In order to verify the theoretical results, Circular Disk - Annular Ring Antenna is produced as a prototype. Measurements of antenna parameters, electromagnetic field and circuit properties are interpreted to show compliance with theoretical and simulation results. The values of deviation between theoretical and experimental results are also discussed.
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PARTHASARATHY, KRISHNAN V. "MUTUAL COUPLING IN PATCH ANTENNA ARRAYS." University of Cincinnati / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1148325728.
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Orr, Robert Mervyn. "Application of frequency selective surfaces in circular polarization antenna technologies." Thesis, Queen's University Belfast, 2014. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.675421.
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The objective of the work in this thesis is to design lightweight, low profile, circular polarization (CP) antenna technologies which have potential for use in satellite communication systems. A new class of CP Fabry-Perot (FP) cavity antenna which may be used as a replacement for bulky CP horn antennas is developed. A double-sided partially reflective surface (PRS) is employed in the design. The resulting class of antennas are appealing as they allow a specified gain in CP to be achieved while maintaining the simplicity of a single cavity structure and a linearly polarized (LP) primary feed. An example demonstrator antenna with a gain of approximately 21 dB at 15 GHz is designed using the full-wave electromagnetic simulation tool, CST Microwave Studio (MWS). A prototype is produced and measured in order to validate the simulation results. Frequency selective surfaces (FSS) are employed as quasi-optical diplexers in satellite communication systems to facilitate multiband reflector antenna operation therefore allowing multiple feed antennas to share the same aperture. In this thesis quasi-optical diplexers suitable for CP dual frequency band operation are considered. A new class of polarizing surface is developed which in a given frequency band reflects incident linearly polarized waves with circular polarization (CP) while at other frequencies it is transparent allowing incident waves to be transmitted. In addition, a new type of CP FSS which conserves a CP signal upon reflection and transmission is designed. The axial ratio in the reflection and transmission bands is reported for both structures. Numerical EM simulation supported as necessary with analytical analysis is used throughout.
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Hussain, Asif Jamshaid. "Design of an Ultra Wideband (UWB) Circular Disc Monopole Antenna." Thesis, Linnéuniversitetet, Institutionen för datavetenskap, fysik och matematik, DFM, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-34605.
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My task was to design a circular disc monopole antenna in the Ultrawideband range i.e. 3.1 - 10.6 GHz using the ADS (Advanced Design System) package. In order to achieve the desired matching I simulated dierent sizes of the radiator, feed line and the ground plane of the antenna and observed the current flow in a circular monopole at different frequencies. I did some miniaturization (circular shape and chopping) of the antenna and observed the current flow and radiation pattern in 2D and 3D.
11
Lardies, Joseph. "Etude d'antennes acoustiques a directivite constante sur une large bande." Toulouse 3, 1987. http://www.theses.fr/1987TOU30214.
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Cette etude porte sur la conception et la realisation d'antennes acoustiques a largeur de faisceau constante sur une large bande. On examine deux techniques, dont l'une est basee sur un reseau d'antennes maintenant la largeur du lobe principal constant sur plusieurs octaves, tandis que l'autre methode permet de maintenir la largeur du faisceau d'une antenne constante sur plusieurs octaves. Etude de l'estimation de la direction et de la puissance de signaux acoustiques en vue d'applications possibles
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Ng, Stewart Siew Loon. "Smart antenna in DS-CDMA mobile communication system using circular array /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Mar%5FNg.pdf.
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Seow, Tian Beng. "Circular antenna array applications in coded DS-CDMA mobile communication systems /." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2003. http://library.nps.navy.mil/uhtbin/hyperion-image/03Mar%5FSeow.pdf.
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Zhu, Danny. "Source localization within a uniform circular sensor array /." Online version of thesis, 2007. http://hdl.handle.net/1850/4628.
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Magnusson, Patrick. "Antenna for GNSS Reception in GEO-Orbit." Thesis, KTH, Rymd- och plasmafysik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149283.
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There are a number of global navigation satellite systems (GNSS), in use or planed, which are used for navigation on earth but also for autonomous navigation of satellites in low earth orbit (LEO). It would be desirable to also have autonomous navigation in geosynchronous earth orbit (GEO) to reduce costs and make it possible to get higher accuracy on the position of the satellite. One part of the navigation system is the GNSS antenna which is examined in this master thesis. The specifications of the antenna were first decided and then three antenna alternatives were investigated in greater detail: a monofilar helix antenna, a three element circular array antenna and a twelve element circular array antenna. The result was that they would all work as a GNSS antenna in GEO but none could be judged to be the best under all circumstances. The size requirement for the mission and the used GNSS receiver would primarily decide which fits the mission best.Det finns ett antal världstäckande navigeringssystem (GNSS), i användning och planerade, som används för navigation på jorden fast också för autonom navigation för satelliter i låg bana runt jorden. Det skulle också vara önskvärt att använda autonom navigation för satelliter i geostationär omloppsbana (GEO) för att reducera kostnaden och få högre positions noggrannhet. En del av navigationssystemet är GNSS antennen vilken är undersökt i detta examensarbete. Specifikationerna för antennen bestämdes först och sedan undersöktes tre olika antennalternativ i detalj: en monofilär helixantenn, en tre elements cirkulär gruppantenn och en tolv elements cirkulär gruppantenn. Resultatet var att alla alternativen skulle fungera som en GNSS antenn i GEO-bana fast inget av alternativen är bäst i alla förhållanden. Storlekskraven för uppdraget och vilken GNSS mottagare som skall användas påverkar vilket av alternativen som passar uppdraget bäst.
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Pesik, Lisa Josephine. "Practical investigation of Butler matrix application for beamforming with circular antenna arrays." Thesis, University of Bristol, 2007. http://hdl.handle.net/1983/650cf9d2-e075-4efb-b03d-6b5fa0b5dd67.
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Ammula, Veneela Rao S. M. "Design and implementation of a dual excited planar circular array antenna for base stations." Auburn, Ala., 2009. http://hdl.handle.net/10415/1933.
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Garcia, Gamez Laura. "Analysis and design of compact antennas in cavity based on metasurfaces for multiband GNSS applications." Thesis, Rennes 1, 2020. http://www.theses.fr/2020REN1S014.
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Les systèmes de navigation par satellites globaux (GNSS) sont aujourd'hui largement utilisés pour pléthore d'applications civiles ou pour la défense, incluant la navigation de plateformes volantes ou roulantes. Galileo, GPS ou Glonass sont trois des constellations GNSS considérées dans cette thèse. L'objectif de ce travail est de développer des antennes compactes capables de couvrir plusieurs bandes GNSS ; trois autour de 1575 MHz dans un premier temps (L1, G1, E1), puis la totalité de la bande GNSS ([1164-1610] MHz). Ces antennes sont destinées à être intégrées dans des projectiles, constitués principalement de métal. Pour cette raison, l'antenne doit être intégrée dans une cavité métallique pour ne pas affecter les propriétés aérodynamiques ni la stabilité mécanique du porteur. Intégrer des antennes imprimées dans des cavités métalliques offre plusieurs avantages : la miniaturisation, l'isolation ou la réduction des ondes de surface. Néanmoins, cela amène également une réduction importante de la bande passante. La solution immédiate pour limiter cet effet est d'agrandir la dimension de la cavité. Cependant, cette approche ne peut pas être appliquée aux nombreux cas où le porteur impose des limitations d'encombrement. Au vu des spécifications ci-dessus, l'emploi d'une antenne imprimée basée de métasurfaces est proposé et étudié, d'autant plus que des résultats antérieurs ont montré que des structures d'antennes classiques ne peuvent répondre aux spécifications demandées. Les objectifs de cette thèse sont de concevoir et de caractériser des antennes à polarisation linéaire et à polarisation circulaire couvrant plusieurs bandes GNSS. La polarisation linéaire est considérée pour les premières études, car ces antennes ne sont pas destinées à être utilisées dans un environnement souffrant de trajets multiples. La polarisation circulaire est considérée dans un second temps. Finalement, l'extension de la bande passante à la globalité de la bande GNSS est considéréeGlobal Navigation Satellite Systems (GNSS) are widely used today for a plethora of civil and defense applications, including navigation of flying or moving platforms. Galileo, GPS or Glonass are three of the GNSS constellations considered in this thesis. The aim of this work is to develop a compact antenna, which is able to cover multiple GNSS bands: three around 1578 MHz (L1, G1, E1) in a first time and the whole band ([1164-1610] MHz) in a second time. These antennas are intended to be integrated into projectiles mainly constituted of metal. For this reason, the antenna must be embedded in a metallic cavity to not affect the carrier aerodynamic properties and nor its mechanical stability. Integrating microstrip antennas in metallic cavities offers several advantages, like miniaturization, isolation or surface wave reduction; however, this leads to a drastic reduction of the antenna bandwidth. The most straightforward solution to circumvent this limitation consist in enlarging the metal cavity size. Nonetheless, this approach cannot be applied in many cases when the carrier imposes stringent dimensional limitations. Owing to the above-mentioned specifications, the use of a metasurface-inspired microstrip antenna is proposed and investigated, since previous results have demonstrated that classical antenna structures do not comply with the requirements. The objectives of the thesis are to design and characterize linearly-polarized and circularly-polarized antennas covering multiple bands of GNSS. Linear polarization is considered for the first studies, as these antennas are not intended to be used in an environment with multi-path signals. Circular polarization is addressed in a second time. Finally, the extension of the bandwidth to the whole GNSS bands is considered
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Hinostroza, Israel. "Design of wideband arrays of spiral antennas." Phd thesis, Supélec, 2013. http://tel.archives-ouvertes.fr/tel-00830469.
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This work focuses on the design of wideband dual polarized arrays using spiral antennas. These antennas are known for having wideband properties. But, due to the presence of the grating lobes, the bandwidth is decreased when using an array instead of a single antenna. In order to obtain a dual polarized array, it is needed to use elements of opposite polarization, which creates great distances between same polarization elements, meaning an earlier presence of the grating lobes. In this work, an analytic method was developed to estimate the bandwidth of the spiral arrays. This method showed that the maximum bandwidth of uniform spiral arrays is about an octave, for the mono-polarized case, and nonexistent for the dual polarized case. Working on the validation of the method, some resonances were observed. Explanations are presented, as well as possible solutions. Trying to expand the bandwidth of the array, it was found that it is possible and suitable to use at the same time the two current design paradigms for wideband arrays. Using this idea, a 6:1 bandwidth concentric rings array using connected spirals was achieved. Perspectives are also presented.
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Peng, HongLi, Zheng Huang, and WenBin Han. "FE-BI METHOD FOR ANALYZING P-BAND CYLINDRICAL CONFORMAL MICROSTRIP ANTENNA AND ARRAY." International Foundation for Telemetering, 1997. http://hdl.handle.net/10150/607547.
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International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, NevadaAn edge-based hybrid finite element boundary integral (FE-BI) method using cylindrical shell elements is described for analyzing conformal quarter-wave patches embedded in a circular cylinder. Special care is also taken to deal with weight functions, dyadic Green’s function, and feed model. Some types of the patch arrays embedded in different circular radius have been developed. The tests of their VSWRs and radiation characteristics are in good agreement with the theoretical results.
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Khattak, Muhammad Kamran, Osama Siddique, and Waqar Ahmed. "Design and Simulation of Microstrip Phase Array Antenna using ADS." Thesis, Linnéuniversitetet, Institutionen för datavetenskap, fysik och matematik, DFM, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-11715.
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The aim of this project is to design a microstrip phase array antenna in ADS (Advance Design System) Momentum. The resonant frequency of which is 10 GHz. Two circular patches with a radius of 5.83 mm each are used in designing the array antenna. RT-DURROID 5880 is used as a substrate for this microstrip patch array design. These circular patches are excited using coaxial probe feed and transmission lines of particular lengths and widths. These transmission lines perfectly match the impedance of the circular patches. Various parameters, for example the S-parameters, two dimensional and three dimensional radiation patterns, excitation models, gain, directivity and efficiency of the designed antenna are obtained from ADS Momentum.
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Han, Chul Min. "Dual-band reflectarrays using microstrip ring elements and their applications with various feeding arrangements." Texas A&M University, 2006. http://hdl.handle.net/1969.1/4416.
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In recent years there has been a growing demand for reduced mass, small launch
volume, and, at the same time, high-gain large-aperture antenna systems in modern
space-borne applications. This dissertation introduces new techniques for dual-band
reflectarray antennas to meet these requirements. A series of developments is presented
to show the dual-band capability of the reflectarray.
A novel microstrip ring structure has been developed to achieve circular
polarization (CP). A C/Ka dual-band front-fed reflectarray antenna has been designed to
demonstrate the dual-band circular polarized operation. The proposed ring structure
provides many advantages of compact size, more freedom in the selection of element
spacing, less blockage between circuit layers, and broader CP bandwidth as compared to
the patches.
An X/Ka dual-band offset-fed reflectarray is made of thin membranes, with their
thickness equal to 0.0508 mm in both layers. Several degrading effects of thin substrates
are discussed. To overcome these problems, a new configuration is developed by
inserting empty spaces of the proper thickness below both the X and Ka band
membranes. More than 50 % efficiencies are achieved at both frequency ranges, and the proposed scheme is expected to be a good candidate to meet the demand for future
inflatable antenna systems.
An X/Ka dual-band microstrip reflectarray with circular polarization has also been
constructed using thin membranes and a Cassegrain offset-fed configuration. It is
believed that this is the first Cassegrain reflectarray ever developed. This antenna has a
0.75-meter-diameter aperture and uses a metallic sub-reflector and angular-rotated
annular ring elements. It achieved a measured 3 dB gain bandwidth of 700 MHz at Xband
and 1.5 GHz at Ka-band, as well as a CP bandwidth (3 dB axial ratio) of more than
700 MHz at X-band and more than 2 GHz at Ka-band. The measured peak efficiencies
are 49.8 % at X-band and 48. 2 % at Ka-band.
In summary, this dissertation presents a series of new research developments to
support the dual-band operation of the reflectarray antenna. The results of this work are
currently being implemented onto a 3-meter reflectarray with inflatable structures at the
Jet Propulsion Laboratory and are planned for other applications such as an 8-meter
inflatable reflectarray in the near future.
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Wei, Wenlong. "Contribution à l'étude et la conception d'antennes pour la génération d'ondes radiofréquences transportant du moment angulaire orbital." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S048/document.
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Il est bien connu dans la théorie de Maxwell que le rayonnement électromagnétique (EM) d'une onde porte à la fois du moment linéaire (énergie) et du moment angulaire. Ce dernier possède deux parties: le Moment Angulaire de Spin (ou SAM) qui est également connu sous le nom de la polarisation et le Moment Angulaire Orbital (ou OAM). Le SAM ne comprend que deux états (gauche et droite) et est utilisé en télécommunications pour doubler la capacité du canal. Par contre, le moment angulaire orbital (OAM) peut en théorie, avoir un nombre infini d'états appelés les modes OAM. Par conséquent, en radiofréquences, les premières applications de l'OAM ont été proposées dans le domaine des communications sans fil. Mais, tout d'abord, il est nécessaire de développer des antennes générant de telles ondes. L'objectif de cette thèse est de concevoir des antennes pour générer des ondes ayant un OAM. Le manuscrit se décompose en trois parties. Dans la première partie, un réseau d'antennes « patches » utilisant un déphaseur original est développé et testé. Ce réseau génère une onde ayant de l'OAM. Dans la deuxième partie, une cavité Fabry-Perot (FP) est utilisée pour apporter plus de directivité à ce réseau d'antennes. Enfin, la troisième partie consiste à générer des ondes guidées possédant du moment OAM. Ces ondes ont ensuite été utilisées pour exciter des antennes en cornet et rayonner des faisceaux directifs transportant du moment angulaire orbitalIt is well known from Maxwell’s theory that electromagnetic (EM) radiation carries both linear momentum (energy) and angular momentum. The latter has two parts: Spin Angular Momentum (SAM) which corresponds to the polarization of an EM wave and Orbital Angular Momentum (OAM) which is associated with the spatial distribution of an EM wave. The SAM has only two states (left and right) and is used to double the channel capacity in telecommunications. On the other hand, the OAM can theoretically have an infinite number of states called the OAM modes. Therefore, the first applications of OAM have been proposed in wireless communications at radio frequencies. However, first of all, it is necessary to develop the antennas for generating such waves. The objective of this thesis is to design the antennas for the generation of radio waves bearing OAM. The manuscript contains three parts. In the first part, an antenna using 4 patches and an original phase shifter is developed and tested to generate an OAM wave. In the second part, a Fabry-Perot (FP) cavity is used to enhance the directivity of this antenna. The third part is to generate guided OAM waves. Some horn antennas are used to radiate these waves with good directivity
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Tastan, Mehmet. "Analysis And Design Of A Circularly Polarized Microstrip Antenna." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12607868/index.pdf.
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In this study we tried to design a microstrip antenna, to get a suitable radiation pattern for a LEO satellite. Our aim is to get a radiation pattern that has a maximum power which is not in the broadside direction to the antenna surfaceinstead broadside radiation has a relatively lower power density. Maximum power radiation is desired to be at about 30 &ndash
50 degrees angle beyond the normal to the antenna surface. We desire circularly polarized radiation. We used two concentric antennas
one is a circular patch at the center and the other is an annular ring which is used at the outer region. By using Ansoft Ensemble 8.0 software, we design an antenna which has a resonance frequency at 8.2 GHz. Using the result of the program we design the real antenna. The measurement results are compared with the simulation results.
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Paryani, Rajesh. "DESIGN OF A WIDEBAND DUAL-POLARIZED CAVITY BACKED SLOT ANTENNA." Doctoral diss., University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2832.
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A new technique for designing wideband dual-polarized cavity-backed slot antennas is presented. The structure is in the form of a double-resonant, dual-polarized slot antenna backed by a shallow substrate integrated cavity with a depth of approximately one tenth the free space wavelength. The presence of the cavity behind the slot enhances the antenna s directivity and reduces the possibility of surface wave propagation in the antenna substrate when the element is used in an array environment. Moreover, the dual-polarized nature of this radiating element may be exploited to synthesize any desired polarization (vertical, horizontal, RHCP, or LHCP). The double-resonant behavior observed in this substrate-integrated cavity-backed slot antenna (SICBSA) is utilized to enhance its bandwidth compared to a typical cavity-backed slot antenna. A prototype of the proposed antenna is fabricated and tested. Measurement results indicate that a bandwidth of 19%, an average gain of 5.3 dB, and a wideband differential isolation of 30 dB can be achieved using this technique. The principles of operation along with the measurement results of the fabricated prototype are presented and discussed in this dissertation. The SICBSA is investigated as a candidate for use as an array element. A uniform two element phased array is demonstrated to locate the main beam from boresight to thirty degrees. The potential effects of mutual coupling and surface wave propagation are considered and analyzed.Ph.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering PhD
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Urbaník, Jaroslav. "Bikónická dipólová anténa s kruhovou polarizací." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219968.
Full textAbstract:
Tato diplomová práce se zabývá teoretickými poznatky a návrhem bikónické antény pracující v kmitočtovém rozsahu 4 až 8 GHz. V rámci práce jsou také popsány způsoby impedančního přizpůsobení a vybrané typy polarizátorů elektromagnetických vln a radioprůzračných krytů. Na základě teoretických poznatků je určena koncepce návrhu bikónické antény a vybrán vhodný polarizátor pro zajištění kruhové polarizace vyzařovaných elektromagnetických vln.
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Schopis, Joel L. "Single-Element GNSS Patch Antenna Pattern Control." Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1438285370.
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Farooqui, Muhammad Fahad. "Compact circularly polarized slot-ring antenna and microstrip bandpass filter using triangular open-loop resonators." Texas A&M University, 2006. http://hdl.handle.net/1969.1/4969.
Full textAbstract:
In this thesis two different research topics are undertaken, both in the area of compact
RF/microwave circuits design. The first topic involves the design of a compact circularly
polarized (CP) slot-ring antenna. A study of several compact CP microstrip and slotline
antennas reported in the past has been carried out. In this research, a method of reducing
the size of a printed slot-ring antenna is proposed. The reduction in size is achieved by
introducing meandered-slot sections in the ring. Circular polarization is achieved by
introducing an asymmetry, also a meandered-slot section, and feeding the antenna at an
angle of 45o from the asymmetry using a microstrip feed line. The minimum axial ratio
of 0.4 dB is obtained at 2.46 GHz, which is the operating frequency of the antenna. The
size of the proposed antenna is reduced by about 50% compared to a conventional CP
slot-ring antenna and it displays a CP bandwidth of about 2.5%. The simulated and
measured results are presented, and they are in good agreement. The small size of the
antenna makes it very suitable for use in modern RF/microwave wireless systems which
require compact, low cost, and high performance circuits. Moreover, its CP behavior
makes it more attractive for applications such as satellite communications. The second topic in the thesis involves the design of a compact microstrip bandpass
filter using triangular open-loop resonators. A new compact three-pole microstrip
bandpass filter using four triangular open-loop resonators is presented. A fourth
resonator is placed to provide cross-coupling in the structure which gives a better skirt
rejection. The measured pass-band center frequency is 2.85 GHz. The filter demonstrates
about 7% bandwidth with insertion loss of less than 1 dB in the passband, a return loss
of greater than 15 dB and out-of-band rejection of greater than 30 dB. The simulated
and measured results are in good agreement. The proposed filter is very attractive for use
in modern wireless systems which require bandpass filters having compact size, low
insertion loss, high selectivity, and good out-of-band rejection.
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Balcells, Ventura Jordi. "Radiation pattern reconfigurable microfabricated planar millimeter-wave antennas." Doctoral thesis, Universitat Politècnica de Catalunya, 2011. http://hdl.handle.net/10803/32032.
Full textAbstract:
Els serveis de telecomunicacions i sistemes radar estan migrant a freqüències mil•limètriques (MMW), on es disposa d 'una major amplada de banda i conseqüentment d'una major velocitat de transmissió de dades. Aquesta migració requereix de l'ús de diferents tecnologies amb capacitat d'operar a la banda de freqüències mil•limètriques (30 a 300 Ghz), i més concretament en les bandes Ka (26,5 - 40GHz), V (50 – 75GHz) i W (75 – 110GHz). En moltes aplicacions i sobretot en aquelles on l'antena forma part d'un dispositiu mòbil, es cerca poder utilitzar antenes planes, caracteritzades per tenir unes dimensions reduïdes i un baix cost de fabricació. El conjunt de requeriments es pot resumir en obtenir una antena amb capacitat de reconfigurabilitat i amb un baix nivell de pèrdues en cada una de les bandes de freqüència. Per tal d'afrontar aquests reptes, les dimensions de les antenes mil•limètriques, juntament amb els tipus de materials, toleràncies de fabricació i la capacitat de reconfigurabilitat ens porten a l'ús de processos de microfabricació.
L'objectiu d'aquesta tesis doctoral és l'anàlisi dels conceptes mencionats, tipus de materials, geometries de línia de transmissió i interruptors, en el context de les freqüències mil•limètriques, així com la seva aplicació final en dissenys d'antenes compatibles amb els processos de microfabricació. Finalment, com a demostració s'han presentat dissenys específics utilitzables en tres aplicacions a freqüències mil•limètriques: Sistemes de Comunicació per Satèl•lit (SCS) a la banda Ka, Xarxes d'àrea personal inalàmbriques (WPAN) a la banda V i sistemes radar per l'automoció a la banda W.
La primera part d'aquesta tesis consisteix en l'anàlisi d'algunes tecnologies circuitals a freqüències mil•limètriques. S'han presentat els materials més utilitzats a altes freqüències (Polytetrafluoroethylene or Teflon (PTFE), Quartz, Benzocyclobuten polymer (BCB) i Low Temperature Co-fired Ceramic (LTCC)) i s'han comparat en termes de permitivitat i tangent de pèrdues. També s'inclou un estudi de pèrdues a altes freqüències en les principals línies de transmissió (microstrip, stripline i CPW). Finalment, es presenta un resum dels interruptors RF-MEMS i es comparen amb els PIN diodes i els FET.
En la segona part, es presenten diferents agrupacions d'antenes amb la capacitat de reconfigurar la polarització i la direcció d'apuntament. S'han dissenyat dos elements base reconfigurables en polarització: CPW Patch antena i 4-Qdime antena. La primera antena consisteix en un element singular amb interruptors RF-MEMS, dissenyada per operar a les bandes Ka i V. La segona antena consisteix en una arquitectura composta on la reconfigurabilitat en polarització s'obté mitjançant variant la fase d'alimentació de cada un dels quatre elements lineals. La fase és controlada mitjançant interruptors RF-MEMS ubicats en la xarxa de distribució. L'antena 4-Qdime s'ha dissenyat per operar en les bandes V i W. Ambdós elements base s'han utilitzat posteriorment pel disseny de dues agrupacions d'antenes amb capacitat de reconfigurar l'apuntament del feix principal. La reconfigurabilitat es dur a terme utilitzant desfasadors de fase d'1 bit.
La part final de la tesis es centra en les toleràncies de fabricació i en els processo de microfabricació d'agrupacions d'antenes mil•limètriques. Les toleràncies de fabricació s'han estudiat en funció dels error d'amplitud i fase en cada element de l'agrupació, fixant-se en les pèrdues de guany, error d'apuntament, error en l'amplada de feix, errors en el nivell de lòbul secundari i en l'error en la relació axial. El procés de microfabricació de les diferents antenes dissenyades es presenta en detall. Els dissenys de l'antena CPW Patch reconfigurable en polarització i apuntament operant a les bandes Ka i V, s'han fabricat en la sala blanca del Cornell NanoScale Science & Technology Facility (CNF). Posteriorment, s'han caracteritzat l'aïllament i el temps de resposta dels interruptors RF-MEMS, i finalment, el coeficient de reflexió, el diagrama de radiació i la relació axial s'han mesurat a les bandes Ka i V per les antenes configurades en polarització lineal (LP) i circular (CP).Telecommunication services and radar systems are migrating to Millimeter-wave (MMW) frequencies, where wider bandwidths are available. Such migration requires the use of different technologies with the capability to operate at the MMW frequency band (30 to 300GHz), and more specifically at Ka- (26.5 to 40GHz), V- (50 to 75GHz) and W-band (75 to 110GHz). For many applications and more concretely those where the antenna is part of a mobile device, it is targeted the use of planar antennas for their low profile and low fabrication cost. A wide variety of requirements is translated into a reconfiguration capability and low losses within each application frequency bandwidth. To deal with the mentioned challenges, the MMW antenna dimensions, together with the materials, fabrication tolerances and reconfigurability capability lead to microfabrication processes. The aim of this thesis is the analysis of the mentioned concepts, materials, transmission lines geometries and switches in the MMW frequencies context and their final application in antenna designs compatible with microfabrication. Finally, specific designs are presented as a demonstration for three MMW applications: Satellite Communication Systems (SCS) at Ka-band, Wireless Personal Area Network (WPAN) at V-band and Automotive Radar at W-band. The first part of this thesis consist to analyze some MMW circuit technologies. The four most used materials at MMW frequencies (Polytetrafluoroethylene or Teflon (PTFE), Quartz, Benzocyclobuten polymer (BCB) and Low Temperature Co-fired Ceramic (LTCC)) have been presented and compared in terms of permittivity (εr) and loss tangent (tanδ). An study of the main transmission lines attenuation (microstrip, stripline and CPW) at high frequencies is included. Finally, an overview of the RF-MEMS switches is presented in comparison with PIN diodes and FETS switches. The second part presents different polarization and beam pointing reconfigurable array antennas. Two polarization-reconfigurable base-elements have been designed: CPW Patch antenna and 4-Qdime antenna. The first consists of a single reconfigurable element with integrated RF-MEMS switches, designed to operate at Ka- and V-band. The second antenna presented in this thesis has a composed architecture where the polarization reconfigurability is obtained by switching the phase feeding for each of the four linear polarized elements in the feed network with RF-MEMS switches. The 4-Qdime antenna has been designed to operate at V- and W-band. The two base-elements have been used to design two beam pointing reconfigurable antenna arrays. Using phased array techniques, beamsteering is computed and implemented with 1-bit discrete phase-shifter. The final part of the thesis is focused into the fabrication tolerances and microfabrication process of Millimeter-wave antenna arrays. The fabrication tolerances have been studied as a function of the amplitude and phase errors presented at each elements array, focusing on the gain loss, beam pointing error, Half-Power Beamwidth (HPBW) error, sidelobe level error and axial ratio error. The microfabrication process for the designed antennas is presented in detail. Polarization- and pointing- reconfigurable CPW Patch antenna operating at Ka- and V- band have been fabricated in a clean-room facility at Cornell NanoScale Science & Technology Facility (CNF). The RF-MEMS switches isolation and time response have been characterized. Finally, the reflection coefficient, radiation pattern and axial ratio have been measured at Ka- and V-band for the fabricated antennas configured in Linear Polarization (LP) and Circular Polarization (CP).
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Yang, Zhijun. "Numerical Study on the Characteristics of Metal Insulator Metal Diode Integrated with Spiral Optical Antenna." University of Dayton / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1386242290.
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Addepalli, T., A. Desai, Issa T. Elfergani, N. Anveshkumar, J. Kulkarni, C. Zebiri, J. Rodriguez, and Raed A. Abd-Alhameed. "8-Port Semi-Circular Arc MIMO Antenna with an Inverted L-Strip Loaded Connected Ground for UWB Applications." MDPI, 2021. http://hdl.handle.net/10454/18536.
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yesMultiple-input multiple-output (MIMO) antennas with four and eight elements having connected grounds are designed for ultra-wideband applications. Careful optimization of the lines connecting the grounds leads to reduced mutual coupling amongst the radiating patches. The proposed antenna has a modified substrate geometry and comprises a circular arc-shaped conductive element on the top with the modified ground plane geometry. Polarization diversity and isolation are achieved by replicating the elements orthogonally forming a plus shape antenna structure. The modified ground plane consists of an inverted L strip and semi ellipse slot over the partial ground that helps the antenna in achieving effective wide bandwidth spanning from (117.91%) 2.84–11 GHz. Both 4/8-port antenna achieves a size of 0.61 λ × 0.61 λ mm2 (lowest frequency) where 4-port antenna is printed on FR4 substrate. The 4-port UWB MIMO antenna attains wide impedance bandwidth, Omni-directional pattern, isolation >15 dB, ECC 4.5 dB making the MIMO antenna suitable for portable UWB applications. Four element antenna structure is further extended to 8-element configuration with the connected ground where the decent value of IBW, isolation, and ECC is achieved.
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蔡文益. "Broadband Fractal Circular-Monopole Antenna." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/ejrb2e.
Full textAbstract:
碩士景文科技大學
電腦與通訊研究所
99
In this paper, a novel broadband Fractal circular-monopole antenna is presented. This antenna consists of printed circular iteration with two iterating level and ground-plane with radius 25mm, making it easy to making it easy to combine directional, high gain and wide bandwidth. A prototype is designed to operate at 1.5GHz-5.86GHz, the measured 10 dB bandwidth is nearly 1:2 at the center frequency of 3.775GHz. Experimental results are shown to verify the validity of theoretical work. Fractal monopole antenna is formed with hollow of circle, which featuring of minification, multi-frequency bands and wide bands. The planar fractal monopole antenna is based on the Sierpinski carpet concept and to modified, the Sierpinski fractal has generated two iterations, use the decomposition algorithm by circular, and compare these with integrators and initiator type. Firstly, base on generally circular disc to generate hollow of circular, this initiator has a circumference of and 1mm trace width. In the decomposition algorithm, a geometric ratio of circle is taken and joining the midpoints of union of the circles central, reduce the circle to 1/3 diameter and canonical Sierpinski carpet algorithm to fill the circle with twice mathematics equals 1/9 diameter by 2nd iteration.The geometrical structure and dimensions of the proposed monopole type antenna is printed on FR4 substrate and is simulated by using FEM based electromagnetic simulator, Ansoft HFSS. All of them describe a multiband behavior of fractal antenna. This behavior is consistent from the input return loss and gain; moreover radiation patterns planes of view. The same scale factor existing among similar structures in the fractal circular-shape. It can be summarized that the self-similarity properties of the fractal structure are translated into its electromagnetic behavior. The current density distributions have a similar and vary in complicated among bands as well. Such distributions allows flexibility in matching multi- and width band operations in which a larger frequency required, such as FemtoCell and UMTS base station application including LTE, UMTS, GPS L1, WIFI, and WiMax. The circular monopole type is based on fractal structure and refers to the Sierpinski gasket self-similarity algorithm, a prototype of the design is successfully implemented with close agreement between measurement and simulation. The fractal geometry and overall size can be effectively utilized ID or Logo surface for integrating with other components in IT products.
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wang, ping yu, and 王平宇. "STUDY OF CIRCULAR POLARIZATION ANTENNA." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/84615043627801543964.
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碩士中華技術學院
飛機系統工程研究所
97
ABSTRACT In This Paper Represents Two Different Style Antenna ，One Is Conical Spiral frequency range From 1,035 GHZ To 1.855 GHZ Occupied 56.74% Of Impedance Bandwidth ，Gain Still Remained 11.5dbi，The Other Novel PIFA Its frequency Bandwidth is 1.45 GHZ To 1.79 GHZ Almost 21% Of Impedance Bandwidth and gain catch 13 dBi，.All Of Them Owned Excellent Performance As High Gain Especially Among Broad Band，Their frequency Bandwidth Overcoming 20% should name UWB (Ultra Wide Band) Antenna.。 Such Light Weight、Minimized Size Antenna are Easy To Carry、Install And Replace Dish Reflector (Mesh Or Solid ) Antenna which Used Before， Technical Developments And Advantage Function Will Help Connectivity Under All Kind Of Severe Weather & Environment Condition, Key Word： PIFA Antenna、Impedance Bandwidth、Circular Polarization 、Conical Spiral Etc.
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Chen, Cheng-chi, and 陳正棋. "Design of Circular Polarization Slot Antenna." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/85705245705752325225.
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碩士逢甲大學
電機工程所
95
A novel design of a coplanar waveguide-fed circularly polarized printed annular ring slot antenna is proposed. Circular polarization (CP) radiation of the proposed design is achieved by introducing proper asymmetry structure in the annular ring slot. The asymmetry structure introduced in the proposed design is a G-typed stub section and the proposed CP design can be applied to printed annular ring slot antenna. Experimental results show that good CP radiation performances are obtained and the 3-dB axial-ratio CP bandwidth obtained for the annular ring slot antenna is about 9.2%. By properly choosing the location and the size of the tuning stub, a wide impedance bandwidth of 73% can be obtained, which is about 2.1 times that of a conventional coplanar waveguide-fed annular ring slot antenna with a simple tuning stub. Then, a new type of metallic electromagnetic structure has been developed that is characterized by having frequency selective surface (FSS). Unlike normal conductors, this new surface that its image currents are not phase reversed. We vary several important parameters, such as the distance between the frequency selective surface superstrate and the ground plane of the slot antenna, and the dimensions of the frequency selective surface superstrate, to determine their effect on the resonant frequency and their gain, directivity and radiation pattern. The above study enables to derive some design guidelines for an optimum array size of the frequency selective surface superstrate that eventually leads to a maximum gain for the frequency selective surface antenna composite. It’s demonstrated that gain of antenna with an optimized array size of the frequency selective surface superstrate increases about 2~3 dBi, as compared to that of the slot antenna alone.
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WANG, JIAN-CHENG, and 王健丞. "CPW Monopole Antenna Application Circular Polorization." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/26wa3a.
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碩士大葉大學
電機工程學系
104
This paper presents to the CPW fed monopole antenna can be use in global positioning system(GPS)and 4G(LTE).This antenna thourgh suitable cutting one side of a metal ground plane, so that the original monopole resonance disappears, forming a dipole resonance, and output and has two orthogonal linearly polarization 90° to achieve circular polarization. On the other side of the metal ground plane, with inverted L-shaped metal patch antenna bandwidth is increased so that the coating on the 4G(LTE)band.In addition, the antenna design can be simple,low -cost production, and easy to combine with the microwave components.
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Han, Yueh-Lin, and 韓岳霖. "DUAL-BAND CIRCULAR POLARIZATION SLOT ANTENNA." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/75205485952677252938.
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碩士大同大學
通訊工程研究所
98
A combination of a C-shaped and an L-shaped slot antenna excited by a microstripline is presented in this thesis. The C-shaped slot is modified from a square slot ring by replacing one segment of the slot ring with a metal. It is studied by embedding one L-shaped slot inside the C-shaped slot, a dual-band circularly polarized antenna can be formed. The main controlling parameter is the width of the L-shaped slot. After tuning, we can get 5.7% axial ratio bandwidth and 6.1% axial ratio bandwidth respectively in 1.575GHz and 2.45GHz band
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Liang, Yi-chung, and 梁議中. "Ultra-broadband CPW-fed circular monopole antenna." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/67601833182890315268.
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碩士國立中央大學
電機工程研究所
95
A ultra-broadband, planar, circular monopole antenna (PCMA) fed by coplanar waveguide (CPW) structures is demonstrated. The CPW configuration permits easy integration with the uniplanar monolithic integrated circuits/monolithic microwave integrated circuits. Two modifications on the CPW ground plane are applied to improve the impedance bandwidth and radiation characteristics of the CPW-fed PCMA. First, the edges around the circular monopole are tapered to drastically increase the impedance bandwidth. Plus, the antenna gain is increased at the lower frequencies of the band. Second, the tapered edges are corrugated with rectangular gratings to significantly improve the radiation patterns, particularly at the frequencies around the higher band edge. The demonstrated CPW-fed PCMA features an over 151% VSWR=2 fractional bandwidth and satisfactory radiation characteristics over the whole band.
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Shih, Meng Hong, and 施孟宏. "Research of Slot Antenna with Circular Polarization." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/an45fk.
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碩士國立臺南大學
電機工程學系碩博士班
103
A wideband microstrip-fed open-slot antenna with dual-band circular polarization has been presented in this thesis. A bent feeding structure and three slots, including a T-shaped and two inverted-L topologies etched in the ground plane, are designed in order to excite two orthogonal E vectors with equal amplitude and 90° phase difference ( PD ) for radiating right-hand circularly polarized ( RHCP ) wave at 1.57 GHz and left-hand circularly polarized ( LHCP ) wave at 2.33 GHz. The two bands are the operated bandwidth of the global positioning system ( GPS ) and satellite digital audio radio ( SDAR ) service system. To improve the impedance bandwidth at the low-frequency band, a parasitic rectangular patch is added on the top plane of the substrate. Several resonances are merged and thus, a wide impedance bandwidth is obtained. The measured impedance bandwidth of a reflection coefficient < - 10 dB ranges from 1.45 to 3.93 GHz, and thus covers most of commercial wireless communication systems, such as GPS, DCS, PCS, IMT-2000, SDAR, WLAN, and LTE. The 3-dB axial ratio ( AR ) bandwidths are about 65 MHz at the lower band ( 1.57 GHz ) and 107 MHz at the upper band ( 2.33 GHz ).
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TSENG, BO-FEI, and 曾泊斐. "Analysis of Planer Circular Polarization Monopole Antenna." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/tsvysu.
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碩士大葉大學
電機工程學系
105
In this research, Different circularly polarized structures are studied on monopole antennas. The circular polarization characteristics are generated by different structures. The first antenna produces a wideband circular polarization characteristic using an offset feed current. The second antenna produces dual-band circular polarization characteristics by an orthogonal structure coupled to the diamond - shaped ground plane. The third antenna produces dual-band circular polarization characteristics using an asymmetric ground plane and a special structure. Frequency bands in this study include WLAN, WiMAX, LTE, etc. The operable frequency band is based on a reflection coefficient below -10 dB and an axis ratio below 3 dB.
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Tango, Kung-Sheng, and 唐宮聖. "GPS Dual-Band Circular Polarized antenna Design." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/p8qpdh.
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碩士元智大學
電機工程學系乙組
107
In this thesis,We study GPS dual-frequency circularly polarized antenna. This thesis has 5 chapters. The first chapter introduces the motivation and purpose of this paper,Generally,the GPS antenna on the market is a single L1 (1575MHz) with other frequency bands (WIFI, 3G/4G/5G, Bluetooth, etc.).If the antenna has dual-frequency GPS circular polarization,it can increase the application and improve the delay through the ionosphere [20]. The second chapter is GPS introduction, positioning method and microstrip line theory. The third chapter is to derive the antenna size of a single-frequency antenna. When the antenna surface is increased in truncated angle design，the single-frequency antenna has a circular polarization effect; In order to reduce the difficulty of implementation，we change the thickness of the PCB to increase the bandwidth. In Chapter 4, using the resonance effect of the slot structure, We open 2 slots on the antenna surface to generate 2 or more operating bands. We look for the operating band of GPS L1 (1575MHz) / L2 (1227MHz) by changing the length and width of the antenna,the size of the slot, the slot position and the feed point. Then we use several slots on the backplane to improve the axial ratio to make it closer to circular polarization. Finally,by comparing the measurement and simulation data,the L2 (1227MHz) frequency band S parameter simulation data is preferably 1227MHz, the bandwidth is 11MHz,the measurement data is 12275MHz, the bandwidth is 20MHz,and the offset is about 5MHz; The L1 (1575MHz) frequency band S parameter simulation data is preferably 1575MHz,the bandwidth is 10MHz,the measurement data is 1585MHz, the bandwidth is 27.5MHz, the offset is 10MHz, if the dielectric constant is changed from 4.2 to 4.17，the simulation data and The measured data can be more consistent.
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Huang, Jia-Min, and 黃嘉民. "The Compact Designs of Planar Loop Antenna with Circular PolarizationThe Compact Designs of Planar Loop Antenna with Circular Polarization." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/54856492807664407955.
Full textAbstract:
碩士北台灣科學技術學院
機電整合研究所
96
The Compact Designs of Planar Loop Antenna with Circular Polarization(CP) have been investigated in this dissertion. The study of serpentine construction to increase current path and reduce dimension arrive at Circular Polarization. There are two designs in this dissertation.The single layer compact is designed by Coplanar Waveguide and the double layer compact is designed by Microstrip-Line. To compare oringinal size antenna with compact size antenna to analysis and discussion. The input impedance of planar loop antenna can be matched by serpentine meander line and serpentine microstrip patch to save antenna area.The antennas operation frequency designs can be used to 802.11b/g (2.4~2.45GHz). In this dissertation, experimental result proved the single layer Compact designed by Coplanar Waveguide has been scaled-down dimension from 51mm*42mm to 39.75mm*37.25mm(69.12%) and the double layer compact designed by microstrip line has been scaled-down dimension form 40mm*24mm to 35mm*20mm(72.92%).
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Li, Kuo-Pin, and 李國彬. "The Design of Ring Antenna Array of the Circular Polarization Microstrip Antenna." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/44002077493100064615.
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碩士中原大學
電機工程研究所
100
Abstract For this thesis, we use a Zeland Analysis Software IE3D to design a circular polarization microstrip antenna. We used low-cost materials to design a microstrip antenna and made use of it to easily assemble the structure and to conveniently move it around. As a result, we replace the inconvenience of using large helical antenna motor rack receiver. Thus, we came up with the subject of making an application in satellite signal reception. In this thesis, we propose several key points: for the first part, we deal with selection of materials. In accordance with the circular polarization microstrip antenna’s theory and equations, we use the Zeland Analaysis Software IE3D to simulate circular polarization microstrip antenna. In order to achieve the special features of the stimulation of circular polarization of antenna, the antenna feed design uses single feed penetration rule and truncated 2 relative angle of the rectangular receiver surface. The second part is the implementation of the antenna body and adoption of the antenna array method. We place each antenna body to rotate 90 degrees into the antenna array to achieve the purpose of a circular polarization array. The third part is the implementation of the satellite signal receiver, spectrum measurement, and analysis of the circular polarized microstrip array antenna design. In addition, performance comparison with large-scale helical antenna will be given. And as shown from our research, its efficiency and cost are both advantageous to large-scale helical antenna. In this thesis, we will present the following contributions: (1) Replacement：The thesis’ circular polarization microstrip array antenna design can be used as immediate replacement when experiencing failure for large helical antenna. This will avoid interruption in receiving task, resulting in data loss. (2) High Quality of Signal：Circular polarization microstrip array antenna makes use of array method to enhance the gain, improve directivity, and reach the narrow beam characteristic. At the same time, it reduces the level of interference signal influence, resulting to enhanced quality of signal reception of satellite communications. (3) Low-Cost-Effectiveness：This thesis’ circular polarization microstrip array antenna design doesn’t require a large amount of money to complete the antenna production. This not only meets low-cost-effectiveness, but also provides easy installation and removal. Finally, we can know that the circular polarization microstrip array antenna design presented in this thesis can effectively improve the antenna body gain, reduce the antenna cost and enhance the efficiency of signal reception. Accordingly, it increases the communications flexibility and other advantages.
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Tseng, Chien-Hua, and 曾建華. "Novel Designs of Planar Antenna with Circular Polarization." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/75927613014311948321.
Full textAbstract:
碩士正修科技大學
電子工程研究所
97
A novel circular polarization patch antenna having a shorting mechanism has been proposed. The proposed antenna placed on the center of the system ground plane consists of a highεr dielectric substrate, an upper patch electrode, an antenna ground plane, a system ground plane, a shorting pin system and a feeding point. The purposes of the proposed antenna are to achieve circular polarization and easy to produce. For antenna construction, the shorting pins were set on the corner(s) of the antenna ground plane of the ceramics substrate to improve impedance matching. For bandwidth, it can be reached about 10MHz and tuned by capacitance coupling feed. For axial ratio, it can be controlled by the shape of the upper patch. In this study, the bandwidth of the axial ratio less then 3dB is about 2 MHz. Additional, there is a good agreement between Ansoft HFSS and practical measurement. There are several advantages of the proposed antenna, including low profile, SMT, good axial ratio and sufficient bandwidth.
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陳登御. "Broadband partially shorted microstrip antenna with circular polarization." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/06157882776819192471.
Full textAbstract:
碩士國立彰化師範大學
電信工程研究所
96
Abstract In this thesis, we propose a broadband circularly polarized shorted wall antenna, which design procedure of broadband circularly polarized fed by an L-probe. For the broadband circularly polarized antenna design, the antenna dimension is made suited for operating in 1.80 GHz band. The distance between patch antenna and ground plan is 0.96λ0. Use a horizontal rectangular metal strip and a vertical cylinder copper to form L-probe feed. The impedance of the antenna can be controlled by tuning the length and width of the rectangular metal strip. This shorted wall antenna has two shorting to form vertical field and can obtain the circularly polarized radiation characteristic. Achieving the 3-dB axial ratio bandwidth of 44.4% and the 10-dB impedance bandwidth of 50%. The shorted wall is designed using CST STUDIO SUITE 2006 microwave electromagnetic simulation software.
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chen, wei-hung, and 陳威宏. "Small circular polarization slot antenna wide band design." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/21102675927601941458.
Full textAbstract:
碩士國防大學理工學院
電子工程碩士班
97
In this thesis, we propose two antenna designs of printed slot antennas with broadband circularly-polarized (CP) operations. The main features of the first proposed antenna for largely improving CP bandwidth than that of conventional CP antenna designs are a pair of hat-shaped grounded patches embedded in the annular-ring slot along the direction 45o to the feed line and a bent signal strip protruded from 50 microstrip-feed-line. Simulated and experimental results show that the first proposed broadband CP antenna has a 3-dB axial-ratio bandwidth of as large as 50% with a reduced antenna size than that of before designs. Moreover, impedance matching with the criteria of VSWR < 2 within the largely enhanced CP bandwidth of the proposed antenna can be obtained using a matching method of widening signal strip in the annular-ring slot. With a lengthened and widened slot size at two ends of an inverted-L-shaped slot and a narrowed width of the signal strip at the end of the CPW feed-line, the second proposed broadband CP antenna fed by a coplanar waveguide transmission line can obtain a 3-dB axial-ratio bandwidth of as large as 58%. Moreover, good impedance matching with a criterion of VSWR < 2 can be obtained by embedding an inclined metal strip at the properly-chosen place on the edge of the slot.
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CHEN, HONG TWU, and 陳宏圖. "Studies of a Spherical-Circular Microstrip Patch Antenna." Thesis, 1994. http://ndltd.ncl.edu.tw/handle/01317156182078229808.
Full textAbstract:
博士國立中山大學
電機工程研究所
82
The spherical-circular microstrip patch antenna is studied extensively in this dissertation. Formulation and numerical results for the problems of resonance, radiation, scattering, and probe-fed excitation are presented. Most of the problems are solved by using a full-wave analysis incorporating Galerkin''s moment method. And, for the excitation problem of using a coaxial probe feed, both the full-wave and the cavity- model analyses are used for the theoretical treatment. Wave propagation inside a uniaxially anisotropic medium is first derived in spherical coordinates. It is found that, the effects of the uniaxial anisotropy can be included in the formulation simply by introducing a modified spherical Bessel function into the field expression. The derivation procedure for the modified spherical Bessel function is described. A scattering problem of a uniaxial sphere illuminated by a plane wave is solved to verify the correctness of the results. For the purpose of improving the bandwidth of the spherical microstrip antenna, a novel structure with an airgap between the substrate and the ground sphere is developed. In this study, the full-wave analysis is used for the theoretical treatment, and the information of the half-power bandwidth is obtained from the complex resonant frequency. This study is performed by solving the resonance problem of a spherical- circular microstrip structure with an airgap. Numerical results indicate that, with increasing airgap thickness, the antenna bandwidth can be considerably enhanced.
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HUANG, HUAN-SHENG, and 黃煥昇. "Analysis of elliptical microstrip antenna with circular polarization." Thesis, 1986. http://ndltd.ncl.edu.tw/handle/56483723400349993356.
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Wu, Jui-Shuan, and 吳睿軒. "LINEAR AND CIRCULAR POLARIZATION VAN ATTA ARRAY ANTENNA." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/t67gz7.
Full textAbstract:
碩士大同大學
通訊工程研究所
95
A simple passive microstrip array design is introduced comprising four ring antenna elements, and each element was excited by stripline-coupled fed from two orthogonal feeding ports. The striplines is arranged to form a Van-Atta retrodirective array which has two-dimensional self-tracking ability. We validate that this structure is catered for both linear and circular polarizations by simulation with IE3D and experiment. The fields retransmitted by all the antenna pairs spatially combine in the wave-incidence direction while interfere with each other in other directions, so that the reradiated field is smooth. The measured 10 dB responding beamwidth at 5GHz for linear polarization is 140°, and the measured 10dB responding beamwidth at 10GHz for circular polarization is 130°, both of them are much wider than the beamwidth of reflection from metal sheet with the same size.
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Chi, Li-pin, and 齊立平. "Design and Application of Optical-controlled Phase Array Antenna and Circular Polarization Antenna." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/88031420022494207469.
Full textAbstract:
博士逢甲大學
電機與通訊工程所
98
The aim of this thesis is to study the application of optical on beam synthesis and scanning mechanism of phase array antenna, circular polarization antenna applied in optical-controlled phase array antenna system and design approaches of circular polarization antenna. Comparison is made through a simulation experiment and actual measurement analysis to find out the optimize approaches and design parameters. There is an increasing demand for wireless communication due to fast advancement of science and technology, especially on the development of high frequency and wideband. However, this has accompanied with frequency saturation, interferences and other problems. Therefore, we think it is a feasible solution to use as much as possible optical wave to replace electromagnetic wave, and optical fiber to replace transmission circuit. As optical fiber and wave are lightweight, low loss in transmission, not affected by electromagnetic interference, wideband and other characteristics, they feature the merits over traditional RF and microwave circuit. In addition, there are shortcomings of traditional scanning antenna being high-power consumption, high mechanical wear, complex structure, cumbersome correction procedure, high cost and uneasy to adjust; The previous papers have mentioned the using of multi-section uniform fiber grating or chirped fiber grating to work as time-delay device to control the phase changes of antenna array. In the process of array antenna researching, we find antenna array performance operation in circular polarization better than single antenna, and induce our interest in further study circular polarization antenna. Therefore, in Part One of this thesis we carry out literature review to discuss the characteristics of various optical gratings, and attempt to use reflection spectrum’s multi-channels and time-delay features of superstructure fiber grating to work as the array antenna and phase control mechanisms. This part of the study includes the conversion of optical wave and microwave, and the application of optically controlled antenna phase to obtain the feasible results through simulation and practices. In Part Two of the thesis we discuss the suitable for application of microstrip antenna in photoelectric conversion. We propose the traditional linear polarization microstrip antenna that has gone through special geometric configuration to make it into broadband dipole antenna, but instead has generated a circularly polarized field pattern. So, using microstrip dipole antenna to conduct circularly polarized operation is an extremely unique design. Apart from being able to obtain dual-band operation, it has no doubt expanded the application scope and conveniences of microstrip antenna. In this part, we use reflection coefficient, axial ratio, radiation pattern, bandwidth, current distribution, etc. to perform simulation and actual measurement. The outcomes indicate that the simulated results are consistent with the trend of actual measurement, and the errors are within the reasonable scope and so we are able to summary the reasons. The overall performance is superior to single antenna. The thesis perform individual analysis on every geometric parameters to obtain the optimize design result to provide follow-up designers as an index reference In Part Three, we take broadband and circular polarization antenna as the different design concept. The traditional of circular polarization antenna usually uses cutting cross-corner on square radiation metal which makes it to generate two currents in 90∘phase difference. But here we submit a new approach, which stimulate two currents on different metal layers to cause circular polarization, these layers cover each other on small square area. And then, we discuss the design parameters of circular polarization antenna array. Through simulation and practice, we have improved the overall efficiency. In process of research, the author submits the design and evaluation approach for anechoic chamber based on real experience. In conclusion, we emphasize the value and contribution of this research, and the further research direction.
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Huang, Chung-Shao, and 黃仲紹. "Higher-Order Mode Excitation and Circularly Polarized Radiation of CPW-fed Circular Microstrip Antenna." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/81495092823507124363.
Full textAbstract:
碩士國立臺灣大學
電信工程學研究所
90
Higher-order mode excitation and circularly polarized radiation are two important applications of coplanar waveguide (CPW) fed circular microstrip antenna. In this thesis, design and analysis for these applications are presented. The experimental procedure and results are also described in detail. For excitation of higher-order modes, we introduce the capacitive and inductive coupled feeding structures. By tuning the dimensions of coupled slot and the feed position, higher order modes that we expected from circular microstrip antenna can be excited successfully. Experimental results show that the far-field radiation patterns of these higher-order modes are satisfactory and are suitable for various wireless communication applications. For radiation of circularly polarized wave, we analyze the mechanism of circularly polarized (CP) radiation by using the equivalent circuit, and discuss some of the CPW-fed CP antennas presented in the literature. We found that the transmittion mode of CPW has a strong interference on the radiator. Thus, the linear resonant mode of this radiator can not be separated into two orthogonal components with perturbed 90° phase difference. Therefore, it is difficult to perform CP radiation by a direct CPW feed. For this reason, we propose a symmetric CPW to slotline feeding structure to overcome this problem and the perturbation is employed to generate CP wave. Moreover, unlike the 90° hybrid configuration in [24], this symmetric feeding structure is convenient for antenna array design and the slotline mode of the CPW can hardly be excited. Finally, we design a series of CPW-fed CP antenna and antenna array by using the above symmetric feeding structure. Experiments have shown all of our designs can radiate good and stable CP waves. This symmetric feeding structure can be applied not only to the circular patch antenna but also to various other shapes of the patch antenna. This indirectly proves the influence of CPW on CP radiation and provides the important consultation for CP antenna design.