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1
Wu, Liang. "Substrate integrated waveguide antenna applications." Thesis, University of Kent, 2015. https://kar.kent.ac.uk/50526/.
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The research objective of this thesis is to provide a better solution for signal interference and reduce the size of waveguide antenna. The background investigations of different waveguide fabrication technologies and switch control methods are detailed in the introductory part of this thesis. Several novel substrate integrated waveguide (SIW) antennas for different purpose are demonstrated in the body of the thesis. The designs are mainly divided into two kinds. The first focuses on the switch beam SIW antennas working at 2.4 GHz frequency band. Compared to the corresponding waveguide antennas of multiple-input and multiple-output (MIMO), phased array and switch beam, the proposed SIW antennas have advantages in compact size, easy fabrication and high gain. By DC biasing the surface mounted PIN diodes, the waveguide slots radiate at diode-off state of reverse bias, and are shielded at diode-on state of forward bias. Based on different requirement, the SIW antennas can achieve two-direction, four-direction and six-direction transmission. The gain can be easily changed by extending the size of reflector walls. The second focuses on reducing the volume of SIW antennas, working at 5 GHz frequency band. A new folded SIW antenna is introduced. By folded the antenna front end part to second layer, the SIW antenna reduces the total length by the size of one-quarter guided wavelength. This folded antenna can radiate either monopole mode or dipole mode, based on the metal surface area. Another two new SIW antennas reduce the total length by directly cutting the front-end part at the slot center. By utilized the intrinsic coupling radiation, the SIW antennas use two half-length slots at different broad-wall plane to achieve 360 degree propagation and wide-band end-fire radiation.
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Dogan, Doganay. "Dual Polarized Slotted Waveguide Array Antenna." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613016/index.pdf.
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An X band dual polarized slotted waveguide antenna array is designed with very high polarization purity for both horizontal and vertical polarizations. Horizontally polarized radiators are designed using a novel non-inclined edge wall slots whereas the vertically polarized slots are implemented using broad wall slots opened on baffled single ridge rectangular waveguides. Electromagnetic model based on an infinite array unit cell approach is introduced to characterize the slots used in the array. 20 by 10 element planar array of these slots is manufactured and radiation fields are measured. The measurement results of this array are in very good accordance with the simulation results. The dual polarized antenna possesses a low sidelobe level of -35 dB and is able to scan a sector of ±35 degrees in elevation. It also has a usable bandwidth of 600 MHz.
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Alhuwaimel, Saad. "Fully polarimetric slotted waveguide antenna array." Thesis, University College London (University of London), 2018. http://discovery.ucl.ac.uk/10041045/.
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Multistatic radar system provides a great number of advantages over monostatic radar systems via exploitation of geometrical diversity which gives the ability to view targets from multiple perspectives. These advantages include target signature enhancement, improved detection, higher immunity against countermeasures and provide more information about targets and hence enhance targets classification. Furthermore, the passive receive-only nodes are more compact, hence lighter weight, and can be mounted on UAV which leads to a great advantage to surveillance systems and military applications. Over the last two decades, University College London and the University of Cape Town have collaborated to develop multistatic radar systems. This collaboration resulted in developing an S-band system (NetRAD). Recently, a new version of the system (NeXtRAD) that operates in X and L bands has been developed. The NeXtRAD system has two channels at X-band which allows for receiving fully polarimetric data from clutter and targets utilising dual-polarised antenna. The first addressed task of this work was to investigate all possible antenna candidates to be used for the NeXtRAD system. Resonant SWGAA was chosen among the antenna options as it fit best all desired criteria and due to its relative design simplicity, high power-handling capabilities and cost-effective fabrication. The SWGAA can be designed to be a dual-polarised antenna. The procedures for designing a low sidelobe level (SLL) S-band SWGAA are demonstrated in this work. The azimuth beamwidth of a SWGAA is controlled by the number of slots carved in a waveguide. Eight slots distributed around the centre-line of waveguide broad wall found to meet the desired beamwidth. Four SWGAAs were designed and fabricated. The anechoic chamber measurements of each SWGAA showed excellent agreement with the simulation results. A single element SWGAA has a fan elevation beamwidth. This beamwidth has to be narrowed to achieve the desired width. Stacking identically designed SWGAAs was found to be an effective and simple method to narrow the antenna elevation beamwidth. The four SWGAAs were stacked on top of each other. The mitigation of mutual coupling between stacked SWGAAs was investigated. A cost-effective method of inserting dielectric sheets between stacked SWGAAs helped in mitigating the mutual coupling and assist in arriving at the desired antenna performance. The stacked SWGAAs shows a very good performance with very low SLL and high polarisation purity (low cross-polarisation level). The stacked SWGAAs antenna performance was validated in field experiments and compared to similar characteristics antenna. The SWGAA shows better performance compared to the other antenna. A new simple and efficient design of a dual-polarised SWGAA by having two similar set of stacked waveguides with one set rotated by 90ᵒ relative to the other one was proposed. Two designs with two different elevation beamwidths were simulated. Both designs showed excellent performance that met all the desired criteria. The same designs and tests procedures were followed in designing and testing the X-band SWGAA and simulating dual-polarised antennas. No field experiments were performed using this antenna as the NeXtRAD system is based at UCT and no access to any other X-band radar system at UCL.
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Byrne, Benedikt. "Etude et conception de guides d'onde et d'antennes cornets à métamatériaux." Phd thesis, Toulouse, INPT, 2016. http://oatao.univ-toulouse.fr/17299/7/byrne.pdf.
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Afin de répondre aux besoins croissants d’équipements de communication pour les applications spatiales, il est important de réduire, le plus possible, la taille et la masse de l’équipement des satellites. Cela conduit à une réduction des coûts de lancement des satellites sur leur orbite ou laisse la possibilité d’ajouter des équipements dans la fusée. Ceci compte aussi pour les composants radioélectriques. L’objectif étant de réduire les dimensions sans pour autant détériorer les performances en rayonnement (directivité, polarisation croisée, bande monomode, etc.). Il est possible de contrôler la propagation des ondes électromagnétiques dans les antennes cornets et les guides d’onde à l’aide de surfaces anisotropes (corrugations, métamatériaux). Ainsi, contrairement à ce que prédisent les lois physiques sur la propagation et le rayonnement d’ondes électromagnétiques dans des structures classiques, les performances des structures à parois anisotropes peuvent être radicalement améliorées : pour le guide d’onde, réduction de la fréquence de coupure ; pour l’antenne cornet, amélioration de la directivité ou réduction du niveau des lobes secondaires. D’après l’état de l’art, même si les résultats de simulations et de mesures obtenus sont très prometteurs, le dimensionnement de la structure des métamatériaux est sujet à optimisation, donc gourmand en ressources informatiques. L’apport principal de cette thèse a été de développer une nouvelle méthodologie de conception s’appuyant sur une Théorie Modale Elargie (TME) analytique pour des guides d’onde à parois anisotropes. Elle permet de dimensionner très rapidement des surfaces à métamatériaux les plus adaptées aux applications requises. Un prototype de guide d’onde et un prototype d’antenne ont été conçus, fabriqués et mesurés grâce à cette méthodologie. Les résultats obtenus démontrent l’intérêt, l'efficacité et le caractère général de la méthode proposée pour la conception de dispositifs hyperfréquences guidés à parois anisotropes.
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Schoeman, Karla. "Waveguide antenna feed for the Square Kilometre Array." Thesis, Stellenbosch : University of Stellenbosch, 2011. http://hdl.handle.net/10019.1/6833.
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Thesis (MscEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2011.ENGLISH ABSTRACT: The aim of this thesis is to investigate the suitability of TEM (Transverse Electromagnetic) horn antennas for use as feed structures for the Square Kilometre Array (SKA) radio telescope, in particular with regard to the roundness of the radiation pattern. A literature study shows that existing TEM horn designs do not yield a round radiation pattern over a wide bandwidth and that an alternative is required. The Method of Moments (MoM) is a computational electromagnetic (CEM) technique typically used in the analysis of TEM horn antennas. An in-house MoM solver is successfully developed to analyse such antennas and is able to calculate the current density on the surface of a conductor, as well as the farfield patterns of an antenna. A modification to an exponential TEM horn antenna is proposed and simulations show the modification is successful in yielding a round radiation pattern over a wide bandwidth. The modified exponential TEM horn has a convex triangular arc at the end of each antenna plate and is constructed for measurement. Due to limited construction capabilities, the measurements deviate slightly from the simulated results but still indicate the potential of the structure to yield a round radiation pattern over a wide bandwidth.
AFRIKAANSE OPSOMMING: Die doel van hierdie tesis is om die geskiktheid van transverse elektromagnetiese (TEM) horing antennas te ondersoek vir die gebruik as voerstrukture vir die Square Kilometre Array (SKA)- radioteleskoop, veral met betrekking tot die rondheid van die stralingspatroon. ’n Literatuurstudie toon dat bestaande TEM horing ontwerpe nie ’n ronde stralingspatroon oor ’n wye bandwydte lewer nie, en dat ’n alternatief nodig is. Die metode van momente is ’n rekenbare elektromagnetiese tegniek wat tipies gebruik word in die ontleding van TEM horing antennas. ’n In-huis metode van momente ontleder is suksesvol ontwikkel om sulke antennas te analiseer en is in staat om die stroomdigtheid op die oppervlak van ’n geleier, sowel as die vêrveld patrone van die antenna te bereken. ’n Wysiging van ’n eksponensiële TEM horing antenna word voorgestel en simulasies toon dat die veranderings suksesvol is om ’n ronde stralingspatroon oor ’n wye bandwydte te skep. Die verander eksponensiële TEM horing het ’n konvekse driehoekige boog aan die einde van elke antenna plaat en is gebou vir meting. Weens beperkte konstruksie vermoëns, toon die metings ’n afwyking van die gesimuleerde resultate, maar dui nogsteeds die potensiaal aan van die struktuur om ’n ronde stralingspatroon te lewer oor ’n wye bandwydte.
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Bandaru, S. "Beam formation using radial waveguide antenna array techniques." Thesis, Queen's University Belfast, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411062.
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Mcknight, James W. "A cavity-backed coplanar waveguide slot antenna array." [Tampa, Fla] : University of South Florida, 2009. http://purl.fcla.edu/usf/dc/et/SFE0003299.
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Ouedraogo, Samir. "Antenne Multifonction pour Radar et Communication." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLC010/document.
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Afin de répondre à la demande croissante de nouveaux services, les objets que nous utilisons au quotidien (les smartphones, les voitures, les avions, etc.) tendent à intégrer de plus en plus de systèmes radio tandis que l’espace disponible pour l’intégration de ces éléments est de plus en plus réduit. Ces systèmes radio nécessitent l’utilisation de plusieurs antennes devant répondre à des critères de compacité, d’isolation, de coût, etc. À titre d’illustration, un smartphone contient plusieurs antennes pour assurer des fonctions telles que la téléphonie, la navigation, la connexion à internet par WiFi, les liaisons Bluetooth, la technologie NFC (Near-Field Communications) et ce nombre tend à s’accroitre considérablement avec l’émergence de nouveaux services. Le même phénomène se retrouve également au niveau des plateformes aéroportées où des fonctions telles que la communication, la navigation, le radar, etc. sont utilisées. Cela conduit donc à la nécessité de réduire le nombre d’antennes en regroupant par exemple plusieurs fonctions au sein d’une même et unique antenne. Dans de précédents travaux de recherches, J. Euzière a démontré la possibilité de combiner une fonction radar et une seconde fonction (ici de communication) en utilisant un réseau de 16 monopoles initialement dédié au seul radar, grâce au Time Modulated Array (TMA). De cette façon, les deux fonctions utilisaient la même fréquence et étaient alimentées par une seule source. L’objectif principal de cette thèse est de proposer une solution d’antenne multifonction pour radar et communication encore plus compacte (constituée d’une seule antenne). L’idée est de partir d’une solution antennaire déjà existante et d’y apporter les modifications nécessaires à l’ajout d’une seconde fonction, sans pour autant augmenter la surface de l’antenne ni la complexité du systèmeIn order to respond to the increasingly demand of new services, the objects we use on a daily basis (such as mobile phones, cars, airplanes etc.), tend to integrate more and more radio systems while the space available is limited. These radio systems require the use of many antennas that must meet multiple requirements such as compactness, isolation, costs, etc. A smart-phone, for example, contains several antennas for global navigation satellite system (GNSS), WiFi, TV, FM radio, Bluetooth, near-field communications (NFC) and the number is expected to increase as new systems are added. Another example is in airborne platforms where multiple functions such as communication, navigation, radar, electronic warfare are used. This leads to the need of reducing the number of associated antennas by regrouping several radio functions into a single antenna. However, combining the functionality of several antennas into one shared radiating element while maintaining the functionality of the various radio systems presents a great challenge. During its Ph.D, J. Euzière demonstrated the possibility to combine a radar function and a secondary function from a 16-monopole array originally dedicated to radar operation by using Time Modulated Array (TMA) technique. By this way, the two functions were operating at the same frequency and the system was powered by a single source.The main objective of this thesis is to propose a more compact antenna (a single antenna) dedicated to radar and communication operations instead of using antenna array as J. Euzière did it. The idea is to start from an existing antenna solution and make the necessary modifications to add a second function without adding additional surface and complexity. As we are interested in radar applications, we will choose a directive antenna: a horn antenna. The goal is then to study the possibility to modify the radiation pattern of the horn antenna through controllable elements (slots) and to transmit a direct modulated signal at the antenna level for the communication function. Furthermore, polarization diversity is an attractive way to increase the isolation between two applications. Thus, this aspect will be taken into account in the design of the antenna solution
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Jin, Lukui. "Waveguide-based antenna arrays in multi-chip module technology." Thesis, University of Leeds, 2014. http://etheses.whiterose.ac.uk/6859/.
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For mm-waves, two types of low-loss waveguide are analysed, designed and measured. One is the hollow substrate integrated waveguide (HSIW) in which the inner dielectric of a traditional substrate integrated waveguide (SIW) is removed to resemble the propagation characteristics of a standard rectangular waveguide (RWG). The measured attenuation of a WR28-like HSIW is 2 Np/m or 17 dB/m throughout the Ka band. The second is the dielectric insular image guide (DIIG) in which an insular layer is added between the dielectric and the metallic ground to further reduce the conductor loss. The measured attenuation of a Ka band DIIG is 26 dB/m at 35 GHz. Based on the two waveguides, two high-gain antenna arrays operating in the Ka band are designed and measured. One is a 6 x 6 slot antenna array, centrefed by the HSIW. The Taylor-distribution technique is applied in two orthogonal directions to suppress the sidelobe level. The measured gain of this antenna array is 17.1 dBi at the centre frequency of 35.5 GHz. The other is a double-sided 10- element dielectric insular resonator antenna (DIRA) array, end-fed by the DIIG. The Taylor-distribution technique is also applied here to achieve a gain of 15.8 dBi at the centre frequency of 36 GHz. The great potential of these high-performance antennas is that they can be integrated with other microwave components (filters, power amplifiers, etc.) to form a complete front-end or transceiver in multi-chip module (MCM) technology.
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Top, Can Baris. "Design Of A Slotted Waveguide Array Antenna And Its Feed System." Master's thesis, METU, 2006. http://etd.lib.metu.edu.tr/upload/3/12607642/index.pdf.
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Slotted waveguide array (SWGA) antennas find application in systems which
require planarity, low profile, high power handling capabilities such as radars. In
this thesis, a planar, low sidelobe, phased array antenna, capable of electronically
beam scanning in E-plane is designed, manufactured and measured. In the design,
slot characterization is done with HFSS and by measurements, and mutual coupling
between slots are calculated analytically. A MATLAB code is developed for the
synthesis of the SWGA antenna. Grating lobe problem in the scanning array, which
is caused by the slot positions, is solved using baffles on the array.
A high power feeding section for the planar array, having an amplitude tapering to
get low sidelobes is also designed using a corrugated E-plane sectoral horn. The
power divider is designed analytically, and simulated and optimized with HFSS.
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Mahmud, Rashad Hassan. "Synthesis of waveguide antenna arrays using the coupling matrix approach." Thesis, University of Birmingham, 2016. http://etheses.bham.ac.uk//id/eprint/6564/.
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With the rapid development in communication systems recently, improvements in components of the systems such as antennas and bandpass filters are continuously required to provide improved performance. High gain, wide bandwidth, and small size are the properties of antennas which are demanded in many modern applications, and achieving these simultaneously is a challenge. This thesis presents a new design approach to address this challenge. The coupling matrix is an approach used to represent the circuits made of coupled resonators such as filters and multiplexers. The approach has been utilised here to integrate a single resonator-based antenna with an n\(^t\)\(^h\) order filter. The integrated component is capable of providing a controllable bandwidth and introduces the filtering functionality. The approach is further developed in order to integrate bandpass filters with N×N resonator-based antenna arrays. This is to increase the gain of the array as well. Six novel components have been fabricated for the purpose of validation. This thesis also looks at a 300 GHz communication system which is proposed at The University of Birmingham with the objective to build a 10 metre indoor communication link. A 300 GHz (8×8) waveguide antenna array has been designed and fabricated for the system.
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Kawser, Mohammad Tawhid. "Investigation of a Novel Dual Band Microstrip/Waveguide Hybrid Antenna Element." Thesis, Virginia Tech, 2005. http://hdl.handle.net/10919/33660.
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Microstrip antennas are low in profile, light in weight, conformable in structure and are now developed for many applications. The main difficulty of the microstrip antenna is its narrow bandwidth. Several modern applications like satellite communications, remote sensing and multi-function radar systems will find it useful if there is dual band antenna operating from a single aperture. Some applications require covering both transmitting and receiving frequency bands which are spaced apart. Providing multiple antennas to handle multiple frequencies and polarizations becomes especially difficult if the available space is limited as with airborne platforms and submarine periscopes.
Dual band operation can be realized from a single feed using slot loaded or stacked microstrip antenna or two separately fed antennas sharing a common aperture. The former design, when used in arrays, has certain limitations like complicated beam forming or diplexing network and difficulty to realize good radiation patterns at both the bands. The second technique provides more flexibility with separate feed system as beams in each frequency band can be controlled independently. Another desirable feature of a dual band antenna is easy adjustability of upper and lower frequency bands.
This thesis presents investigation of a new dual band antenna, which is a hybrid of microstrip and waveguide radiating elements. The low band radiator is a Shorted Annular Ring (SAR) microstrip antenna and the high band radiator is an aperture antenna. The hybrid antenna is realized by forming a waveguide radiator in the shorted region of the SAR microstrip antenna. It is shown that the upper to lower frequency ratio can be controlled by the proper choice of various dimensions and dielectric material. Operation in both linear and circular polarization is possible in either band. Moreover, both broadside and conical beams can be generated in either band from this antenna element.
Finite Element Method based software, HFSS and Method of Moments based software, FEKO were employed to perform parametric studies of the proposed dual band antenna. The antenna was not tested physically. Therefore, in most cases, both HFSS and FEKO were employed to corroborate the simulation results.Master of Science
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Theodossopoulos, Konstantinos. "Rectilinear slot model of an inclined slot radiator in rectangular waveguide." Thesis, Heriot-Watt University, 2000. http://hdl.handle.net/10399/577.
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Vašina, Petr. "Měřicí hřebenová trychtýřová anténa." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219967.
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The thesis deals with broadband antennas for measurement purposes. A ridged horn antenna has been selected for this concept, designed for the frequency range 0.9 GHz to 9 GHz. This work contains general theoretical description of antennas and further it focuses on a specific design of the ridged horn antenna, beginning with the calculation of its dimensions, modeling and optimization to obtain desired antenna properties. Finally, the antenna was constructed and measured. The reflection factor s11
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Maritz, Andries Johannes Nicolaas. "Investigation and design of a slotted waveguide antenna with low 3D sidelobes." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/4161.
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Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2010.ENGLISH ABSTRACT: An investigation into the cause of undesired sidelobes in the 3D radiation pattern of slotted waveguide arrays is conducted. It is hypothesized that the cross-polarization of the antenna is at fault, along with the possibility that an error is made when designing a linear array. In investigating and finding a solution to the problem, the “Z-slot ” is introduced in conjunction with polarizer plates. The base components are used by a custom optimization algorithm to design reference and solution antennas. Results of the antennas are then compared to ascertain the cause and possible solutions for the unwanted sidelobes. The generic nature of the process may be used to characterize other arbitrary aperture configurations and to design larger antennas.
AFRIKAANSE OPSOMMING: ‘n Ondersoek om die oorsaak van ongewensde sylobbe in die 3D uitstraalpatroon van golfleier-antennas vas te stel. Die hipotese is dat die probleem ontstaan uit die kruis-polarisasie van die antenna, tesame met ‘n verkeerdelikke aanname dat die opstelling liniêr is. Die “Z-Gleuf” tesame met polariseringsplate word voorgestel as hulpmiddel om die moontlikke oorsake te ondersoek. ‘n Gespesialiseerde optime erings-algoritme benut hierdie basiskomponente om beide verwysings- en oplossing-antennas te ontwerp. Resultate van die ontwerpde antennas word dan vergelyk om die oorsaak van die ongewensde sylobbe te vas te stel. Die generiese aard van die proses kan toegepas word op enige gleuf-konfigurasie en om groter antennas mee te ontwerp.
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McCormick, A. H. I. "Application of the moment method to the design of slotted waveguide array antennas." Thesis, Heriot-Watt University, 1988. http://hdl.handle.net/10399/1962.
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Nithianandam, Jeyasingh. "L-Band Coplanar Slot Loop Antenna for iNET Applications." International Foundation for Telemetering, 2010. http://hdl.handle.net/10150/605925.
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ITC/USA 2010 Conference Proceedings / The Forty-Sixth Annual International Telemetering Conference and Technical Exhibition / October 25-28, 2010 / Town and Country Resort & Convention Center, San Diego, CaliforniaIn this article we present a design of an L-band slot loop antenna with a dielectric loaded conductor backed coplanar waveguide (CBCPW) feed. The coplanar slot loop antenna has a transmission line resonator in series. We used full wave electromagnetic simulations with Ansoft's high frequency structure simulator (HFSS) software in the design of the coplanar slot loop antenna. The series transmission line resonator helps to tune the coplanar slot loop antenna and reduce its size. We present here results on return loss and radiations patterns of coplanar slot loop antenna obtained from HFSS simulations.
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Eshrah, Islam A. "Waveguide and metaguide excitation of dielectric resonator antenna arrays using slots and probes /." Full text available from ProQuest UM Digital Dissertations, 2005. http://0-proquest.umi.com.umiss.lib.olemiss.edu/pqdweb?index=0&did=1267222711&SrchMode=1&sid=1&Fmt=2&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1184857149&clientId=22256.
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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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Martincová, Kateřina. "Trychtýřová hřebenová anténa pro měření EMC." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-377112.
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The thesis deals with the design and realization of a horn antenna for electromagnetic compatibility measurement. First it focuses on general theory of antennas, than it focuses more on horn antennas and their design. Second part deals with description of antenna realization and comparison of simulated results.
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Cha, Jun Ho. "A steerable array antenna using controllable microwave dielectric slab phase shifters on a coplanar waveguide /." Thesis, Connect to this title online; UW restricted, 2006. http://hdl.handle.net/1773/5824.
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Liu, Yuanzhi. "Compact Omnidirectional Millimeter-Wave Antenna Array Using Substrate Integrated Waveguide Technique and Efficient Modeling Approach." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42031.
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In this work, an innovative approach for effective modeling of substrate integrated waveguide (SIW) devices is firstly proposed. Next, a novel substrate integrated waveguide power splitter is proposed to feed antenna array elements in series. This feed network inherently provides uniform output power to eight quadrupole antennas. More importantly, it led to a compact configuration since the feed network can be integrated inside the elements without increasing the overall array size. Its design procedure is also presented.
Then, a series feed network was used to feed a novel compact omnidirectional antenna array. Targeting the 5G 26 GHz mm-wave frequency band, simulated results showed that the proposed array exhibits a broad impedance bandwidth of 4.15 GHz and a high gain of 13.6 dBi, which agree well with measured results. Its attractive features indicate that the proposed antenna array is well suitable for millimeter-wave wireless communication systems.
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Clauzier, Sébastien. "Conception et réalisation d'antennes intégrables en mâture pour les plateformes navales : applications aux communications V/UHF et à un radar de navigation à balayage électronique en bande X." Thesis, Rennes 1, 2013. http://www.theses.fr/2013REN1S067.
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En raison des conflits maritimes qui s'étendent (piraterie, embargo,...), les besoins de communiquer et de détecter les menaces sont de plus en plus importants. Ceci conduit irrémédiablement à l'augmentation du nombre d'aériens à bord des plateformes navales. Afin de gérer au mieux cet accroissement du nombre d'antennes, qui conduit à des effets de couplage et à une augmentation de la signature radar du navire, les principales entreprises du secteur ont mis en place des structures de mâts intégrés. C'est dans un contexte d'amélioration de leur mâture intégrée compacte (Cmast™) que les Constructions Mécaniques de Normandie (CMN) de Cherbourg en collaboration avec l'IETR de Rennes et INEO Défense ont proposé cette thèse. Ces travaux ont pour objectifs le développement de deux systèmes antennaires intégrables au sein de cette mâture intégrée compacte : une antenne de communication en bande V/UHF et une antenne de radar de navigation à balayage électronique en bande X. Une première étude a permis le développement d'une antenne conique large bande (225-400MHz) dont les paramètres géométriques ont été optimisés pour assurer une communication entre les navires et des aéronefs. Un prototype de cette antenne a été réalisé et a permis une validation expérimentale de ses performances. Une seconde étude a permis le développement d'une antenne d'un radar de navigation à balayage électronique en bande X. Cette antenne est basée sur une technologie transmit-array comprenant une source illuminante et un réseau permettant la formation du diagramme. Un effort particulier a été porté sur la source illuminante qui doit éclairer, à des distances très courtes (<550mm), un réseau qui présente des dimensions particulières (1530mmx100mm). Plusieurs sources utilisant un principe de focalisation en zone champ proche ont été développées et validées expérimentalement. Enfin deux architectures d'antennes transmit-array ont été étudiées, utilisant respectivement une technologie imprimée et une technologie en guide. Le fonctionnement de l'antenne complète (source illuminante + réseau transmit-array) a été étudié théoriquementThe need to communicate and detect potential enemies increases with the extension of maritime conflicts. This need impacts directly the number of antennas on naval platforms. However, this increase of aerials leads to several damaging effects: like coupling or high radar signature. To limit this effect, some companies have developed integrated mast design. This structure limits the coupling effect between aerials by a subdivision of the mast and provides an omnidirectional coverage for all antennas inserted inside the mast. The objective of the thesis is to design two antenna systems for the compact integrated mast (CmastTM) developed by the Constructions Mécanique de Normandie (CMN): a communication antenna in the V/UHF band and an electronically scanning antenna for a maritime navigation radar in X-band. For the communication in the V/UHF band, a broadband conical antenna has been developed (225-400MHz). This antenna provides an optimized radiation pattern to insure the communications between the ship and the aircrafts. An experimental validation has been done with a prototype. In the second study, we have developed an electronically scanning antenna for a navigation radar. This antenna is based on a transmit-array technology including an illuminating feed and an antenna which generates the appropriate radiation pattern. A large part of the study has been done on the feed, which illuminates an array with specific dimensions (1530mmx100mm). Three different near-field focusing feeds have been developed and some of them have been validated experimentally. Then, two architectures of transmit-array antennas have been studied, using two different technologies: printed technology and a mixed technology with waveguide and horn
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Almhmadi, Raed Ali M. "Optical True Time Delay Device for mm-Wave Antenna Array Beamforming." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1566073503380698.
Full text
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Ferrando, Rocher Miguel. "Gap Waveguide Array Antennas and Corporate-Feed Networks for mm-Wave band Applications." Doctoral thesis, Universitat Politècnica de València, 2019. http://hdl.handle.net/10251/115933.
Full textAbstract:
[ES] Esta tesis aborda temas de especial interés en el diseño de antenas en la banda de milimétricas. Hui en dia, implementar components passius per a operar en la banda de mil·limètriques i assegurar el contacte i l'alineament metàl·lic apropiat entre peces, resulta un desafiament complex. Habitualment les línies de transmissió i les guies d'ones metàl·liques són les solucions adoptades, però en el primer cas es presenten pèrdues al ser solucions impreses i en el segon cas un mal contacte metàl·lic comporta fugues de camp. Per tant, s'estan explorant nous conceptes que solucionen estos problemes.
La tecnología Gap Waveguide (GW) resulta adecuada ya que no requiere de contactos metálicos. En los últimos años han surgido las agrupaciones de antenas basadas en la tecnología Gap Waveguide y son un candidato prometedor para satisfacer algunas de las necesidades mencionadas. La tecnología GW ha demostrado ser atractiva para dispositivos de milimétricas porque permite redes de distribución completamente metálicas de una manera más simple que las guías de onda convencionales. Por tanto, estas redes tienen muy bajas pérdidas pero además son simples de fabricar. Esto es posible gracias a la capacidad de las GW de confinar de forma segura la propagación de ondas electromagnéticas por medio de una estructura que no requiere de contacto.
Durante la última década, se han hecho avances importantes en la tecnología GW y en la literatura se pueden encontrar un buen número de antenas basadas en GW. Esta tesis va un paso más allá en la contribución de este tipo de antenas. Aquí, no solo se presentan antenas con polarización lineal, como suelen ser las desarrolladas hasta ahora, sino también con polarización dual, circular y duales en banda. Estas aportaciones son especialmente atractivas dentro del campo de las comunicaciones por satélite en movimiento (SATCOM on-the-move). Además, se han explorado nuevas redes de distribución que permiten antenas planas más compactas, más ligeras.[CAT] Esta tesi aborda temes d'especial interés en el disseny d'antenes en la banda de mil.limètriques. Hui en dia, implementar components passius per a operar en longituds d'onda tan xicotetes (de l'orde de mil.límetres) i assegurar el contacte i l'alineament metàl-lic apropiat entre peces, resulta un desafiament complex. Habitualment les línies de transmissió i les guia d'ones metàl.liques són les solucions adoptades, però en el primer cas es presenten pèrdues al ser solucions impreses i en el segon cas un mal contacte metàl.lic comporta fugues de camp. Per tant, s'estan explorant nous conceptes que solucionen estos problemes. La tecnologia Gap Waveguide (GW) resulta adequada ja que no requerix de contactes metàl.lics. En els últims anys han sorgit les agrupacions d'antena basades en la tecnologia Gap Waveguide i són un candidat prometedor per a satisfer algunes de les necessitats mencionades. La tecnologia GW ha demostrat ser atractiva per a dispositius de banda d'ones mil-limètriques perquè permet xarxes de distribució completament metàl-liques d'una manera més simple que les guies d'onda convencionals. Per tant estes xarxes tenen baixes pèrdues peró, a més, són simples de fabricar. Açò és possible gràcies a la capacitat de les GW de confinar de forma segura la propagació d'ones electromagnètiques per mitjà d'una estructura que no requerix de contacte. Durant l'última dècada, s'han fet avanços importants en la tecnologia GW i en la literatura es poden trobar un bon nombre d'antenes basades en GW. Esta tesi va un pas més enllà en la contribució d'este tipus d'antenes. Ací, no sols es presenten antenes amb polarització lineal com solen ser les desenrotllades fins ara, sinó també antenes amb polarització dual, circular i inclús antenes duals en banda. Estes aportacions són especialment atractives dins del camp de les comunicacions per satèl.lit en moviment (SATCOM on-the-move). A més també s'han explorat noves xarxes de distribució que permeten obtindre antenes planes més compactes, més lleugeres.
[EN] This thesis deals with topics of special interest regarding the design of antennas at the mm-wave band. Today, implementing passive components that operate in the mm-wave band and to ensure the appropriate metallic contact is challenging. Commonly, conventional planar transmission lines and hollow metallic waveguides are the usual solutions but they present high losses or they do not ensure a good metallic contact. So, new concepts must be explored. Gap Waveguides (GWs), result suitably since they do not require metallic contact for shielding. Antenna arrays in Gap Waveguide Technology (GW) emerges as one promising candidate to naturally meet some of the mentioned needs. GW technology has demonstrated to be effective for mm-wave band devices because it enables full-metal distribution networks in a much simpler way than conventional waveguides. Very low distribution losses can be achieved preserving at the same time the assembly simplicity of multilayer microstrip feeding networks. This unique feature is a consequence of gap waveguides ability to safely confine the electromagnetic wave propagation through a contactless structure. During the last decade, there have been important advances in GW technology and a good number of gap waveguide-based arrays can be found in the literature. This thesis goes a step further in the contribution to mm-wave gap waveguide antennas. Here, antennas with linear polarization as well as circular or dual polarization are proposed. Dual band antennas has also been explored. These contributions have been carried out with a focus on satellite communications on-the-move. In addition, new distribution networks have also been explored to obtain more compact, low-profile and lighter antennas.
Ferrando Rocher, M. (2018). Gap Waveguide Array Antennas and Corporate-Feed Networks for mm-Wave band Applications [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/115933
TESIS
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Cox, Gavin J. "Techniques for pattern control of a dielectric rod antenna suitable for use in mobile communications." Thesis, Loughborough University, 2002. https://dspace.lboro.ac.uk/2134/12693.
Full textAbstract:
This thesis describes the development of antennas suitable for mobile coinmunication systems based on a dielectric rod antenna fed from circular waveguide. Pattern control of the antenna is implemented using a combination of Frequency Selective Surface (FSS) elements and metallic endcaps placed on the antenna Both linear and circular polarised feeds have been made for these antennas to ensure they are suitable for a wide range of applications. The suitability of the dominant and next, higher order, waveguide mode were investigated and conclusions drawn as to their suitability for this type of antenna. The antennas were extensively modelled using a commercial TLM based solver and the results of these simulations were compared to the comprehensive set of antenna pattern measurements and S-parameter measurements obtained for the prototype antennas.
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Kim, Christopher Yong Jae. "Wave Chaos and Enhancement of Coherent Radiation with Rippled Electrodes in a Photoconductive Antenna." Diss., Temple University Libraries, 2016. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/412812.
Full textAbstract:
PhysicsPh.D.
Time-domain terahertz spectroscopy is now a well-established technique. Of the many methods available for a terahertz source for terahertz spectroscopy, the most widely used may be the GaAs-based photoconductive antenna, as it provides relatively high power at terahertz frequencies, commercially available up to 150 µW, and a wide-bandwidth, approximately 70 GHz to 3.5 THz. One of the limitations for developing more accurate and sensitive terahertz interrogation techniques is the lack of higher power sources. Because of our research interests in terahertz spectroscopy, we investigated detailed design and fabrication parameters involved in the photoconductive antenna, which exploits the surface plasma oscillation to produce a wideband pulse. The investigation enabled us to develop a new photoconductive antenna that is capable of generating a high power terahertz beam, at least twenty times stronger than those currently available. Throughout this research, it was discovered that antenna electrodes with particular geometries could produce superradiance, also known as the Dicke effect. Chaotic electrodes with a predisposition to lead charge-carriers into chaotic trajectories, e.g. rippled geometry, were exploited to reduce undesirable heat effects by driving thermal-electrons away from the terahertz generation site, i.e. the location of the surface plasma, while concentrating the removed charge-carriers in separate locations slightly away from the surface plasma. Then, spontaneous emission of coherent terahertz radiation may occur when the terahertz pulse generated by the surface plasma stimulates the concentrated carriers. This spontaneous emission enhanced the total coherent terahertz beam strength, as it occurs almost simultaneously with the primary terahertz beam. In principle, the spontaneous emission power increases as N^2, with the number N of dipole moments resulted from the concentrated charge carriers. Hence, if the design parameters are optimized, it may be possible to increase the strength of coherent terahertz beam by more than one order of magnitude with a photoconductive antenna containing rippled electrodes. However, as the parameters are yet to be optimized, we have only demonstrated 10-20 % enhancement with our current photoconductive antennas. Photoconductive antennas were fabricated via photolithography and characterized by time-domain terahertz spectroscopy and pyroelectric detection. In addition to chaotic electrodes, a variety of other parameters were characterized, including GaAs substrate thickness, GaAs crystal lattice orientation, trench depth for electrodes, metal-semiconductor contact, and bias voltage across electrodes. Nearly all parameters were found to play a crucial role influencing terahertz beam emission and carrier dynamics. By exploiting wave chaos and other antenna parameters, we developed a new photoconductive antenna capable of continuous operation with terahertz power twenty times larger than that of the conventional photoconductive antennas, improving from 150 µW to 3 mW. With further optimizations of the parameters, we expect more dramatic improvement of the photoconductive antenna in the near future.
Temple University--Theses
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Lambor, Jiří. "Experimentální bezdrátový spoj v kmitočtovém pásmu 60 GHz." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-220348.
Full textAbstract:
This thesis is focused on a wireless link operating in 60 GHz frequency band. In this band, the attenuation due to resonance of oxygen is high. Thanks to this property, we are able to ensure a proper insulation of communication links working in two close bands. The document compares commercially available modules of offered by different manufacturers for the operation in this band. The design, the simulation and the fabrication of a antenna and its feeder are described in the next part of the thesis. The system is fabricated using a SIW technology.
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Mrnka, Michal. "Ozařovač do bezodrazové anténní komory s dvojí kruhovou polarizací." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-219983.
Full textAbstract:
The purpose of the thesis is to design transmitting antenna based on septum polarizer solution for indoor measurement range. The antenna is considered for both senses of circular polarization. The design is divided into three main sections. First section is devoted to analysis and selection of a suitable waveguide. Ridge waveguide as a crucial part of a septum polarizer is mentioned in this section. Second part is the most critical; here the septum polarizer is analyzed and based on simple procedure also designed. Two suitable horn apertures are then developed as a part of the third section. Individual transmitting antenna parts are assembled together into one model and simulated with excellent results for axial ratio, cross-polarization discrimination, return loss and isolation between ports.
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Zechmeister, Jaroslav. "Anténní systém pro automobilový radar." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2018. http://www.nusl.cz/ntk/nusl-377020.
Full textAbstract:
This thesis deals with the design of lens antennas for automotive radar in 77 GHz bandwidth. The work explains methods of designing waveguides as well as horn antennas and dielectric lens. A simulation of three designed horn antennas is performed in CST Microwave Studio. Antennas with spherical and hyperbolical lens are simulated as well and subsequently optimized for maximal gain. The thesis also investigates effects of the lens permittivity on its properties. Furthermore, the work deals with a design of an antenna system with minimalized antenna coupling. Nylon, ABS and photopolymer lens are designed and compared afterwards. ABS and photopolymer lens were produced by 3D print
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Gaja, Tomáš. "Návrh anténní řady pro MSPS radar pracující v pásmu L." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-316426.
Full textAbstract:
This thesis deals with the design of an antenna array for the MSPS Radar L band application. The introduction covers a research for a suitable antenna element which can be used as an element of steerable antenna array. The control of the main beam is enabled in the vertical plane. Based on a presented theory, a slotted waveguide antenna array with an omnidirectional radiation in the vertical plane is designed. The operating frequency is set to 1 367.5 MHz. Slotted array achieves 20° width of the main beam in elevation plane. The achieved gain of the array is 9.15 dBi. Further attention of this work is focused on the beam steering that is allowed by diode switching. The last part of the thesis presents manufacturing process of the designed model. The CST Microwave Studio software was used for the antenna array designing process.
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Salem, Hesari Sara. "Substrate integrated waveguide antenna systems." Thesis, 2018. https://dspace.library.uvic.ca//handle/1828/10564.
Full textAbstract:
Due to high demand for planar structures with low loss, a considerable amount
of research has been done to the design of substrate integrated waveguide (SIW)
components in the mm-wave and microwave range. SIW has many advantages in
comparison to conventional waveguides and microstrip lines, such as compact and
planar structure, ease of fabrication, low radiation loss, high power handling ability
and low cost which makes it a very promising technology for current and future
systems operating in K-band and above. Therefore, all the work presented in this
dissertation focuses on SIW technology. Five di erent antenna systems are proposed
to verify the advantages of using SIW technology.
First, a novel K-band end- re SIW circularly polarized (CP) antenna system on
a single layer printed-circuit board is proposed. A high gain SIW H-plane horn and a
Vivaldi antenna are developed to produce two orthogonal polarizations in the plane of
the substrate. CP antennas have become very popular because of their unique characteristics and their applications in satellites, radars and wireless communications.
Second, a K-band front-end system for tracking applications is presented. The circuit comprises an antenna array of two Vivaldi antennas, a frequency-selective power combiner, and two frequency-selective SIW crossovers, which eliminate the need for subsequent ltering. The integration of monopulse systems in planar, printed circuit
SIW technology combined with the added bene ts of ltering functions is of great importance to the antennas and propagation community.
Third, a phased array antenna system consisting of 24 radiating element is designed
as feed system for reflector antennas in radio astronomy applications. A Ku-band antipodal dipole antenna with wide bandwidth, low cross-polarization and wide beamwidth is suggested as the radiating element.
Forth, four di erent right-angled power dividers including in-phase and out-of-phase
dividers as feed systems for antenna arrays are introduced. TE10 - to - TEq0 mode transducers are used for obtaining two, three, and four output dividers with phase control ability at K- and Ka-band. This feature is practical, for instance, when designing tracking systems since they are employed to obtain controllable phase distributions over the output ports.
Fifth, a Ku-band beam steering antenna system which is applicable to use for wireless communications, radar systems, and also 5G applications is proposed. This antenna system uses variable reflection-type phase shifters which electrically steer the beam over a 50-degree scan range.
Therefore, the SIW technology's reliability and also promising behavior in the microwave frequency range is proven for di erent applications.Graduate
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Loizou, Loizos. "A Non-Pyramidal Rectangular-to-Trough Waveguide Transition and Pattern Reconfigurable Trough Waveguide Antenna." Thesis, 2010. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8908.
Full textAbstract:
Trough waveguides (TWG) have been utilized in a variety of radio frequency
(RF) and other related applications including radar, the treatment of hypothermia and in
the generation of plasmas. Perturbing the guided wave in these structures with blocks,
rods, dielectrics, and other structures can create reconfigurable periodic line sources.
These trough waveguide antennas (TWA) are then capable of providing both fixedfrequency
and frequency-dependent beam steering. This was originally performed using
electro-mechanical “cam-and-gear” mechanisms. Previous work related to the excitation
of TWG and the performance of TWA topologies are limited when compared to more
common antenna designs, yet they possess many desirable features that can be exploited
in a modern system.
This thesis will examines an S-band rectangular-to-trough waveguide transition
and trough guide antenna that has been designed for broadband reconfigurable antenna
applications considering as well the airflow characteristics for sensing applications. The
design, fabrication, and electromagnetic performance (mode conversion, impedance matching, and antenna performance) are discussed, including the use of metallic
cantilever perturbations placed along the troughguide sidewalls that are designed to
provide improved impedance matching when steering the beam from the backward
quadrant through broadside, towards the forward quadrant. Impedance matching
techniques such as use of circular holes at the edge of each actuated cantilever are used
to reduce power reflections and provide a low voltage standing wave ratio (VSWR)
along the S-band. Finite element simulations will provide a demonstration of the airflow
and turbulence characteristics throughout the entire structure, where the metallic
cantilevers are used to manipulate the flow of air, to distribute it across the surfaces of
the structure better and improve its potential for sensing operations.
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Liu, Hung-long, and 劉杭龍. "Design of Coplanar Waveguide Fed Planar Multi-Band Antenna and Slot Antenna." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/67037843528686599024.
Full textAbstract:
碩士逢甲大學
產業研發碩士班
95
The applications of wireless communication technology are much more in our daily life. The more lighter, more thinner, and more smaller of the communication equipments we required, the more important role the antenna plays in a whole wireless communication system, and therefore, the more worth we want to study and develop the design work of the antenna. The proposed antennas in this thesis are fed by using the CPW (coplanar waveguide), in addition to the advantages of low cost, lightweight, easy to fabricate, they are especially suitable for dual-frequency applications. The proposed antennas are suitable for WLAN ( Wireless Local Area Network ) application in 2.4 GHz and 5.2 GHz, the operation frequency are fit for IEEE 802.11 b ( 2.4 GHz ) and 802.11 a ( 5.2 GHz ) . The antenna has been constructed based on theories from textbooks and papers, which also verified by commercial electromagnetic simulation software-IE3D. The measured input impedance, return loss and radiation pattern are presented and discussed.
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Huang, Yao-Nan, and 黃耀南. "THE SHIELDED COPLANAR WAVEGUIDE DIPOLE-FED SLOT ANTENNA." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/38245259888758329159.
Full textAbstract:
碩士大同工學院
電機工程學系
84
In this thesis, a new structure antenna, namely the diople fed slot antenna on the shielded coplanar waveguide (SCPW) is being studied. This antenna is suitable for circuit integration with SCPW that avoids the difficulty of the coaxial line fed connection or the difficulty of the layout of the strip line and the antenna on the same plane. For accurate experimental measurement of the antenna, a calibration method is introduced to correct errors caused by the imperfect connection between the coaxial line and the SCPW. The input impedances are measured and studied for various structures of SCPW antenna by varying the length of dipole feed, the length of the slot antenna and the slot shape. Best impedance matching or low return loss of the antenna at designed frequency can be achieved by adjusting both the length of dipole feed and the length of slot antenna. The dumbbell shaped slot and the H-shaped slot show the effect to shorten the total length of the antenna at given frequency. The antenna pattern of the SCPW slot antenna is similar to that of the half wave dipole antenna. Moreover, under best impedance matching condition, the gain of SCPW slot antenna can be higher than that of the electric half wave dipole in free space.
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Wang, Qianqian. "A Coplanar Waveguide UWB Antenna With Notch Filter." Thesis, 2012. http://hdl.handle.net/1828/4678.
Full textAbstract:
Due to the release of 3.1-10.6 GHz band, UWB systems have a rapidly progressive development. They have been widely employed in short-range communication applications and large-bandwidth handheld devices. As part of the system, the UWB antenna plays an extremely important role. Due to the trend towards integrated printed circuits, co-planar waveguide technology is a feasible solution for designing the UWB antenna.
This thesis focuses on designing a UWB co-planar waveguide antenna with a band-stop filter. This band-stop filter offers rejection to unwanted frequencies in the range of the operating band in order to avoid unnecessary interference from other communication applications and improve its own system’s performance. In addition, it can divide the whole wide band into a few sub-bands. This will create more flexibility for practical applications.
The professional full-wave field solver software package CST Microwave Studio is used as the analysis tool to obtain the performances of this antenna. It operates from 3.1 GHz to 10.6 GHz with a VSWR < 2 in the pass bands, and a VSWR > 2 in the stop bands. The selected frequencies demonstrate nearly omni-directional characteristics in radiation patterns. Comparing with other published UWB antenna designs, relatively reasonable group delay results are achieved. Measurements on a fabricated prototype validate the design approach.Graduate
0537
wang@uvic.ca
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Bronte, MacIntosh-Hobson. "Slotted substrate integrated waveguide array antenna & feed system." Thesis, 2008. http://spectrum.library.concordia.ca/976150/1/MR45491.pdf.
Full textAbstract:
In this thesis we investigate substrate integrated waveguides and their application as a slotted waveguide antenna array. The standard slotted waveguide antenna is designed following Elliot's modified design procedure. Elliot's modified design procedure not only takes into account the effects of mutual coupling from the neighboring slots in the array but also the internal higher order modes that are scattered off adjacent slots. The antenna is then converted to a slotted substrate integrated waveguide antenna by carefully placing two rows of metallic via holes to simulate the sidewalls of the rectangular waveguide. The size and location of the via holes are calculated such that they contain the electromagnetic fields inside the substrate integrated waveguide with negligible leakage loss and that the substrate integrated waveguide has the same propagation constant and characteristic impedance as its equivalent rectangular waveguide. Integrating the waveguide into a substrate allows the entire circuit to be fabricated within the substrate and eliminates the need for complicated transitions that link a rectangular waveguide to a planar circuit. The antenna is fed by a 50] shielded stripline. The stripline is shielded by two rows of via holes placed symmetrically on each side of the trace of the stripline. The transition is composed of a single via hole that links the shielded stripline to the substrate integrated waveguide. Back-to-back transitions between a shielded stripline and a substrate integrated waveguide are designed and simulated for three different frequency bands; C band, Ku band & Ka band. The bandwidth of the transitions ranged from 20-35% in all cases. A back-to-back transition was fabricated for the C-band. The fabrication was done by hand using electrical tape for the stripline inner conductor and screws as the via holes. The bandwidth of the measured results show a smaller bandwidth compared to the simulated results. This disparity is due to the imperfections associated with fabricating the transition by hand. A uniform antenna array of 8 slots is designed and simulated with the feed network. A good radiation pattern with sidelobes 14dB below the main beam is observed. The antenna has an impedance bandwidth of 1GHz at the operating frequency of 15GHz.
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Hsu, Chia-Jui. "Coplanar waveguide fed patch antenna design and bandwidth enhancement." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-0607200420553700.
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Wang, Ying-Chih. "Coplanar Waveguide Fed Multi-Band Spiral Slot Antenna Design." 2004. http://www.cetd.com.tw/ec/thesisdetail.aspx?etdun=U0001-0607200417420600.
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Yin, You-Zheng, and 尹又正. "Design and Applications of a Coplanar Waveguide Antenna Biosensor." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/18153600717866741203.
Full textAbstract:
碩士國立臺灣大學
醫學工程學研究所
100
As the demand for biomedical sensing applications increase, an innovative techniques and architectures are required. To overcome the limitations of traditional methods, noninvasive near-filed electromagnetic sensing technique is proposed for biomedical applications. An antenna based biosensor is developed to investigate the near-field electromagnetic interaction between antenna and sample with different dielectric properties. These dielectric properties can be determined by analyzing the electromagnetic coupling between the antenna and the test samples without labeling or chemical reaction. The antenna biosensor is developed by applying the coplanar waveguide (CPW) feeding mechanism, a surface-strip transmission line (TL), which consists of a strip on thin metallic film deposited on the surface of a dielectric slab with two ground electrodes running adjacent and parallel to the strip on the same surface. The coplanar waveguide offers a variety of advantages over the conventional micro-strip line, it can be placed conveniently in contact with one side of the test material and therefore provide non-destructive measurements. The coplanar waveguide (CPW) antenna biosensor is modeled and simulated with Ansoft HFSS and fabricated on inexpensive FR-4 substrate of thickness 0.8 mm, the overall dimension of the antenna biosensor is (20x20x0.8)mm3. Two measurement methods were applied in this research, one supply the sample to the surface of the antenna with a tape boundary, and another by a fluidic channel attached on the backside of the coplanar waveguide antenna biosensor, all measurements were taken by Agilent E5071B Network Analyzer. Experimentally validated the liquid samples with different dielectric properties, different concentrations of ethanol, methanol, glucose, sodium chloride solution, and different daily beverage like beer, red wine and liquor were measured and determined with the proposed coplanar waveguide antenna biosensor. The results exhibit the potential applications in bio-sensing.
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Chen, Te-Hsing, and 陳德興. "Coplanar Waveguide Fed Broadband Circularly Polarized Square Slot Antenna." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/51687270264892438571.
Full textAbstract:
碩士國立中央大學
電機工程學系在職專班
101
This thesis describes the design with simplification structure and fabrication on the same plane of FR-4 substrate. At first studying the single band CPW-fed slot antenna, and then designing of proposed broadband circular polarization CPW-fed slot antenna, which is achieved by an asymmetry ground plane makes the adjacent resonant mode to merge into a wide operation bandwidth and etching C-shaped ground strip on the edge of left side of ground plane to offer the current path, two orthogonal electric fields with a 90°phase difference for exciting a circular polarization radiation wave. On the other hand, a C-shaped slot is embedded at the bottom right corner of ground plane. It is used for broadband AR and impedance matching. The measured impedance bandwidth (VSWR 2) is 0.92 GHz (46% relative to the center frequency at 2 GHz). The 3-dB axial ratio bandwidth (ARBW) is 0.65 GHz (32.5% relative to the center frequency at 2 GHz), and antenna peak gain is 3.31 dBi with variations of less than 1 dBi. This antenna is suitable for wireless communication system (1.71－2.17 GHz) and navigation system (1.57－1.61 GHz).
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Chou, Ke-Ru, and 周克儒. "Design and Applications of Waveguide Slot Linear Array Antenna." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/4mfmjr.
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Chen, Chih-Sheng, and 陳致勝. "Design of Substrate-Integrated-Waveguide Antenna with High Directivity." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/rm3625.
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碩士國立虎尾科技大學
航空與電子科技研究所
101
Abstract In this thesis, two antenna elements with the substrate-integrated-waveguide (SIW) structure were designed for use in the C-band (4-8 GHz) and X-band (8-12 GHz), and high directivity radiation characteristic was achieved from applying different design technologies to these designs as well. The first design is a missile-mounted SIW antenna with high directivity for data transmission. The proposed antenna was fed by a microstrip line and designed based on a horn structure composed from periodic vias to achieve the effect of high directional radiation. Meanwhile, with use of both the parasitic rectangular element and the rectangular slot, the antenna’s front-to-back ratio (F/B) can be increased, whereas the side and back lobes are effectively suppressed. For measurement and validation, the scaled models of the SIW antenna and the missile were built. The measured results show the antenna has high directivity and which is in accordance with the simulation. Also, the result shows that the antenna still has high directivity when mounted on the missile. The second design is a double-layer SIW antenna with high directivity. It is also fed by a microstrip line and composed from a double-layer structure to suppressed the side-lobe radiation. In addition, by dig rectangular slot on the upper portion of the antenna the value of front-to-back ratio can be increased. Finally, we further improved the directivity from adjusting the metal structure sited between the superstrate and the substrate.
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Hsu, Chia-Jui, and 許家睿. "Coplanar waveguide fed patch antenna design and bandwidth enhancement." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/82723993965318297276.
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碩士國立臺灣大學
電信工程學研究所
92
In this thesis, circularly polarized patch antennas fed by coplanar waveguide are designed for 60GHz (V-band) WLAN systems. To obtain wider bandwidth, two approaches are investigated. One is to taper the etched shapes on the patch, and the other is to add a series LC matching network to the input end. For verification, they are implemented and measured at 5GHz with FR4 PCB and results show good bandwidth enhancement. In addition, a CPW-fed coplanar patch antenna is presented. Both linearly polarized and circularly polarized antennas are designed at 10GHz. This structure can also be utilized for V-band applications.
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Wang, Ying-Chih, and 王盈智. "Coplanar Waveguide Fed Multi-Band Spiral Slot Antenna Design." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/25224262685493774510.
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碩士國立臺灣大學
電信工程學研究所
92
The CPW-fed multi-band rectangular and oblique spiral slot antennas are studied in this paper. The input impedance and the radiation characteristics of these antennas are investigated using the software package Ensemble. In the design of the antenna, the slot dipole antennas are used as the basic unit. Then different lengths and widths of the slots in the spiral slot are used to achieve the desired resonant frequencies. The antennas cover the IEEE 802.11a and b frequencies which are 2.4~2.48 GHz, 5.15~5.35 GHz, and 5.725~5.825 GHz. In order to clarify our design, both the CPW-fed multi-band rectangular and oblique spiral slot antennas are designed and fabricated. Comparing the simulated and experimental results, these antennas are proved to be correct and practical.
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Yang, Su-Che, and 楊肅哲. "A Beam Steering Antenna Design based on Switched Waveguide Walls." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/87998800944261759917.
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碩士國立交通大學
電信工程研究所
100
This paper presents a novel beam-steering antenna design based on Switched Waveguide Walls. A monopole is located inside a parallel-plate structure as excitation, which is surrounded by Switched Waveguide Walls in radial arrangement. Specifically, PIN diode placed on each Switched Waveguide Walls unit cell is either turned on or off to control its transmission characteristic in the desired operation frequency. The direction of main beam possesses 360 degree of freedom on X-Y plane with resolution angle of 18 degree by turning on selected PIN diodes. Unlike conventional beam-steering antenna design employing phase shifter or phased array, this paper has greatly reduced the complexity of feeding network of entire structure. Due to the advantages of easy fabrication, robustness, and low-cost issue, such an antenna can be a potential candidate for wireless communication system and base station antenna application.
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Yau, Chyi-kwei, and 邱其奎. "Microstrip Line to Substrate Integrated Waveguide Transition and Antenna Applications." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/96225178319729886543.
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碩士國立臺灣大學
電信工程學研究所
95
This thesis proposes two kinds of vertical transitions between microstrip line and substrate integrated waveguide (SIW), and a slot array antenna feeding by our transition structure. All these structures are fabricated on low-temperature co-fired ceramic (LTCC) substrate. This thesis also presents the equivalent circuits of both transition structures. The microstrip line is on the upper layer, and the SIW is on the bottom layer with the vertical metal walls realized by closely spaced vias. The first transition design is realized by a shorted via between the end of the microstrip line and the bottom layer of SIW. A current is induced on the via and energy is coupled to SIW. Another transition structure is realized by opening a slot on the top wall of SIW and feeding by a 1/4λg microstrip line open stub. With the magnetic current induced on the slot, the transition is achieved. The design of slot array antenna is also achieved by opening slots on SIW, and the power is radiated from the slots. The radiated power and center frequency are adjusted by the slot position and slot length. All our structures are designed at Ka-band. Both the transition structures exhibit about 40% fractional bandwidth with -15dB return loss and the measurement results agree with our simulation.
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Fang, Ruei Ying, and 方瑞穎. "Planar Circuits to Rectangular Waveguide Transitions Using Bow-Tie Antenna." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/41514253869750662169.
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碩士國立臺灣科技大學
電子工程系
95
In order to realize a broadband slotline-to-rectangular waveguide transition, we adopt a truncated bow-tie antenna, which possess a broadband characteristic. This transition is designed in X-band (8.2-12.4 GHz) to make the insertion loss as small as possible and the return loss as large as possible in the full band of X-band. A complete analysis, design procedure, and measurement verification are discussed in the following contents of this thesis. Through proper design, the simulation results show a wideband response for a single transition with a insertion loss smaller than 0.1 dB and a return loss larger than 15 dB. In order to verify our results, we fabricate a back to back transition composing of two single transitions connected back to back. The simulation and measurement results of the back to back transition agree well in the full band of X-band. The simulation and measurement insertion losses are smaller than 0.25 dB and 0.4 dB in the full band of X-band, respectively and the simulation and measurement return losses are larger than 13 dB and 15 dB, respectively. While the wideband slotline-to-rectangular waveguide transition is accomplished, it is used to implement a wideband CPW-to-rectangular waveguide transition by integrating it with a CPW-to-slotline transition. The simulation results show that the return loss is larger than 14 dB and the insertion loss is smaller than 0.2 dB over the entire X-band, which means that a wideband performance could be easily achieved by this structure, also.
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Mandelbaum, Idan. "Phase tunability in a conductor backed coplanar waveguide patch antenna." Thesis, 2000. http://library1.njit.edu/etd/fromwebvoyage.cfm?id=njit-etd2000-005.
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Chen, Jyun-Ting, and 陳俊廷. "Design of the Microstrip-Fed Rectangle Substrate Integrated Waveguide Antenna." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/88bs3j.
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碩士國立虎尾科技大學
航空與電子科技研究所
100
The primary research of this thesis is focused on the design of Substrate Integrated Waveguide (SIW) antenna for X band, putting the different fed and geometric figure to design two kinds of SIW antennas. First, we utilize an antenna designed by micro-strip line, analyzing the difference between the micro-strip line antenna and substrate integrated waveguide antenna with its construction and affection. By etching two loops rectangular slots at the end of micro-strip line and adjusting its quantities and slots could improve its impedance matching. Its overall size is just only 17x25 which could generate a resonance at 10.05GHz. Secondly, we use the coplanar waveguide thesis to design a new type antenna; according to the thesis, the impedance is decided by the width of signal line and the width of both sides of the slot. We obtain return loss by observing the variation of distance. Because of the principle of SIW is to utilize Upper and lower levels of metal plate and Around two rows of via hole array to limit the radiation electromagnetic wave, backplane should be set in the range of via hole array to make the integral structure of the aerial become a combination of three structures includes CPW-microstrip-SIW. Then analyze the impact of the backplane of the antenna structure and found that when the increase the length of the backplane, thebackplane and between the microstrip line and the ground plane of the LC resonance effect, seriously affecting the impedance matching of the antenna. when the resonance frequency is at 8.66GHz, the front-to-back ratio of antenna can achieve 9dB, and its overall size is 17x20