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1
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 ±<br>35 degrees in elevation. It also has a usable bandwidth of 600 MHz.
2
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.
3
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.
4
Römer, Christian. "Slotted waveguide structures in phased array antennas /." Karlsruhe : IHE, 2008. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=016491138&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
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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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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.<br>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.<br>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.
7
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.
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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.
8
Tekkouk, Karim. "Développement d'antennes multi-faisceaux multicouches de la bande Ku à la bande V." Thesis, Rennes 1, 2014. http://www.theses.fr/2014REN1S165.
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Les travaux de cette thèse portent sur la conception d'antennes multi-faisceaux. Ces dernières permettent à plusieurs faisceaux de partager la même partie rayonnante et offrent la possibilité d'avoir simultanément un fort gain et une grande couverture angulaire. Pour leur fonctionnement, ces antennes se basent sur des réseaux à formation de faisceaux, qui peuvent être groupés en deux catégories : les réseaux formateurs de faisceaux de type quasi-optique et les réseaux formateurs de faisceaux de type circuit. Plusieurs structures antennaires reposant sur ces types de réseaux à formation de faisceaux sont proposés dans cette thèse : structures pillbox simples intégrant les deux variantes de la technique mono-pulse pour augmenter la résolution angulaire de l'antenne, lentilles de Rotman bicouche et multicouche, pour le cas quasi-optique ; réseaux phasés pour applications SATCOM (projet ANR) et matrice de Butler avec circuit de contrôle des niveaux de lobes secondaires pour le cas circuit. Les différents concepts ont été étudiés dans différentes bandes de fréquences : Ku, K et V. Pour des raisons de coût essentiellement, deux technologies ont été retenues : La technologie SIW (Substrate Integrated Waveguide), qui associe les avantages de la technologie des circuits imprimés et celles de la technologie guide d'ondes. Des efforts particuliers ont été faits pour l'implémentation de structures multicouches car nous arrivons à ce stade à la limite du savoir faire industriel national dans ce domaine. La technique de « Diffusion Bounding » développée au « Ando and Hirokawa lab » du TIT (Tokyo Institute of Technology) et qui consiste à assembler de fines couches métalliques sous haute température et haute pression. Cette technique permet le développement d'antennes en guides creux avec des efficacités supérieures à 80% en bande millimétrique<br>This PhD thesis deals with the design of multi-beam antennas. A single radiating aperture is used to generate several beams with high gain and a large field of view. The multi beam operation is achieved by using two topologies of Beam Forming Networks (BFN): quasi optical BFN, and circuit-based BFN. For each category, several solutions have been proposed and validated experimentally. In particular, for the quasi-optical configurations, pillbox structures, mono-pulse antennas in pillbox technology, and multi-layer Rotman lenses have been considered. On the other hand, for circuit-based multi-beam antennas, two solutions have been analyzed: a phased array for SATCOM applications in the framework of a national ANR project and a Butler matrix with controlled side-lobe levels for the radiated beams within a collaboration with the Tokyo Institute of Technology, Japan. The proposed concepts and antenna solutions have been considered in different frequency bands: Ku, K and V. Two technologies have been mainly adopted for the fabrication of the various prototypes: Substrate Integrated Waveguide technology (SIW) which combines the advantages in terms of cost of the printed circuit board (PCB) fabrication process with the efficiency of classical waveguide technology. Considerable efforts have been devoted to the implementation of multilayer SIW structures to overcome and go beyond the current state of the art at national level on PCB fabrication process. Diffusion Bounding Technique, developed at “Ando and Hirokawa lab” at the Tokyo Institute of Technology, which consists of bonding laminated thin metal plates under high temperature and high pressure. This technique allows the fabrication of planar hollow waveguide structures with efficiencies up to 80% in the millimeter wave-band
9
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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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.<br>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.<br>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.
11
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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Zhao, Kunchen. "3D Printed Frequency Scanning Slotted Waveguide Array with Wide Band Power Divider." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1555589955819802.
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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.
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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.
16
Sumanam, Satya Parthiva Sri. "A Conductor Backed, Coplanar Waveguide Fed, Linear Array Comprised of Bowtie Antennas for a Varactor Tuned Radiation Pattern." University of Dayton / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1470346770.
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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.
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[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.<br>[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.<br>[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.<br>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<br>TESIS
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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 système<br>In 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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Abusitta, M. M. "Design and modelling of beam steering antenna array for mobile and wireless applications using optimisation algorithms. Simulation and measrement of switch and phase shifter for beam steering antenna array by applying reactive loading and time modulated switching techniques, optimised using genetic algorithms and particle swarm methods." Thesis, University of Bradford, 2012. http://hdl.handle.net/10454/5745.
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The objectives of this work were to investigate, design and implement beam steering antenna arrays for
mobile and wireless applications using the genetic algorithm (GA) and particle swarm optimisation (PSO)
techniques as optimisation design tools. Several antenna designs were implemented and tested: initially, a
printed dipole antenna integrated with a duplex RF switch used for mobile base station antenna beam
steering was investigated. A coplanar waveguide (CPW) to coplanar strip (CPS) transition was adopted to
feed the printed dipole. A novel RF switch circuit, used to control the RF signal fed to the dipole antenna
and placed directly before it, was proposed. The measured performance of the RF switch was tested and
the results confirmed its viability. Then two hybrid coupled PIN diode phase shifters, using Branchline
and Rat-Race ring coupler structures, were designed and tested. The generation of four distinct phase
shifts was implemented and studied. The variations of the scattering parameters were found to be realistic,
with an acceptable ±2 phase shift tolerance.
Next, antenna beam steering was achieved by implementing RF switches with ON or OFF mode
functions to excite the radiating elements of the antenna array. The switching control process was
implemented using a genetic algorithm (GA) method, subject to scalar and binary genes. Anti-phase
feeding of radiating elements was also investigated. A ring antenna array with reflectors was modelled
and analysed. An antenna of this type for mobile base stations was designed and simulation results are
presented.
Following this, a novel concept for simple beam steering using a uniform antenna array operated at 2.4
GHz was designed using GA. The antenna is fed by a single RF input source and the steering elements
are reactively tuned by varactor diodes in series with small inductors. The beam-control procedure was
derived through the use of a genetic algorithm based on adjusting the required reactance values to obtain
the optimum solution as indicated by the cost function. The GA was also initially used as an optimisation
tool to derive the antenna design from its specification.
Finally, reactive loading and time modulated switching techniques are applied to steer the beam of a
circular uniformly spaced antenna array having a source element at its centre. Genetic algorithm (GA)
and particle swarm optimisation (PSO) processes calculate the optimal values of reactances loading the
parasitic elements, for which the gain can be optimised in a desired direction. For time modulated
switching, GA and PSO also determine the optimal on and off times of the parasitic elements for which
the difference in currents induced optimises the gain and steering of the beam in a desired direction.
These methods were demonstrated by investigating a vertically polarised antenna configuration. A
prototype antenna was constructed and experimental results compared with the simulations. Results
showed that near optimal solutions for gain optimisation, sidelobe level reduction and beam steering are
achievable by utilising these methods. In addition, a simple switching process is employed to steer the
beam of a horizontally polarised circular antenna array. A time modulated switching process is applied
through Genetic Algorithm optimisation. Several model examples illustrate the radiation beams and the
switching time process of each element in the array.
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Kubín, Petr. "Dielektrická rezonátorová anténa na bázi vlnovodu integrovaného do substrátu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2013. http://www.nusl.cz/ntk/nusl-220271.
Full textAbstract:
The Master’s thesis deals with the design of the dielectric resonator antenna array based on the substrate integrated waveguide. The work describes various feed methods of the dielectric resonator antenna and the technique of the design of the antenna. The antenna array was designed in the simulative program ANSYS HFSS at the frequency 10 GHz, subsequently fabricated and measured. The antenna array has the bandwidth of 570 MHz for S11 better than –10 dB and the gain of 12.1 dBi.
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Abusitta, Musa M. "Design and modelling of beam steering antenna array for mobile and wireless applications using optimisation algorithms : simulation and measrement of switch and phase shifter for beam steering antenna array by applying reactive loading and time modulated switching techniques, optimised using genetic algorithms and particle swarm methods." Thesis, University of Bradford, 2012. http://hdl.handle.net/10454/5745.
Full textAbstract:
The objectives of this work were to investigate, design and implement beam steering antenna arrays for mobile and wireless applications using the genetic algorithm (GA) and particle swarm optimisation (PSO) techniques as optimisation design tools. Several antenna designs were implemented and tested: initially, a printed dipole antenna integrated with a duplex RF switch used for mobile base station antenna beam steering was investigated. A coplanar waveguide (CPW) to coplanar strip (CPS) transition was adopted to feed the printed dipole. A novel RF switch circuit, used to control the RF signal fed to the dipole antenna and placed directly before it, was proposed. The measured performance of the RF switch was tested and the results confirmed its viability. Then two hybrid coupled PIN diode phase shifters, using Branchline and Rat-Race ring coupler structures, were designed and tested. The generation of four distinct phase shifts was implemented and studied. The variations of the scattering parameters were found to be realistic, with an acceptable ±2 phase shift tolerance. Next, antenna beam steering was achieved by implementing RF switches with ON or OFF mode functions to excite the radiating elements of the antenna array. The switching control process was implemented using a genetic algorithm (GA) method, subject to scalar and binary genes. Anti-phase feeding of radiating elements was also investigated. A ring antenna array with reflectors was modelled and analysed. An antenna of this type for mobile base stations was designed and simulation results are presented. Following this, a novel concept for simple beam steering using a uniform antenna array operated at 2.4 GHz was designed using GA. The antenna is fed by a single RF input source and the steering elements are reactively tuned by varactor diodes in series with small inductors. The beam-control procedure was derived through the use of a genetic algorithm based on adjusting the required reactance values to obtain the optimum solution as indicated by the cost function. The GA was also initially used as an optimisation tool to derive the antenna design from its specification. Finally, reactive loading and time modulated switching techniques are applied to steer the beam of a circular uniformly spaced antenna array having a source element at its centre. Genetic algorithm (GA) and particle swarm optimisation (PSO) processes calculate the optimal values of reactances loading the parasitic elements, for which the gain can be optimised in a desired direction. For time modulated switching, GA and PSO also determine the optimal on and off times of the parasitic elements for which the difference in currents induced optimises the gain and steering of the beam in a desired direction. These methods were demonstrated by investigating a vertically polarised antenna configuration. A prototype antenna was constructed and experimental results compared with the simulations. Results showed that near optimal solutions for gain optimisation, sidelobe level reduction and beam steering are achievable by utilising these methods. In addition, a simple switching process is employed to steer the beam of a horizontally polarised circular antenna array. A time modulated switching process is applied through Genetic Algorithm optimisation. Several model examples illustrate the radiation beams and the switching time process of each element in the array.
22
Sedláček, Petr. "Štěrbinová anténní řada na bázi vlnovodu integrovaného do substrátu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219844.
Full textAbstract:
The Master’s Thesis deals with the design of slot antenna array based on the substrate integrated waveguide (SIW). Various supply methods are described and the design procedure is approached. The antenna array was designed for Wi-Fi band of 5 GHz in the Ansoft HFSS simulation software. The optimalized parameters are impedance bandwidth (low reflection coefficient at antenna input in the desired frequency band) and the gain (the maximum value). As the result of the work 3 antenna arrays based on the substrate integrated waveguide are designed and fabricated: antenna arrays 2x1, 2x2 and antenna array 2x2 supplemented with housing for outdoor use. The work also contains a comparison of simulated and measured parameters of antennas.
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Špůrek, Jan. "Textilní štěrbinová anténa." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242116.
Full textAbstract:
This diploma thesis is focused on design of various antenna structures, based on slot antennas, created in the wider wall of a rectangular-shaped waveguide. As the substrate, it is used a 3D textile material, while its properties are examined. They were designed structures, that operate with linear and circular polarization, and other related structures, that are used for feeding and power division. Structures are designed to operate at central frequency of 8 GHz and its vicinity.
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Mansutti, Giulia. "Analysis and design of innovative antenna systems for telecommunications and health applications." Doctoral thesis, Università degli studi di Padova, 2018. http://hdl.handle.net/11577/3421863.
Full textAbstract:
In this thesis the study of different innovative antenna systems is presented. The antenna designs that have been analyzed and that are described in this thesis can be divided in three main groups based on their application: phased-array antennas working on surfaces that change shape in time, millimeter-wave antennas for skin cancer diagnosis, and gaseous plasma antennas for satellite communications.
As far as the first topic is concerned, the research activity presented in this thesis focuses on the study of the strengths and limitations of a specific pattern recovery technique: the projection method. This technique has been adopted to retrieve the radiation properties of linear and planar arrays placed on surfaces whose shape changes in time according to different geometrical deformation; moreover, its effectiveness was assessed for both broadside and beam steering arrays, leading to a novel and simpler formulation of this pattern recovery technique for arrays whose beam is tilted towards different directions. The results have been obtained both through full-wave numerical simulations in CST Microwave Studio and through measurements performed in collaboration with the North Dakota State University (NDSU), Fargo, North Dakota, USA.
Regarding skin cancer diagnosis, a novel substrate integrated waveguide probe for early-stage skin cancer detection has been designed as well: this probe is cheap and easy to fabricate and can achieve high accuracy in detecting small early-stage skin cancer, thus providing a tool with the potential of being adopted as a real aid for skin cancer diagnosis. The probe has been tested both through full-wave numerical simulations and through measurements on a skin phantom realized at The University of Queensland with the support of the Microwave Team.
The study about gaseous plasma antennas for satellite communications has been mainly numerical. Different designs have been conceived with the aim of exploiting the advantages of using plasma elements while at the same time avoiding the limitations related to this novel technology. A practical implementation of these designs is now the subject of a collaboration with CISAS B. Colombo, an aerospace research center of the University of Padova.
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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.
Full textAbstract:
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 théoriquement<br>The 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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Li, Jinfeng. "Structure and optimisation of liquid crystal based phase shifter for millimetre-wave applications." Thesis, University of Cambridge, 2019. https://www.repository.cam.ac.uk/handle/1810/288407.
Full textAbstract:
The delivery of tunable millimetre-wave components at 60GHz is of research and development interests with the advent of 5G era. Among applications such as high-data-rate wireless communications, high-precision automotive radars and hand-gesture sensing, variable phase shifters are vital components for antenna arrays to steer an electromagnetic beam without mechanical movement. However, present microwave technology has limited scope in meeting more and more stringent requirements in wavefront phase control and device performance for those cutting-edge applications in the millimetre-wavelength range. Although some existing microwave switchable techniques (such as RF MEMS and solid-state p-i-n diodes) can offer ultra-fast speed for phase modulation, their binary beam-steering nature is resolution-limited and thereby degrades the beam-scanning performance. In response to this, continuously-tunable phase shifting can be realised by using tunable dielectric materials such as ferroelectric BST and liquid crystals (LCs). BST thin films can offer relatively fast switching and modest tunability. However, the increased dielectric loss beyond 10GHz impedes their implementation for higher frequency applications. By comparison, liquid crystals (LCs) have drawn attention in recent years because of their continuous tunability as well as low losses especially at millimetre-wavebands. The principle of shifting the phase continuously is based on the shape anisotropy of LC molecules for variable polarizabilities and hence tunable dielectric constants, which allows wave speed to be controlled with ease by a low-frequency field of only up to 10V. However, LC-based tunable delay lines are not well established in the frequency regime of 60GHz-90GHz because of the limited status of LC microwave technology in which most of the LC based devices have been designed for below 40GHz. It is the aim of this PhD research to bridge the gap and address future societal needs based on our group's focus and experience in developing cutting-edge LC-based agile microwave components. In this work, a liquid crystal (LC) based 0-180˚continuously-variable phase shifter is developed with insertion loss less than -4.4dB and return loss below -15dB across a wide spectrum from 54GHz to 67GHz. The device is driven by a 0-10V AC bias and structured in a novel enclosed coplanar waveguide (ECPW) including an enclosed ground plate in the design, which significantly reduces the instability due to floating effects of the transmission line. This structure screens out interference and stray modes, allowing resonance-free quasi-TEM wave propagation up to 90GHz. The tunable ECPW is optimised by competing spatial volume distribution of the millimetre-wave signal occupying lossy tunable dielectrics versus low-loss but non-tunable dielectrics and minimising the total of dielectric volumetric loss and metal surface loss for a fixed phase-tuning range. A variety of influences affecting the actual device performance are studied, experimented and optimised. Fabricated prototypes exhibit wideband low-loss performance and 0-π continuous tuning with low power consumptions and high linearity compared with the state-of-the-arts. Potentially, the ECPW-fed phased antenna array will be incorporated with advanced beam-forming algorithms to develop compact beam-steering systems of improved performances and targeted for ultra-high-data-rate wireless communications, inter-satellite communications, current road safety improvement, futuristic autonomous driving, and other smart devices such as the hand-gesture recognition.
27
Weigel, Filip. "Rekonfigurovatelná štěrbinová anténní řada." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2016. http://www.nusl.cz/ntk/nusl-242136.
Full textAbstract:
This master's thesis deals with the basic principles of slot antennas. Models of antennas were simulated in a selected electromagnetic simulator CST MICROWAVE STUDIO (CST MWS). There are several models of slot antennas which are optimized for communication in the car at a frequency 8 GHz.
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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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Chen, Hsin-Liang, and 陳信良. "Conductor-Backed Coplanar Waveguide Slotted Antenna Array with Improved Aperture Efficiency." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/70643890605028506124.
Full textAbstract:
碩士<br>國立交通大學<br>電信工程系所<br>97<br>Conductor-backed coplanar waveguide (CBCPW) propagates electromagnetic waves via dominant modes (coplanar waveguide mode), and excites leaky wave which propagates toward both sides despite the value of the frequency. In general, there are two applications based on this structure: first is to use such property to design the antenna; the other is to suppress the leaky wave through some methods in order to decrease the unnecessary couplings and crosstalk.
Implementing the full wave analysis on the CBCPW structure, we can discover that the leaky wave propagates along a particular angle relative to the main CPW line, causing the wave to propagate as if in a parallel plate waveguide (PPW). Therefore, we can etch rectangular slots along the ground planes with the angle we have acquired. If the length of the slot is significantly longer than the width and approximately equals to half the guided wavelength, the slots fed by CBCPW will radiate power efficiently and we can thus obtain a centralized broadside radiation pattern. We then derive a method to improve the aperture efficiency of the antenna by analyzing the equivalent circuit of the slot antenna and also by applying Full Wave Spice, and eventually design a highly efficient antenna with a high main beam gain perpendicular to the array plane.
The antenna for direct broadcast from satellites (DBS) is operated at 12 GHz and demands high gain and efficiency, which is also the frequency our antenna operates in, resulting in a radiation pattern with 30.14dBi and a bandwidth of 4.2GHz.
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Chien, Hsiao-Ching, and 錢曉晴. "Circular Polarized Slotted Antenna Array Based on Double-Layer Substrate Integrated Waveguide." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/10370523284292600048.
Full textAbstract:
碩士<br>國立交通大學<br>電信工程研究所<br>99<br>The thesis based on the concept of the waveguide coupling employs resonant slots to couple power from the main waveguide to crossed branch waveguides. An antenna array which is composed of the circularly polarized (CP) four-slots radiated elements can result in a high gain at the broadside direction. The side lobe level (SLL) can be greatly reduced by appropriate design. In the substrate integrated waveguide (SIW), the guided wavelength is less than the wavelength in air. When the array spacing is around a guided wavelength, the grating lobe can be avoided.
The circularly polarized element consists of two orthogonal rectangular slots pair. One rotated with positive angle excites zero phase of electric field and the other one with negative angle excites the ninety degrees phase of electric field. In order to achieve the varies excitations for our design, we control the length of rectangular slot. Therefore every element must be slightly off-resonance. The varies slots geometries cause the varies phase excitations. We can choose array spacing to do phase compensation to get equiphase excitations of the array element.
Finally, we design the circularly polarized array antenna at the 12GHz frequency band which can be applied to the satellite antenna. It has better performance than traditional waveguide, especially high gain, high directivity and more compact size.
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Lin, Yow-Shyan, and 林侑賢. "Circularly Polarized Slotted Conductor-Backed Coplanar Waveguide Antenna Arrays with Sequential Rotation Feeding Method." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/01369908970549073503.
Full textAbstract:
碩士<br>國立交通大學<br>電信工程系所<br>97<br>Conductor-backed coplanar waveguide (CBCPW) exists two dominant modes including CPW and parallel plate modes with no cutoff frequency. The latter one causes the power leakage into transverse direction. We use the characteristic to design it as a good transmission line.
Implementing the full wave analysis (Spectral Domain Approach) on the CBCPW structure, we can acquire the information that the surface wave propagates along a particular angle relative to the main CPW line. So, we etch rectangular slots along the angle on the two side ground planes. Because the slots are separated one guided wavelength, they are excited in the same phase. If the long dimension of the slot is significantly longer than the wide one and approximately equals to a half of guided wavelength, the slots fed by CBCPW can radiate power efficiently. Finally, we derive a broadside radiation pattern.
Modern satellite communication systems use circular polarization (CP) to maximize the polarization efficiency. We use the sequential rotation feeding method to produce circular polarization antennas with linearly polarized elements. The antenna for direct broadcast from satellites (DBS) is operated at 12 GHz and asked for high gain and efficiency. We design our antenna to operate at this frequency. Finally, we have the measured radiation pattern with 24.84 dBiC and the measured axial ratio 3 dB bandwidth with 330 MHz.
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Chin, Chien-Hou, and 秦健候. "Aperture Efficiency and Cross-Polarization Improvement of Sequentially-Fed Circularly Polarized Slotted Conductor-Backed Coplanar Waveguide Antenna Arrays." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/58493656676482103603.
Full textAbstract:
碩士<br>國立交通大學<br>電信工程研究所<br>99<br>The slotted conductor-backed coplanar waveguide antenna features high gain, and belongs to linearly polarized antenna. According to the sequential rotation feeding method, a circularly polarized array can be composed of linearly polarized elements. Therefore, the slotted conductor-backed coplanar waveguide antenna is applicable to this theory, and can compose a circularly polarized array. In this thesis, we use the technique to produce circular polarization, and improve the performance with more linearly polarized elements. The antenna for direct broadcast from satellites (DBS) is operated at 12 GHz and asked for high gain and efficiency. We design our antenna to operate at this frequency. Finally, we have the measured radiation pattern with 26.12 dBiC and the measured axial ratio 3 dB bandwidth with 1 GHz.
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Yeh, Jing-pei, and 葉璟霈. "Coplanar Waveguide fed Circular Polarization Slotted Annular Ring Monopole Antenna." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/96121392848674553596.
Full textAbstract:
碩士<br>國立中央大學<br>電機工程研究所<br>98<br>The design and analysis of a planar, circularly polarized, and slotted annular ring monopole antenna are presented. In contrast to traditional planar circularly polarized patch antenna and slot antennas poised for narrowband applications, the presented antenna is of relatively broad operating bandwidth by exploiting the broadband monopole antenna structure. Specifically, the proposed antenna consists of a coplanar-waveguide (CPW) fed annular ring monopole with a gap near the CPW feed. The circular polarization is essentially realized with the circular current flow on the slotted annular ring and the unsymmetrical surface current on the ground plane. Furthermore, additional circularly polarized operation bands can be realized with the incorporation of stretched-out quarter-wavelength inverted-L sleeves on the ground plane edges. In this thesis, a single-band and a dual-band CPW-fed slotted annular ring monopole antennas are demonstrated. The single-band antenna features circular polarization at the L1 band, while the dual-band antenna is of circular polarization at the L1 band, as well as at 1.96 GHz. In addition, both antennas is of operating frequencies ranging from 1.5 GHz to 3 GHz for the GPS, DCS, PHS, WCDMA, and Bluetooth applications.
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Zeng, Guan-Ling, and 曾冠菱. "Dual-Polarized Slotted Conductor-Backed Coplanar Waveguide Leaky-Wave Antenna." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/85695786639881797377.
Full textAbstract:
碩士<br>國立交通大學<br>電信工程研究所<br>104<br>Conductor-backed coplanar waveguide (CBCPW) propagates electromagnetic waves via dominant modes (coplanar waveguide mode), and excites leaky wave which propagates toward both sides despite the value of the frequency. In general, there are two applications based on this structure: first is to use such property to design the antenna; the other is to suppress the leaky wave through some methods in order to decrease the unnecessary couplings and crosstalk.
Implementing the full wave analysis (Spectral Domain Approach) on the CBCPW structure, we can discover that the leaky wave propagates along a particular angle relative to the main CPW line, causing the wave to propagate as if in a parallel plate waveguide (PPW). Therefore, we can etch rectangular slots along the ground planes with the angle we have acquired. If the length of the slot is significantly longer than the width and approximately equals to half the guided wavelength, the slots fed by CBCPW will radiate power efficiently .We can thus obtain a centralized broadside radiation pattern and a dual-polarization antenna.
35
Chen, Han-Feng, and 陳漢峰. "Design and Analysis of Slotted Waveguide Antenna Integrate on Microwave Laminate." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/d8zbnu.
Full textAbstract:
碩士<br>北臺灣科學技術學院<br>機電整合研究所<br>99<br>Three different kinds of novel designs of slotted waveguide printed antennas have been investigated and analyzed in this dissertation. The proposed slotted waveguide antenna has a number of advantages over the traditional ones, such as reduced size, low costs, and easily to be integrated with planar circuits. The structure of antenna consists of a 50Ω microstrip-line feed and a rectangular slotted waveguide as radiate element. Three different kinds of slot arrangements were designed and simulated on the plant slotted waveguides by Ansoft HFSS 11 software. From the simulated results, they are found that the slotted waveguide antennas can provide extra-wide bandwidth with acceptable gain.
Index Terms: Substrate Integrated Waveguide (SIW), Printed Antennas, Microstrip, Slotted Waveguide.
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Perovic, Una. "Investigation of rectangular, uni-directional, horizontally polarised waveguide antennas with longitudinal slotted arrays operating at 2.45 GHz." Thesis, 2006. http://hdl.handle.net/10539/1673.
Full textAbstract:
Student Number : 0002066T -
MSc dissertation -
School of Electrical and Information Engineering -
Faculty of Engineering and the Built Environment<br>Investigations of uni-directional, horizontally polarized waveguide antennas with longitudinal slotted arrays operating at 2.45GHz and their applications to wireless local area
networks (WLAN) are presented in this paper. Requirements,
considerations, and limitations associated with the design process
of this particular waveguide are discussed and presented. Various antenna parameters were simulated using MATLAB®
and SuperNEC® software simulation programs, and were
applied to a sensitivity analysis of antenna design. End-fed and
center-fed antennas were designed, built, and measured at
WLAN frequencies. Measured antennas had high gain above 15dBi, broad beam around the azimuth, and high efficiency, but
were limited by their impedance dependency and narrow bandwidth. The center-fed antenna had 3dBi higher gain than
the 18dBi gain of the end-fed antenna. The VSWR ratio of both
antennas was less than 1:1.5 at the operating frequency. The
center-fed antenna had broader azimuth and elevation patterns
by 40° and 10°, respectively. The end- fed antenna had more stable gain and VSWR, 50% wider VSWR bandwidth of
100MHz, and more directional elevation pattern. The design
criteria generated using waveguide theory and simulated analysis
was validated by the physical design and performance of the measured antennas.
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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.
Full text
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Tseng, Yen-Jung, and 曾彥融. "A 4-by-4 slotted array antenna employed in WiMAX base station." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/47063314399585181471.
Full textAbstract:
碩士<br>國立交通大學<br>電信工程系所<br>96<br>In this thesis, a 4-by-4 two-dimensional slotted array antenna was designed, fabricated and measured. Such an array antenna consists of four series-fed sub-array antennas and a metal reflector for achieving single-side radiation. Moreover, the four sub-array antennas are fed by a 1-by-4 power divider made up of three 1-by2 power dividers. By the antenna theory, adjusting the progressive phase delay angle, the main beam angle can be steered toward any desired direction. In this research, the progressive phase delay angle is designed at 0 degree for obtaining the radiation main-beam toward broadside direction （perpendicular to the plan of slots）. Additionally, the slot inclines 45degree with respect to the micro-strip line for generating two polarized electric-field along two orthogonal directions. This may enhance the receiving performance in a complex environment. Due to the advantages of easy fabrication, robustness and low-cost issue, such an array antenna can be a potential candidate for serving a point-to point planar array antenna in WiMAX applications around 3.5GHz
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Chang, Ting-Wei, and 張庭瑋. "A Dual Band Beam Tilted Slotted Substrate-Integrated-Waveguide Antenna for the Radiometer Application." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/26805050725576169439.
Full textAbstract:
碩士<br>國立交通大學<br>電信工程研究所<br>99<br>In this thesis, we introduce a dual band beam tilted slotted substrate–integrated -waveguide antenna. The antenna in the thesis is a two- layer structure; the bottom layer is the conventional slotted waveguide, and the waveguide structure is realized by substrate integrated waveguide(SIW); the top layer is a metal patch array which is just above the slot array on the waveguide surface. The two layers both use the Duroid5880 10mil substrate. Conventional slotted waveguide use the fast wave region in the fundamental mode to radiate. By the effect of the top layer patches, we can excite the high order mode of the waveguide structure to acquire another fast wave radiation region.
We use the full wave simulator, HFSS, to analyze the dispersion of the unit cell such that 24GHz and 36GHz are in the fast wave region of the fundamental mode and high order mode respectively, and we organize a 16 units dual band beam tilted slotted substrate-integrated- waveguide and verify the experiment result to the simulation result.
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Dai, Kai-Ming, and 戴凱明. "A Dual Band Slotted Substrate-Integrated-Waveguide Antenna with Tilted Beam for The Radiometer Application." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/70667446868236257747.
Full textAbstract:
碩士<br>國立交通大學<br>電信工程研究所<br>101<br>In this thesis, we introduce a dual band tilted beam slotted substrate–integrated -waveguide antenna. The antenna in the thesis is a two- layer structure; the bottom layer is the conventional slotted waveguide, and the waveguide structure is realized by substrate integrated waveguide(SIW); the top layer is a metal patch array which is just above the slot array on the waveguide surface with two-layers Duroid5880 substrate. Conventional slotted waveguide use the fast wave region in the fundamental mode to radiate. By the effect of the top layer patches, we can excite the high order mode of the waveguide structure to acquire another fast wave radiation region.
Using the full wave simulator, HFSS, to analyze the phase constant and the attenuation constant of the unit cell such that 24GHz and 36GHz are in the fast wave region of the fundamental mode and high order mode respectively, and we organize a 15 units dual band tilted beam slotted substrate-integrated- waveguide and verify the experiment result to the simulation result.
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Yusuf, Derry Permana, and 尤德睿. "Ka-/E-Band Multi-Layer Full-Corporate-Feed Waveguide Slot Array Antenna." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/wg8cqg.
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碩士<br>國立臺灣大學<br>電信工程學研究所<br>106<br>A corporate feed waveguide slot array antenna with broad bandwidth characteristics is designed for the 38-GHz (Ka-band) and 73.5-GHz (E-band) in order to increase the operating frequency band and the gain at the satellite communication frequency. The proposed antennas use multi layer feeding structure for stable fabrication process. For Ka-band frequency, a 8×8-element array antenna shows 27.7 dBi antenna gain with over 80% antenna efficiency and more than 3.923 GHz or 10.27% for 8×8-elements (36.254-40.177 GHz), a 16×16-element array antenna shows 33.8 dBi antenna gain with over 80% antenna efficiency and more than 3.867 GHz or 10.16% for 16×16-elements (36.133-40GHz), and 32×32-element array shows 39.8 dBi antenna gain with over 70% antenna efficiency and more than 3.583 GHz or 9.43% for 32×32-elements (36.19-39.773GHz), respectively. For E-band frequency, an 8×8-element array antenna shows 27.8 dBi antenna gain with over 80% antenna efficiency and 7.016GHz or 9.56% bandwidth (69.9-76.9GHz), while 16×16-element array antenna shows 33.8 dBi antenna gain with over 80% antenna efficiency and more than 7.042 GHz or 9.6% bandwidth (69.85-76.9GHz), and 32×32-element array shows 39.9 dBi antenna gain with over 70% antenna efficiency and more than 6.926GHz or 9.48% bandwidth (69.63-76.55GHz), respectively.
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周佑軒. "45-Degree Polarization High-gain Compound Slot Pair substrate-Integrated-Waveguide Antenna Array." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/61893495146879768900.
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碩士<br>國立交通大學<br>電信工程研究所<br>101<br>In this thesis, we will propose a high gain 45-degree polarization compound slot pair SIW (substrate integrated waveguide) array antenna design for a long-range vehicle collision avoidance warning radar.
Substrate integrated waveguide has advantage of low-loss and it is also easy to integrated with circuit.
This antenna is a double-layer substrate structure, and feed line layer are separated from the antenna layer to reduce the area of the antenna. With microstrip line central-fed structure, it can avoid the beam offset, increasing the antenna pattern bandwidth.
The operating frequency of this antenna is from 76 to 77GHz, and it detects long distance and angle. The characteristics of this antenna are narrow beam and high gain. The beam width covers from plus eight degrees to minus eight degrees. Moreover, with 45-degree polarization, it can reduce the interference from opposite lane. The design of compound slot can increase the array design varieties, and improve the gain of the array.
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Hua, Yu Bau, and 尤寶樺. "A 38-GHz Waveguide-Fed Microstrip Antenna Array Using A Novel Beam-Steering Technique." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/30653068240683263503.
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碩士<br>國立交通大學<br>電信工程系<br>89<br>This thesis presents a novel beam-steering technique using microstrip antenna arrays fed by rectangular waveguide. We can control the radiated direction of the antenna arrays by changing the phase delay between the adjacent apertures, It is the way by varying the width of waveguide with installing a metal plate. When the thickness or position of the metal plate we installed is different, the propagation constant is also different. It is easy to design the change of the width of waveguide for the scanning angular range.
The excitation of the individual series-fed array was achieved by varying the dimension of the aperture and the length of open stub. Series-fed antenna array was designed and simulated by IE3D. There are the least loss of microstrip line for microstrip antenna array fed by waveguide. It is most important that, changing the width of the waveguide slightly could scan a big angular range.
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Chen, Yihong. "Waveguide-hologram-based true-time delay modules for K-band phased-array antenna system demonstration." 2002. http://wwwlib.umi.com/cr/utexas/fullcit?p3099431.
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Bartlett, Chad. "Design of an 8x8 cross-configuration Butler matrix with interchangeable 1D and 2D arrays." Thesis, 2019. http://hdl.handle.net/1828/10989.
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An ever-increasing demand for wider bandwidths in communication, radar, and imaging systems has emerged. In order to facilitate this growing demand, progressive research into millimeter-wave technologies has become vital in achieving next generation networks such as 5G. Being cost effective and easy to manufacture, Substrate Integrated Waveguide (SIW) circuits have been demonstrated as a viable candidate for high-frequency applications due to their low-loss, high quality-factor, and high power-handling capabilities.Research on beam-forming networks, specifically the Butler matrix, has demonstrated powerful beam-steering capabilities through the use of passive component networks. Through these clever configurations, a cost effective and robust option is available for us to use. In order to further millimeter-wave research in this area, this thesis presents a modified configuration of the Butler Matrix in SIW that is physically reconfigurable; by separating the Butler matrix from the antenna array at a pre-selected point, the array can be easily interchanged with other 1-Dimensional,and 2-Dimensional slot antenna arrays. Although this system does not fall under the rigorous definitions of Reconfigurable Antennas, it should be noted that the interchangeability of 1 and 2 dimensional arrays is not typically expressed in Butler matrix configurations. Design and simulations are carried out in CST Microwave Studio to inspect individual components as well as system characteristics. Circuit prototypes are then manufactured and tested in an anechoic chamber to validate simulation results and the design approach.<br>Graduate<br>2020-07-17
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Nafe, Ahmed A. "Substrate Integrated Waveguide Based Phase Shifter and Phased Array in a Ferrite Low Temperature Co-fired Ceramic Package." Thesis, 2014. http://hdl.handle.net/10754/314674.
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Phased array antennas, capable of controlling the direction of their radiated beam, are demanded by many conventional as well as modern systems. Applications such as automotive collision avoidance radar, inter-satellite communication links and future man-portable satellite communication on move services require reconfigurable beam systems with stress on mobility and cost effectiveness.
Microwave phase shifters are key components of phased antenna arrays. A phase shifter is a device that controls the phase of the signal passing through it. Among the technologies used to realize this device, traditional ferrite waveguide phase shifters offer the best performance. However, they are bulky and difficult to integrate with other system components.
Recently, ferrite material has been introduced in Low Temperature Co-fired Ceramic (LTCC) multilayer packaging technology. This enables the integration of ferrite based components with other microwave circuitry in a compact, light-weight and mass producible package.
Additionally, the recent concept of Substrate Integrated Waveguide (SIW) allowed realization of synthesized rectangular waveguide-like structures in planar and multilayer substrates. These SIW structures have been shown to maintain the merits of conventional rectangular waveguides such as low loss and high power handling capabilities while being planar and easily integrable with other components.
Implementing SIW structures inside a multilayer ferrite LTCC package enables monolithic integration of phase shifters and phased arrays representing a true System on Package (SoP) solution. It is the objective of this thesis to pursue realizing efficient integrated phase shifters and phased arrays combining the above mentioned technologies, namely Ferrite LTCC and SIW.
In this work, a novel SIW phase shifter in ferrite LTCC package is designed, fabricated and tested. The device is able to operate reciprocally as well as non-reciprocally. Demonstrating a measured maximum reciprocal phase shift of 132o and maximum non-reciprocal shift of 118o at 12 GHz. Additionally a slotted SIW antenna is designed and integrated with the phase shifter in an array format, demonstrating a beam scanning of ± 15o. The design is highly suitable for mobile automotive radars and satellite communications systems.
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Frid, Henrik. "On millimeter and submillimeter wave focal plane arrays implemented with MEMS waveguide switches." Licentiate thesis, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-197339.
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This thesis presents research towards enabling micromachined millimeter and submillimeter wave focal plane arrays (FPAs). The FPAs operate under the following principle: a switch network consisting of microelectromechanical (MEMS) switches, integrated with micromachined waveguides, is used to feed an array of antenna elements, located in the focal plane of a high-gain quasi-optical system. Hence, it is possible to switch between a set of narrow beams in different directions. Such beam steering systems are needed for future millimeter and submillimeter wave imaging and communication systems. The contributions to future MEMS-switchable FPAs presented here are organized in three papers, as described below. Paper I presents a criterion on the spacing between adjacent FPA elements which results in -3 dB overlap between the switched beams, for the special case when an extended hemispherical dielectric lens is used as the optical system. A key step towards this criterion is a closed-form relation between the scan angle and the FPA element's position, which results in an expression for the effective focal length of extended hemispherical lenses. A comparison with full-wave simulations demonstrates an excellent agreement with the presented theoretical results. Finally, it is shown that the maximum feasible FPA spacing when using an extended hemispherical lens is about 0.7 wavelengths. Paper II presents a numerical study of silicon-micromachined planar extended hemispherical lenses, with up to three matching regions used to reduce internal reflections. The effective permittivity of the matching regions is tailor-made by etching periodic holes in the silicon wafer. The optimal thickness and permittivity of the matching regions were determined using TRF optimization, in order to yield the maximum wide-band aperture efficiency and small side-lobes. We introduce a new matching region geometry, referred to as shifted-type matching regions, and it is demonstrated that using three shifted-type matching regions results in twice as large aperture efficiency as compared to using three conventional concentric-type matching regions. Paper III presents a submillimeter-wave single-pole single-throw (SPST) 500-750 GHz MEMS waveguide switch, based on a MEMS-reconfigurable surface inserted between two waveguide flanges. A detailed design parameter study is carried out to select the best combination of the number of horizontal bars and vertical columns of the MEMS-reconfigurable surface, for achieving a low insertion loss in the transmissive state and a high isolation in the blocking state. A method is presented to model the non-ideal electrical contacts between the vertical cantilevers of the MEMS surface, with an excellent agreement between the simulated and measured isolation. It is shown that the isolation can be improved by replacing an ohmic contact by a new, capacitive contact. The measured isolation of the switch prototype is better than 19 dB and the measured insertion loss is between 2.5 and 3 dB.<br>Denna avhandling presenterar forskning som syftar till att möjliggöra fokalplans-gruppantenner (FPAs) för våglängder i millimeter och submillimeterområdet. Principen för en sådan FPAs funktion är följande: ett nätverk bestående av mikroelektromekaniska (MEMS) switchar, används för att välja mellan de olika antenn-elementen i en gruppantenn, som placerats i fokalplanet av ett optiskt system. Därmed blir det möjligt att välja från en uppsättning av smala lober i olika riktningar. Sådana lob-styrningssystem behövs för framtida radar- och kommunikationssystem i millimeter och submillimeterområdet. Resultaten är uppdelade i tre vetenskapliga artiklar, som beskrivs nedan. I den första artikeln (Paper I) presenteras ett villkor för avståndet mellan närliggande FPA-element som resulterar i -3 dB överlappning mellan de switchade loberna, för specialfallet då en förlängd hemisfärisk lins används som optiskt system. Det viktigaste steget mot att hitta detta villkor är att bestämma en analytisk relation mellan avsökningsvinkeln och FPA-elementens position. Detta resulterar i ett uttryck för den effektiva fokallängden för denna typ av lins. En utmärkt överensstämelse har funnits mellan dessa relationer och simuleringar. Slutligen visas det att de största möjliga FPA-avstånden för en förlängd hemisfärisk lins är ungefär 0.7 våglängder, vilket uppnås för linser med låg permittivitet. I den andra artikeln (Paper II) presenteras en numerisk studie av plana förlängda hemisfäriska linser, som kan produceras från en kiselskiva. Linserna har upp till tre matchningsregioner, som används för att reducera interna reflektioner. Den effektiva permittiviteten av de matchande regionerna skräddarsys genom etsning av periodiska hål i kiselskivan. Den optimala tjockleken och permittiviteten av de matchande regionerna har bestämts med hjälp av TRF-optimering, för att ge maximal bredbandig direktivitet och minimala sidlober. En ny geometri introduceras för matchningsregionerna, som vi kallar matchningsregioner av skiftad typ. Vi visar att användning av tre matchningsregioner av skiftad typ resulterar i en dubbelt så hög apertur-effektivitet, jämfört med att använda tre konventionella matchningsregioner av koncentrisk typ. I den tredje artikeln (Paper III) presenteras en MEMS-switch för rektangulära vågledare, för frekvensområdet 500-750 GHz. Baserat på en designparameterstudie har den bästa kombinationen av antalet horisontella rader och vertikala kolumner hos den MEMS-konfigurerbara ytan valts ut, för att uppnå låga förluster i det öppna tillståndet och hög isolation i det blockerande tillståndet. I artikeln presenteras en metod för att modellera icke-perfekta elektriska kontakter mellan de fixerade och de rörliga delarna i MEMS-ytan. Denna metod uppvisar en utmärkt överensstämmelse mellan den simulerade och den uppmätta isolationen. Vi visara att isolationen kan förbättras med hjälp av en ny typ av kapacitiv kontakt. Den uppmätta isolationen hos den presenterade switch-prototypen är högre än 19 dB, och den uppmätta förlusten är mellan 2.5 och 3 dB.<br><p>QC 20161206</p>
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Hussaini, Abubakar S., Yasir I. Abdulraheem, Konstantinos N. Voudouris, et al. "Green flexible RF for 5G." 2015. http://hdl.handle.net/10454/9163.
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No<br>5th Generation mobile networks (5G) and mobile communications technologies beyond 2020 will need to be energy aware so as to support services that are likely to be intelligent and bandwidth hungry, as well as to support multi-mode operation (LTE, LTE+, HSDPA, 3G among others) in a HetNet environment. This imposes stringent design requirements on the RF transceiver, a key consumer of power in networks today. This chapter will investigate the key RF subsystems forming part of the 5G RF transceiver, where energy efficiency and full radio flexibility are at the forefront of system design. In particular, we target advanced designs on antenna systems, RF power amplifiers and the challenges facing cross-talk in MIMO architectures.