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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Směrová anténa pro kmitočtové pásmo 60 GHz / Directional antenna for 60 GHz frequency band

Kratochvíl, Jakub January 2018 (has links)
The aim of this diploma thesis is to study the possibilities and problems of low-profile antennas and subsequently to design a directional antenna with spherical reflector for millimeter wavelengths. The theoretical part deals with basic information about horn and reflector antennas, and about SIW technology. In addition, the thesis deals with the specific design and modeling of the antenna using CST Microwave Studio. The simulated design achieved a sufficient bandwidth to cover ISM (57 GHz to 64 GHz) with gain 13.6 dBi at 60 GHz frequency. On fabricated antenna, the antenna impedance ratios were worse and the target bandwidth was not reached. Antenna gain was 14.33 dBi at 60 GHz frequency.
12

Transmitter design in the 60 GHz frequency band / Conception de l'émetteur dans la bande de fréquence 60 Ghz

Sarimin, Nuraishah 13 December 2017 (has links)
Avec la prolifération des appareils électroniques portables et mobiles communicants, il est recommandé de pouvoir échanger des données rapidement et commodément entre les appareils. Avec la pénurie de bande passante et la congestion dans le spectre des fréquences faibles, la technologie de communication à ondes millimétriques (Mm-wave) est considérée comme l'une des technologies clés du futur pour permettre des applications sans fil à débit élevé grâce à son large spectre abondant. Les nœuds de technologie CMOS avancés sont dotés de ft et fmax plus élevés qui permettent une utilisation peu coûteuse et généralisée de ce spectre. Cependant, de nombreux défis associés à la conception de circuits et de systèmes RF millimétriques en utilisant des technologies CMOS avancées ont été identifiés. L’amplificateur de puissance (PA) a été identifié comme étant le bloc le plus difficile à concevoir dans un émetteur-récepteur intégré RF millimétrique. Le concept au niveau du système de l’architecture basse puissance est d’abord étudié et des blocs clés tels que l’antenne 60 GHz et le modulateur OOK dans la technologie CMOS 130nm ont été présentés. Cette thèse explore également les défis de conception de l’amplificateur de puissance à ondes millimétriques dans la technolgie 28nm UTBB-FDSOI. Trois conceptions différentes d’amplificateur de puissance de 60 GHz ont été démontrées dans 28nm LVT FDSOI : 1) Un PA cascode à deux étages, 2) Un PA différentiel à deux étages à base de transformateur, 3) Un PA différentiel à deux étages à puissance combinée. Les performances simulées, y compris la prise en compte des parasites principaux de disposition ont été présentées. Les travaux futurs incluront l’intégration sur puce avec le PA. / With the proliferation of portable and mobile electronic devices, there is a strong need to exchange data quickly and conveniently between devices encouraging to overcome challenges in bandwidth shortages and congestion in the lower frequencies spectrum. Millimeter-wave (Mm-wave) technology is considered as one of the future key technologies to enable high data rates wireless applications due to its large abundant spectrum. Advanced CMOS technology nodes comes with high ft and fmax, enable low cost and widespread use of this spectrum. However, many associated challenges ranging from device, circuit and system perspectives for the implementation of a highly integrated mm-wave transceiver especially the power amplifier (PA) which identified to be the most challenging RF block to be designed. The system level concept of low power architecture is firstly studied and key blocks such as 60 GHz antenna and OOK modulateur in 130nm CMOS technology were presented. This thesis also explores the design challenges of mm-wave power amplifier in 28nm UTBB-FDSOI technology. Three different designs of 60 GHz power amplifier were demonstrated in 28nm LVT FDSOI : 1) A two-stage cascode PA, 2) A two-stage differential PA with low-km TMN, 3) A power combined two-stage differential PA with low-km TMN. The simulated performance including the consideration of key layout parasitics were presented. Future work will include for on-chip integration with the PA.
13

Cost Optimized Radio-over-Fiber System

Damas, Jacqueline 06 February 2024 (has links)
The demand of smaller and portable electronic devices has contributed to the realisation of compact embedded systems using PCB miniaturization techniques. The commercial market is faced with competition of handheld users’ devices in medical, communication and automotive industries which are smaller and lighter electronic devices. The possibilities of higher degree of integration in planar technology using cost effective electronic components has lead to different art of design and fabrication of compact units. In this work, a central station and a base station front-end with small form factor have been realized using commercial components on PCBs. These electronic compacts units were integrated in the IF-over-Fiber system architecture. The IF-over-Fiber architecture comprised of miniaturized electronic components for quadrature modulation and upconversion. The central station supports multi-Gbps data rate modulation formats in order to increase the spectral efficiency of the transmitted information. Multilevel modulation formats are considered spectrally efficient and can double the transmission capacity by transmitting more information in the amplitude, phase, polarization or a combination of all. The BS front-end comprises of the 60 GHz upconverter and a 60 GHz planar 2×2 microstrip antenna. The 10 GHz IF carrier allows an optical transmission with higher spectral efficiency in optical domain, as well as it is less susceptible to dispersion induced power fading inherent in optical fiber. Characterization of the designed central station and base station front-end through measurements are presented and discussed. The IF-over-Fiber system analysis is made for the 2 Gbps QPSK transmission with respect to error vector magnitude (EVM), eye and constellation diagrams.
14

Developments of 60 GHz Antenna and Wireless Interconnect inside Multi-Chip Module for Parallel Processor System

Yeh, Ho-Hsin January 2013 (has links)
In order to carry out the complicated computation inside the high performance computing (HPC) systems, tens to hundreds of parallel processor chips and physical wires are required to be integrated inside the multi-chip package module (MCM). The physical wires considered as the electrical interconnects between the processor chips, however, have the challenges on placements and routings because of the unequal progress between the semiconductor and I/O size reductions. The primary goal of the research is to overcome package design challenges - providing a hybrid computing architecture with implemented 60 GHz antennas as the high efficient wireless interconnect which could generate over 10 Gbps bandwidth on the data transmissions. The dissertation is divided into three major parts. In the first part, two different performance metrics, power loss required to be recovered (PRE) and wireless link budget, on evaluating the antenna's system performance within the chip to chip wireless interconnect are introduced to address the design challenges and define the design goals. The second part contains the design concept, fabrication procedure and measurements of implemented 60 GHz broadband antenna in the application of multi-chip data transmissions. The developed antenna utilizes the periodically-patched artificial magnetic conductor (AMC) structure associated with the ground-shielded conductor in order to enhance the antenna's impedance matching bandwidth. The validation presents that over 10 GHz -10 dB S11 bandwidth which indicates the antenna's operating bandwidth and the horizontal data transmission capability which is required by planar type chip to chip interconnect can be achieved with the design concept. In order to reduce both PRE and wireless link budget numbers, a 60 GHz two-element array in the multi-chip communication is developed in the third part. The third section includes the combined-field analysis, the design concepts on two-element array and feeding circuitry. The simulation results agree with the predicted field analysis and demonstrate the 5dBi gain enhancement in the horizontal direction over a single 60 GHz AMC antenna to further reduce both PRE and wireless link budget numbers.
15

Channel modeling for 60 GHz Body Area Networks

Mavridis, Theodoros 28 August 2015 (has links) (PDF)
The smart environments and the connected human seems to be the future of wireless communications. The development of new frequency bands in the millimeter range will allow us to create high data rate communications which will led to the Wireless Body Environment Networks. In this kind of scenarios, it is expected that the user and the environment will interact. In order to develop such new applications, it is necessary to first study the propagation mechanisms and then, the communication channel underlying body centric environments. This thesis treats of channel models for 60 GHz Body Area Networks and more particularly of three kinds of scenarios: (i) the communication between an external base station and a worn node (off-body); (ii) the communication between two worn nodes (on-body); the communication between an external base station and a hand-held device (near-body). An indoor off-body channel model is numerically proposed and implemented. The model is based on the IEEE 802.11ad indoor standard channel at 60 GHz and a fast computation solution of the scattering of a plane wave by a circular cylinder. The model is developed for two orthogonal polarizations and the communications performances are studied. The on-body propagation is studied for two different configurations: line-of-sight and non-line-of-sight communications on the body. These scenarios led to different solutions for the channel knowing as, respectively, Norton’s equations and creeping formulations. These solutions are obtained using simplified geometries which has been experimentally validated. Further, in order to improve the propagation on the human body, a technique using metallic plates has been proposed. This technique has been theoretically studied using Milligton’s equations and experimentally assessed on a flat phantom with the properties of the human skin. The proposed method allows to save up to 20 dB. Finally, the near-body communication scenario has been introduced and studied. The near-body region is extended from 5 to 30 cm away of the user body which corresponds to the arm’s reach and models a handheld device. A numerical algorithm has been proposed to model indoor near-body environments. Also, a special has been given to statistical body shadowing. It has been shown that the fading follows a Two-Wave Diffuse Power distribution. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished
16

Architectures multi-bandes en mode impulsionnel et circuits pour des applications nomades très haut débit autour de 60GHz

Abdaoui, Rahma 10 December 2012 (has links) (PDF)
Avec la croissance actuelle du marché des applications de transfert de données multimédia à très haut débit, les bandes de fréquences autour de 60 GHz sont une nouvelle alternative promettant des performances intéressantes en terme de débits mais soulèvent des défis techniques et technologiques au niveau des architectures et circuits. C'est dans ce cadre que s'inscrit cette thèse, qui propose une approche multi bande impulsionnelle MBOOK avec un récepteur à détection d'énergie, et qui analyse plus spécifiquement les verrous au niveau de l'émetteur. L'étude du canal de propagation à 60 GHz, basée sur les modèles de canaux du standard IEEE 802.15.3c, a permis de démontrer la potentialité de cette architecture et permet d'atteindre des débits de 2 Gbps à 2metres dans un environnement de type résidentiel. Le dimensionnement de l'architecture ainsi que des performances des principaux blocs ont conduit à plusieurs possibilités pour l'architecture de l'émetteur MBOOK à 60 GHz. Les critères ont été d'assurer un compromis performances, consommation. Une étude approfondie sur l'étude des imperfections de certains blocs critiques et l'impact sur l'impulsion transmise, et donc sur les performances du système ont été établies. Le banc de filtres, nécessaire à l'émission et à la réception, représente l'un des verrous, et nous proposons une solution de filtrage à base de lignes couplées. L'étude des solutions de génération d'impulsions, des étages de commutation, et des étages d'amplification de l'émetteur sont détaillées et discutées dans les deux derniers chapitres
17

Integrated Circuit and Antenna Technology for Millimeter-wave Phased Array Radio Front-end

Nezhad Ahmadi Mohabadi, Mohammad Reza January 2010 (has links)
Ever growing demands for higher data rate and bandwidth are pushing extremely high data rate wireless applications to millimeter-wave band (30-300GHz), where sufficient bandwidth is available and high data rate wireless can be achieved without using complex modulation schemes. In addition to the communication applications, millimeter-wave band has enabled novel short range and long range radar sensors for automotive as well as high resolution imaging systems for medical and security. Small size, high gain antennas, unlicensed and worldwide availability of released bands for communication and a number of other applications are other advantages of the millimeter-wave band. The major obstacle for the wide deployment of commercial wireless and radar systems in this frequency range is the high cost and bulky nature of existing GaAs- and InP-based solutions. In recent years, with the rapid scaling and development of the silicon-based integrated circuit technologies such as CMOS and SiGe, low cost technologies have shown acceptable millimeter-wave performance, which can enable highly integrated millimeter-wave radio devices and reduce the cost significantly. Furthermore, at this range of frequencies, on-chip antenna becomes feasible and can be considered as an attractive solution that can further reduce the cost and complexity of the radio package. The propagation channel challenges for the realization of low cost and reliable silicon-based communication devices at millimeter-wave band are severe path loss as well as shadowing loss of human body. Silicon technology challenges are low-Q passive components, low breakdown voltage of active devices, and low efficiency of on-chip antennas. The main objective of this thesis is to investigate and to develop antenna and front-end for cost-effective silicon based millimeter-wave phased array radio architectures that can address above challenges for short range, high data rate wireless communication as well as radar applications. Although the proposed concepts and the results obtained in this research are general, as an important example, the application focus in this research is placed on the radio aspects of emerging 60 GHz communication system. For this particular but extremely important case, various aspects of the technology including standard, architecture, antenna options and indoor propagation channel at presence of a human body are studied. On-chip dielectric resonator antenna as a radiation efficiency improvement technique for an on-chip antenna on low resistivity silicon is presented, developed and proved by measurement. Radiation efficiency of about 50% was measured which is a significant improvement in the radiation efficiency of on-chip antennas. Also as a further step, integration of the proposed high efficiency antenna with an amplifier in transmit and receive configurations at 30 GHz is successfully demonstrated. For the implementation of a low cost millimeter-wave array antenna, miniaturized, and efficient antenna structures in a new integrated passive device technology using high resistivity silicon are designed and developed. Front-end circuit blocks such as variable gain LNA, continuous passive and active phase shifters are investigated, designed and developed for a 60GHz phased array radio in CMOS technology. Finally, two-element CMOS phased array front-ends based on passive and active phase shifting architectures are proposed, developed and compared.
18

Cellular and peer-to-peer millimeter wave channel sounding in outdoor urban environments

Ben-Dor, Eshar 17 February 2012 (has links)
Millimeter wave (mm-Wave) systems have become very attractive recently as lower frequency spectrums used for mobile device communications have been experiencing a “spectral crunch” due to the dissemination of smartphones. Channel characterization of the outdoor urban environment, where networks for mobile devices require the highest data capacity, has been quite scarce and even non-existent for cellular (rooftop to ground) setting measurements. Our project characterizes the urban environment at 38 GHz in a cellular setting and 38 and 60 GHz in a peer-to-peer setting. A sliding correlator channel sounder with an 800 MHz RF bandwidth at 38 GHz and 1.5 GHz RF bandwidth at 60 GHz was constructed to measure the channel using a bandwidth that is larger than the expected bandwidths of future mm-Wave channels. Directional antennas were utilized during the measurements to imitate mm-Wave systems using beam steering antenna arrays, which also allowed for AOA characterization. Path loss and RMS delay spread statistics are provided. Finally, an outage study was performed to test the outage likelihood in an urban environment with many multi-story buildings. / text
19

Integrated Circuit and Antenna Technology for Millimeter-wave Phased Array Radio Front-end

Nezhad Ahmadi Mohabadi, Mohammad Reza January 2010 (has links)
Ever growing demands for higher data rate and bandwidth are pushing extremely high data rate wireless applications to millimeter-wave band (30-300GHz), where sufficient bandwidth is available and high data rate wireless can be achieved without using complex modulation schemes. In addition to the communication applications, millimeter-wave band has enabled novel short range and long range radar sensors for automotive as well as high resolution imaging systems for medical and security. Small size, high gain antennas, unlicensed and worldwide availability of released bands for communication and a number of other applications are other advantages of the millimeter-wave band. The major obstacle for the wide deployment of commercial wireless and radar systems in this frequency range is the high cost and bulky nature of existing GaAs- and InP-based solutions. In recent years, with the rapid scaling and development of the silicon-based integrated circuit technologies such as CMOS and SiGe, low cost technologies have shown acceptable millimeter-wave performance, which can enable highly integrated millimeter-wave radio devices and reduce the cost significantly. Furthermore, at this range of frequencies, on-chip antenna becomes feasible and can be considered as an attractive solution that can further reduce the cost and complexity of the radio package. The propagation channel challenges for the realization of low cost and reliable silicon-based communication devices at millimeter-wave band are severe path loss as well as shadowing loss of human body. Silicon technology challenges are low-Q passive components, low breakdown voltage of active devices, and low efficiency of on-chip antennas. The main objective of this thesis is to investigate and to develop antenna and front-end for cost-effective silicon based millimeter-wave phased array radio architectures that can address above challenges for short range, high data rate wireless communication as well as radar applications. Although the proposed concepts and the results obtained in this research are general, as an important example, the application focus in this research is placed on the radio aspects of emerging 60 GHz communication system. For this particular but extremely important case, various aspects of the technology including standard, architecture, antenna options and indoor propagation channel at presence of a human body are studied. On-chip dielectric resonator antenna as a radiation efficiency improvement technique for an on-chip antenna on low resistivity silicon is presented, developed and proved by measurement. Radiation efficiency of about 50% was measured which is a significant improvement in the radiation efficiency of on-chip antennas. Also as a further step, integration of the proposed high efficiency antenna with an amplifier in transmit and receive configurations at 30 GHz is successfully demonstrated. For the implementation of a low cost millimeter-wave array antenna, miniaturized, and efficient antenna structures in a new integrated passive device technology using high resistivity silicon are designed and developed. Front-end circuit blocks such as variable gain LNA, continuous passive and active phase shifters are investigated, designed and developed for a 60GHz phased array radio in CMOS technology. Finally, two-element CMOS phased array front-ends based on passive and active phase shifting architectures are proposed, developed and compared.
20

A Novel Variable Inductor-Based VCO Design with 17% Frequency Tuning Range for IEEE 802.11AD Applications

Meng, YIN FEI 23 January 2014 (has links)
This thesis focuses on the design and analysis of a novel variable inductor (VID) based VCO solution to the frequency tuning range (TR) limitation of the IEEE 802.11ad compliant radio systems. The IEEE 802.11ad standard has drawn strong attention from the industry as the next generation affordable multi-gigabit speed wireless communication standard. Prepared for the global market, IEEE 802.11ad compliant systems are required to cover a broad 8 GHz TR centered on 60 GHz. This wide TR at V band imposes significant challenge to the VCO design in radio transceivers, and makes the TR of the integrated VCO a major bottleneck to the successful commercialization of many IEEE 802.11ad compliant radio systems today. As an effort to solve the current TR problem for the IEEE 802.11ad compliant radio systems, 2 VCOs designs based on this novel VID-based solution and a conventional Colpitts-Clapp VCO design are presented in this thesis report. The novel VCOs integrate a VID into the differential Colpitts configuration to create a feasible solution to the aforementioned TR problem. The VID in the VCO tank eliminates the base node varactors and their fixed parasitic capacitance that degrades TR in conventional VCO designs, while the differential Colpitts configuration provides advantageous performance at mm-wave frequencies and high output power for real-world applications. Also, a fundamental 30 GHz Colpitts-Clapp VCO was developed in conjunction with the other 2 VCOs for comparison purposes. One of the 2 VID-based VCO designs is a fundamental 30 GHz VID-based Colpitts VCO that covers 17% TR for proof of concept to the novel topology. Another is an IEEE 802.11ad compliant 60 GHz VCO chain consists of the 30 GHz VID-based Colpitts VCO and a frequency doubler covering 17% TR with 3 dBm output power and -115.7 dBc/Hz phase noise at 10 MHz offset. The conventional Colpitts-Clapp VCO is used to compare with the other 2 VID-based VCOs. As the measurement results indicate, this VID-based VCO topology provides a viable solution to overcome the TR bottleneck in the current IEEE 802.11ad compliant VCO development. All 3 VCOs are fabricated using a 130 nm SiGe BiCMOS process. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2014-01-23 13:40:31.258

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