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Simple and fast sidelobe cancellation techniques for phased array antennas using parallel microprocessor controlEl-Azhary, Ismail January 1989 (has links)
No description available.
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MIMO radio-over-fibre distributed antenna system for next generation wireless communicationYang, Yumeng January 2018 (has links)
This thesis introduces low-cost implementations for the next generation distributed antenna system (DAS) using analogue radio over fibre. A multiple-input-multiple-output (MIMO) enabled radio over fibre (RoF) system using double sideband (DSB) frequency translation system is proposed. In such a system, the 2x2 MIMO signals can be transmitted to the remote antenna units (RAUs) from the base station via a single optical link. By using the DSB frequency translation, the original single-input-single-output (SISO) DAS can be upgraded into the MIMO DAS without implementing parallel optical links. Experimentally, the DSB frequency translation 2x2 MIMO RoF system transmits 2x2 LTE MIMO signals with 20MHz bandwidth in each channel via a 300m MMF link. The condition number of the system is < 10dB within the power equaliser bandwidth which means the MIMO system is well-conditioned and the crosstalk between the channels can be compensated by the MIMO signal processing. To install the DSB frequency translation system in a wideband service-agnostic DAS, the original MIMO signals need to be translated into unoccupied frequency bands over the DAS, which are usually occupied by specific applications that are not to be transmitted over the DAS. The frequency spectrum allocation of the wireless services is analysed showing that by choosing a particular LO frequency (2.2GHz in the UK), in the DSB frequency translation system, the original MIMO signals can always be translated into unoccupied frequency bands so that the same infrastructure can support multiple services. The idea of DSB frequency translation system can not only support MIMO radio over fibre but can also improve the SFDR of a general radio over fibre system. Because when the upper sideband and the lower sideband of the signal after translation are converted back to the original frequency band, the noise adds incoherently but the signals add-up coherently, this gives the system theoretically 2dB 3rd order SFDR improvement. If the idea of the DSB frequency translation is extended into a higher number of sidebands, the system SFDR can be further improved. Experimentally, the system 3rd order SFDR can be improved beyond the intrinsic optical link by 2.7dB by using quadruple sideband (QSB) frequency translation. It means the optical bandwidth in a general RoF system can be traded for the electrical SFDR. By integrating the analogue and the digital RoF systems, a hybrid DAS has been demonstrated, showing that the EVM dynamic range for the 4G LTE service (using digital RoF link) can be improved to be similar to the 3G UMTS service (using analogue RoF link), so that fewer number of RAUs for the LTE services are needed.
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Priorização de tarefas e otimização do diagrama de arranjo de antenas em radares cognitivos multifuncionais / Tasks prioritization and pattern optimization of phased arrays antenna in multifunction cognitive radarsPompeo, Bruno Suarez, 1985- 04 May 2013 (has links)
Orientadores: Rafael Santos Mendes, João Bosco Ribeiro do Val / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-22T19:45:23Z (GMT). No. of bitstreams: 1
Pompeo_BrunoSuarez_M.pdf: 6905835 bytes, checksum: 5e239e161c70da4b62932eb7a24b0130 (MD5)
Previous issue date: 2013 / Resumo: Radares cognitivos multifuncionais são considerados a próxima geração de sistemas de radar. Atualmente, ao redor do mundo, muitas pesquisas estão voltadas para esses tipos de sistemas. Sendo assim, _e de suma importância que o Brasil também comece a pesquisar sistemas dessa natureza. O presente trabalho insere-se nesse contexto, propondo duas principais contribuições: O agendamento das tarefas de busca e rastreio de vetores aéreos levando em consideração parâmetros operacionais e critérios de priorização e a otimização na criação do diagrama de antena gerado por um arranjo de antenas. O primeiro consiste na criação de uma função objetivo que gera a ordem de atividades a serem efetuadas pelo sistema de radar. Dessa forma, essa decisão é feita automaticamente pelo sistema, podendo o operador interferir ou não. Após decidida a ordem das tarefas a serem realizadas, o diagrama de antena é modificado, respeitando certos requisitos impostos pelo operador ou pelo cenário, alterando as alimentações dos elementos ativos do arranjo de antena, no intuito de realizar a atividade de forma otimizada. Para demonstrar a integração dos dois procedimentos citados, um simulador foi desenvolvido para servir como um modelo simples e operacional de um radar cognitivo. Analisam-se os resultados obtidos em alguns cenários propostos no trabalho / Abstract: Multifunction Cognitive Radar refers to the next generation of radar systems. Many current researches are focused on these types of systems around the world. Therefore, it is extremely important that Brazil begins studying such systems. Within this context, the present work proposes two main contributions: Scheduling tasks of searching and tracking of targets based on operational parameters and prioritization criteria and Pattern optimization in phased array antennas. The former consists in creating an objective function that generates the scheduling tasks to be performed by the radar system. Thus, this decision is automatically made and the operator could or could not interfere. The latter consists in changing the antenna pattern, complying with requirements imposed by operator or environment, feeding the actives elements with phase and amplitude calculated to optimize it, after the tasks were chosen. In order to demonstrate the above procedures integration, a simulator was developed and will be used as a simple cognitive radar operational model. It were analyzed the results obtained in some scenarios proposed in the present work / Mestrado / Automação / Mestre em Engenharia Elétrica
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Television in Education: a Survey of Current Practices and a Consideration of Its Applicability to the Field of MusicPhillips, Hattie Lucile 05 1900 (has links)
The use of television as an aid to music education is a relatively new and unexplored field. It is so new, in fact, that to undertake a study of what has been accomplished until the present may seem at first rather premature and unfruitful. It is my belief, however, that if television is to become the prominent factor in education that has been predicted, there is a definite need for a study of what has been done to date toward the development of this new medium. This will provide the background and foundation for further experiment and use. The study shall include, therefore, a brief history of television itself, general educational experiments in television, experiments in televised music education, problems involved in presenting musical television programs, and suggestions for the development of this newest of teaching aids.
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IoTデバイスに向けたマイクロ波無線電力伝送システムの開発田中, 勇気 26 September 2022 (has links)
京都大学 / 新制・課程博士 / 博士(工学) / 甲第24232号 / 工博第5060号 / 新制||工||1790(附属図書館) / 京都大学大学院工学研究科電気工学専攻 / (主査)教授 篠原 真毅, 教授 小嶋 浩嗣, 教授 山本 衛 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM
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Substrate integrated waveguide antenna systemsSalem Hesari, Sara 29 January 2019 (has links)
Due to high demand for planar structures with low loss, a considerable amount
of research has been done to the design of substrate integrated waveguide (SIW)
components in the mm-wave and microwave range. SIW has many advantages in
comparison to conventional waveguides and microstrip lines, such as compact and
planar structure, ease of fabrication, low radiation loss, high power handling ability
and low cost which makes it a very promising technology for current and future
systems operating in K-band and above. Therefore, all the work presented in this
dissertation focuses on SIW technology. Five di erent antenna systems are proposed
to verify the advantages of using SIW technology.
First, a novel K-band end- re SIW circularly polarized (CP) antenna system on
a single layer printed-circuit board is proposed. A high gain SIW H-plane horn and a
Vivaldi antenna are developed to produce two orthogonal polarizations in the plane of
the substrate. CP antennas have become very popular because of their unique characteristics and their applications in satellites, radars and wireless communications.
Second, a K-band front-end system for tracking applications is presented. The circuit comprises an antenna array of two Vivaldi antennas, a frequency-selective power combiner, and two frequency-selective SIW crossovers, which eliminate the need for subsequent ltering. The integration of monopulse systems in planar, printed circuit
SIW technology combined with the added bene ts of ltering functions is of great importance to the antennas and propagation community.
Third, a phased array antenna system consisting of 24 radiating element is designed
as feed system for reflector antennas in radio astronomy applications. A Ku-band antipodal dipole antenna with wide bandwidth, low cross-polarization and wide beamwidth is suggested as the radiating element.
Forth, four di erent right-angled power dividers including in-phase and out-of-phase
dividers as feed systems for antenna arrays are introduced. TE10 - to - TEq0 mode transducers are used for obtaining two, three, and four output dividers with phase control ability at K- and Ka-band. This feature is practical, for instance, when designing tracking systems since they are employed to obtain controllable phase distributions over the output ports.
Fifth, a Ku-band beam steering antenna system which is applicable to use for wireless communications, radar systems, and also 5G applications is proposed. This antenna system uses variable reflection-type phase shifters which electrically steer the beam over a 50-degree scan range.
Therefore, the SIW technology's reliability and also promising behavior in the microwave frequency range is proven for di erent applications. / Graduate
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DESIGN AND IMPLEMENTATION OF MICROSTRIP MONOPOLE AND DIELECTRIC RESONATOR ANTENNAS FOR ULTRA WIDEBAND APPLICATIONSMorsy, Mohamed Mostafa 01 December 2010 (has links)
Ultra wide-band (UWB) technology is considered one of the very promising wireless technologies in the new millennium. This increases the demand on designing UWB antennas that meet the requirements of different UWB systems. In this dissertation, different UWB antennas are proposed such as an antenna that covers almost the entire UWB bandwidth, 3.5-11 GHz, as defined by the federal communication commission (FCC). This antenna has a size of 50×40×1.5mm3. Miniaturized worldwide UWB antennas are also introduced. Miniaturized worldwide UWB antennas that have compact sizes of (30×20×1.5) mm3, and (15×15×1.5) mm3 are also investigated. The designed worldwide UWB antennas cover the UWB spectrums defined by the electronic communication committee (ECC), 6-8.5 GHz, and the common worldwide UWB spectrum, 7.4-9 GHz. A system consisting of two identical antennas (transmitter and receiver) is built in the Antennas and Propagation Lab at Southern Illinois University Carbondale (SIUC) to test the coupling properties between every two identical antennas. The performance of that system is analyzed under different ii conditions to guarantee that the transmitted signal will be correctly recovered at the receiver end. The designed UWB antennas can be used in many short range applications such as wireless USB. Wireless USB is used in PCs, printers, scanners, laptops, MP3 players, hard disks and flash drives. A new technique is introduced to widen the impedance bandwidth of dielectric resonator antennas (DRAs). DRA features compactness, low losses, and wideband antennas. Different compact UWB DRAs are investigated in this dissertation. The designed DRAs cover a wide range of frequency bands such as, 6.17-24GHz, 4.23-13.51GHz, and 4.5-13.6GHz. The designed DRAs have compact sizes of 1×1×1.5cm3, 0.9×0.9×1.32cm3, 0.6×0.6×1cm3, and 0.6×0.6×0.9cm3; and cover the following frequency bands 4.22-13.51GHz, 4.5-13.6GHz, 6.1-23.75GHz, and 6.68-26.7GHz; respectively. The proposed DRAs may be used for applications in the X, Ku and K bands such as military radars and unmanned airborne vehicles (UAV).
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Разработка антенной системы метеорологической станции : магистерская диссертация / Development of the antenna system of the meteorological stationМихалев, Н. Е., Mikhalev, N. E. January 2015 (has links)
В данной выпускной квалификационной работе стоит цель разработать антенную систему МС, в которую войдут одна антенна: секторная или кольцевая ФАР, с возможностью сканирования пространства в горизонтальной плоскости в диапазоне от 0 до 360 градусов. Обязательное требование, предъявляемое к антенне с электронным сканированием – при отклонении ДН на определённый угол уровень равносигнального направления между соседними ДН не должен быть ниже -2 дБ. Это позволит стабилизировать связь при переключении между соседними каналами с метеорологическим зондом, который может находиться в любом направлении относительно стационарного пункта наблюдения на МС. / In this final qualifying work is the aim to develop an antenna system MS, which will include one antenna: sector or ring of lights, with the ability to scan space in a horizontal plane in the range from 0 to 360 degrees. Mandatory requirement for the antenna with electronic scanning – rejecting days to a certain angle the level of the equisignal direction between adjacent days should not be below -2 dB. This will allow to stabilize the connection when switching between adjacent channels with a meteorological probe, which can be in any direction relative to a stationary point of observation on the MC.
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Diseño de un sistema distribuido de antenas para la optimización de cobertura en la estación central del metropolitanoGutiérrez Salinas, Xavier André, Rivera Cardenas, Juan Gabriel January 2015 (has links)
La presente tesis consiste en el diseño de un sistema MIMO mediante la tecnología DAS (Distributed Antenna System), orientada a una red RF Indoor en la estación central del metropolitano, mejorando la cobertura de señal de los sistemas 2G, 3G y 4G.
La tesis se ha organizado de la siguiente forma:
En el primer capítulo se presenta el planteamiento del estudio de investigación, identificando las problemáticas existentes, trazando objetivos a lograr al final de la tesis. Parte importante de este capítulo es la justificación del estudio y su importancia que posee, así también identificar las variables, para finalmente tener un claro concepto de la problemática.
En el segundo capítulo se presenta el marco teórico. Primero se describe los antecedentes del estudio de investigación relacionadas a las estaciones macro y sistemas Indoor que se ven involucrados en la estación central del metropolitano, así también la descripción de las bases teóricas vinculadas al problema, se elaboró un glosario de los términos que a la comprensión de la tesis.
En el tercer capítulo se muestra el diseño metodológico, teniendo claro el tipo de investigación que será realizado, así mismo la operacionalización de las variables, que son segmentadas para poder ser medidas y/o controladas, por último la técnica de investigación a realizar.
En el cuarto capítulo se muestra el cronograma de trabajo, aspectos económicos como presupuestos y financiamientos en base a los recursos a utilizar en el estudio.
En el quinto capítulo se muestran las mediciones actuales de los parámetros de cobertura móvil en la estación central del Metropolitano. El sexto capítulo presenta las conclusiones y observaciones de la presente tesis.
This thesis is about the design of a system MIMO using technology DAS (Distributed Antenna System), oriented to an RF Indoor network in the metropolitan central station, improving signal coverage of 2G, 3G and 4G systems.
The thesis is organized as follows:
In the first chapter, the approach of the research study was made identifying existing problems, tracing objectives to be achieved at the end of the thesis. An important part of this chapter is the justification of the study and its importance that it has, this we help us to identify variables to finally have a clear understanding of the problem.
The second chapter presents the theoretical framework. First the background of the research study related to macro-stations and Indoor systems that are involved in the metropolitan central station and also the description of the theoretical basis related to the problem, a glossary of terms was made that support us to the understanding of the thesis.
In the third chapter the methodological design is shown, knowing clearly the type of research to be done, likewise the operationalization of the variables, which are separated with the objective of be measured or controlled. Lastly, investigative technique to perform is shown.
In the fourth chapter, we show the work schedule, budget and economic issues such as financing based on the resources used in the study sample.
In the fifth chapter we show the current measurements of the parameters of mobile coverage in the metropolitan central station. The sixth chapter presents the conclusions and observations of this thesis.
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Design of Cellular and GNSS Antenna for IoT Edge DeviceBroumas, Ioannis January 2019 (has links)
Antennas are one of the most sensitive elements in any wireless communication equipment. Designing small-profile, multiband and wideband internal antennas with a simple structure has become a necessary challenge. In this thesis, two planar antennas are designed, simulated and implemented on an effort to cover the LTE-M1 and NB-IoT radio frequencies. The cellular antenna is designed to receive and transmit data over the eight-band LTE700/GSM/UMTS, and the GNSS antenna is designed to receive signal from the global positioning system and global navigation systems, GPS (USA) and GLONASS. The antennas are suitable for direct print on the system circuit board of a device. Related theory and research work are discussed and referenced, providing a strong configuration for future use. Recommendations and suggestions on future work are also discussed. The proposed antenna system is more than promising and with further adjustments and refinement can lead to a fully working solution.
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