Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 58 for “"Antenna System"”.
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A base station smart antenna system for CDMA cellular
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1998.
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Development of an antenna system for a relay-based wireless network
… These stations should be equipped with an antenna system capable of establishing communication between base station (backhaul link) and end users (access link). This thesis focuses on the design and development of a new antenna system that is suitable for a relay-based wireless network. …
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MIMO RADIO-OVER-FIBRE DISTRIBUTED ANTENNA SYSTEM FOR NEXT GENERATION WIRELESS COMMUNICATION
… 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 …
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Error Analysis of Angle and Range Estimation in a Range Limited Antenna System Using Music and Modified Root Pisarenko Algorithms
The Range Limited Antenna (RLA) has the ability to track and pin-point RF devices operating within a certain accepted range. Using two antenna arrays, each made up of several elements, direction-finding algorithms such as MUSIC and Modified Root Pisarenko (MRP) are used to estimate the angles of …
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Development And Characterization Of Beamforming Antenna Systems
… discusses the development of the beamforming antenna systems as a scaled model for customized RFID systems. In this work, an Fabry-Perot Cavity (FPC) antenna system consisting of a single source and frequency selective surface (FSS) is proposed (chapter 2) and investigated. Since the FPC …
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Interference mitigation in colocated wireless systems
… one colocated transmitter can radiate into the antenna system of a second colocated transmitter. The signals enter the second transmitter in the reverse direction and mix in the output stage of its power amplifier to produce intermodulation products. These ‘reverse’ intermodulation products get …
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Substrate integrated waveguide antenna systems
… 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 …
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Beam scanning offset Cassegrain reflector antennas by subreflector movement
… is being affected by human activity. One of the systems required for the mission was a wide scanning, high gain reflector antenna system for use in radiometric remote sensing from geostationary orbit. This work describes research conducted at Virginia Tech into techniques for beam scanning offset …
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Bandwidth enhancement techniques for low-profile antennas: Theory and experiment
… for bandwidth enhancement for low-profile antennas. The first method involves the use of coupled resonators. In particular, two cavity-backed slot antennas are coupled through an aperture in a common wall. One cavity-backed slot antenna, of the coupled antenna system, is driven. This …
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Wideband active antenna cancellation
There exists a simultaneous transmit and receive antenna system where the transmitted signal is creating wideband interference of the receiver. To resolve this interference problem, the isolation between the transmit antenna and the receive antenna must be increased. This thesis analyzes and …
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Analysis and Optimization of Reflector Antenna Systems (Pattern Calculation, Optimum Directivity, Sidelobe Reduction)
… pattern of a perfectly conducting reflector antenna system being illuminated by an array feed with arbitrary location, polarization, and orientation. The methods of analysis used are physical optics (PO) and the application of the Fast Fourier Transform (FFT) to the aperture fields obtained …
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Analysis of infinite arrays of arbitrarily shaped planar radiating elements using a Floquet mode based Method of Moments approach
Large phased array antennas are theoretically capable of delivering the directive gain of similarly sized aperture antennas while offering electronic beam scanning capabilities and greater operational flexibility. Unfortunately, the high cost associated with large phased antenna arrays has limited …
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A deployable bottom fed conical log-spiral antenna for CubeSat applications
The requirements for deployable antenna systems on micro-satellites, specifically on the CubeSat platform, are ever changing. This thesis will address the possible antenna systems that would best be deployed on a CubeSat, with the major focus on the conical log-spiral antenna (CLSA) due to its …
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Ultra-Wideband Antenna Characterization and Modeling
… methodology is presented for characterizing an antenna system both in the time and frequency domain with one set of parameters using a singularity expansion method representation. A minimal set of parameter modeling antenna systems using the Matrix-Pencil method has been demonstrated. It has …
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Numerical models of new HF shipboard communication antenna systems for improved survivability
There are many shipboard communication antenna problems where the number, type, location, or survivability of a given antenna in the system is a parameter which can be varied to determine the overall optimal system. This thesis investigates computer numerical models f or improving the time that an …
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Performance Comparison Between Music And Esprit Algorithms For Direction Estimation Of Arrival Signals
… Arrival (DOA) of incoming signals to the smart antenna. The comparison of these two algorithms was done on the basis of parameters like number of array elements, number of incoming signals, angle difference between the incoming signals, number of the samples taken of signal, processing time and …
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Standalone Antenna Demonstration System
Antenna systems play a significant role in today’s electronic communications. They are essential for cell phones, satellites, radio, and radar among many other important applications. This paper describes the design, assembly, and operation of an antenna demonstration system designed to instill …
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Mobile array designs with ANSERLIN antennas and efficient, wide-band PEEC models for interconnect and power distribution network analysis
"A mobile, wide-band antenna system has been developed around the ANSERLIN antenna element and a 3-dB splitter design. The size of the antenna elements was reduced over previous versions by introducing dielectric substrates. Additionally, new variations of the antenna were designed to influence …
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Smart Antennas at Handsets for the 3G Wideband CDMA Systems and Adaptive Low-Power Rake Combining Schemes
Smart antenna technology is a promising means to overcome signal impairments in wireless personal communications. When spatial signal processing achieved through smart antennas is combined with temporal signal processing, the space-time processing can mitigate interference and multipath to yield …
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Absolute Flux Density Measurement and Associated Instrumentation for Radio Astronomy below 100 MHz
… also reports new measurements of the antenna temperature due to the diffuse Galactic background between 30-78 MHz, addressing a paucity of existing measurements in this band. These measurements are relevant especially in the context of contemporary interest in radio astronomy and 21 cm …
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