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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 22 for “"Antenna pattern"”.
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Antenna Pattern Synthesis
Made available in DSpace on 2014-12-04T21:02:33Z (GMT). No. of bitstreams: 1 0003133.pdf: 5113231 bytes, checksum: be923674dbf03f454f8ac79a87043c56 (MD5) Previous issue date: 1951
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Time domain antenna pattern measurements
Multipath on far-field antenna ranges causes distortion of antenna pattern measurements: The multi path components have differing path lengths and hence can be separated by illuminating the antenna under test with short-duration pulses. Alternatively, antenna measurements can be made in the …
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Resolution enhancement techniques for antenna pattern measurements
Thesis (M.Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2000.
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Use of Computational Electromagnetics to Enhance the Accuracy and Efficiency of Antenna Pattern Measurements
… used to improve the accuracy and efficiency of antenna pattern measurements. </p> <p>This can be accomplished in many different ways, such as moving a single probe over the measurement plane to generate accurate planar near field to far field transformation methodology over the classical Fourier …
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Influence of antenna pattern on synthetic aperture radar (SAR) imaging and complex permittivity extraction from images of multilayered media
… information. To this end, it is found that the antenna pattern, and not just its beamwidth, affects SAR image resolution and image sidelobe level. Hence, a general approach is proposed that provides for a comprehensive analysis of the effect of antenna pattern on SAR image resolution and image …
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Retrieval of Free Space Radiation Patterns through Measured Data in a Non-Anechoic Environment
<p>Antenna pattern measurements are usually carried out in an anechoic chamber. However, a good anechoic chamber is very expensive to construct. Previous research has attempted to compensate for the effects of extraneous fields measured in a non-anechoic environment to obtain a free space pattern …
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Performance prediction and improvement of a Bistatic Passive coherent location Radar.
… the development of the prediction method, an antenna pattern was synthesised and applied to an array of folded dipoles in order to place a null in the direction of the strong transmitter. The synthesised antenna pattern and its improvement on the performance of the PCL system was then …
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Antenna effects on indoor wireless channels and a deterministic wide-band propagation model for in-building personal communication systems
While the application of antenna diversity in a narrow band communication system is well understood, little research has been done on antenna effects in wide-band channels. Research has shown that circular polarization (CP) is more robust in combating multipath than linear polarization in …
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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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Computer-aided design-based high-frequency electromagnetic wave scattering from complex bodies
… (RCS) problems, cavity radiation problems, and antenna pattern predictions of complex electrically large structures, thereby showing that it is feasible to accurately approximate the electromagnetic wave scattering from general complex bodies using CAD techniques and high frequency scattering …
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Adaptive Pattern Modeling for Large Reflector Antennas
This thesis presents methods for modeling the pattern of large axisymmetric paraboloidal focus-fed reflector antenna systems. The intended application of these methods is to improve the performance of time-domain interference canceling (TDC) in radio astronomy. The first method yields a closed-form …
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High Resolution Simulation of Synthetic Aperture Radar Imaging
… that takes advantage of the forward motion of an antenna mounted on a moving platform (such as an airplane or spacecraft) to synthetically produce the effect of a longer antenna. Since most SAR images used for military ATR are classified and not available to the general public, all academic …
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COOPERATIVE COMMUNICATIONS FOR LTE-ADVANCED SYSTEMS: DOWNLINK RELAY AND PERFORMANCE OPTIMIZATION
… of each scheme are analyzed for each relay type, antenna pattern as well as power and frequency resources allocation.
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An open source array antenna toolbox implementation
… of radio waves by means of phased array antennas was demonstrated. Since then, the further development of phased array radars was largely driven from a military point of view, with operational phased array systems implemented as far back as the second World War. In recent times, phased …
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Interference aware wireless networks with point to point beamforming
… the effects of change in beam width of the antenna pattern and some other antenna parameters. In our work we investigate and build a model that could possibly overcome interference by changing such physical layer parameters and using them to exploit the benefits not only in the physical …
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Antenna element pattern reconfigurability in adaptive arrays
… benefits of utilizing radiation reconfigurable antennas in an adaptive array setting. The work centers on arrays composed of a small number of widely spaced elements. Such array configurations (1) mitigate the effects of mutual coupling between reconfigurable elements, thereby maximizing their …
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Analysis of Highly Coupled Wideband Antenna Arrays Using Scattering Parameter Network Models
… in the array. Previous efforts by Virginia Tech Antenna Group has shown that the strong coupling can be utilized in arrays to obtain broadband frequency response while maintaining a small element spacing. However, mutual coupling between elements in a tightly coupled array can sometimes …
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Transmission Lines For Ir Signal Routing
… point of view of developing interconnections for antenna-coupled infrared detectors operating in the 8- to 12-micron wavelength range. To our knowledge, no previous efforts have been made to study the performance of metallic-wire transmission lines at infrared frequencies. Both the design and …
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Adaptive antenna systems for mobile broadband communications
… wireless communications is the use of adaptive antennas at the transceivers, along with the associated advanced array signal processing, to improve cell coverage, link quality and system capacity. This dissertation first provides a framework of adaptive antenna systems for wireless …
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Investigation of a cylindrically conformed reconfigurable microstrip parasitic array
Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2027-05-01
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