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 95 for “"beam steering"”.
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An electronic beam-steering antenna using a tunable FSS
Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-05-01
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On-Chip Planar Lens Architectures for Optical Beam Steering
Free-space optical beam steering is an important technological capability because of its applications in optical communication links and sensing such as light detection and ranging (lidar). Over the past decade, there has been significant efforts to develop a beam steering architecture that can …
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Modeling and algorithms for optimizing beam steering optical crossconnects
One of the most significant applications of Micro-Electromechanical Systems (MEMS) technology in optical communications today is in building large non-blocking optical crossconnects based on arrays of tiltable micro-mirrors. The complexity for these crossconnects to make all possible connections …
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Middle infrared beam-steering using liquid crystals for spatial light modulation
Middle infrared beam-steering is attractive for a number of applications, particularly in the defence sector, where infrared countermeasures are a cornerstone in protecting lives and assets from infrared seeking weapons. Liquid crystal based alternatives to the current opto-mechanical state of the …
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High Angular Resolution Beam Steering Terahertz Antenna Arrays for Imaging Applications
… radar imaging, where a narrow FMCW radar beam is swept across a scene to produce a depth image which, unlike LIDAR, is tolerant to environmental conditions such as rain and snow. However, challenges exist in the design of large dense THz arrays, limiting demonstrations to hundreds of …
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Design of a photonic crystal planar Luneburg lens for optical beam steering
Optical beam steering has numerous applications including light detection and ranging (LIDAR) for three-dimensional (3D) sensing, free space communications, additive manufacturing, and remote sensing. In particular, there is an increasing demand for LIDAR in a variety of applications including …
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Digital Control Board for Phased Array Antenna Beam Steering in Adaptive Communication Applications
… spatial filtering through planar antenna array beam forming.</p> <p>This thesis describes the development of a digital system that adaptively controls a phased array antenna. The radiating structure of the phased antenna array is tetrahedral-shaped and contains four antenna elements on each of …
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Terahertz beam-steering imager using a scalable 2D-coupled architecture and multi- functional heterodyne pixels
… a 32 x 32 array. This chip is capable of digital beam steering, too. The first version of the chip prototype with a 10 x 10 array is fabricated using a 130-nm SiGe BiCMOS process and tested.
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Reconfigurable phased microstrip antenna array with defected ground structure and defected microstrip structure for beam steering application
Beam steering is defined as the ability to electronically steer the beam maximum of an antenna electric field pattern to some predefined point in space. The performance of a phased antenna array for beam steering without moving the antennas is important to military and civil applications. A …
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Liquid lens beam steering and environmental testing for the miniature optical steered antenna for inter-satellite communication
… deformable liquid lenses to achieve wide-angle beam steering for CubeSat laser communication (lasercom) crosslinks. Liquid lenses are lenses that can non-mechanically alter focal length based on an applied voltage or current. We evaluate two commercial liquid lens manufacturers, Corning …
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Proton beam steering control system for high precision radiotherapy at iThemba LABS : an investigation on actuator saturation constraints
… with special application to the Proton beam steering control at iThemba LABS. The steering of charged particles occurring in research plants is one of the interests of control systems. In this work an investigation of the algorithm for the control of the proton beam steering system in …
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Nineteen-Element Phased-Array Feed Development and Analysis on Effects of Focal Plane Offset and Beam Steering on Sensitivity
… how sensitivity was affected by electronic beam steering and offset of the phased array feed (PAF) relative to the focal plane of the reflector. These simulated results were then compared to experimental data.
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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.
… 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 …
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Integrated optical phased arrays : augmented reality, LiDAR, and beyond
… results, and applications are presented. First, beam-steering optical phased arrays for LiDAR are shown, including the first beam-steering optical phased arrays powered by monolithically-integrated on-chip rare-earth-doped lasers, the first beam-steering optical phased arrays controlled using …
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Coherently-coupled vertical-cavity laser arrays
… laser (VCSEL) arrays offer a unique approach to beam steering and high-radiance applications, and have many advantages such as small size, low cost, high speed, durability and manufacturing ease. Previous work on coherently-coupled VCSEL arrays has left unfinished the tasks of determining the …
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A Compact RF/Photonic Antenna using a Quantum Dot Mode Locked Laser as a Source
… antenna array is designed to achieve beam steering. By manipulating the applied voltage bias of each QDMLL, one can achieve beam steering without the use of external RF phase shifters yielding a more compact design of an RF/photonic antenna on a chip. The 2-element integrated prototype …
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Evanescently Coupled Vertical Cavity Laser Arrays
… communications, image processing, and electronic beam-steering. Past work in coherently coupled VCSEL arrays has resulted in out-of-phase arrays or more desirable in-phase arrays, which suffer from complex fabrication processes. This work examines two types of evanescently coupled VCSEL arrays: …
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Novel DMD-based Lidar and Display Systems
… Second, DMD-based programmable blazed grating beam steering is multiplexed with spatial modulation for Angular Spatial Light Modulation (ASLM). The ASLM technique is employed as a holographic beam steering mechanism for a lidar system for increased angular resolution and field of view. Third, …
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Millimeter wave communications : from point-to-point links to agile network connections
… between the transmitter's and receiver's beams, a process that takes up to a few seconds. This delay is problematic in a network setting where the base station needs to quickly switch between users and accommodate mobile clients. This research encompasses the implementation and testing of …
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Design and Simulation of a Two-Dimensional Beam Steered Millimeter-Wave Phased Array Antenna at W-Band (75 – 110 GHz, respectively 4 – 2.7 m)
… because they can dynamically aim their primary beam (the strongest possible radiation) in the direction of the target.<br/><br/>The front end of a 75 GHz phased array antenna that supports electronic beam steering in two dimensions is the subject of this report’s design and study. To investigate …
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