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 33 for “"phase shifter"”.
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A high speed digital, X-band phase shifter.
Massachusetts Institute of Technology. Dept. of Electrical Engineering. Thesis. 1965. M.S.
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Structure and Optimisation of Liquid Crystal based Phase Shifter for Millimetre-wave Applications
… radars and hand-gesture sensing, variable phase shifters are vital components for antenna arrays to steer an electromagnetic beam without mechanical movement. However, present microwave technology has limited scope in meeting more and more stringent requirements in wavefront phase control …
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Theory and design of mixed lumped-distributed cross-coupled filters with applications to linear phase shifter and tunable filters
… both sharp rejection characteristics and linear phase slopes. In order to achieve this performance, various types of combline filters are suggested. Various simulation tools (commercial linear circuit and E-M simulators), as well as the developed pole-zero locator program, were used to design a …
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High-efficiency Waveguide Tunable Leaky-wave Antennas and Phase-shifters
… in varactors, we introduce a new tunable phase shifter based on surface waves with high efficiency. The proposed phase shifter can be used for the implementation of phased arrays with low loss at high frequencies. The design of the proposed phase-shifter is based on maximizing its …
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Power efficient Transmit/Receive (T/R) Elements for Integrated mm-Wave Phased Arrays
… and high-resolution imaging systems. Large-scale phased arrays have been exploited in such application for their beam forming and null steering capabilities, resulting in high directivity and improved SNR. But growing DC power consumption (Pdiss) in such large scale arrays has become an on-going …
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Digitally-Assisted RF IC Design Techniques for Reliable Performance
… techniques: self-calibration system for RF phase shifters and wide dynamic range LNAs.</p> <p>Due to PVT variations in scaled technologies, RF phase shifter design becomes more challenging with device scaling. In the proposed self-calibration topology, we devised a novel phase sensing method …
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Tunable Optical Group Delay in Active Semiconductor Optoelectronic Devices
… and operating regimes. A microwave photonic phase-shifter is then proposed and demonstrated using wavelength conversion in a distributed-feedback laser. This scheme provides microwave phase shifts greater than 140° over GHz bandwidths, and is relatively insensitive to the input …
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Modeling of DFB surface emitting lasers and semiconductor laser arrays
… the device length, optical coupling and phase shifter in the device.
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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.
… its viability. Then two hybrid coupled PIN diode phase shifters, using Branchline and Rat-Race ring coupler structures, were designed and tested. The generation of four distinct phase shifts was implemented and studied. The variations of the scattering parameters were found to be realistic, with …
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Development and optimization of reconfigurable planar lenses and reflectors
… a modular design: the radiating elements and the phase shifter are optimized independently. For the best reconfigurability capabilities, the phase shifter should be continuous, offering full phase control range, low insertion losses and loss variation, while keeping a small circuit footprint for …
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Design of an ICRF fast matching system on Alcator C-Mod
… to design guidelines for a high power ferrite phase shifter and a fast-matching network using such tuners.
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High-Speed and Power Efficient Integrated Electro-Optic Modulators
… I have demonstrated a SOI platform-based optical phase shifter by combining the through and drop ports of a silicon add-drop MRR modulator. The measured intensity spectra for different bias voltages show that, our proposed phase shifter combining the through and the drop ports show ∼4.29 dB less …
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EFFECTS OF STRAIN ON DIELECTRIC PROPERTIES OF FERROELECTRIC Ba0.5Sr0.5TiO3 FILMS
… high performance and cost reduction, such as phase shifters, tunable oscillators, delay lines, and antennas. These tunable devices require large change in the dielectric constant with applied field and a low loss at microwave frequencies. As one of the promising ferroelectric materials, barium …
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RF Feedforward Interference Cancellation For Wide-band Signals using Adjustable Band-stop Resonators
… which later becomes an input to the cancellation phase of the system. The system is tested using two generated LTE modulated signals, modeling the interference and the wanted signals, which are 20, 15 and 10 MHz apart. The test results have shown successful cancellation for 9 MHz wide interference …
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Phase Shift Control: Application and Performance Limitations With Respect to Thermoacoustic Instabilities
… and is often impractical on a large scale. Phase shift control of the instabilities is perhaps the simplest and most popular technique employed but often does not provide good performance in that controller induced secondary instabilities are generated with increasing loop gain. This thesis …
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Novel modulated antennas and probes for millimeter wave imaging applications
… millimeter wave VNA, a custom-designed waveguide phase shifter based on sub-resonant loaded slots is introduced. The proposed MLS method, modulated elliptical slot, dual-loaded modulated aperture probe, and VNA are thoroughly investigated and their efficacy for microwave and millimeter wave …
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Advanced silicon photonics for microwave frequency down-conversion
… incident powers, and a depletion mode optical phase shifter with a V[subscript [pi]]L of 0.9 V xcm and an electro-optical bandwidth of several gigahertz were designed and tested. Finally, all of these components were assembled in a novel architecture to create an integrated silicon photonic …
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A photon-photon interface with an atomic ensemble in an optical cavity
… transistor, a nondestructive photon detector, a phase shifter, and a quantum state generator. These devices rely on a nonlinear optical interface comprised of a few thousand atoms inside of a high-finesse optical cavity. Signal light is sent through a mode transverse to the cavity and is stored …
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Integrated LIDAR with optical phased arrays in silicon photonics
… is then extended by utilizing optical phased arrays as a transmitter and receiver for solid-state beam steering. The phased array utilized has a grouped cascaded phase shifter architecture and is shown to have a steering range of 46°x36°. This is the first integrated coherent LIDAR …
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Physical Layer Security in Millimeter-Wave Communication
… implementations. In addition, we consider the phase quantization errors of the phase shifters in the phased-array antennas. The phase quantization errors have adverse effects on the PLS mmWave communication performances. Lastly, we consider to reduce the hardware costs and simplify the …
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