http://hdl.handle.net/2104/4749 2013-06-18T07:58:23Z 2013-06-18T07:58:23Z Wang, Loria LayShay. http://hdl.handle.net/2104/8601 2013-05-15T19:00:19Z 2013-05-15T00:00:00Z

Side lobe modulation of radar antenna pattern utilizing an auxiliary array. Wang, Loria LayShay. In the area of electronic countermeasures, disabling the ability of an individual to “listen” to the transmitted waveform is of great interest. Most often, an individual can intercept the transmitted radar signal through the side lobes of the transmitted radiation pattern. Reducing these transmitter side lobes may eliminate the ability of unauthorized listeners to intercept a transmitted signal. Most traditional radar systems utilize antennas that do not possess the capability of shaping the transmitted radiation pattern. Instead of replacing the existing radar antenna with large adaptive arrays, the combination of the existing system with an auxiliary low cost array will extend the system capability to include techniques such as side lobe modulation, cancellation, and adaptive beam forming.

2013-05-15T00:00:00Z Trower, John W. http://hdl.handle.net/2104/8600 2013-05-15T18:59:32Z 2013-05-15T00:00:00Z

Accelerating path planning algorithms with high level synthesis tools and FPGAs. Trower, John W. Accelerating path planning algorithms with field programmable gate arrays (FPGA) allows the designer to achieve significant performance increases over using a traditional central processing unit (CPU). Converting an algorithm to run on an FPGA is a complicated and time consuming process. This thesis develops and verifies a design framework that demonstrates how to design a path planning algorithm in a high level language, then convert the algorithm into hardware description languages using high level synthesis tools. This design framework will be used to demonstrate the acceleration of a genetic algorithm.

2013-05-15T00:00:00Z Martin, Joshua Lee. http://hdl.handle.net/2104/8585 2013-05-15T18:43:08Z 2013-05-15T00:00:00Z

Adaptive load impedance optimization for power amplifiers in reconfigurable radar transmitters. Martin, Joshua Lee. A fundamental tradeoff exists in radar transmitter design between linearity and efficiency due to the signal amplification. These transmitters are driven into saturation in order to increase efficiency, but may potentially violate regulatory spectral mask limitations. An adaptive method for optimizing linearity and efficiency for power amplifiers in radar transmitters is presented. This approach uses intelligent search techniques with load-pull measurements for power-added efficiency (PAE) and adjacent channel power ratio (ACPR) to dynamically maximize the PAE while meeting spectral requirements. Using load-tuning, an algorithm performs a steepest ascent search for the PAE optimum load reflection coefficient, followed by a steepest descent search for ACPR. The steepest descent search, when begun at the PAE optimum, approximates the Pareto optimal frontier between the two objectives. This trace enables PAE to be maximized for an imposed limit on ACPR, optimizing the performance of adaptive radar transmitters under spectral mask constraints.

2013-05-15T00:00:00Z Mailen, Russell. http://hdl.handle.net/2104/8582 2013-05-15T18:39:56Z 2013-05-15T00:00:00Z

Investigation of induced thermo-mechanical response and cure kinetics during processing of carbon fiber reinforced plastics. Mailen, Russell. The manufacture of laminated composite materials using a thermosetting resin matrix is a complex process that can be understood with a knowledge of cure kinetics, heat transfer, and structural mechanics. During laminate manufacture, reinforcing fibers are impregnated with resin and subjected to catalytic conditions. Under these conditions, the resin transforms from liquid to solid as polymer chains form a crosslinked network. During this process, the phenomenological events of gelation and vitrification influence the ability to process the resin. Prediction of these events with kinetic modeling allows the optimization of the manufacturing process and insight into the final material properties. This thesis investigates the application of kinetic models to, specifically, the Pro-Set 117LV/229 epoxy system. Additionally, it is demonstrated that residual stresses develop in laminated composite as cure progresses. The residual stress state is affected by the processing history of the component and has an impact on component dimensionality and strength.

2013-05-15T00:00:00Z