Theses and Dissertations at Montana State University (MSU)
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Item Phase alignment of asynchronous external clock controllable devices to periodic master control signal using the Periodic Event Synchronization Unit(Montana State University - Bozeman, College of Engineering, 2009) Ostrander, Charles Nicholas; Chairperson, Graduate Committee: Brock LaMeresThe Periodic Event Synchronization Unit aligns devices without the ability to be triggered by an external source. The primary function of the unit is to align the pattern trigger pulses of two pulse pattern generators which supply four inputs of a multiplexer. The pulse pattern generators lack the ability to start their code according to an external signal. When operating, the designed unit maintains a specific pattern alignment of two binary data streams of 5 gigabits per second as a multiplexer combines them into a data stream of four times the bit rate. In addition to alignment, the unit can introduce offsets of up to 50 nanoseconds to the pattern alignment which corresponds to 250 bits. The unit is designed to allow the alignment of other devices as well, requiring as input the two event signals of the same frequency which need to be aligned. In order to align the devices providing the event pulses, one of the devices must either accept an external clocking source or have the ability to frequency modulate the internal clock. In practice, the test system was able to achieve and maintain the desired signal characteristics from the output of the multiplexer. The unit's robust design is shown by providing alignment of patterns for the full operating range of the pulse pattern generators and allowing a generator pattern to be aligned to a generic event pulse. Use of multiple units allows alignment of additional devices. The development of the Periodic Event Synchronization Unit provided an inexpensive solution to creating very high bit rate signals using preexisting equipment, as no commercial products were found to accomplish the same function.Item Enhanced step mode FTIR position control(Montana State University - Bozeman, College of Engineering, 2005) Inberg, R. Brandon; Chairperson, Graduate Committee: Steven R. ShawThis thesis presents a modification to a typical Fourier transform infrared (FTIR) spectrometer to achieve finer spatial sampling and increased frequency range for step-scan experiments with little modification to the existing hardware. Commercially available step-scan FTIR spectrometers currently have the ability to measure spectra up to 15798 cm_1, which is limited by a HeNe reference laser used for controlling the mirror's position. The proposed technique involves using a digital signal processor (DSP) to measure the HeNe reference signal and estimate the mirror position. The DSP then outputs a new synthetic signal that is used by the spectrometer to control the mirror to finer steps, allowing it to measure spectrums up to 47394 cm_1. Enhanced closed-loop mirror position data is presented to show the quality of the DSP estimate along with spectrograms taken of an erbium crystal to show the overall spectral improvements. To validate the erbium crystal enhanced step-scan spectrogram, a continuous scan experiment is given for comparison. The results demonstrate previously unattainable step-scan performance.