Browsing by Subject "Dielectric measurements"
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Item Dielectric optical notch filter at 1.55 micrometers(Texas Tech University, 1999-05) Geng, CunfangAll-dielectric optical notch filters centered at 1.55 µm has been constructed, tested and analyzed. Optical notch filter design considerations such as choice of dielectric material pair, best structure of filters will be discussed. The actual optical notch filters show some absorption at 1.55 µm. Special single Si and Si02 layers have been deposited in the same deposition condition as that for the construction of optical notch filters. Material analysis including absorption analysis has been done to figure out why optical notch filters show absorption and where absorption come from.Item Parameter extraction and characterization of transmission line interconnects based on high frequency measurement(2006) Kim, Jooyong; Neikirk, Dean P.New materials have been, and continue to be, introduced in an effort to reduce the impact of interconnect delay on performance. The accurate experimental characterization of on-wafer transmission lines, particularly lines using copper and low-k materials, is critically important to on-going high-speed digital integrated circuit designers. This dissertation aimed to examine the accurate electrical parameter extraction and characterization of on-wafer embedded microstrip transmission line test structures using high frequency measurements up to 40GHz in determining on-going high-speed digital integrated system performance. In particular we aimed to determine the dielectric constant and loss of low-k dielectric materials, as well as the accurate de-embedding network model of pads on interconnect parameter extraction, the impact of finite measurement precision and error propagation in on-wafer microwave measurement, and the impact of probe placement on high frequency on-wafer measurement.Item Physics of dielectric surface flashover at atmospheric pressures(Texas Tech University, 2003-12) Krile, John T.The limits of the application of dc, ac, or pulsed high voltage are determined by breakdown along insulators or insulating support structures. It is of major technical importance to predict breakdown voltages for given structures, with parameters such as geometry, material, and temporal characteristics of the applied voltage. The impact of atmospheric conditions such as humidity, pressure, temperature, and types of gas present is also important. In order to determine the processes involved in surface flashover, the test setup is designed to produce and closely monitor breakdowns across various gap distances and insulator geometries at atmospheric conditions with varying humidity. Current, voltage, luminosity, and optical emission spectra are measured with nanosecond to sub-nanosecond resolution. Spatially and temporally resolved light emission data is also collected. Results obtained from the light emission data show that a short light emission pulse is first detected at the cathode, a result of electron emission at the cathode. Approximately 100 ns later, significantly more light is detected at the anode when the electron avalanche strikes it. Finally, 50ns later, light is detected at the center of the gap, as the streamer reaches the cathode and the gap closes. The fast imaging data shows a distinct trend for the spark in air to closely follow the surface even if a strong normal electrical field component is present. This tendency is lacking in the presence of gas such as nitrogen, where the spark develops and remains away from the surface. Finally, the breakdown voltage is shown to decrease significantly with an increase in humidity.