No description available.

Thesis (Ph.D)--University of Western Australia, 2007.

No description available.

This thesis investigates the use of an avalanche Platinum Silicide (PtSi) Schottky Barrier Diode as a detector in fiber optic communication systems for the 1.3 to 1.5 mum spectral region. The avalanche process is used to amplify the signal prior to electrical interfacing in order to enhance the signal-to-noise ratio. The amount of multiplication is predicted by the impact ionization coefficients for electrons and holes, alpha and beta, respectively. By using PtSi Schottky diodes, where alpha > beta, pure electron injection can be accomplished by irradiating with photons of energy psi hnu Eg (where psi is the Schottky Barrier height and Eg is the bandgap of silicon), thus maximizing multiplication and minimizing noise. An alternative means for avalanching involves the quantum effects of impurity-band ionization. By using a heavily doped semiconductor and operating at low temperatures, one can achieve noise-free gain at lower electric field strengths. (Abstract shortened with permission of author.)

Not available / text

published_or_final_version / Electrical and Electronic Engineering / Master / Master of Philosophy

No description available.

Professional paper (MS)--Montana State University--Bozeman, 2008. / Typescript. Chairperson, Graduate Committee: Joseph A. Shaw. Includes bibliographical references (leaves 118-120).

This thesis is based on modifications performed on the U.S. Army TACOM (Tank Automotive Command, Warren, Michigan) Thermal Imaging Model (TTIM). It discusses the TTIM computer model of a staring thermal imaging sensor with respect to spatial nonuniformities. The spatial nonuniformities in a staring sensor is caused by fixed pattern noise or responsivity variations across the sensor. The objective of the thesis is to present the correction schemes for spatial nonuniformities present on a staring thermal imaging sensor and the data analysis of the corrections using flat field and bar chart targets of known temperatures. The signal-to-noise ratios (S/Ns) of the images will be calculated and measured before and after the correction. A simulated image after a one-point correction will be evaluated by comparison with an image from a real system using a platinum silicide thermal imaging sensor. The limits and assumptions of the simulation also will be discussed.

Approved for public release; distribution is unlimited / The objective of this thesis is to investigate the requirements and limitations of boost phase ballistic missile intercept systems that contain an interceptor and its guidance sensors (both radar and infrared). A three- dimensional computer model is developed for a multi-stage target with a boost phase acceleration profile that depends on total mass, propellant mass and the specific impulse in the gravity field. The radar cross-section and infrared radiation of the target structure is estimated as a function of the flight profile. The interceptor is a multi- stage missile that uses fused target location data provided by two ground-based radar sensors and two low earth orbit infrared sensors. Interceptor requirements and limitations are derived as a function of its initial position from the target launch point and the launch delay. Sensor requirements are also examined as a function of the signal-to- noise ratio during the target flight. Electronic attack considerations within the boost phase are also addressed including the use of decoys and noise jamming techniques. The significance of this investigation is that the system components within a complex boost phase intercept scenario can be quantified and requirements for the sensors can be numerically derived. / Captain, Turkish Air Force