Engineering Commons^™

Design Of A Highly Constrained Test System For A 12-Bit, 16-Channel Wilkinson Adc, Zachary William Pannell

Masters Theses

Outer space is a very harsh environment that can cause electronics to not operate as they were originally intended. Aside from the extreme amount of radiation found in space, temperatures can also change very dramatically in a relatively small time frame. In order to test electronics that will be used in this environment, they first need to be tested on Earth under replicated conditions. Vanderbilt University designed a dewar that allows devices to be tested at these extreme temperatures while being radiated. For this thesis, a test setup that met all of the dewar's constraints was designed that would allow …

A Novel Frequency Based Current-To-Digital Converter With Programmable Dynamic Range, Xiaoyan Yu

Doctoral Dissertations

This work describes a novel frequency based Current to Digital converter, which would be fully realizable on a single chip.

Biological systems make use of delay line techniques to compute many things critical to the life of an animal. Seeking to build up such a system, we are adapting the auditory localization circuit found in barn owls to detect and compute the magnitude of an input current.

The increasing drive to produce ultra low-power circuits necessitates the use of very small currents. Frequently these currents need to accurately measured, but current solutions typically involve off-chip measurements. These are usually slow, …

Reconfigurable Rf Front End Components For Multi-Radio Platform Applications, Chunna Zhang

Doctoral Dissertations

The multi-service requirements of the 3G and 4G communication systems, and their backward compatibility requirements, create challenges for the antenna and RF front-end designs with multi-band and wide-band techniques. These challenges include: multiple filters, which are lossy, bulky, and expensive, are needed in the system; device board size limitation and the associated isolation problems caused by the limited space and crowd circuits; and the insertion loss issues created by the single-pole-multi-through antenna switch.

As will be shown, reconfigurable antennas can perform portions of the filter functions, which can help solve the multiple filters problem. Additionally, reconfigurable RF circuits can decrease …

Plume Source Localization And Boundary Prediction, Samir Sahyoun

Masters Theses

Plume location and prediction using mobile sensors is the main contribution of this thesis. Plume concentration values measured by chemical sensors at different locations are used to estimate the source of the plume. This is achieved by employing a stochastic approximation technique to localize the source and compare its performance to the nonlinear least squares method. The source location is then used as the initial estimate for the boundary tracking problem. Sensor measurements are used to estimate the parameters and the states of the state space model of the dynamics of the plume boundary. The predicted locations are the reference …