Masters Theses

Lei Hua

Keywords and Phrases

Distributed optical sensing||Material characterization

Abstract

"A new concept, the microwave-assisted reconstruction of an optical interferogram for distributed sensing, was developed to resolve both the position and reflectivity of each sensor along an optical fiber. This approach involves sending a microwave-modulated optical signal through cascaded fiber optic interferometers. The optical spectrum of each sensor can be reconstructed by sweeping the optical wavelength and detecting the modulation signal. A series of cascaded fiber optic extrinsic Fabry-Perot interferometric sensors was used to prove the concept. The microwave-reconstructed interferogram matched well with those recorded individually from a traditional optical spectrometer. The application of distributed strain measurement was also investigated. The wavelength shift of the interferogram increases linearly as a function of the applied strain, and the increasing strain did not incur noticeable loss in the reflection spectra"--Abstract, page iv

Signal integrity (SI) and power integrity (PI) modelling and design require accurate knowledge of dielectric properties of printed circuit board (PCB) laminate dielectrics. Dielectric properties of a laminate dielectric can be obtained from a set of the measured S-parameters on a PCB stripline with a specially designed through-reflect-line (TRL) calibration pattern. In this work, it is proposed to extract dielectric properties from the measurements of S-parameters on the two 50-Ohm stripline structures of the same length, but different widths of the trace, designed on the same layer of a PCB. The dielectric properties on these two lines should be identical. However, an application of the simplest "root-omega" technique to extract dielectric properties of the substrate would lead to the ambiguity in the extracted data. This is because the conductor surface roughness affects the measured S-parameters and is lumped in the extracted dielectric data. This problem of ambiguity in the dielectric properties extraction can be overcome using the approach analogous to the recently proposed method to separate dielectric and conductor losses on PCB lines with different widths and roughness profiles"--Abstract, page 48.

Advisor(s)

Xiao, Hai, Dr.
Fan, Jun, 1971-

Committee Member(s)

Tsai, Hai-lung

Department(s)

Electrical and Computer Engineering

Degree Name

M.S. in Electrical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Summer 2014

Journal article titles appearing in thesis/dissertation

  • Characterization of PCB dielectric properties using two striplines on the same board

Pagination

xi, 70 pages

Note about bibliography

Includes bibliographical references.

Rights

© 2014 Lei Hua, All rights reserved.

Document Type

Thesis - Open Access

File Type

text

Language

English

Subject Headings

Printed circuits -- DesignDielectric devicesSignal integrity (Electronics) -- Microwave measurements -- Computer simulationOptical fiber communication

Thesis Number

T 10513

Electronic OCLC #

894580696

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