Masters Theses

Abstract

"An orthogonally-fed, small, resonant elliptical slot, loaded by a varactor diode, is designed through full-wave simulation for use in synthetic aperture radar imaging arrays. The varactor diode provides electronic control over the slot's resonant frequency, allowing it to be tuned over a few GHz within the K-band (18-26.5 GHz) frequency range. The final slot design employs two varactor diodes resulting in 3.5 GHz of tunable bandwidth. The broadest dimensions of the antenna are restricted to being less than λ/2 as a consequence of the required spacing in a 2D imaging array. The feed design uses a coplanar waveguide (CPW) with a 90° bend, RF coupled to the antenna. The manufactured slot is tested using a vector network analyzer (VNA) showing good agreement with the simulation results. Since the feed line is a CPW, one can readily incorporate a commercial surface-mount switch onto the feed board, allowing a single input port to be connected to four antenna elements in the array. Two four-element arrays are manufactured and a one-sided imaging apparatus is formed by properly aligning them. Each array is connected to one port of a two-port VNA, and they are raster scanned over several test samples. Reflection measurements (using one array) and transmission measurements (i.e., bi-static; from one array to the other) are made during the scans, along with some reference measurements. A correction method is developed and implemented to provide a common phase reference between frequencies. The characteristics of the switch dominate the reflection measurements, although this effect is mitigated by applying a proper correction algorithm. The system works best in transmission (hi-static) mode. The data is processed to generate 30 holographic SAR images showing indications of the targets in several test samples"--Abstract, page iii.

Advisor(s)

Zoughi, R.

Committee Member(s)

Beetner, Daryl G.
Ghasr, Mohammad Tayeb Ahmad, 1980-
Pommerenke, David

Department(s)

Electrical and Computer Engineering

Degree Name

M.S. in Electrical Engineering

Publisher

Missouri University of Science and Technology

Publication Date

Spring 2013

Pagination

ix, 78 pages

Note about bibliography

Includes bibliographical references (leaves 74-77).

Rights

© 2013 Mark Andrew Baumgartner, All rights reserved.

Document Type

Thesis - Restricted Access

File Type

text

Language

English

Library of Congress Subject Headings

Microwave imaging -- Computer simulation
Microwave devices -- Design -- Computer simulation
Millimeter wave devices -- Design -- Computer simulation
Nondestructive testing -- Computer simulation
Antennas (Electronics) -- Design
Synthetic aperture radar
Varactors
Orthogonal arrays

Thesis Number

T 10321

Print OCLC #

861334118

Electronic OCLC #

908569015

Link to Catalog Record

Electronic access to the full-text of this document is restricted to Missouri S&T users. Otherwise, request this publication directly from Missouri S&T Library or contact your local library.

http://laurel.lso.missouri.edu:80/record=b10119040~S5

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