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 (pages 74-77).
Rights
© 2013 Mark Andrew Baumgartner, All rights reserved.
Document Type
Thesis - Restricted Access
File Type
text
Language
English
Subject Headings
Microwave imaging -- Computer simulationMicrowave devices -- Design -- Computer simulationMillimeter wave devices -- Design -- Computer simulationNondestructive testing -- Computer simulationAntennas (Electronics) -- DesignSynthetic aperture radarVaractorsOrthogonal arrays
Thesis Number
T 10321
Print OCLC #
861334118
Electronic OCLC #
908569015
Recommended Citation
Baumgartner, Mark A., "Frequency-tunable orthogonally-fed elliptical slot imaging array" (2013). Masters Theses. 5994.
https://scholarsmine.mst.edu/masters_theses/5994
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