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Electromagnetics Research
Associated Laboratories and Centers:
Virginia Tech Antenna Group
ElectroMagnetic Interactions Laboratory
(EMIL)
Fiber & Electro-Optics Research Center
(FEORC)
Optical Image Processing Laboratory
Optical Sciences and Engineering Research
Center (OSER)
Photonics Laboratory
Time Domain Laboratory
Electromagnetics research at Virginia Tech ranges from the
fundamental to the very applied. Research topics include antennas,
wireless applications, fiber optics, sensors and materials, propagation,
optical image processing, upper atmospheric processes, scattering,
transients, as well as microwave modeling, measurements, design,
and materials.
Representative Research Projects in
electromagnetics.
ECE Faculty
Gary Brown, Director
Robert Adams
Bradley Davis
EMIL continues to work toward (a) obtaining a better understanding
of how electromagnetic waves interact- with the natural environment
and (b) how to best model this interaction. On the applications
side, EMIL is assisting NASA Goddard Space Flight Center in trying
to determine the source of anomalous data coming from the TOPEX/POSIEDON
radar altimeter. This same sensor first detected the onset of
El Niño. Preliminary indications are that the sources
of the anomalous data are the relatively smooth patches on the
ocean's surface that can frequently be seen from aircraft.
The problem that EMIL is primarily involved in is modeling
the effect of these on the radar, and designing ways to circumvent
their contamination of the radar data. On the fundamental side,
EMIL has completed a study of scattering by wedge-like perturbations
on a planar surface for the purpose of quantifying just how much
the wedge tip contributes to the scattering of the incident em
wave. Although the primary intent of this study was to improve
models for propagation over rough surfaces for the U.S. Army,
an unexpected auxiliary result was some new insight gained into
the low grazing backscattering problem.
In particular, a new source of polarization dependant low
grazing angle backscattering was found. EMIL is also conducting
an investigation for the U.S. Air Force on predicting when a
radar can penetrate a canopy of foliage, propagate down to a
target on the surface, and scatter back up to the radar with
an identifiable and a detectable signal level. EMIL has developed
one model that is particularly amenable to "calibration"
by comparing the model with actual radar data. Such "calibration"
ensures that the parameters in the model are derived from (limited)
actual data with the aim of using the model to predict penetration
over other similar regions. In a program sponsored by the Office
of Naval Research, EMIL has developed a model for low-grazing
electromagnetic wave scattering by the ocean surface that includes
the refraction in the atmosphere above the surface. The inclusion
of both refractivity and surface roughness is done in an exact
manner and is particularly important in ship self-defense.
Propagation in an urban environment with particular emphasis
on wave diffraction in the off-specular direction by objects
having sharp edges is a project being sponsored by the U.S. Army
Research Office. EMIL researchers have also developed the only
known model for the effects of roughness on diffraction of an
electromagnetic wave by a rough knife-edge boundary. Finally,
EMIL is conducting basic research on new models for wave scattering
by two-dimensionally rough surfaces that are both robust in their
range of applicability and fast in their implementation. These
models build upon some unique mathematical capability that researchers
in EMIL have developed for recasting conventional electromagnetic
scattering problems into new forms that are much more amendable
to efficient and robust solutions. This research is sponsored
by the University of Delaware, under a U.S. Air Force MURI on
Computational Electromagnetics.
The Fiber & Electro-Optics
Research
Center (FEORC)
www.ece.vt.edu/~feorc
ECE Faculty
Richard O. Claus, Director
Ira Jacobs
Roger Stolen
FEORC was founded at Virginia Tech by Virginia's Center for
Innovative Technology, primarily to provide university research
to support development of the state's fiber optics industry.
Over the past 15 years, the lightwave industry has spread across
the entire state, including an area with a high concentration
of businesses in the southwestern part of Virginia known as "Silica
Valley." Since its inception, the Center has developed many
intellectual properties that have been commercialized, including
optical materials, devices, sensors and networks. FEORC developments
during the past year include the incubation of a new research
center on campus: the Optical Sciences and Engineering Research
Center (OSER).
For several years, FEORC has collaborated with the Center for
Transportation Research on the communications network for Virginia's
"Smart Road." This multimillion-dollar testbed highway
is finally a reality, and well equipped for many ITS (intelligent
transportation systems) applications.
FEORC is currently involved in several new multidisciplinary
programs including a university-sponsored ASPIRES program with
the College of Veterinary Medicine for the optical detection
of biological functions, and an industry- and government-sponsored
program to develop new nanostructured electro-optic materials.
The Center's mission within the university community is to teach
graduate and undergraduate students about optical materials and
devices, instrumentation and communications systems through research
projects and formal classroom and laboratory teaching. FEORC
has the largest fiber optics research and instructional program
in the United States.
Currently the Center has 20 full-time research staff members
and more than 30 graduate students. Each year approximately 300
students take fiber optics related courses, such as fiber optics
communications, networks and systems, polymer optoelectronic
devices, fiber optic applications, and electrical theory, taught
by three primary faculty members.
The Center's efforts to provide support to industry in the state
have been successful and, over the years, have included cooperative
efforts with more than 250 Virginia companies and providing the
impetus for the establishment of 17 spin-off firms in Virginia
and one in Minnesota.
Optical Image Processing Laboratory
www.ece.vt.edu/~oiplab/
T.-C. Poon, Director
The Optical Image Processing (OIP) Laboratory creates an
environment for progressive, practical scholarship in all aspects
of hybrid (optical/electronic/digital) information processing
technology. Its comprehensive academic research and education
program complements the growing need for photonic instrumentation
and the economic development of the electro-optics industry.
The OIP Laboratory supports research in the areas of acousto-optics,
optical scanning holography, 3-D microscopy, optical 3-D coding
and decoding, 3-D display, and optical recognition of 3-D objects.
Equipment includes two large vibration isolation optical tables
with associated optical, mechanical, and electronic instrumentation.
Specialized equipment includes an electron-beam-addressed spatial
light modulator and an optically addressed spatial light modulator
(long-term partnership loan from Hamamatsu Photonics K.K., Japan),
and x-y optical scanning systems. The program of the OIP Laboratory
actively encourages mutual collaboration with other research
institutes. Typical sponsors include Army Research Office, Hamamatsu
Corporation, National Science Foundation, NASA, National Institutes
of Health, and the U.S. Navy.
Optical Sciences and Engineering Research
Center (OSER)
www.oser.vt.edu
Richard Claus, Associate Director
The Optical Sciences & Engineering Research Center (OSER)
conducts research and engineering activities involving optics
and other disciplines to create knowledge and technology to benefit
the medical, biomedical and veterinary fields, while supporting
the practical goals of improving services and reducing the costs
of health care.
Established in 2000, OSER investigates advanced laser surgery optics, biocompatible material for implants, and diagnostic patches and other diagnostic and drug delivery tools. The Center employs optics to provide new biological research tools for visualization, measurement, analysis and manipulation. The Optical Sciences and Engineering Research center (OSER) is part of a unique collaboration among Virginia Tech, the Carilion Health System and the University of Virginia. The umbrella organization for this partnership is the Carilion Biomedical Institute in Roanoke, Virginia. The institute is primarily responsible for prototype development, commercialization and the spin-off of technology created by its supporting research centers at the two universities: OSER at VT and the Medical Automation Research Center (MARC) at UVa.
Research center activities range from basic biomedical research
to experimental device development and laboratory demonstrations.
Results of center R&D activities are transferred to the institute
for prototype and product development leading to new biotechnology
start-up companies and the creation of new jobs in Virginia.
ECE Faculty
Anbo Wang, Director
Ahmad Safaai-Jazi
Russell May
The Photonics Laboratory, created in 1997, is dedicated to
education and research in photonics, the technology of generating,
harnessing, and manipulating light to perform useful functions.
The 8,000 square ft. office and laboratory space and more than
$2 million annual external funding supports research in fiber
optics for sensing, communications, and biophotonics.
The Photonics Laboratory is currently the largest university
optical fiber sensor research group in the country. The research
in this area is focused on innovative sensors for harsh environment
applications where conventional measurement devices are difficult
to apply. The research covers all the major aspects concerning
fiber sensors, including materials, new sensing mechanisms, fiber
modifications, advanced packaging, optoelectronic signal processing,
and instrumentation systems. The research has recently yielded
a number of successful new sensors capable of operation at temperatures
as high as 1700°C. Research also includes investigation of
various methods for multiplexing of thousands of sensor elements
along a fiber for distributed measurement.
In communications, the research is concentrated on special fibers
and passive fiber components for long-haul and metro systems.
Representative work in special fibers includes large effective
area fiber for nonlinearity reduction, hermetic fiber for long-term
'dry' operation, lateral-to-longitudinal coupling fiber for off-axis
broadband signal transmission, and photonic crystal (holey) fibers
for better control of dispersion and modal characteristics. In
components, the work is directed toward the design and development
of low-cost devices for metro systems based on fiber modifications,
thermal fusion and/or thin film technology.
In biophotonics, the work covers 3-D topographic mapping, surface
temperature measurement, and early-stage identification of molecular
signatures of cancers. The center has developed various key technologies
for 3-D surface mapping, including PM fiber pigtailed high power
diode laser systems, miniaturized light illumination modules
for generation of structured light patterns, fiber-based self-calibrated
mapping systems, and image processing algorithms. 3-D thermal
imaging is also demonstrated based on the combination of commercially
available thermal imaging devices with the developed 3-D mapping
technology. Currently the center is collaborating with Virginia
Tech's Veterinary School to demonstrate a new method for identification
of molecular signatures of cancers for non-invasive early cancer
detection and diagnosis.
 Photonics
Laboratory researchers have joined the fight against cancer.
Visiting scholar Bing Qi showed that the Raman peaks corresponding
to the resonance of b-carotene have significantly different levels
in healthy people and in those with cancer. In order to develop
a blood serum test based on this work, the Photonics Laboratory
is developing the Raman spectrometer necessary for sera measurement,
along with a signal acquisition and analysis unit so that data
can be processed on a personal computer.
Time Domain & RF Measurement Laboratory
www.ece.vt.edu/~tdl/
Sedki M. Riad, Director
The laboratory's main research interest is in wideband measurements and characterization problems using time domain and frequency domain techniques. This includes the development of the measurement techniques; the characterization and modeling of devices, networks, or materials; the development of the necessary signal processing and data reduction methods; and the design and construction of related measurement instrumentation and setups. The laboratory contains facilities for wideband measurements from DC into the microwave and millimeter wave (70 GHz) frequency regions. This facility enables wideband measurements in both the time domain and the frequency domain.
ECE Faculty
William A. Davis, Acting Director
Ahmad Safaai-Jazi
Sanjay Raman
Warren L. Stutzman
VTAG Affiliates
Northrop Grumman
Turbowave
The Antenna Group performs research on new antenna geometries,
analysis methods, and measurement techniques, working closely
with industry and government to meet their needs. Several new
antennas have been developed and are being used on a variety
of applications. The recent advances in antenna research include:
· VTAG, in cooperation with MPRG, produced significant
results for two smart antenna experiment systems. The smart handheld
terminal test bed investigated antenna diversity and beamforming
with up to four antennas. It was found that significant signal
improvement and interference rejection is possible with a compact
antenna configuration.
· The second smart antenna experiment uses a base station
on the roof of Whittemore Hall. Three forms of antenna diversity
(spatial, polarization, and angle) were investigated simultaneously
with a mobile transmitter operating at points on campus. All
three diversity techniques were found to be very effective in
reducing signal fading.
· Wideband antenna research sponsored by the Navy and
Harris Corp. resulted in the invention and patent disclosure
for the Fourpoint Antenna. This antenna is capable of 3:1 bandwidth
in a low-profile, compact package. The application being pursued
is for dual polarized base station antennas that cover from cellular
through and above PCS frequencies in a single antenna. This reduces
costs and hardware mounted on the tower.
· A patent disclosure was filed for a new antenna for
handsets. The Wideband Compact PIFA Antenna has up to 50% bandwidth
with a size that fits inside handheld terminals. This antenna
can support multiple frequency bands.
The laboratory continues to expand its technology base and facilities.
Efforts currently include new measurement systems and methods,
evaluation of large electromagnetic codes, and a new emphasis
on embedded antennas for use in handsets and mobile radio applications.
In 2000, the Group began full use of its new $500,000 tapered
anechoic chamber. The chamber includes both far-field and near-field
measurement equipment. VTAG continues to use its roof top antenna
range also.
Representative
Research Projects in Electromagnetics
Advanced Propagation Modeling for Military Communications
EM Scatter Modeling in Support of Space Sensing
MURI95: Mathematical and Numerical Methods for Analysis and Design
of EM Fields
FOPEN Modeling for Target Detection
Airborne Radar Waveform Returns from Foliage Covered Terrain
System Study of Optical Fiber Use in Automobiles
Analysis, Design, and Performance Evaluation of Optical Fiber
Spectrum-Sliced
Twisted-Pair Cable Measurements for Computer Networks
Computer Networks Loop Reconstruction Using Time Domain Reflectometry
Characterization and Applications of Substrate Material Systems
and Fabrication Technologies
Three-dimensional Optical Pattern recognition
Study of Spatial Light Modulators with Applications to 3-D Image
Projection and Display
3D Imaging by Novel Annular Illumination
REU Supplement: 3-D Optical Pattern Recognition
Microwave Reprocessing of Thermal Runaway Materials
Theoretical and Simulation Studies of Stimulated Radiation During
Ionospheric Heating
Theoretical and Simulation Studies of Expanding Ionospheric Dust
Clouds
Research into Signal Recovery Algorithms in Support of Spectral
Spatial Interference Cancellation Systems (SSICS): Phase II Research
Effort
NAVCIITI Multifunctional Antennas
Sensors for Harsh Environments
Optical Fiber Strain Sensor Instrumentation for High Temperature
Aerospace Structural Monitoring
Optical Fiber Sensor Technologies for Efficient Economic Oil
Recovery
High-Temperature Optical Fiber Sensor Instrumentation for Gas
Flow Monitoring in Gas Turbine Engines
Optical Fiber Sensor Technologies for Efficient and Economical
Oil Recovery
Further Investigation of PD Detection Using Fiber Optic SCIIB
Acoustic Sensors
Single-Crystal Sapphire Optical Fiber Sensor Instrumentation
Optical Fiber Sensor-Based Techniques for On-Line Detection and
Location of Partial Discharges in Transformers
Optical Fiber Sensors for Infrasound Detection
High Temperature Optical Fiber Sensor Research
AASERT Program Support for Air Force Smart Metallic Structures
Program
Fabrication of High-Nonlinearity Lead Iridium Phosphate Glass
Optical Fibers
Fiber Gratings for High Power Laser Applications
Raman Amplification in Optical Fibers
Electrostatically Self-Assembled Multifunctional Materials and
Structures
Bulk Optic Magnetic Field Sensors
ESA Processes for Fabrication of MEMS Materials and Devices
Feasibility Study of Self-Assembling Retinal Protein-Based Optoelectronic
Devices
Data Driven Device Fabrication by ESA Processing
Integrated Water Quality Monitoring System
NLO Thin films and Photonic Devices
Electrostatically Self-Assembled Multifunctional Materials and
Structures
Linear and Nonlinear Optical Thin Films and Devices
Thin Film Coating Products for Spectacle lenses
Fiber Optic Model Force Balance System for Wind tunnels
Optical Materials and Device Testing Program
Molecular Nanocluster Synthesis
NAVCIITI Multifunctional Optical Display
ESA Processes for Synthesis of Electro-Optic Crystal Devices
Self Assembled Advanced Materials
High Performance Fiber-based Meteorological Sensors
Self-Assembled Coatings with Tailorable Optical Properties
Synthesis, Fabrication and Evaluation of Thin Film Materials
by Self-Assembly
Self-Assembled Adaptive Optical Components
Optical Sciences Research
Fuel Analyzer for Multi-Fuel Engine Optimization
NLO Thin Films and Photonic Devices
Underwater Procurable Adhesive attachment System Development
and Characterization
AASERT Optical Fiber Interconnects and Sensors for Power Electronic
Building Blocks
Polarized, Kilowatt Level Fiber Lasers
Navy Collaborative Integrated Information Technology Initiative
(NAVCIITI)
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