Transcript Microwave Teaching and Research at Northumbria University

Microwave Teaching and
Research at Northumbria
University
Prof. David Smith
School of Computing, Engineering
and Information Technology
Outline of Presentation
• How do microwaves fit in
• Facilities within School
• Microwave Research Outline
• Details on Microwave Holography
• Results of Microwave Holography
How do Microwaves fit in ?
• Undergraduate courses
• B. Eng. Hons. CE 1 20 Point unit final yr,
•
40 Point final yr individual project
• B. Sc Hons. MCT 1 20 Point unit final yr
• Post Graduate Taught Courses
• M. Sc Opto and Comms 1 10 Point unit
•
80 Point individual project
• Research Students
• 5 Ph. D. Full Time Students
New Facilities within School
• Agilent sponsored Microwave Research
Laboratory
• Agilent sponsored Microwave Teaching
Laboratory
• Agilent sponsored Opto and RF Research
Laboratory
Microwave Research / Teaching
Facilities
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Hardware – Major Items
Vector Analysis
PNA to 50 GHz, PNA to 40 GHz, Old VNA
NSI Near Field Antenna Measurement System
Spectrum Analysis, to 26.5 GHz
Synthesised sources, 50 GHz, 40 GHz, 20 GHz
Vector Signal Generator to 6 GHz
Dielectric Measurement Kit
Microwave Research / Teaching
Facilities
• Software
• Concerto - Full 3D EM simulator
• Microstripes – Full 3D EM simulator
• Genesys Microwave Design Software
• General Mathematical Software
• Mathcad, MATLAB
• Labview for automatic control
RF / Microwave Research Personnel
• 4 Full Time Academic Staff ( Teaching )
• 2 Visiting Professors
• 1 Visiting Fellow
• 2 Post Doc Researchers
• 5 Post Graduate Researchers
• ( Full time Ph. D. students )
Areas of Research
• Main areas
• Linear Amplification using Non-Linear
Components ( LINC )
• Microwave holography
• Other areas
Linear Amplification using NonLinear Components ( LINC )
• Allow high efficiency non-linear amps to
be used
• Divide signal into in-phase and quadrature
components
• Amplify
• In-phase signals add - quadrature signals
subtract
Microwave Holography
• Similar to Optical Holography
• Only measure Intensity – inexpensive
• Called Hologram
• Have developed techniques for doing this
at microwave frequencies
• Can reconstruct Complex Field from
hologram
• Can use this information to obtain 3D
images
Holography Outline
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Combine coherent scattered wave and reference wave
Phase difference appears as change in intensity
( Hologram )
Illuminate with original reference wave to reconstruct
complex field
• As phase is recovered we can get 3D image
Applying Holography
• We have successfully applied these
techniques in a number of areas
• Microwave Antenna Testing
• Security Imaging
• Medical Imaging
Antenna Testing
• Change conventional near field testing
using Vector Analyser
• Measure Holographic Intensity Patterns
• Don’t need Vector Analyser, just a power
meter
• Can use same mathematical techniques to
find far field radiation patterns
• Can reconstruct aperture fields for
antennas
Antenna Testing
• Holographic Near Field Testing System
Antenna Testing
• Adaptation of Conventional Near Field Testing
Techniques
0
Antenna Testing Results
20
40
10
8
6
4
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0
2
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6
8
10
2
4
6
8
10
A ndrew s FF Measurements
Indirect H olography
D irect H olography
H-Plane
Magnitude (dB)
0
E-Plane
0
10
20
20
40
10
8
6
4
2
A ndrew s FF Measurements
Indirect H olography
D irect H olography
0
2
4
6
8
10
10
8
6
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A ndrew s FF Measurements
Indirect H olography
D irect H olography
(b)
Angle (degrees)
30
2
0
Angle (degrees)
0
• Parabolic dish antenna far field radiation
10
patterns
20
30
10
8
6
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A ndrew s FF Measurements
Indirect H olography
D irect H olography
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0
2
4
6
8
10
(c)
Security Imaging
• Only record Intensity
• Quick and Cheap
• Can reconstruct Magnitude and Phase of
original scattered wave
• Can use magnitude information to detect
metallic objects
• Need Phase information to detect nonmetallic objects
• Plastic explosives
Security Imaging
Rea l Im a ge Magnitude
Real Im age Phase
• Holographic Images of Gun cut-out
re bpM
rebpP1
8
• Left8 – Magnitude
Right
- Phase
Security Imaging
Magnitude
Phase
• Magnitude and Phase reconstructions of
simulated plastic explosive
Medical Imaging
• Non-ionising imaging offers advantages
over X-ray mammography
• High contrast ratio between healthy and
malignant tissue
• Ability to resolve small targets
• Good penetration into tissue
• No health risk
Medical Imaging – Experimental
System
Illuminating
Antenna
Receiving
Antenna
Medical Imaging
Im m e rsio n
M e d iu m
 r 3 
h
B reast
T issue
 r 2 
d1
T um or
 r 1 
d2
Conclusions
• Outlined facilities for Microwave Research
• Outlined areas of research
• Outlined areas of application for
microwave imaging
• Presented results for these areas
• Interested in developing these techniques
for other areas
Thank You