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Periodic Leaky-Wave Antennas for Orbital Angular Momentum Multiplexing System Amar Al-Bassam 23.06.2014 Master Thesis Final Presentation
Periodic Leaky-Wave Antennas forOrbital Angular Momentum Multiplexing
System
Amar Al-Bassam
23.06.2014
Master Thesis
Final Presentation
2
Outline
Master Thesis 23.06.2014 – Amar Al-Bassam
I. INTRODUCTION
II. CONCEPT OF GENERATION
III. ELECTROMAGNETIC MODELING
IV. DESIGN & EXPERIMENTAL RESULTS
CONCLUSIONS & QUESTIONS
3 Master Thesis 23.06.2014 – Amar Al-Bassam
I. INTRODUCTION
II. CONCEPT OF GENERATION
III. ELECTROMAGNETIC MODELING
IV. DESIGN & EXPERIMENTAL RESULTS
CONCLUSIONS & QUESTIONS
4 Master Thesis 23.06.2014 – Amar Al-Bassam
Orbital Angular Momentum
Images courtesy of physics.gla.ac.uk/Optics
Orbital Angular MomentumHelical phase-fronts
Spin Angular MomentumElliptical polarization
Photons cannot have zero spin.
Linear polarization is
combination of RHCP and
LHCP
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Magnitude & Phaseof Vortex Beams
Master Thesis 23.06.2014 – Amar Al-Bassam
6 Master Thesis 23.06.2014 – Amar Al-Bassam
I. INTRODUCTION
II. CONCEPT OF GENERATION
III. ELECTROMAGNETIC MODELING
IV. DESIGN & EXPERIMENTAL RESULTS
CONCLUSIONS & QUESTIONS
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Leaky-Wave Antenna (LWA) Types
Master Thesis 23.06.2014 – Amar Al-Bassam
invariant along propagation axis
dominant or higher mode
fast-wave mode
periodic along propagation axis
space harmonics (SH)
using fast SH (0 slow), -1
BWD and FWD
“Truly” Periodic “Quasi”-Uniform
CRLH
topologically periodic,
but electromagnetically
uniform
period <<
using fast SH: n = 0
Uniform Periodic
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Full-Space Scanning
Report 29.11.2013 – Amar Al-Bassam
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Vortex Beam Generation Concept
Master Thesis 23.06.2014 – Amar Al-Bassam
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Phase Front of Linear & Circular LWA
Master Thesis 23.06.2014 – Amar Al-Bassam
• Off-broadside operation
• Titled phase front by
• Off-broadside operation
• Spiral phase front around
propagation axis
11 Master Thesis 23.06.2014 – Amar Al-Bassam
I. INTRODUCTION
II. CONCEPT OF GENERATION
III. ELECTROMAGNETIC MODELING
IV. DESIGN & EXPERIMENTAL RESULTS
CONCLUSIONS & QUESTIONS
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Surface Current Density
Master Thesis 23.06.2014 – Amar Al-Bassam
*Eigenmode simulation in HFSS
Radial current (Shunt Mode) Azimuthal current (Series Mode)
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Dyadic Green’s Function
Master Thesis 23.06.2014 – Amar Al-Bassam
Scalar Green’s function
Dyadic Green’s function
R. E. Collin, Field Theory of Guided Waves, 2nd
ed.
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EM Modeling of CircularArray
Master Thesis 23.06.2014 – Amar Al-Bassam
Circular array of radially directed electric dipoles
Constant separation between elements
and constant radius
Propagation constant
Arbitrary magnitude and phase excitation
15 Master Thesis 23.06.2014 – Amar Al-Bassam
EM Modeling of CLWA
(*) S. Otto, Z. Chen, A. Al-Bassam, A. Rennings, K. Solbach and C. Caloz, “Circular Polarization of Periodic Leaky-Wave
Antennas with Axial Asymmetry: Theoretical Proof and Experimental Demonstration,” TAP 2014.
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Numerical Results
Master Thesis 23.06.2014 – Amar Al-Bassam
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Example: Uniform Current
Master Thesis 23.06.2014 – Amar Al-Bassam
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Example: Decaying Current
Master Thesis 23.06.2014 – Amar Al-Bassam
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Example: Decaying Currentwith Two Points Exciation
Master Thesis 23.06.2014 – Amar Al-Bassam
20 Master Thesis 23.06.2014 – Amar Al-Bassam
I. INTRODUCTION
II. CONCEPT OF GENERATION
III. ELECTROMAGNETIC MODELING
IV. DESIGN & EXPERIMENTAL RESULTS
CONCLUSIONS & QUESTIONS
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MIM-CRLH Unit Cell Design
Master Thesis 23.06.2014 – Amar Al-Bassam
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Simulation Results of One Unit Cell
Master Thesis 23.06.2014 – Amar Al-Bassam
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Two Halves CLWA
Master Thesis 23.06.2014 – Amar Al-Bassam
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Simulation Results
Master Thesis 23.06.2014 – Amar Al-Bassam
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Feeding Network
Master Thesis 23.06.2014 – Amar Al-Bassam
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Simulation of the Feeding Network
Master Thesis 23.06.2014 – Amar Al-Bassam
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Maximizing Radiation Efficiency
Master Thesis 23.06.2014 – Amar Al-Bassam
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Prototype
Master Thesis 23.06.2014 – Amar Al-Bassam
29 Master Thesis 23.06.2014 – Amar Al-Bassam
Measurement & Simulation Comparison
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Cylindrical Near-Field Measurement
Master Thesis 23.06.2014 – Amar Al-Bassam
• E-Field sampling on a cylindrical surface
• Near-field to far-field transformation
• Back transformation to planar near-field
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Results of Near-Field Measurement
Master Thesis 23.06.2014 – Amar Al-Bassam
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Transmission MeasurementSetup
Master Thesis 23.06.2014 – Amar Al-Bassam
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Circular Phased Array:An Alternative to CLWA
Master Thesis 23.06.2014 – Amar Al-Bassam
Radial patch array
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Simulation Results
Master Thesis 23.06.2014 – Amar Al-Bassam
37 Master Thesis 23.06.2014 – Amar Al-Bassam
I. INTRODUCTION
II. CONCEPT OF GENERATION
III. ELECTROMAGNETIC MODELING
IV. DESIGN & EXPERIMENTAL RESULTS
CONCLUSIONS & QUESTIONS
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Conclusions
Master Thesis 23.06.2014 – Amar Al-Bassam
EM modeling of CLWA
- valid in near- and far-field
- models the series and shunt modes
independently
- pahse & amplitude relations
Experimental Validation
- near-field measurement
- two channels multiplexing
Thank You!
