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ELEG 648 Plane waves II. Mark Mirotznik, Ph.D. Associate Professor The University of Delaware Email: mirotzni@ece.udel.edu. Uniform Plane Waves: Propagation in Any Arbitrary Direction. z. H. f. E. q. y. x. Uniform Plane Waves: Propagation in Any Arbitrary Direction. z. H. f. E.
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ELEG 648Plane waves II Mark Mirotznik, Ph.D. Associate Professor The University of Delaware Email: mirotzni@ece.udel.edu
Uniform Plane Waves: Propagation in Any Arbitrary Direction z H f E q y x
Uniform Plane Waves: Propagation in Any Arbitrary Direction z H f E q y x
z H f E q y x Uniform Plane Waves: Propagation in Any Arbitrary Direction Since E and b are at right angles from each other. where and
Uniform Plane Waves: Propagation in Any Arbitrary Direction Summary and Observations: Frequency Domain Time Domain Observation 1. E, H and b vectors are pointing in orthogonal directions. Observation 2. E and H are in phase with each other, however, H’s magnitude is smaller by the amount of the wave impedance
Uniform Plane Waves: Propagation in 2D y H E Can we write this a bit more compact? q x
Uniform Plane Waves: Propagation in 2D y H Can we write this a bit more compact? E q x
Uniform Plane Waves: Propagation in 2D y H E What about the polarization of E? q x
Uniform Plane Waves: Propagation in 2D y H E What about the polarization of E? q x
Uniform Plane Waves: Propagation in 2D y H E What about the polarization of E? q x
Uniform Plane Waves: Propagation in 2D What about the polarization of E? Two cases y y Parallel Polarization Perpendicular Polarization H H E E q q x x
Uniform Plane Waves: Propagation in 2D y H What about H? E q x
Uniform Plane Waves: Propagation in 2D What about the polarization of H? Two cases y y Parallel Polarization Perpendicular Polarization H H E E q q x x
Reflection and Transmission Write down the electric fields in the two regions (2 unknowns, R and T)
Reflection and Transmission Next find the magnetic fields in each region
Reflection and Transmission Apply boundary conditions
Reflection and Transmission Write down the E field in both regions (4 unknowns, R, T, qr and qt)
Reflection and Transmission Find the H field in both regions
Reflection and Transmission Apply boundary conditions 2 equations and 4 unknowns We need two more equations. How do we get them?
Example: Reflection from an Ocean Interface Reflection Coefficient Angle of Incidence, Degrees
Region I Region III Region II z=d z=0 Reflection and Transmission from Dielectric Slabs 1. Normal Incidence
Reflection and Transmission from Dielectric Slabs Region I: Region II: Region III: Boundary Conditions z=d z=0
Reflection and Transmission from Dielectric Slabs Boundary Conditions z=0 z=d Four equations and four unknowns Solution for the Reflection Coefficient:
Region I Region III Region II z=l2/2 z=0 Reflection and Transmission from Dielectric Slabs Special Cases I. Half Wavelength Thickness Slab
Reflection and Transmission from Dielectric Slabs Special Cases II. Quarter Wavelength Thickness Slab Region I Region III Region II z=l2/4 z=0
Reflection and Transmission from Dielectric Slabs: Example Region III Region I Region II z=0.25m z=0
Reflection and Transmission from Dielectric Slabs: Example |R| Frequency, MHz
How do we broaden the bandwidth around the zero reflection point? |R| Frequency, MHz
Reflection and Transmission from Dielectric Slabs 1. Oblique Incidence ( Parallel Polarization) fII ft fr fII fi Region I Region II Region III z=d z=0
Reflection and Transmission from Dielectric Slabs Region I: Region II:
Reflection and Transmission from Dielectric Slabs Region III: Boundary Conditions z=d z=0 Phase Matching Conditions
Reflection and Transmission from Dielectric Slabs Six Equations and Six Unknowns
Reflection and Transmission from Dielectric Slabs: Solution (parallel polarization) *note we have assumed all non-magnetic materials here
Reflection and Transmission from Dielectric Slabs: Solution (perpendicular polarization) *note we have assumed all non-magnetic materials here
fi Region III Region I Region II z=0.25m z=0 Reflection and Transmission from Dielectric Slabs: Example