Lecture VIII Antennas & Propagation -1- Antennas & Propagation Mischa Dohler King’s College London Centre for Telecommunications Research.

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Antennas

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Propagation

Mischa DohlerMischa Dohler

King’s College LondonKing’s College London

Centre for Telecommunications ResearchCentre for Telecommunications Research

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Books for Propagation

- Simon Saunders Simon Saunders “Antennas & Propagation”“Antennas & Propagation”

- William Jakes William Jakes “Microwave Mobile “Microwave Mobile

Communications”Communications”

- Kaveh Pahlavan Kaveh Pahlavan “Wireless Information “Wireless Information

Networks”Networks”

- try to omit articles and books from: try to omit articles and books from:

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Overview of Lecture VIII

- ScenariosScenarios

- Propagation MechanismsPropagation Mechanisms

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Satellite

Mega Cells

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Outdoor-Outdoor

Macro, Micro and Umbrella Cells

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Outdoor-Indoor

Macro and Micro Cells

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Indoor-Indoor

Micro and Pico Cells

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Losses and Deterioration

Propagation Mechanisms:

(1) Free Space Propagation

(2) Reflection and Transmission

(3) Scattering

(4) Diffraction

Distortions:

(5) Multipath Propagation

(6) Doppler Effect

Propagation Conditions:

(a) Line of Sight (LOS)

(b) non Line of Sight (nLOS)

(c) obstructed Line of Sight (oLOS)

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Free Space Propagation

Frii’s Transmission Formula:

Variations with Distance d:

The dB mysticism:

‘Loss’ Myth:

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Reflection and Transmission

TE and TM waves

Snell’s Law:

Fresnel Coefficients:

‘Object Size’ Myth:

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Reflection and Transmission

Reflection: TE and TM waves

Transmission: TE and TM waves

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Reflection and Transmission

Circular Elliptical After Reflection or

Transmission of non-linear

polarisation we always

obtain elliptical

polarisation.

Elliptical Elliptical

Linear Linear

i < Brewster i > Brewster

Left Right

Right Left

Left Left

Right Right

Change of Polarisation

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Scattering

Smooth Rough Rougher

Fraunhofer Criterion for

smooth surfaces

Rayleigh Criterion for

smooth surfaces

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Scattering

Correlation Function

Correlation Length

Correlation Height

Roughness Factor

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Diffraction

Huygen's Principle

‘Sharp Edges’ Myth

Consequences of Diffraction

Field-Strength in

shadowed areas

Rapid Field-strength

fluctuations

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Diffraction

Optical and Shadow Region

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Diffraction

Diffraction Coefficient

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Diffraction

Diffraction Coefficient

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Diffraction

Diffraction Coefficient