PROT EE20090
Paul Leonard
Ivan Astin
Transmission Lines and Antennas
EM waves.
Assessment
80 % EXAM 15 % LAB (2 labs PROT1 PROT2 )
PJL resources  see moodle.
Electronic:
 Hand written lecture notes (scans on moodle).
 Demos .
Handouts:
 Summary of equations
 Fawwaz : Applied Electromagnetics (5th edition)
Chapter 2 (TML) Chapter 9 (Antennas)
Lecture Summary (Antennas)
Types of antenna
Properties
- Radiation resistance
- Loss Resistance, Efficiency
- Directivity / Gain / Polarization
Radiated Power (Poynting vector ExH)
Electric (Hertzian) dipole example.
- Spherical coordinates
Isotropic antenna (fictitious)
- solid angles
- Directivity
Effective aperture (receiver).
Friis transmission formula
Radar
 Radar cross section (RCS)
 Radar equation
5 % MCQ
Lecture Summary (TML).
What is a transmission lines (Radio/signals) --- Speed of light.
Types of TML.
Issues (Power transfer/losses/reflections ringing)
The wave equation (tine transient) introduction.
- solution of losses time transient eqn. (forward / backward waves)
Quick overview of concepts (for the first LAB).
- Pulse down a wire
- Characteristic impedance 𝑍0
- Reflection coefficients. 𝛤𝐿 𝛤𝑠
Time transient examples
- Pulse
- Step
Properties of a TML . Line parameters L R G C (all per meter)
- Lossy lines / lossless lines (R and G = 0)
- Dependency of L R C G on materials, geometry and frequency.
Lumped parameter equivalent circuit.
Derivation of the wave equation (a.c. signals d/dt  jw)
- Telegrapher’s equations 
- The wave equation
- Propagation constant.
o Attenuation constant (Nepers)
o Phase constant  Electrical length
General solution of the wave equation in terms of forward and backward waves.
Velocity of the waves for a lossless line.
Lossy lines – attenuation + dispersion
Derivations of
- Characteristic impendence 𝑍0
- Reflection coefficients
- Driving point impedance.
Impedance matching (minimize losses / reflections)
- Quarter wave transformer. (small section of TML)
- Transformer (usual sort)
- Stubs
Power in TML