ENGINEERING
TRIPOS PART IB
PAPER 5 
ELECTRICAL ENGINEERING (3)
Electromagnetic Fields and
Waves
Leader: Prof A. C. Ferrari
Timing: Weeks 68
Lent term
Structure: 6
lectures, 2 lectures/week
Handouts:
Handout1;
Handout2;
Handout3;
AIMS
 Starting from the first year background work
of phasors, capacitance and inductance, the aim is to explain why one
needs both E and H to describe electromagnetic waves and to show how
these waves propagate in free space.
OBJECTIVES
As the frequency of electronic circuits rises, one
can no longer assume that voltages and currents are instantly
transmitted by a wire. The objectives of this course are that students
should be able to:
 Appreciate when a wave theory is needed.
 Derive and solve simple transmission line
problems
 Understand the importance of matching to the
characteristic impedance of a transmission cable.
 Understand basic principles of EM waves
propagation in freespace, across interfaces and the use of antennae
SYLLABUS
 Descriptive introduction of how information is
sent along wires and through free space.
 A descriptive introduction of propagation
along two wires. Capacitance per unit length. Inductance per unit
length. Resistance per unit length.
 Equations for V and I in differential form.
Normalisation to a characteristic impedance.
 Solutions  forward and reverse waves  phase
velocity and significance of characteristic impedance. Effects of load
resistances of the wrong characteristic impedance.
 One dimensional wave motion with Maxwell's
equations seen as a transmission line analogy with E corresponding to V
and H corresponding to I. Implications for transmission in free space
and along optical fibres (descriptive only).
REFERENCES
Please see the Booklist
for Part IB Courses for references for this module.
