The study of antennas and wave propagation is essential to
(Figure 1), energy in the form of electromagnetic (radio) waves is generated
by electrical equipment (a radio transmitter) and fed to an antenna by
special transmission lines. The antenna radiates this energy into space at
the speed of light (300,000,000 meters per second).
placed in the path of this traveling wave of energy, absorb part of the
The ability to communicate by radio waves depends chiefly on the power
output of the transmitter, the distance between the transmitter and the
receiver, and the sensitivity of the receiver. Without the proper antenna
system and its correct use, you cannot communicate by radio.
Some basic electronic terms are used throughout this
These terms are defined here for better understanding as you
proceed through the course.
An electric current that continually changes
in amplitude and periodically reverses direction.
space or to intercept waves from space.