An oscilloscope is an important and sophisticated electronic device used to
study electrical signals. An oscilloscope can graph electrical waves, pulses,
and patterns. It has an x-axis that represents time and a y-axis that
represents voltage. There are usually two y-axis voltage inputs so that two
waves can be observed and measured at the same time. A sine wave, as it would
appear on an oscilloscope, is shown in Figure
. The traditional
picture of a sine or square wave expresses voltage as a function of time. This
is the representation of the wave in the time domain.
Figure
shows
standing energy, in green, around an electric dipole antenna that is aligned
vertically with the computer screen. The standing energy varies with time. The
purple grid shows the radial portion, which represents outbound power.
Time-domain analysis can be used to see the standing energy and outbound energy
in relation to each other.
One of the most important facts of the
information age is that data can be represented electrically by voltage
patterns on wires and in electronic devices. This is important for the study of
WLANs since WLANs are made up of electronic devices. The data in electronic
devices, which is represented by voltage patterns, can be converted to radio
waves and radio waves can be converted to voltage patterns. Since voltages are
much easier to measure than directly measuring the radio waves, an
understanding of voltage patterns can be very helpful in the study of WLANs.