Nokia 3585I Online User's Manual page 112

spectrum. Some of the other forms of energy in the electromagnetic
spectrum are gamma rays, x-rays and light. Electromagnetic energy (or
electromagnetic radiation) consists of waves of electric and magnetic
energy moving together (radiating) through space. The area where these
waves are found is called an electromagnetic field.
Radio waves are created due to the movement of electrical charges in
antennas. As they are created, these waves radiate away from the
antenna. All electromagnetic waves travel at the speed of light. The major
differences between the different types of waves are the distances covered
by one cycle of the wave and the number of waves that pass a certain
point during a set time period. The wavelength is the distance covered by
one cycle of a wave. The frequency is the number of waves passing a
given point in one second. For any electromagnetic wave, the wavelength
multiplied by the frequency equals the speed of light. The frequency of an
RF signal is usually expressed in units called hertz (Hz). One Hz equals
one wave per second. One kilohertz (kHz) equals one thousand waves per
second, one megahertz (MHz) equals one million waves per second, and
one gigahertz (GHz) equals one billion waves per second.
RF energy includes waves with frequencies ranging from about 3000
waves per second (3 kHz) to 300 billion waves per second (300 GHz).
Microwaves are a subset of radio waves that have frequencies ranging
from around 300 million waves per second (300 MHz) to three billion
waves per second (3 GHz).
2. How is radio frequency energy used?
Probably the most important use of RF energy is for
telecommunications. Radio and TV broadcasting, wireless phones,
pagers, cordless phones, police and fire department radios, point-to-point
links and satellite communications all rely on RF energy.
Other uses of RF energy include microwave ovens, radar, industrial
heaters and sealers, and medical treatments. RF energy, especially at
microwave frequencies, can heat water. Since most food has a high water
content, microwaves can cook food quickly. Radar relies on RF energy to
track cars and airplanes as well as for military applications. Industrial
heaters and sealers use RF energy to mold plastic materials, glue wood
products, seal leather items such as shoes and pocketbooks, and process
Section 4: Safety Guidelines and Warranty Information
106 4A: Safety