Polarization
When an alternating current is applied to an antenna, an electromagnetic wave is produced. From Chapter 1, you learned that the wave has two components: an electrical field wave and a magnetic field wave. The electrical portion of the wave will always leave the antenna in a certain orientation. For example, most Cisco antennas produce a wave that oscillates up and down in a vertical direction as it travels through free space. Other antennas might be designed to produce waves that oscillate back and forth horizontally. Still others might produce waves that actually twist in a three-dimensional spiral motion.
The wave’s orientation is called the antenna polarization. Antennas that produce vertical oscillation are vertically polarized; ...
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