Europe, france, spain, japan A wlan receiver can use any of these channels, and can automatically hop from channel to channel if interference is encountered.
Omnidirectional antennas oriented vertically are widely used for nondirectional antennas on the surface of the Earth because they radiate equally in all horizontal directions, while the power radiated drops off with elevation angle so little radio energy is aimed into the sky or down toward.
You can see the signal radiating out the slots at the left of the image.
Microwave text books have been written by academics who revel in every detailed equation.
From left to right, the elements mounted on the boom are called the reflector, driven element, and director.
Yagi antenna, the log-periodic antenna, and the corner reflector antenna, which are frequently combined and commercially sold as residential.
Another type is the Omnidirectional Microstrip Antenna (OMA).