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Ð Highly directional antennas are used for line-of-sight propagation routes. Transmission frequencies are in the range
4 to 12 GHz. Depending on their distance, the antennas’ diameters can range from 12 inches to several feet and are
typically parabolic.
Signals
Microwave
antenna
Terrestrial Microwave
Ð ÐSatellite Type Microwave Transmission: The electronic wave used in satellite-type microwave transmission is
electromagnetic in nature and is transmitted by a source. The source contains transmitting antennae, which amplify
the source wave—a signal—and rebroadcast it to the recipient antennae. One of the finest satellite type microwave
transmission applications is the Global Positioning System (GPS).
Satellite
UP link Down link
First Earth Station Second Earth Station
Infrared
Infrared transmission is used for short-range communication. Between 300 GHz and 400 THz is the infrared spectrum’s
frequency region. It is employed for close-quarters contact, such as data transfer between two cell phones, TV remote
control operation, and data transfer between a computer and a cell phone. The data rate will be very high because
it allows a large amount of bandwidth. The walls block the passage of infrared radiation. Thus, the adjacent rooms
cannot interfere with infrared communication taking place in one room.
Television Infrared Radiations Remote
122 Touchpad Web Applications-XI

