Microwave the term refers to electromagnetic energy having a frequency exceeding 1 gigahertz (billions of cycles per second), corresponding to the length of 30 inches shorter than wave.
Microwave signals propagate in a straight line and are affected very little by the troposphere. Is not refracted or reflected in the regions ionized in the upper atmosphere. Microwave beams not easily diffract around obstacles such as hills, mountains and large man-made structures. Some attenuation occurs when the microwave energy passes through trees and wooden houses. Radio frequency energy (RF) at wavelengths longer wavelength is affected to a lesser extent by such obstacles.
The microwave band is very suitable for wireless transmission of signals having high bandwidth. This portion of the electromagnetic radiation spectrum covers many RF thousand megahertz. Compare this with the call shortwave band extending from 3 MHz to 30 MHz and whose total bandwidth available is only 27 MHz. In communications, a large bandwidth allowed results in high data rate. The short wavelengths permit the use of dish antennas having diameters manageable. These antennas produce high power gain in transmission applications, and has excellent sensitivity and directional characteristics for receiving signals.
Mar 6th, 2015
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