Microwave Technology.

A microwave is an electromagnetic wave ranging from one meter to one millimeter. Microwave energy has a frequency ranging from 0.3 gigahertz (GHz) to 300 GHz. The high frequency of microwaves provides the microwave band with a very large information-carrying capacity. The band has a bandwidth thirty times that of the radio spectrum below it. Microwave signals propagate in straight lines, and thus, are limited to line-of-sight transmission. Unlike lower-frequency radio waves, they cannot pass around hills or mountains and are not refracted or reflected by atmospheric layers. In addition to the familiar microwave oven, applications include communications, radar, radio astronomy, navigation, and spectroscopy.