0·1 MICROWAVE FREQUENCIES The term microwave frequencies is generally used for those wavelengths measured in centimeters, roughly from 30 cm to 1 mm (1 to 300 GHz). However, microwave really indicates the wavelengths in the micron ranges. This means microwave frequencies are up to infrared and visible-light regions. In this revision, microwave frequencies refer to those from 1 GHz up to 106 GHz. The microwave band designation that derived from World War II radar security considerations has never been officially sanctioned by any industrial, professional, or government organization. In August 1969 the United States Department of Defense, Office of Joint Chiefs of Staff, by message to all services, directed the use of a new frequency band breakdown as shown in Table 0-1. On May 24, 1970, the Department of Defense adopted another band designation for microwave frequencies as listed in Table 0-2. The Institute of Electrical and Electronics Engineers (IE...