Provided by: IOSR Journal of Engineering
Date Added: Feb 2013
The frequency band of Millimeter Wave (MM Wave) in Electromagnetic spectrum is 30-300 GHz and is sometimes called the Extremely High Frequency (EHF) range. Apart from Radar system, communication system is another important application of MM Waves which proved better than Microwaves/optics in certain features. Certain characteristics of the earth's atmosphere pose both problems and solutions for millimeter wave applications. For example, at 60 GHz (5 mm or 0.2 inches wavelength) oxygen molecules will interact with electromagnetic radiation and absorb the energy. This means 60 GHz is not a good frequency for use in long-range radar or communications, because the oxygen absorbs the electromagnetic radiation - and the signal.