Microwave Energy

Microwave energy, like ultraviolet energy, visible light, and infrared radiation, is a form of electromagnetic energy. Unlike these other forms of energy, the wavelength of a microwave is longer (equivalently, the frequency of the wave is lower, usually classified between 300 MHz and 300GHz) and the available quanta are lower in energy. Because of their long wavelangth, microwaves can be transported and guided from their source through hollow (non-magnetic) metal tubes. They can be broadcast long distances in space. They are absorbed by molecules with dipoles, but bypass chemically similar molecules that lack dipoles. They penetrate into many materials very deeply, transforming energy directly into heat by exciting molecules into rapid oscillatory motion. With such unique attributes, microwave energy offers several practical advantages over conventional heating methods, including reduced thermal gradients, selective heating, rapid energy deposition, and acceleration of certain chemical reactions. Microwaves have been found to be useful in many industrial applications, including the drying and curing of rubber products, the sintering of ceramics, and the treatment of contaminated soils. The ability of a material to absorb microwave energy is determined by the dielectric properties of the material and of the frequency of microwave energy applied. The absorption is most pronounced in condensed phases such as liquids and solids. CHA Corporation microwave research deals with microwaves at frequencies of 2450 MHZ. This frequency is the same as that found in home microwave ovens and equipment for generating and applying this frequency of power are commonly available. Examples of materials that are excellent absorbers of 2450 MHz microwave energy include: water, organic compounds, activated carbons, and silicon carbide. Materials that are poor absorbers of 2450 MHz energy include ceramics, glasses, Teflon, and quartz. Nearly all metals will reflect microwave energy.