Dielectric materials are insulators used for their exceptional dielectric properties. An important property of a dielectric is its ability to support an electrostatic field while dissipating minimal energy in the form of heat. The lower the dielectric loss (the proportion of energy lost as heat), the more effective is a dielectric material. Another consideration is the dielectric constant, the extent to which a substance concentrates the electrostatic lines of flux. Substances with a low dielectric constant include a perfect vacuum, dry air, and most pure, dry gases such as helium and nitrogen. Materials with moderate dielectric constants include ceramics, distilled water, paper, mica, polyethylene, and glass. Metal oxides, in general, have high dielectric constants. This paper discusses the various dielectric properties such as capacitance, permittivity, dielectric constant, loss tangent, and resistivity. Various losses such as insertion loss, return loss and power absorption are also discussed.
