Millimeter-Wave Dielectric Permittivity of Glasses

A dielectric study of new glass specimens is reported using free-space quasi-optical spectroscopy over a frequency range spanning from 40 GHz to 120 GHz. This wide band spectroscopy makes use of a backward wave oscillator as a high power tunable source of radiation. It enables the achievement of relatively higher output power compared to other non-contact techniques. It is more preferable for the complex permittivity measurement of highly absorbing materials due to the higher level of radiation transmission through the specimen.