Broad-band millimetre wave spectroscopy of common materials

Millimetre wave transmittance measurements of common materials have been performed from 30 to 120 GHz. A free space quasi-optical millimetre wave spectrometer, equipped with a set of high power sources of tuneable coherent radiation has been successfully applied. Frequency dependences of real and imaginary parts of the dielectric permittivity have been obtained in a broad-band millimetre wave frequency range. It has been shown that the quasi-optical free-space spectrometer is a promising, fast, non-contact instrumentation for the collection of the spectral "signature" data of various types of materials. This study turns out to be a step towards identifying both hoax elements and biologically and/or chemically active materials, including warfare agents and explosives.