Absorption coefficient and refractive index measurements of water in the millimetre spectral range

Abstract

The absorption coefficient, α, and refractive index, n, of water have been measured in the millimetre and submillimetre frequency region (50–300 GHz). The measurements were carried out using a free-space technique at room temperature with backward wave oscillators as the sources. The measured values of α and n are presented and discussed in comparison with the existing literature data.