A millimeter wave apparatus for free-space measurement of dielectric constants at high temperature

Radome materials are being required to withstand increasingly higher temperatures. There is, therefore, a continuing need to measure the dielectric properties of these materials at elevated temperatures, particularly at millimeter wavelengths where the data base is still relatively sparse. At the Naval Weapons Center (NWC) an apparatus has been constructed to measure the complex transmission coefficient of flat panel samples at 35 GHz. The complex permittivity of the sample is calculated from the transmission measurements which are made in free-space bridge.