Dielectric Measurements in the 60-GHz Band Using a High-Q Gaussian Beam Open Resonator

摘要

A full confocal Gaussian beam open resonator system that determines the dielectric properties of low-loss materials in the 60-GHz band is developed. To achieve high Q values a quasi-optical coupling method is used to feed the resonator. It is connected to a computer-controlled HP 8510C vector network analyzer for automatic measurement. The frequency variation method is used and the data are processed using the open resonator scalar theory. Results from 96% and 99.5% alumina samples with thicknesses ranging from 0.38 mm to 1 mm, are presented in the V band, with loss tangent values of the order of 100 μ radians. This system should be able to measure substrates as thin as less than 0.1 mm to 0.3 mm, which are the thicknesses of substrates in practical use.