Accurate measurement of the Q factor of an open resonator in the W-band frequency range

Abstract

It is important to be able to measure accurately the Q factor of an open resonator to compute loss tangent of low‐loss dielectric materials. In this paper, we report the results of the heterodyne detection technique used to measure the Q factor of an open resonator in the W‐band frequency range. A more general algorithm is used for determining the Q factor. This algorithm offers some advantages over the commonly used ‘‘half‐power frequencies’’ method of measurement of the Q factor. The effect of signal/noise ratio on the accuracy of measurement of the Q factor is experimentally studied. It is shown that with the set up used, it is possible to measure the Q factor to an accuracy of better than 1%.