Permittivity measurements at millimeter wave frequencies using dielectric rod resonator excited by NRD-guide

摘要

A method of measuring the relative complex permittivity (epsilon_r = epsilon' -j epsilon", tan delta = epsilon''/epsilon') for low-loss dielectric materials at millimeter wave frequencies has been developed, using a dielectric rod resonator excited by the nonradiative dielectric waveguide (NRD-guide). Relative peimittivity (epsilon') and loss factor (tan delta) of the rod specimen are determined by the resonant frequency (f_0) and unloaded Q-factor (Q_u) of a TE_(0m1) mode resonator The effective conductivity (sigma) of conducting plates for short-circuiting the rod resonator is determined using TE_(021) and TE_(02 delta) mode sapphire resonators. Temperature dependence of epsilon' and tan delta of sapphire and cordierite ceramics were evaluated at 60 GHz This method has been adopted as the Japanese Industrial Standard (JIS R 1660-3) and is being prepared for the IEC international standard. Several standardized specifications are presented.