Abstract
The measurement accuracy of complex permittivity in the dielectric rod resonator method has been investigated. The measurement error of relative permittivity is 0.05% (standard deviation), which is permissible for the applications of resonators. The dielectric loss was measured by setting conducting plates at both ends of the dielectric resonator. The frequency dependence of the conductivity due to the surface roughness of the plates was investigated using three kinds of standard rod resonators. It is concluded that the measurement error of tan δ can be reduced to 1.5×10-6 (standard deviation) for a dielectric specimen with εr=30.2 at 10 GHz by using the high-Q standard dielectric rod resonators which are placed between conducting plates with surface roughness less than the skin depth at the measurement frequency.