Measurement of complex permittivity in the microwave range

The present development concerns the determination of permittivity epsr (epsr bigger than 1 0) and dielectric loss factor tan delta of low loss dielectrics in the microwave range. Experiments are based on TEM delta 01 resonance mode excitation using the network analyser HP8720C (50 MHz to 20 GHz). The dielectric losses are deduced from the unloaded quality factor with resolution smaller 10-4. The permittivity epsr, is calculated from resonance frequency using the modified Itoh and Rodukas model. The uncertainty is smaller 5% for the measured epsr. The measuring method was tested using commercial ceramic dielectric resonators.