Calibration-independent measurements for complex permittivity determination of low-loss dielectric materials at microwave frequencies

The work of this article is a contribution to the characterization of new materials at microwave frequencies and enrichment the existing database. the transmission/reflection technique for complex permittivity determination is employed to characterize a set of low-loss dielectric materials. the algorithm for permittivity extraction eliminates mathematically the systematic errors of the experimental setup. this technique needs two uncalibrated scattering parameter measurements by the vector network analyzer; the first is done with a partially filled rectangular waveguide by a standard dielectric teflon sample (ptfe),and the second is performed with the sample under test. the relative complex permittivity of delrin,peek,spanish peek,nylatron,vulkollan,arnite and celotex materials are measured over the x-band frequencies (8.2 - 12.4 ghz),and the average relative errors between the calibrated and uncalibrated results are calculated. as other non-resonant methods,rough results are indicated of the imaginary part of the permittivity for very low-loss samples.