An enhanced algorithm for complex permittivity extraction at microwave frequencies

Abstract

An efficient technique of complex permittivity extraction is employed to characterize low-loss conventional dielectric materials at microwave Ku-band. The computational approach eliminates mathematically the systematic errors of the experimental setup. This method needs two uncalibrated S-parameter measurements. The first is performed with a sample under test and the second is done with an empty rectangular waveguide. Three low-loss dielectric materials (Celotex, Plexiglas and Teflon) are characterized to validate experimentally the extraction method over the Ku-band frequencies [12-18] GHz. The average relative errors between the calibrated and uncalibrated results are then calculated and compared. The proposed method has been improved using the mobile average to the experimental results obtained from the uncalibrated measurements, therefore, the stability is then enhanced.