Low-loss complex permittivity and permeability determination in transmission/reflection measurements with time-domain smoothing

Abstract

An approach is proposed for determination of the complex permittivity and permeability of low-loss materials, eliminating half-wavelength resonances occurring in transmission/reflection (T/R) measurements. To this end, we apply time-domain smoothing for removing resonant artifacts from the wave impedance obtained with the conventional T/R method, assuming that we do not have such artifacts in the refractive index. Accordingly, the permittivity and permeability are found from the smoothed wave impedance and conventional refractive index. Our method is validated by measurements for two different low-loss materials, nylon and lithium ferrite, and those results are discussed. Further, results from the present approach are compared to those from the approximate approach derived in our previous work.