Developments in techniques to measure dielectric properties of low-loss materials at frequencies of 1–50 GHz

Recent developments in precise measurement methods of the complex permittivity of low and medium loss dielectrics are presented. In particular TE01 mode dielectric resonator, whispering gallery mode resonator (WGMR) and split post dielectric resonator techniques are discussed. It is shown how to optimize the size of metal shield of the TE01 mode dielectric resonator to minimize conductor losses to obtain the highest sensitivity of loss tangent measurements. Conductor and radiation loss limits are discussed for open and closed whispering gallery mode resonators. New constructions of split post dielectric resonators are presented for dielectric measurements at frequencies from 25 to 35 GHz and for measurements of ferroelectrics.