Helical slow wave structure for measuring the permittivity of highdielectric constant materials including bio-samples

Abstract

The helical slow wave structure technique is discussed for measuring the complex permittivity of high-dielectric constant materials, including high-loss bio-samples. The theoretical background of the technique is presented here for measurements on high-permittivity solids, viscous dielectric samples including bio-samples, and aerosols. To prove the feasibility of the technique, ϵ and ϵ— values of the phantom muscle sample (30% gelatine + 69% water + 1% NaCI) are determined experimentally at 2·45 and 2·55 GHz in the S-band and are compared with those values obtained theoretically. © 1993 Taylor & Francis Ltd.