Free space measurement of permittivity

Abstract

This paper presents a free space technique for the measurement of the complex permittivity of a slice of dielectric sample. The experimental set up is described and the technique validated by measurements on well characterised dielectrics at J band whereupon it is concluded that the method would be suitable for use in the millimetre wave band. Measured data on a variety of plastics, glass, building materials and biological tissues samples at 60 GHz is then given and includes new data for the permittivity of skin at this frequency.