A circular waveguide method for measuring the electromagnetic parameters of chiral materials at microwave frequencies

This paper presents a circular waveguide method for simultaneously measurin g the electromagnetic parameters of chiral materials at microwave frequenci es. Only the dominant mode of the electromagnetic wave in the circular wave guide is considered. The rotation angle, the axial ratio and the complex re flection coefficients of short-circuited (the sample is backed with metal) and open-circuited (the sample is not backed with metal) samples are measur ed in the frequency range 8.5-11.5 GHz by using an ordinary microwave circu lar waveguide measurement system. The complex permittivity, complex permeab ility and complex chirality parameter are calculated from the measured rota tion angle, axial ratio and complex reflection coefficients of short-circui ted and open-circuited samples. The dependences of the electromagnetic para meters on the concentrations and handedness of the chiral inclusions are st udied. The results agree basically with those obtained by the free-space me thod.