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

摘要

This paper presents a circular waveguide method for simultaneously measuring the electromagnetic parameters of chiral materials at microwave frequencies. Only the dominant mode of the electromagnetic wave in the circular waveguide is considered.The rotation angle, the axial ratio and the complex reflection coefficients of short-circuited (the sample is backed with metal) and open-circuited (the sample is not backed with metal) samples are measured in the frequency range 8.5-11.5 GHz by using anordinary microwave circular waveguide measurement system. The complex permittivity, complex permeability and complex chirality parameter are calculated from the measured rotation angle, axial ratio and complex reflection coefficients of short-circuitedand open-circuited samples. The dependences of the electromagnetic parameters on the concentrations and handedness of the chiral inclusions are studied. The results agree basically with those obtained by the free-space method.