Chiral Materials Microwave Parameters Of Free Space Test Methods

A method is described for the extraction of the three constitutive parameters, the permittivity, permeability and chirality, of the chiral materials, using measurements of scattering parameters of a slab in free-space. Numerical simulation is fulfilled.Firstly, impedance and wavenumbers of a planar wave are derived from Maxwell formulae and the constitutive relations for chiral medium. Then the model for measuring a slab sample in free-space is described. The propagation of a planar wave through an infinite slab of chiral medium is formulated for oblique incidence and solved analytically for the case of normal incidence. Three scattering parameters, i.e. the reflection coefficient, co-polarized transmission coefficient and cross-polarized transmission coefficient, are formulated by the solved fields for normal incidence. Then the inverse problem from the scattering parameters to the constitutive parameters is analyzed and a method is developed, including some relevant formulae. Ambiguities associated with the inverse problem are discussed and a time-domain technique is given to remove them.The key components of the measurement system are a pair of spot-focusing horn lens antennas and the HP8510B network analyzer. The latter is available in our office. A free-space TRL calibration technique is used for calibrating this measurement system.