The inverse problem for biaxial materials
Abstract
A variety of anisotropic materials have found important applications at microwave frequencies. The electromagnetic theory of anisotropic materials is well established. However, work is needed regarding the experimental techniques for the determination of the constitutive parameters of these materials. The present investigation is concerned with the inverse problem for an important category of anisotropic materials, involving biaxial media. The relative permittivity and permeability tensors for these materials are represented by diagonal matrices in a rectangular Cartesian reference system (x, y, z). The six constitutive parameters are dimensionless numbers and are, in general, complex and frequencydependent. It is tried to determine the parameters from measurements of reflection and transmission coefficients for a biaxial sample inserted in a rectangular waveguide. Attention is given to the boundaryvalue problem, the inverse problem, lossless nondispersive material, lossy dispersive material, and the measurement procedure.
 Publication:

IEEE Transactions on Microwave Theory Techniques
 Pub Date:
 April 1984
 DOI:
 10.1109/TMTT.1984.1132689
 Bibcode:
 1984ITMTT..32..400D
 Keywords:

 Anisotropic Media;
 Electromagnetic Fields;
 Field Theory (Physics);
 Propagation Modes;
 Rectangular Waveguides;
 Signal Measurement;
 Boundary Value Problems;
 Constitutive Equations;
 Lossy Media;
 Magnetic Permeability;
 Microwave Transmission;
 Permittivity;
 Spectral Reflectance;
 Transmittance;
 Electronics and Electrical Engineering