A full-wave integral equation Green's function code in the spectral domain has been implemented using the finite Fourier transform consistent with layered structures modelled in a cross-sectional region. The Green's function handles very complex materials, such as uniaxial and biaxial electric or magnetic crystals, rotated crystals, asymmetric off-diagonal element tensor electric or magnetic materials, non- hermitian tensors, simultaneous electric or magnetic behavior, and optical activity. The basis function due to intrinsic asymmetry caused by the material tensors. This asymmetric basis set may be reduced to a perfectly symmetric set in appropriate cases, if desired. Theoretical issues related to determining the permittivity or permeability tensors from the propagation constant, which may be obtained from a design specification or an experimental measurement, will be covered in mathematical generality for rotated systems or arbitrary bias field orientations. Specialization to principal axis crystallographic orientation or bias field direction with respect to the device coordinates will then be made, and subsequently examination of static electric field induced anisotropy in a ferroelectric loaded multi- layered microstrip structure will be treated in a multi-step computational process of de-embedding the permittivity tensor elements from the propagation constant values.