Nonoverflow Representation of Electromagnetic Field From Dipole Source in Cylindrical Media With Uniaxial Anisotropy

Abstract

A non-overflow representation of electromagnetic (EM) field radiated by dipoles sources in the cylindrical multilayered anisotropic media is presented. The sources include both magnetic and electric triaxial dipoles. The permeability, permittivity, and conductivity of each layer are all uniaxial anisotropic. A set of normalized reflection\transmission coefficients is defined and utilized to describe the propagation of EM wave. The recursive algorithm of EM field in each layer is with respect to the ratios of the outgoing and standing waves. In the expressions, all the Hankel or Bessel functions are in the form of their ratios, which avoid the overflow problem in numerical integral. To improve the stability and accuracy of numerical calculation, we subtract the background field from the total field in spectral domain. The background field is calculated by the algebraic solution in spatial domain rather than its integral representation. The rest of the field, namely the reflection field, has smaller convergence region compared with its total field, and is calculated using the cubic spline interpolation method. The parities of the integrand are discussed by using numerical simulations, which yield the corresponding folded expressions of the field components to accelerate the computational efficiency. This work can be widely used in the applications of geophysical exploration.