Derivation and Fast Computation of Dyadic Green's Functions of Magnetic Vector Potential for Unbounded Uniaxial Anisotropic Media

The dyadic Green's function of the magnetic vector-potential A (DGFA) for unbounded uniaxial anisotropic media is unavailable in literature but it is needed in numerical computation. The equation of the DGFA was directly derived from the Maxwell's equations. Through the Fourier transform and the inverse Fourier transform, the triple integral form of the DGFA in the spatial domain was obtained. And it was finally simplified to Sommerfeld integrals. In order to v erily these formulas, we applied the singularity subtraction technique to evaluate the Sommerfeld integrals rapidly and compared the numerical results with the analytical solutions for degenerated cases for the isotropic unbounded media, as well as the simulated results from a commercial finite element software for uniaxial anisotropic unbounded media. Finally, the effect of the singularity subtraction method was discussed.