Computation of Fields from a Magnetic Dipole in a Conductive Medium Using the QS-DGTD Method

Loop antennas are often used for field generation in low-frequency electromagnetic applications. Since the antenna dimensions are much smaller than the wavelength, the antenna can accurately be replaced by its equivalent magnetic dipole model in simulations. In this paper, low-frequency magnetic dipole radiation fields in a conductive medium are computed using a three-dimensional discontinuous Galerkin Time-Domain (DGTD) scheme. It is shown that this computation can be accelerated using a material scaling scheme under Quasi-Static (QS) approximation, i.e., time step size can be scaled up without sacrificing from the accuracy and the stability of the time marching scheme. Radiated fields from a magnetic dipole in a conductive medium computed by this accelerated scheme are compared to those obtained using analytical expressions. Results are in good agreement.