Acceleration of FDTD Calculation of EM Fields Due to Loop Antennas Used for MHz Band Wireless Transfer System Placed near Human Body

Abstract

The finite difference time domain (FDTD) method is widely used for analyzing various electromagnetic problems including an interaction between antennas and human body. The FDTD method provides the accurate results in most cases, however, it is often encountered for obtaining the valid EM response that the number of FDTD iteration increases dramatically in low frequency range when finer mesh is used. This is due to the Courant stability condition. This paper studies a predicting technique of the steady state responses from the transient data by using the auto-regressive moving average(ARMA) algorithm. The effectiveness of this method is numerically confirmed by analyzing the electromagnetic fields due to loop antennas used for a MHz band wireless power transfer(WPT) system, which are placed near a rectangular human body phantom.