A high-precision electromagnetic technique for modeling and simulation in inhomogeneous media. Issue 1 (2nd January 2020) - Yang, Xin
ABSTRACT: The high-precision method for modeling inhomogeneous media and the precision limit of finite-difference time-domain (FDTD) are studied theoretically and numerically. Firstly, based on the transform-domain idea, a new layered modeling technique for inhomogeneous media is developed, with the control equation of the modeling precision given. Compared with other modeling methods, the paramount advantage of this method is that the modeling process is not restrained by the magnitude range of the data, and that the modeling precision can be controlled easily. Then, the shift operator finite-difference time-domain is adopted to determine the field values in inhomogeneous media, and a high-precision computational method is proposed. This method theoretically proves that the relationship between the FDTD grid size and the calculated field value satisfies a definite function, which is then verified by numerical examples. The significance of the results is that this relationship will provide an effective approach to predict field values during the modeling grid size tending to zero, which can be regarded in theory as an approximation to the true value of the electromagnetic (EM) fields. The advantages of this approach are that it not only inherits the advantages of the FDTD method, but also gives a way out of the difficulty that the EM algorithms available are difficult to provide a high-precision prediction of radio propagation; and it can be seen from the validation process in this paper that this approach could also be used in the algorithms based on the mesh modeling and in the inhomogeneous media for improving their calculation precision.