An Upwind Condition-Based Hybrid FDTD-PITD Method for Multi-scale Electromagnetic Problems with Fine Structures

Multiscale problems with fine structure, involving electrically small fine details and relatively uniform areas, are posing significant challenges to any single algorithm in computational electromagnetics. Thus, a hybrid method combing the finite-difference time-domain (FDTD) method with the preciseintegration time-domain (PITD) method is proposed to handle such problems in this letter. For the hybrid method, the field values in the FDTD and PITD domains are calculated separately and independently. The information exchange between two solution domains is achieved by correcting the interface field components via the upwind condition. Several numerical experiments demonstrate the advantage of the hybrid method.