Implementation of the variable density mesh within the finite difference frequency domain algorithm to analysis of electromagnetic field in building constructions

The paper presents the developed algorithm of the finite difference frequency domain method (FDFD). The proposed formulation allows analyzing some large-scale models using a local refinement of the differential mesh based on the h-adaptation of the rectangular elements. The final form of the algorithm is implemented to estimate field phenomena connected with the propagation of high frequency electromagnetic waves in building constructions. The electrical losses in materials caused by conducting and displacement currents are taken into account. The presented algorithm is applied to analyze electromagnetic field around a pillar of a building, in the band of some local wireless communication systems. The results obtained from the proposed FDFD scheme are confronted with the field distribution computed using FDTD and FEM methods.