Enhanced FEM-Based DBIM Approach for Two-Dimensional Microwave Imaging

The distorted Born iterative method (DBIM) is widely used in microwave imaging to solve the electromagnetic inverse scattering problem iteratively based on the distorted Born approximation. Various methods are used for the forward solver in the DBIM to simulate wave propagation and scattering. In this communication, a new matrix building technique exploiting the basis functions of the finite element method (FEM) is used to create the inverse-problem matrix in a 2-D DBIM algorithm. The proposed approach provides great efficiency as the entries of this matrix are readily calculated from already precomputed matrices in the FEM procedure without the need for interpolation to calculate the field. The FEM-based DBIM is validated with both simulated data and experimental data from a microwave tomography (MWT) system. Results confirm that the proposed FEM implementation can be an efficient and accurate forward solver for this MWT system.