Application of Two-Dimensional Discrete Dipole Approximation in Simulating Electric Field of a Microwave Breast Imaging System

The 2-D electric field distribution of the microwave imaging system is numerically simulated for a simplified breast tumour model. The proposed two-dimensional discrete dipole approximation (DDA) has the potential to improve computational speed compared to other numerical methods while retaining comparable accuracy. We have modeled the field distributions in COMSOL Multiphysics as baseline results to benchmark the DDA simulations. We have also investigated the adequate sampling size and the effect of inclusion size and property contrast on solution accuracy. In this way, we can utilize the 2-D DDA as an alternative, fast, and reliable forward solver for microwave tomography. From a mathematical perspective, the derivation of the 2-D DDA and its application to microwave imaging is new and not previously implemented. The simulation results and the measurements show that the 2-D DDA is a well-grounded forward solver for the specified microwave breast imaging system.