A maxwellian formulation of adjoint sensitivity analysis using the FDTD method

This paper presents an alternative and more simpler formulation of adjoint sensitivity analysis of high frequency structures using the FDTD method. Unlike previous FDTD-based formulations, our formulation does not use the wave equation and is directly based on Maxwell's equations. This formulation is way simpler to implement. Our approach requires one extra adjoint simulation to estimate the sensitivities of the desired objective function or response with respect to all parameters. Our approach is illustrated through one 2D TMz example.