A TLM-Based Wideband Adjoint Variable Method for Sensitivity Analysis of Non-Dispersive Anisotropic Structures

We propose a wideband theory for adjoint variable sensitivity analysis of problems with non-dispersive anisotropic materials. The method is developed based on the transmission line modeling (TLM) technique. The anisotropic material property can be the full tensors of permittivity, permeability, electrical conductivity, magnetic resistivity, magnetoelectric coupling, or electromagnetic coupling. The tensors are assumed constant and may contain non-diagonal elements. Our algorithm estimates the gradient of the desired response with respect to all the designable parameters using at most one extra simulation, regardless of the number of parameters. The theory has been implemented in an algorithm for 2-D and 3-D structures. Our estimated sensitivities match well the computationally expensive central finite difference approximations.