Self‐adjoint sensitivity analysis of lossy dielectric structures with electromagnetic time‐domain simulators

Abstract We present an efficient self‐adjoint approach for the computation of response derivatives in lossy inhomogeneous structures with time‐domain electromagnetic solvers. Our approach yields the responses and their derivatives with only one system analysis regardless of the number of optimizable parameters. The only requirement is to access the field solution at the perturbation grid points. The computation is performed as an independent post‐process outside the solver. This makes our approach easy to implement as stand‐alone software, which aids microwave design based on commercial computer‐aided design packages. We show that our sensitivity analysis approach yields Jacobians of second‐order accuracy for lossy dielectric structures. The approach is verified through 1‐D, 2‐D and 3‐D examples using the time‐domain field solutions obtained with solvers based on the finite‐difference time‐domain (FDTD) and transmission line modeling (TLM) methods. Copyright © 2007 John Wiley & Sons, Ltd.