Evaluation of port immittance gradients using adjoint technique

An important class of network optimization problems is one in which the objective function is defined in terms of port immittances. Since many solution procedures employ a gradient evaluation of the objective function, calculations of the partial derivatives of port immittances with respect to the parameters that vary are required. A procedure is presented for evaluating the partial derivatives of port immittances with respect to\sigmaand\omega, where\sigma + j \omegais the transform frequency variable. Adjoint calculations are central to the method.