Sensitivity formulas for terminated lossless two-ports

Simple, yet very general, formulas are given for the partial derivatives of the loss and phase of both singly and doubly terminated, reciprocal, lossless 2-ports with respect to any internal immittance. This immittance may be of either a wanted or a parasitic component. The formulas have a simple physical interpretation, and are generalizations of earlier results. Their use is illustrated through examples of a conventional ladder filter and of a switched-capacitor filter based on such a prototype.