Comments on "Cost Function Minimization in RC Ladder Networks

Abstract

In the above paper,’ a proper transformation is presented to generate equivalent networks for the minimization of a weighted sum of total resistance, total capacitance, and the reciprocal gain factor. The derivation of the cost function is incorrect. The element values of the continuously equivalent ladder networks are expressed explicitly as .functions of a single variable /3 in (13) (Equations with number 1 up to 47 see’). Since the transformation is applied to the node admittance matrix, these functions are defined in the closed interval 0 < p < 1 only if the element values are given in terms of admittances as there are capacitances CL( /3) (k= 1,2;. . , n) and conductances GL( ,0) (k = 1,2;. . ,n- I), g;(p), g,‘,(P). Because of g;(l)=0 and gA(O)=O, the corresponding resistances with infinite values may be simply omitted from the realization. The authors’ avoid the difficulty of singularities by taking the total resistance formula as