A method includes providing a symbolic power distribution network (PDN) map for a PDN of an circuit design including at least a first mesh that includes a plurality of map nodes; modeling at least one parasitic component that is provided on a branch of the symbolic PDN map and a pair of current sources that are provided at two respective map nodes of the symbolic PDN map; providing a matrix equation based on an interrelated conduction behavior among the parasitic component and the pair of current sources, wherein the matrix equation includes a current source term representing the pair of current sources and an unknown variable term representing a voltage level of at least a map node of the symbolic PDN map; and based on the matrix equation, expanding the unknown variable term in a frequency-domain as a sum of plural mathematical components while keeping the current source term intact.