properties of branches passing through infinity in the root locus of positive feedback systems.

in this paper, construction properties of branches in the root locus of a positive feedback system whose loop transfer function is not strictly proper have been investigated. we have introduced and proved the formulations for calculating the number of branches passing through infinity, point of intersection of the asymptotes on the real axis, and angle of these asymptotes with positive direction of the real axis. we have also considered the gain plots and time response of these systems.