Signal Integrity and Power Integrity

Abstract

When modeling differential signal propagation in a two-conductor transmission line over ground, it is convenient to express the propagation as the sum of two orthogonal modes, common-mode and differential mode. These TEM modes propagate independently as long as there is no change in the electrical balance of the three-conductor configuration. Any change in the electrical balance results in an exchange of power between the two modes at the point of the discontinuity. This effect can be precisely modeled using simple load resistances and dependent sources.