Cascading of Distortion in CATV Trunk Line

The second-and third-order distortion buildup in a CATV repeater system is analyzed by means of the Volterra series expansion of the output signal in terms of the input signal. Expressions for cascaded distortion products are given in terms of the single amplifier distortion product and the low frequency phase intercepts of the amplifier, cable equalizer, and cable itself. From these expressions it is also seen that the low-frequency phase intercepts are the dominant factors in determining the cascaded distortion. Conditions for cancellation of either the second-or third-order distortion products are then given.