The present invention provides a method and apparatus for use with an analog front end circuit of a DCE of a multipoint system for preventing an impedance null from being generated in the frequency bands being used by the DCE. A feedback circuit is employed with the analog front end circuit to force the input current of the analog front end circuit to zero, thus providing the analog front end circuit with a high input impedance, which prevents an impedance null from forming in the frequency bands being used by the DCE. In accordance with the preferred embodiment of the present invention, a sensing resistor is incorporated into the analog front end circuit of the DCE for sensing the input current of the analog front end circuit. A feedback circuit coupled to the sensing resistor detects the input current sensed by the sensing resistor and causes a power driver of the analog front end circuit to force the input current to zero, thus providing the analog front end circuit with a high input impedance that prevents an impedance null from being created in the frequency bands being used by the DCE.