Patent ID: 6624721
Filing Date: 2003-09-23
Classification: H04B

Abstract:
Apparatus for monitoring signals at an intermediate point of a series impedance source terminated unidirectional transmission line, said signals of said transmission line including an incident waveform component and a reflected waveform component, said apparatus comprising:a voltage probe coupled to said intermediate point on said transmission line for monitoring a voltage signal on said transmission line and producing a first output signal in response thereto; a current probe coupled in series with said transmission line at said intermediate point on said transmission line for monitoring a current flowing in said transmission line and producing a second output signal in response thereto; and a combining circuit for combining said first and second output signals to produce a resultant signal at an output, said resultant signal being representative of only one of said incident waveform component and said reflected waveform component; said voltage probe comprises a voltage divider circuit for developing said first output signal and applying said first output signal to said combining circuit; said current probe comprises a transformer having a primary winding and a secondary winding, said primary winding being coupled in series with said transmission line, said secondary winding developing said second output signal and applying said second output signal to said to said combining circuit; and said combining circuit algebraically sums said first and second output signals and produces said resultant signal in response thereto; and wherein,said combining circuit is an amplifier having inverting and non-inverting inputs, and said first output signal is coupled to said non-inverting input and said second output signal is coupled to said inverting input, and said amplifier produces said resultant signal at an output, said resultant signal being representative of only said reflected waveform component.