Patent ID: 6411108
Filing Date: 2002-06-25
Classification: G01R,H04B,H04M

Abstract:
Apparatus, for detecting the signal waveforms of analog and digital signals transmitted individually and, alternately, in combination, in designated transmission frequency bands on a pair of signal conductors, comprising:a probe having first and second electrically conductive plates for capacitively coupling first and second signal samples of the transmitted signals in each designated transmission frequency band from the signal conductors to a related one of a pair of termination impedances associated with each plate, each plate further including an associated electrically conductive shield placed in spaced relation thereto; signal conditioning circuitry, including first and second buffer amplifiers responsive, respectively, to said first and second sample signals at said termination impedances, for providing first and second equivalent sample signals thereof at an output of each amplifier, each said equivalent sample signal having equal signal polarity and substantially equal signal magnitude as its related sample signal, said buffer amplifiers each providing said equivalent sample signal to the commonly associated one of said electrically conductive shields, whereby the voltage signal potential of the conductive shield is substantially equal to the voltage signal potential of its associated plate, said signal conditioning circuitry further including a differential signal amplifier having first and second signal inputs responsive to said first and second equivalent sample signals, respectively, for providing a differential sample signal proportional to the difference sum therebetween; a signal analyzer, for receiving said differential sample signal at each of one or more frequency filters, each said frequency filter having a passband which passes equivalent sample signal frequencies in one of the designated transmission frequency bands and rejects all other signal frequencies, said signal analyzer further including one or more signal annunciators associated with each said frequency filter, said signal annunciators indicating the presence of a designated transmission frequency band signal passed by its associated frequency filter; and a sensor housing, for enclosing said signal conditioning circuitry and said signal analyzer within its main body and for enclosing said probe within a probe portion at one end thereof, said housing having a surface area for mounting said signal annunciators, and being adapted to be placed by a user in proximity to one or more conductors.