The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 22, 1981
Filed:
Jun. 16, 1980
John T Peoples, Berkeley Heights, NJ (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Abstract
Apparatus and method (FIG. 1) for testing inductively loaded telephone transmission lines for immittance irregularities approximate a ladder network of series inductors and shunt capacitors equivalent to the input impedance of the transmission line from the pole and zero frequencies of the differential phase versus frequency characteristic thereof. The differential phase function is obtained (FIGS. 5 and 6 combined or FIGS. 5 and 7 combined) as the Hilbert transform of the logarithmic difference between a direct and delayed impedance measurement extending over a swept-frequency range in the voice-frequency band. Inductance values of the ladder network are proportional to the inductances of the line loads and the capacitor values are proportional to the distances between load inductors spaced along a transmission line.