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:
Sep. 06, 2011
Filed:
Jun. 12, 2008
Herbert R. Jones, Williston, VT (US);
Robert F. Higgins, South Burlington, VT (US);
Henry E. Himberg, Williston, VT (US);
Herbert R. Jones, Williston, VT (US);
Robert F. Higgins, South Burlington, VT (US);
Henry E. Himberg, Williston, VT (US);
ALKEN Inc., Colchester, VT (US);
Abstract
Plural transmitter coils of a magnetic locating system are driven with widely-separated main frequencies. One of the transmitter coils is also driven with a marker frequency close to the main frequency applied to that coil. The receiver determines a phase relationship with the transmitter based on the main and marker frequencies, so that the receiver does not suffer from phase ambiguity. The main and marker frequencies may interfere with one another, and the receiver may correct for such interference based on known characteristics of the signals at the main and marker frequencies.