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:
Apr. 24, 1979
Filed:
Jun. 28, 1977
Raymond Strauch, Viroflay, FR;
Jean-Pierre Tomasi, Velizy, FR;
Abstract
The disclosed system is intended to supply angular and range data regarding the position of an object to be located in a reference system. The system comprises an interrogator which transmits a linearly frequency-modulated signal to a transponder disposed on the object. The transponder is provided with means for shifting the frequency of the received signal in one direction by a predetermined amount characteristic of that transponder and means for retransmitting the received signal. The interrogator further includes a pair of receiving antennas whose signals are used for forming beat signals with the transmitted signal. The interrogator is also provided with means for shifting the frequency of the beat signals in the other direction by the same amount. At least one of the shifted beat signals is applied to a frequency discriminator whose output signal is utilized for controlling the slope of the modulation signal in order to keep the frequency of the shifted beat signal constant.