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. 27, 2005
Filed:
Sep. 04, 2002
Andreas Hagl, Dachau, DE;
Konstantin Aslanidis, Dachau, DE;
Andreas Hagl, Dachau, DE;
Konstantin Aslanidis, Dachau, DE;
Texas Instruments Deutschland GmbH, Freising, DE;
Abstract
A method for the authentication of a transceiver unit with respect to a second transceiver unit, located at a distance to it. A first signal is transmitted via an aerial connected to the first unit, when second unit is located within the reception area of the first unit. The first signal is received by means of the second unit via an aerial connected to it, whereby, on the basis of the first signal received, a value is measured that characterizes the strength of the electro-magnetic field generated by the first signal at the location of the second unit. A second signal is transmitted via the aerial connected to the second unit that contains information relating to the magnitude characterizing the field strength; and the second signal is received via the aerial connected to the first unit, where, on the basis of the second signal received, a value is measured that characterizes the strength of the electro-magnetic field generated by the second signal at the location of the first unit. On the basis of the values characterizing the field strengths measured during the transmission of the first and the second signals, a comparison is made as to whether the two magnitudes of coupling corresponding to the field strengths between the two aerials coincide. Only when coincidence is established, a release signal is generated.