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:
Nov. 01, 2005
Filed:
Feb. 06, 2002
Werner Blatz, Leingarten, DE;
Werner Blatz, Leingarten, DE;
ATMEL Germany GmbH, Heilbronn, DE;
Abstract
In a method of detecting redirection or interception during a bi-directional non-contact making data transmission, the attenuation (A) of the amplitude over the forward path is compared with the attenuation (A) of the amplitude over the return path. The attenuation (A) over the forward path is transmitted in encoded form with the reply signal. If the attenuation values determined thereby are of the same magnitude, then the likelihood of a redirecting process can be excluded. In order to additionally increase the security of the system, the carrier frequency (F) of the interrogation signal can also be compared with the carrier frequency (F) of the reply signal. The signals can also incorporate an ID code.