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:
Jul. 29, 1997
Filed:
Sep. 01, 1995
Siegfried Ritter, Arnstadt, DE;
Wolfgang Tobergte, Halstenbek, DE;
U.S. Philips Corporation, New York, NY (US);
Abstract
The demodulation of binary amplitude-modulated carrier signals gives rise to special problems, for example in the case of contactless data carriers, because the RF signal is then also used for generating the operating voltage which is limited to a fixed value when the energy is sufficiently high. Moreover, strong interference signals are often superposed on amplitude-modulated signals. For reliable demodulation in such circumstances, therefore, a control signal is subtracted from the input signal and the values of one polarity of the difference are integrated. In order to generate the control signal, the values of one polarity of a further difference between the input signal and a further control signal which is proportional to the former control signal are continuously integrated so as to form an integral signal which is periodically reduced by a fixed fraction. The control signals are derived from said integral signal in a non-linear fashion, preferably by way of the input characteristic of a transistor.