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:
Aug. 01, 2006
Filed:
May. 08, 2003
Applicants:
Thomas Hauser, München, DE;
Frank Hürtgen, Düsseldorf, DE;
Christian Kranz, Ratingen Lintorf, DE;
Inventors:
Assignee:
Infineon Technologies AG, Munich, DE;
Primary Examiner:
Int. Cl.
CPC ...
H04M 1/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A detection circuit and method for detecting AC voltage pulses at a defined frequency relate to first transforming an input signal to a low-frequency signal by multiplying the input signal by a mixing frequency. This down-mixed signal can then be filtered and evaluated. The circuit is particularly suitable for identifying charge unit signals in the telephone network.