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:
Jan. 14, 1992
Filed:
Jun. 05, 1990
Eckhard Meissner, Munich, DE;
Siemens Aktiengesellschaft, Munich, DE;
Abstract
Apparatus and method for obtaining a phase insensitive and/or polarization insensitive optical heterodyne reception for a FSK modulated transmission signal which uses a low intermediate frequency relative to the data rate of the transmission signals and at every clock of the transmission signal, the phase is keyed between 0 and 90.degree. at the starting time and in the middle of the clock time the polarization of the signal is keyed between two mutually orthogonal polarization conditions at the start of the second and the start of the fourth quarter of the clock time and the phase independent and/or polarization independent output signal of the receiver is obtained from the signal which is shift keyed in a simple optical heterodyne receiver for FSK modulated transmission signals.