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:
Oct. 12, 1993
Filed:
Jul. 15, 1991
Applicant:
Inventors:
Takao Naito, Kawasaki, JP;
Terumi Chikama, Tokyo, JP;
Shigeki Watanabe, Kawasaki, JP;
Tetsuya Kiyonaga, Kawasaki, JP;
Hiroshi Nakamoto, Kawasaki, JP;
George Ishikawa, Yokohama, JP;
Assignee:
Fujitsu Limited, Kanagawa, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
359192 ; 359191 ; 359195 ;
Abstract
A demodulator comprising an OR/NOR circuit, an exclusive OR/NOR circuit, and a delay circuit is disclosed as that capable of being suitably formed into a monolithic IC. Also, a polarization diversity receiver for coherent optical communication using the above demodulator as its constituent is disclosed as that having a smaller number of variable gain amplifiers and accordingly having the controlling circuit made simpler in structure.