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. 27, 2021
Filed:
Apr. 03, 2017
Nec Corporation, Tokyo, JP;
Tadashi Koga, Tokyo, JP;
NEC CORPORATION, Tokyo, JP;
Abstract
A transmitter includes an optical modulator, a drive unit, a deviation identification signal generation unit, and a bias control unit. The deviation identification signal generation unit generates a signal value in accordance with a deviation of a bias voltage of the optical modulator by amplifying a signal value of a dither signal extracted from a modulated signal output from the optical modulator by a factor set for each of a plurality of modulation schemes so as to generate a uniform signal value. The bias control unit generates a bias value at which a center of a variation range, which is a range from a maximum value to a minimum value of the drive signal, corresponds to transmission characteristics of the optical modulator according to one predetermined adjustment method by using the signal value generated by the deviation identification signal generation unit.