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:
Mar. 18, 2014
Filed:
Jan. 31, 2008
Tetsuya Kawanishi, Koganei, JP;
Takahide Sakamoto, Koganei, JP;
Akito Chiba, Koganei, JP;
Masahiro Tsuchiya, Koganei, JP;
Tetsuya Kawanishi, Koganei, JP;
Takahide Sakamoto, Koganei, JP;
Akito Chiba, Koganei, JP;
Masahiro Tsuchiya, Koganei, JP;
Abstract
A quadrature amplitude modulation (QAM) signal generator, which can obtain optical signals such as QAM signals without handling multilevel electrical signals, can be produced by using a plurality of parallel Mach-Zehnder modulators (MZMs), such as quadruplex parallel MZMs (QPMZM). The quadrature amplitude modulation (QAM) signal generator includes a first waveguide, a first quadrature phase-shift-keying (QPSK) signal generator provided on the first waveguide, a second waveguide connected with the first waveguide at a wave-combining point, and a second quadrature phase-shift-keying (QPSK) signal generator provided on the second waveguide.