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:
Sep. 17, 2002
Filed:
Jan. 27, 1999
Masanori Iida, Katano, JP;
Hiroyuki Asakura, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A narrow-band FM modulator provided with an optical transmitter converts a carrier signal having high carrier frequency higher enough than those of a plurality of signals into a narrow-band FM signal by FM-modulating the carrier signal with a small modulation index for substantially generating only a first sideband in accordance with a multiplexed signal generated by subcarrier-multiplexing the signals and a frequency converter converts a narrow-band FM signal into a low-frequency-converted narrow-band FM signal having a frequency lower enough than the carrier frequency. A semiconductor laser converts an optical signal into an FM optical signal by modulating the optical signal in accordance with a low-frequency-converted narrow-band FM signal and transmits the FM optical signal to an optical receiver through an optical-fiber cable