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:
Apr. 20, 1999
Filed:
Jun. 25, 1996
Koji Kikushima, Yokosuka, JP;
Nori Shibata, Yokosuka, JP;
Kouichi Suto, Yokosuka, JP;
Katsushi Iwashita, Miura, JP;
Satoshi Ikeda, Yokosuka, JP;
Hiroshi Nakamoto, Kodaira, JP;
Chisei Kishimoto, Yokosuka, JP;
Kiyomi Kumozaki, Zushi, JP;
Naoya Sakurai, Tokyo, JP;
Nippon Telegraph and Telephone Corporation, Tokyo, JP;
Abstract
The AM/FM converter of the present invention comprises an optical frequency modulation section which receives multi-channel AM video signals and outputs an optical-frequency-modulated optical signal beam; and an optical heterodyne detection section comprising an optical frequency oscillator composed of a semiconductor local laser which outputs a local oscillator optical beam having an optical frequency separated by a designated intermediate frequency, an optical coupler, and a photoelectric converter composed of a photodiode, which receives the optical signal beam and outputs an electrical batched FM modulation signal which is frequency-modulated and frequency-converted to the intermediate frequency. By means of this configuration, the invention offers an AM/FM converter wherein the frequency band is made considerably wider.