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. 10, 2020
Filed:
Mar. 22, 2017
Nec Corporation, Minato-ku, Tokyo, JP;
Satoshi Mikami, Tokyo, JP;
NEC CORPORATION, Tokyo, JP;
Abstract
Provided is a signal loopback circuit which, in order to loop back a monitoring signal in a relay device for relaying optical signals of a plurality of wavelength bands, connects between a channel of first direction and a channel of second direction through which an optical signal of first wavelength band and an optical signal of second wavelength band are transmitted, wherein the signal loopback circuit is provided with a first coupler for branching the optical signal on the channel of first direction, a first filter for extracting at least one of a monitoring signal of first wavelength band and a monitoring signal of second wavelength band that are used in the channel of first direction from the optical signal branched by the first coupler, and a second coupler for causing the monitoring signal extracted by the first filter to be joined to the channel of the second direction.