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:
Jun. 29, 1999
Filed:
Apr. 29, 1996
Applicant:
Inventor:
Mizuyuki Ushirozawa, Tokyo, JP;
Assignee:
NEC Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H04B / ;
U.S. Cl.
CPC ...
359194 ; 359189 ; 2502011 ; 2502 / ; 330308 ;
Abstract
In an optical receiver including an avalanche photodiode (APD), a monitor circuit monitors the operating point of a preamplifier. A bias control circuit usually transfers a control signal received from an AGC (Automatic Gain Control) control circuit to an APD bias circuit. When the value being monitored by the monitor circuit exceeds a preselected level, the bias control circuit controls the APD bias circuit such that the above value coincides with the preselected level. The various sections of the receiver are free from damage ascribable to an increase in the photocurrent of the APD.