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:
Feb. 08, 2000
Filed:
Jun. 30, 1997
Takashi Harada, Hidaka, JP;
Satoshi Ueno, Ome, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
An optical transmission apparatus includes a feedback amplification circuit having flat and wideband frequency characteristics in which the linearity within a band is excellent. As a result, frequency characteristics of the optical transmission apparatus are improved. A feedback amplification circuit is structured with an amplifier including a transistor receiving an input signal at the base thereof, a first feedback path including a feedback resistance provided between the input terminal and the output terminal of the amplifier, i.e., between the base and the collector of the transistor, in which a substantial phase margin added with the feedback gain thereof is set to a value obtained by adding a predetermined value to 60 degrees, and a second feedback path including an emitter follower circuit composed of a transistor and a constant current source and a feedback resistance, in which a substantial phase margin added with the feedback gain thereof is set to a value obtained by subtracting said predetermined value from 60 degrees or an approximate value thereof, as the basis.