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. 23, 1999
Filed:
Aug. 05, 1997
Ulrich Hugel, Tigard, OR (US);
David J McCormick, Portland, OR (US);
Tektronix, Inc., Wilsonville, OR (US);
Abstract
An automatic output offset control circuit for a DC-coupled RF amplified optical-to-electrical converter has a photodiode for converting an optical signal to an electrical signal. The current from one side of the photodiode is coupled into the input of a bipolar RF amplifier that generates a voltage output. The current from the other side of the photodiode is sensed for generating a voltage that is compared with the output of the RF amplifier. Any mismatch between the sensed current and the RF amplifier generates an error signal that is used to control the DC bias supplies of the RF amplifier. The DC bias supplies are adjusted in unison to produce the correct offset at the amplifier output for the given photodiode current while maintaining a constant AC-gain. The circuit automatically corrects for the DC-coupled output offset drift and variations of the RF bipolar amplifier. The circuit may be implemented using either voltage or current signals to the feedback circuit.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile