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. 21, 1978
Filed:
Feb. 25, 1977
Richard C Eden, Thousand Oaks, CA (US);
Rockwell International Corporation, El Segundo, CA (US);
Abstract
A preamp for coupling to an avalanche photodiode (APD) of an optical receiver has an input stage including a dual gate field effect transistor (FET) and a single gate FET coupled in a cascade arrangement. The dual gate FET has its first gate coupled to the output of the APD, its second gate and source grounded, and its drain driving the gate of the single gate FET in a cascade arrangement. The source of the single gate FET is level-shifted and coupled by means of a feedback resistor to the first gate of the dual gate FET to provide a negative feedback. The output stage is a third FET with its gate coupled through a blocking capacitor to the source of the single gate FET in the input stage and with its drain providing the output of the preamp. In a preferred embodiment, the FETs used are GaAs FETs (GAASFETs).