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:
Nov. 26, 2002
Filed:
Jan. 31, 2001
Japan Radio Co., Ltd., Tokyo, JP;
Abstract
A circuit for biasing an FET, comparing a gate bias voltage of the FET with a reference voltage at an operational amplifier and performing closed-loop control on the gate bias voltage of the FET with the output of the operational amplifier. The temperature characteristics of the mutual conductance of the FET is compensated by setting the temperature characteristics of one or both of two voltage dividing resistors. Variations in a drain bias current due to input signal level and temperature changes can be suppressed. The circuit at the gate and the circuit at the drain are separate, making possible class A, class AB, and class B operations. The voltage drop at the gate resistor can be ignored so that the gate resistor can be designed with priority given to stability of the RF characteristics.