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. 22, 2004
Filed:
Feb. 04, 2003
Thomas W. Arell, Basking Ridge, NJ (US);
Henry Z. Liwinski, North Wales, PA (US);
Anadigics, Inc., Warren, NJ (US);
Abstract
There is disclosed a bias circuit exhibiting good stability over variations in temperature and power supply voltage and capable of generating a plurality of discrete levels of output current for biasing RF power amplifier. In accordance with the invention, the bias circuit includes (1) a master transistor connected to the slave transistor in a current-mirror configuration and having two parallel-connected transistor elements, (2) a switch connected to at least one transistor element to control its operation, and (3) a feedback circuit by which the voltage at the collector of the master transistor may be fed back to control the voltages at the bases of the master transistor and the slave transistor. Moreover, the bias circuit can be operated from a power supply voltage that is just above twice the value of the base-emitter voltage of the transistor in the circuit.