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:
May. 26, 1998
Filed:
Aug. 28, 1996
Joseph Staudinger, Gilbert, AZ (US);
William B Beckwith, Chandler, AZ (US);
Motorola, Inc., Schaumburg, IL (US);
Abstract
A power amplifier (50) includes two transistors (11, 21) and a dynamic biasing circuit (52). The dynamic biasing circuit (52) uses a sampling circuit (54) to generate a bias adjusting signal proportional to the amplitude of an AC signal at a drain electrode of the first transistor (11). The bias adjusting signal is combined with a constant voltage bias signal to generate a dynamic biasing signal applied to a gate electrode of the second transistor (21). As the gain of the first transistor (11) decreases, the amplitude of the AC signal at its drain electrode decreases. Thus, the dynamic biasing circuit (52) generates a lower dynamic biasing signal at the gate electrode of the second transistor (21), thereby decreasing a quiescent drain current in the second transistor (21) and improving the efficiency of the amplifier (50) at low output power levels.