Sifen Luo - Hartsdale NY, US Tirdad Sowlati - Ossining NY, US Chris Joly - North Providence RI, US Kerry Burger - Lincoln NE, US
Assignee:
Philips Electronics North America Corporation
International Classification:
H03F003/04
US Classification:
330/296000
Abstract:
A power amplifier circuit includes an amplifying transistor and a dc bias circuit for biasing the amplifier transistor to obtain a conduction angle of at least about 180. The dc bias circuit includes a self-bias boosting circuit for initially decreasing and then increasing the dc bias voltage provided to a control terminal of the amplifying transistor by the dc bias circuit as the input signal provided to the power amplifier increases. The self-bias boosting circuit is extremely simple and compact in design, and permits the power amplifier circuits to operate in Class B or Class AB with improved power output characteristics.