US 6,982,594 B2
System for developing a secondary control signal in a power amplifier control loop
James R. Snider, Irvine, Calif. (US); and Jason D. Millard, Irvine, Calif. (US)
Assigned to Skyworks Solutions Inc., Irvine, Calif. (US)
Filed on Nov. 13, 2003, as Appl. No. 10/712,136.
Prior Publication US 2005/0104657 A1, May 19, 2005
Int. Cl. H03G 3/20 (2006.01)
U.S. Cl. 330—140 18 Claims
OG exemplary drawing
 
1. A power control system for a power amplifier, comprising:
a first power control loop configured to provide a control signal comprising:
a variable attenuator for adjusting a gain applied to a signal in the first power control loop;
a detector for providing a direct current (DC) baseband signal representing an output of the power amplifier;
a first comparator for comparing the DC baseband signal to a first reference signal and generating an error signal;
a second power control loop comprising:
a second comparator for comparing the error signal to a second reference signal and generating a secondary control signal capable of controlling the variable attenuator.