US 12,267,046 B2
Power amplifier system
Nadim Khlat, Cugnaux (FR)
Assigned to Qorvo US, Inc., Greensboro, NC (US)
Filed by Qorvo US, Inc., Greensboro, NC (US)
Filed on Jan. 20, 2022, as Appl. No. 17/579,796.
Claims priority of provisional application 63/149,556, filed on Feb. 15, 2021.
Prior Publication US 2022/0263474 A1, Aug. 18, 2022
Int. Cl. H03F 1/02 (2006.01); H03F 3/21 (2006.01)
CPC H03F 1/0233 (2013.01) [H03F 1/0288 (2013.01); H03F 3/21 (2013.01); H03F 2200/105 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A power amplifier system comprising:
a carrier amplifier having a first supply node;
a peaking amplifier having a second supply node; and
envelope tracking (ET) circuitry comprising:
a first tracking amplifier configured to generate a first voltage signal at the first supply node;
a second tracking amplifier configured to generate a second voltage signal at the second supply node;
a transistor having a first current terminal coupled the first supply node and a second current terminal coupled to the second supply node; and
a control circuit having a first input coupled to an output of both or either of the first tracking amplifier and the second tracking amplifier and a control output terminal coupled to a control input terminal of the transistor, wherein the control circuit is configured to progressively turn on the transistor to pass current from the first supply node to the second supply node as the peaking amplifier progressively becomes active, wherein the control circuit is configured to cause a rate of change of peaking current supplying the peaking amplifier to be greater than a rate of change of carrier current supplying the carrier amplifier until the carrier current and the peaking current are substantially equal.