US 12,278,602 B2
Power amplifier circuit
Satoshi Goto, Kyoto (JP); Yuri Honda, Kyoto (JP); and Yoshiki Kogushi, Kyoto (JP)
Assigned to MURATA MANUFACTURING CO., LTD., Kyoto (JP)
Filed by Murata Manufacturing Co., Ltd., Kyoto (JP)
Filed on Oct. 18, 2021, as Appl. No. 17/503,919.
Claims priority of application No. 2020-176355 (JP), filed on Oct. 20, 2020.
Prior Publication US 2022/0123698 A1, Apr. 21, 2022
Int. Cl. H03F 3/195 (2006.01); H03F 1/02 (2006.01); H03F 3/24 (2006.01)
CPC H03F 3/245 (2013.01) [H03F 1/0211 (2013.01); H03F 3/195 (2013.01); H03F 2200/168 (2013.01); H03F 2200/318 (2013.01); H03F 2200/451 (2013.01); H03F 2200/541 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A power amplifier circuit comprising:
at least one differential amplifier circuit configured to amplify a radio-frequency signal;
a transformer on an output side of the at least one differential amplifier circuit, the transformer comprising a primary winding and a secondary winding; and
an adjustment circuit coupled to a midpoint of the primary winding of the transformer, the adjustment circuit being configured to adjust a bias current or a bias voltage supplied to the at least one differential amplifier circuit based on a supply voltage controlled in accordance with an envelope of the radio-frequency signal.