Patent ID: 11894816
Assignee: MURATA MANUFACTURING CO., LTD.
Field: Basic communication processes (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A power amplifier circuit comprising:
a first amplifier configured to amplify a first radio frequency (RF) signal supplied to the first amplifier, and to output a second RF signal;
a second amplifier configured to amplify the second RF signal supplied to the second amplifier, and to output a third RF signal;
a bias circuit configured to supply a bias current or a bias voltage to the first amplifier or to the second amplifier; and
a bias adjustment circuit configured to adjust the bias current or the bias voltage based on the first RF signal, the second RF signal, or the third RF signal,
wherein the bias adjustment circuit comprises a first diode having an anode to which a control signal is input, and a cathode connected to ground, the control signal being indicative of the first RF signal, the second RF signal, or the third RF signal,
wherein the bias circuit comprises a bias transistor configured to output the bias current or the bias voltage based on a voltage at the anode of the first diode,
wherein the first amplifier has a first supply terminal to which the first RF signal is supplied, and a first output terminal from which the second RF signal is output,
wherein the second amplifier has a second supply terminal connected to the first output terminal of the first amplifier and to which the second RF signal is supplied, and a second output terminal from which the third RF signal is output,
wherein the bias transistor has an emitter connected to the first supply terminal or to the second supply terminal,
wherein the anode of the first diode is connected to the first supply terminal, the first output terminal, or the second output terminal, and
wherein the bias transistor further has a base connected to the anode of the first diode.