Amplifier biasing circuits and method

A radio-frequency power amplifier circuit comprising:

• an input path configured to receive an input radio-frequency signal;
• an integrated circuit coupled to the input path and configured to generate an amplified radio-frequency signal, the integrated circuit including at least a first circuit stage coupled to a second circuit stage, the first circuit stage including a first bipolar junction transistor having a first base, a first collector, and a first emitter, and the second circuit stage including a second bipolar junction transistor having a second base, a second collector, and a second emitter;
• at least one beta sensing circuit coupled to the first base, the first collector, the second base, and the second collector, and configured to measure a first current gain of the first bipolar junction transistor, generate a first control signal based on a value of the first current gain, measure a second current gain of the second bipolar junction transistor, and generate a second control signal based on a value of the second current gain;
• at least one reference control circuit configured to receive the first control signal and the second control signal, adjust a first operation parameter of the first bipolar junction transistor based on the value of the first current gain, and adjust a second operation parameter of the second bipolar junction transistor based on the value of the second current gain;
• and
• an output path coupled to the integrated circuit and configured to provide the amplified radio-frequency signal.

An amplifier biasing method, the method comprising:

• sensing at least one of a voltage value and a current value at each of a collector and a base of at least one bipolar junction transistor integrated within a radio-frequency signal path of an output stage of a radio-frequency power amplifier;
• determining a current gain of the at least one bipolar junction transistor based on the at least one of the voltage value and the current value at each of the collector and the base;
• generating a control signal based on a value of the current gain of the at least one bipolar junction transistor;
• and
• adjusting an operation parameter of the at least one bipolar junction transistor based on the value of the current gain responsive to receiving the control signal.