Amplifier circuit, bi-stage amplifier circuit, multi-stage amplifier circuit, RF-amplifier circuit, receiver section, RF-transceiver, and integrated circuit

A method of operating an amplifier circuit, the method comprising:

• applying a first input signal to a first input terminal, the first input terminal connected to a first control terminal of a first transistor and coupled to a fourth control terminal of a fourth transistor with a first switch, wherein the first transistor controls a first current between a first supply terminal and a first output terminal;
• applying a second input signal to a second input terminal, the second input terminal connected to a second control terminal of a second transistor and coupled to a third control terminal of a third transistor with a second switch, wherein the second transistor is coupled to the first output terminal and controls a second current between the first output terminal and a second supply terminal, the third transistor controls a third current between the first supply terminal and a second output terminal, and the fourth transistor is coupled to the second output terminal and controls a fourth current between the second output terminal and the second supply terminal;
• and
• operating the first and second switches to control a gain of the amplifier circuit, wherein the first and second input terminals are distinct, and the first and second input signals are different such that a differential is applied to the first and second input terminals.