Amplifier device with gain switching, for a cellular mobile telephone in particular

摘要

An amplifier device with gain switching includes an amplifier, and a configurable load circuit including an inductive element. The configurable load circuit is capable of exhibiting two configurations having two different impedance values. A controllable switch is connected between the amplifier and the load circuit to select one of the two configurations of the load circuit. The load circuit includes two insulated-gate field effect load transistors connected in series, and which operate in a triode mode. The inductive element is connected in parallel with the pair of load transistors, and between a power supply terminal and the switching circuit.