Low consumption multi-stage amplifier, and a vehicle onboard signal receiver having such an amplifier

A multi-stage amplifier of low current consumption, such as an onboard receiver for a motor vehicle for receiving telecontrol systems for opening the doors or interrogation signals for the alarm system of the vehicle, has the polarising networks for the amplification stages connected in series in such a way as to reduce the power consumption of the circuitry in the static state. The amplifier stages are connected in series on the polarising bridge in the static state, and in the dynamic state they are connected in cascade. The output of the first stage is connected to the input of the next stage through an impedance matching reactance. In another aspect, gain is controlled by injection/extraction of current between the output terminal of the amplifier and an injection/extraction terminal on the input of the first stage.