Amplifier using a follower transistor

An amplifier comprising:

• a biasing circuit;
• a transistor called a follower transistor, having its collector connected to a first supply potential and its emitter connected to a second supply potential by a current generator, the follower transistor delivering, at its emitter, an output signal that corresponds to an input signal applied to its base, the following transistor being biased by the biasing circuit;
• wherein the biasing circuit includes:
• a transistor called an image transistor, the emitter current of which, called an image current, is a replica of the emitter current called the emitter bias current of the follower transistor, the emitter bias current and the image current going through the current generator;
• and
• means for injecting into the base of the follower transistor a current constituting a replica of the base current of the image transistor;
• wherein said amplifier further comprises a third transistor and a fourth transistor mounted in common collector mode, the bases of said third and fourth transistors being connected to the collector of the image transistor, the emitter of the third transistor being connected to the base of the image transistor and the emitter of the fourth transistor being connected to the base of the follower transistor.