Patent ID: 7737785

Claim:
An amplifier circuit, comprising: an amplifier element having an amplifier element input; an amplifier adjuster adapted to adjust an amplification of the amplifier element; an amplifier circuit input coupled to the amplifier element input; an impedance element comprising a alterable impedance value and being coupled to the amplifier circuit input; and an impedance adjuster adapted to adjust the impedance value of the impedance element as a function of the amplification of the amplifier element; the alterable impedance element being coupled, at a first terminal of the alterable impedance element, to the amplifier element input, and is coupled, at a second terminal of the alterable impedance element, to a ground terminal or a supply voltage terminal; and the amplifier element comprising a field-effect transistor having a source terminal, a gate terminal, and a drain terminal, one of the source terminal or drain terminal being coupled to a load impedance, and the other of the source terminal or drain terminal forming the input of the amplifier element, and the gate terminal of the field-effect transistor being coupled to a voltage source, and the amplification adjuster being further adapted to generate an amplification adjustment signal and to adjust, as a function of the adjustment signal, an operating-point current of the field-effect transistor and, thus, the amplification of the amplifier element, and the impedance adjuster being further adapted to receive the amplification adjustment signal, and to adjust the impedance value as a function of the amplification adjustment signal received.