Patent ID: 7332963

Claim:
A low noise amplifier comprising: a first variable resistance; at least a first circuit block capable of amplifying a first voltage signal that is input to the amplifier, the first circuit block having at least one first terminal coupled to a first supply voltage by the first variable resistance, at least one second terminal coupled to a second supply voltage by at least one resistor, and at least one further terminal that receives the first voltage signal; at least one output terminal of the amplifier, the at least one second terminal being coupled to the at least one output terminal of the amplifier; a feedback network coupled to the at least one output terminal of the amplifier and to the at least one further terminal of the first circuit block; and a second circuit block coupled between the second supply voltage and the at least one further terminal of the first circuit block, the second circuit block being adapted to compensate for variations in value of the first variable resistance so as to ensure a substantially constant input resistance of the amplifier.