Patent ID: 6600371
Filing Date: 2003-07-29
Classification: H03F,H03G

Abstract:
A low noise amplifier comprising:a first circuit block suitable for converting a first amplifier input voltage signal into current, at least one input terminal of said first circuit block receiving said first amplifier input voltage; a second circuit block adapted to divide the current coming from said first circuit block, said second circuit block being controlled by a second voltage signal, and said first and second circuit blocks conferring a variable voltage gain to the amplifier; at least one first resistor; at least one second resistor; and a feedback network, wherein said at least one first resistor is connected with at least one first output terminal of said second circuit block and with a supply voltage, said at least one second resistor is connected between said at least one first output terminal and at least one second output terminal of said second circuit block, said feedback network is coupled with said at least one first output terminal and is directly connected to said at least one input terminal of said first circuit block which receives the first amplifier input voltage, so as to obtain a constant input impedance, and said at least one second output terminal is coupled with at least one output terminal of said low noise amplifier.