Patent ID: 6603347
Filing Date: 2003-08-05
Classification: H03F

Abstract:
A method of amplifying a low noise RF communication signal by applying the signal to an amplifier circuit comprising:receiving the signal by a circuit input; receiving the signal from the circuit input by a gain stage, the gain stage having an inverter including an inverter input, the gain stage comprising first and second MOS transistors; providing first and second supply voltages to the first and second MOS transistors, respectively, the first and second MOS transistors being connected between the first and second supply voltages, providing an inverter output current by an inverter output to a load circuit, the inverter output current corresponding to a circuit input voltage, the load circuit comprising a first resistive element, the first resistive element comprising at least a third MOS transistor, connected to the inverter output and to the first supply voltage; providing, by the load circuit, a voltage output corresponding to the inverter output current; applying a first voltage, by a first voltage source, to a gate of at least a fourth MOS transistor such that the fourth MOS transistor operates in a linear region, the fourth MOS transistor having a drain and source terminals connected between a circuit output and the circuit input, the fourth MOS transistor operating as a second resistive element and being comprised in a feedback circuit; determining the active input impedance of the amplifier circuit; and adjusting a feedback resistance of the feedback circuit such that the active input impedance of the amplifier is set to a required value.