Patent ID: 7295061
Filing Date: 2007-11-13
Classification: H03F

Abstract:
1. A circuit, comprising: a controller to generate a first control signal and a second control signal for configuring a gain; an adjustable modulation resistance network, in communication with the controller, to receive and modulate an input signal to produce a modulated signal, the adjustable modulation resistance network varying an input resistance, which includes a first switch resistance, responsive to the first control signal; an amplifier having an input and an output and in communication with the adjustable modulation resistance network, the amplifier in communication to receive a direct current offset signal; an adjustable feedback resistance network, in communication with the controller and the amplifier, the adjustable feedback resistance network varying a feedback resistance, which includes a second switch resistance, the feedback resistance being substantially inversely proportional to the input resistance, to make the gain substantially independent of the first and second switch resistances; a suppression circuit, in communication with the input and the output of the amplifier, to produce a feedback signal such that a gain bandwidth associated with the amplifier is substantially independent of the direct current offset signal; a demodulator, in communication with the amplifier, to demodulate the output signal associated with the amplifier so as to restore a substantially original frequency of the input signal; and a filter, in communication with the demodulator, to remove low frequency noise associated with the output signal.