US Patent 7542737 Method for reducing the 2

A transconducting device includes at least one transistor having a control electrode for receiving an input signal whose frequency spectrum contains two different frequencies, an output electrode for delivering an output signal, and a third electrode. The transconducting device further includes a voltage source for delivering a DC reference voltage, and a feedback controller for feedback-controlling the voltage on the third electrode to the DC reference voltage using a negative feedback loop. The negative feedback loop includes resistive damping, connects the third electrode and the control electrode, and has an open-loop gain greater than unity at a frequency equal to the frequency separation between the two different frequencies.