Patent ID: 7710185

Claim:
A CMOS transconductor for cancelling third-order intermodulation of an output current corresponding to an input voltage comprising: a transconductance circuit for generating a first current as a function of said input voltage, said first current having a transconductance gain element and a first third-order intermodulation element, said transconductance circuit comprising a first differential cell having a first and second transistor; a tuneable distortion circuit coupled to said transconductance circuit for generating a second current having a second third-order intermodulation element of opposite phase to said first third-order intermodulation element, said distortion circuit including a second differential cell and a current source; and a controller circuit for tuning said current source of said distortion circuit to adjust said second third-order intermodulation element to substantially equal said first third-order intermodulation element, said distortion circuit and transconductance circuit arranged to sum said first and second currents generating said output current substantially having said transconductance gain element and substantially cancelling said first and second third-order intermodulation elements thereof.