A feedforward linearization technique implemented in IF band for active down-conversion mixers

摘要

A feedforward linearization technique to cancel the third-order intermodulation (IM) of the down-conversion mixers is proposed, in which a low-frequency second-order intermodulation tone (IM) is created and multiplied by the mixer's output to generate the IM tones for the cancellation. The proposed linearization technique is applied to an active mixer operating at 2 GHz. Fabricated in a 0.13-μm CMOS process and operated at 1.2 V supply, the mixer with a unit-gain IF amplifier in series delivers 8.5 dB gain and 2.5 dBm IIP without linearization. The linearization technique achieves 12-dB IIP3 improvement with negligible gain reduction, less than 0.2 dB of noise penalty and an extra current of 4.2 mA.