Low power, highly linear folded mixer employing a multiple gated transistor approach for linearity enhancement

This paper presents the design of a low power and a highly linear folded down-conversion mixer, for wideband applications, implemented in a 65nm CMOS process. Post-layout simulation results are presented. The proposed multiple-gated transistor (MGTR) based mixer achieves a linearity enhancement of 12.68 dB when compared to a conventional folded single balanced mixer operating at an input radio frequency (RF) range of 10.25~13.75 GHz (direct conversion), with a fixed local oscillator (LO) frequency of 12 GHz and a corresponding intermediate frequency (IF) ranging from dc~1.75 GHz. The proposed mixer combines the advantages of both gm3 cancellation and low output impedance in order to maximize linearity without employing a tuned load, hence not limiting the performance of the mixer to narrowband applications.