A Dual-Band Low-Noise CMOS Switched-Transconductance Mixer with Current-Source Switch Driven by Sinusoidal LO Signals

A dual-band low-noise switched-gm active mixer is proposed with a current-source switch stage. Large sinusoidal LO signal driving is used to avoid the traditional RF port noise transferring by LO harmonics. An LC resonance tank structure is exploited to mitigate the high-frequency limitation by the tail parasitic capacitances charging and discharging behavior. Implemented in a 65 nm CMOS process, the proposed mixer prototype operates at an RF dual-band of 2.4/5.2 GHz and provides a maximal conversion gain of 11.2/11.6 dB and IIP3 of 6.7/5.5 dBm. For 5.2 GHz LO, the dual side-band noise figure (NF) of 4.3/3.3 dB is measured at fIF=10/200 MHz, respectively. The mixer core only consumes 8.4 mW from a 1.2 V supply voltage.