A K-Band Ultra-Low-Power High-Linearity Down-Conversion Mixer in CMOS Technology

This paper presents an ultra-low-power down-conversion CMOS mixer in 22–32 GHz frequency band. In the proposed mixer, gm boosting amplifiers are used in the fully differential source-driven topology. The transconductance stage is switched by a local oscillator (LO) signal applied differentially crosswise to the sources of the MOS devices. In this way, the output voltage swing, and therefore the linearity of the mixer will be increased. In addition, through this method, the minimum required supply voltage can be reduced. Thus, with lower supply voltage and power consumption, high IIP3 can be achieved. To further reduce current and power consumption, MOS devices are biased in the weak inversion region. Due to the small third-order nonlinearity coefficient of transconductance in the weak inversion region, the possibility of obtaining a larger IIP3 is realized. The presented mixer was designed and simulated using a 0.18-µm RF CMOS process. The post-layout results show a maximum conversion gain of 13.1dB, a minimum noise figure of 15.1dB, a maximum IIP3 of 17.4dBm, and better isolation of 42dB while consuming only 33µW of DC power from a 1V supply.