A Low Voltage Mixer With Improved Noise Figure

A 5.2 GHz low voltage mixer with improved noise figure using TSMC 0.18 mum CMOS technology is presented in this letter. This mixer utilizes current reuse and ac-coupled folded switching to achieve low supply voltage. The noise figure of the mixer is strongly influenced by flicker noise. A resonating inductor is implemented for tuning out the parasitic components, which not only can improve noise figure but also enhance conversion gain. A low voltage mixer without resonating technique has also been fabricated and measured for comparison. Simulated results reveal that flicker corner frequency is lowered. The measured results show 4.5 dB conversion gain enhancement and 4 dB reduction of noise figure. The down-conversion mixer with resonating inductor achieves 5.8 dB conversion gain, -16 dBm P_1dB, -6 dBm IIP₃ at power consumption of 3.8 mW and 1 V supply voltage.