A CMOS Double Balanced Mixer Using Current Bleeding and Negative Impedance Techniques

S. Kumar, H. Shrimali (Indian Inst. of Techn. Mandi, India)

This paper presents an enhanced active Gilbert-cell mixer implemented in 65-nm RF CMOS technology, operating at 4.6 GHz with a 1 V supply. The proposed design employs current-bleeding and negative-impedance techniques to achieve simultaneous improvements in conversion gain, noise figure, and linearity. The negative-impedance network compensates parasitic resistances at the switching stage, enhancing linearity and extending dynamic range, while the current-bleeding path decouples the transconductance and switching stages, reducing flicker-noise upconversion and improving overall performance. Comprehensive PVT corner simulations show a conversion gain of 20 dB and 18.5 dB, NF of 10.1 dB and 12 dB, IIP3 of 8.2 dB and 7.5 dB, and power consumption of 4.78 mW and 5.2 mW at typical and worst corners, respectively. Monte Carlo analysis indicates a mean gain of 32.25 mV with a 1.02 mV standard deviation, confirming strong robustness. The mixer achieves a figure of merit of –8.4 dB, demonstrating an excellent trade-off among gain, noise, linearity, and power efficiency for low-voltage RF receiver front-end applications