Design of High-Linearity Mixer-First Receivers for mm-Wave Digital MIMO Arrays
Sashank Krishnamurthy, Lorenzo Iotti, Ali M. Niknejad
Abstract
A 10–35-GHz mixer-first receiver is proposed for use in digital multiple-input–multiple-output (MIMO) arrays. Techniques are proposed to enhance the linearity of such receivers, both at baseband and the RF mixer switches. Techniques to mitigate charge sharing due to local oscillator (LO) overlap are also proposed. Detailed simulation results are provided to illustrate the benefits of these techniques. An integrated circuit prototype is fabricated in 28-nm bulk CMOS and fully characterized. The receiver has built-in programmability to tradeoff gain for linearity. The receiver achieves a peak in-band IIP3 of +14.1 dBm, a peak gain of 14.5 dB, and a noise figure of 12.5 dB, in its nominal setting.