A low voltage 0.8V RF receiver in 28nm CMOS for 5GHz WLAN

Abstract

This paper presents a low voltage 5GHz WLAN receiver (RX) with 0.8V power supply. The RX targets 802.11ax standard implemented in CMOS technology node from 28nm to 14nm whose power supply voltage will decrease to 0.8V. The RX presents three key techniques that overcome the challenges for the low voltage operation. An RF amplifier employs a variable source degeneration to improve the linearity. A quadrature demodulator adopts a low noise biasing technique to obtain sufficiently high overdrive voltage in a passive mixer. A 3-stage feedforward operational amplifier increases the gain within 40MHz bandwidth. The RX was fabricated in 28nm CMOS process. The measurement results show the gain from −2 to 54dB, 4.3dB of NF, and −36.1dB of EVM with VHT80 256QAM when the power supply voltage is 0.8V. The presented RX achieves low voltage operation while maintaining sufficient WLAN performances.