A 76–81-GHz Four-Channel Digitally Controlled CMOS Receiver for Automotive Radars

This paper presents a fully-integrated 76-81 GHz four-channel digitally controlled receiver (RX) in 65-nm CMOS, which utilizes a four-channel RX front-end with high linearity, an LO distribution network, and a reconfigurable 4-channel analog baseband (ABB). It achieves high integration level and is capable of flexible reconfigurability automotive radars with wide and flattened temperature characteristic. Each RX front-end consists of a low noise amplifier (LNA) employing a neutralized common source (CS) with configurable high-linearity and an active mixer with linearity-priority design. Additionally, a bias circuit with positive temperature coefficient is used for temperature compensation of the millimeter wave (mm-Wave) amplifiers and mixer. The RX chain offers tunable gain and bandwidth (BW) with digital control and bandwidth tuning for the ABB. The measured results show that the RX achieves an input 1-dB compression point (P
_in,1dB
) of -7 dBm and a noise figure of 11-26 dB across a temperature range from -45 to +125°C, both over the range of 76-81 GHz. The RX has a tunable gain from 18 to 66 dB over the 3-dB programmable IF BW from 0.1 to 10 MHz. The power consumption of the entire receiver is 0.52 W.