Journal Article

A mm‐wave LNA employing current re‐use and non‐linearity cancellation in 28 nm CMOS for automotive RADAR and 6G receivers

Khan, Barha, Rahman, Mustafijur, Kalita, Ellora

2024

Overview

This letter reports an 85 GHz low noise amplifier (LNA) employing derivative superposition based non‐linearity cancellation and a current re‐use topology. The LNA employs a two‐stage stacked architecture, each featuring neutralized differential pairs utilizing the same DC current. In derivative superposition, an auxiliary branch consisting of neutralized differential pairs cells is added in the LNA in parallel to stage 1 to ensure non‐linearity cancellation. Layout‐based capacitive neutralization is implemented to improve GMAX, resulting in simplified routing, reduced parasitics, and a more compact layout. The proposed LNA is fabricated in TSMC 28 nm CMOS process and achieves a peak gain of 8.4 dB at 84.2 GHz with a measured 3 dB bandwidth (BW3dB $\\text{BW}_{3\\text{dB}}$ ) from 79.4 to 92 GHz. The minimum measured noise figure is 12.8 dB. The LNA draws 34 mA of DC current from a 1.2 V supply. The highly linear LNA with IIP3 +6.5 dBm is tailored for automotive RADAR and 6G receivers. A high‐performance 85 GHz stacked low noise amplifier is presented, featuring derivative superposition based non‐linearity cancellation. The two‐stage stacked architecture incorporates neutralized differential pairs with an auxiliary branch in parallel to stage 1 for non‐linearity cancellation. Implemented in TSMC 28 nm CMOS, the low noise amplifier achieves 8.4 dB peak gain at 84.2 GHz with 12.6 GHz as 3‐dB bandwidth, drawing 34 mA from a 1.2 V supply. With IIP3 of +6.5 dBm, it is tailored for automotive RADAR and 6G receivers.

• Publisher: Wiley
• Subject: derivative superposition / low noise amplifiers / millimetre wave circuits / non‐linearity cancellation