Two-Path 77-GHz PA in 28-nm FD-SOI CMOS for Automotive Radar Applications

Abstract

This paper presents a 77 GHz two path power amplifier (PA) for automotive radar applications. It was fabricated in 28-nm fully depleted silicon-on-insulator CMOS technology, which provides transistors with a transition frequency of about 270 GHz and a general-purpose low cost back-end-of-line. The proposed PA consists of a 50 Ω input buffer followed by two power units, which are made up of a current-reuse common source driver for improved efficiency and a stacked cascode power stage for enhanced output power. A peak detector was also embedded into the PA for output power monitoring. The designed PA achieved a saturated output power as high as 17.4 dBm at 77 GHz with an excellent power added efficiency of 19%, while drawing 150 mA from a 2 V power supply. The core die size was 500 μm × 300 μm.