A 94-GHz 4TX–4RX Phased-Array FMCW Radar Transceiver With Antenna-in-Package

A 94-GHz phased-array transceiver IC for frequency modulated continuous wave (FMCW) radar with four transmitters, four receivers, and integrated LO generation has been designed and fabricated in a 130-nm SiGe BiCMOS technology, and integrated into an antenna-in-package module. The transceiver, targeting gesture recognition applications for mobile devices, has been designed using phased-array techniques to reduce the total DC power while still maintaining the required link budget for FMCW operation. The complete array achieves state-of-the-art for W-band per-element power consumption of 106 mW per TX element and 91 mW per RX element, and measurements indicate a per-element output power of 6.4 dBm and single-sideband noise figure of 12.5 dB at 94 GHz. The array is able to achieve a beam steering range of ±20° while maintaining at least 3 dB main lobe to side lobe levels. The complete chip-antenna module has been tested to characterize basic FMCW radar functionality. Initial radar experiments suggest a sub-5-cm range resolution is possible with 3.68 GHz RF sweep bandwidth, which is in line with theoretical predictions.

I. Introduction

Highly integrated millimeter-wave (mm-wave) transceivers, enabled by advances in CMOS and SiGe BiCMOS process technology over the last decade, have found what is seemingly a perfect niche in automotive radar. With many gigahertz of absolute bandwidth available, and a compact antenna size due to the small wavelength at mm-wave, the W-band matches up well with the requirements for adaptive cruise control and similar technologies [1]. The development of mature low-cost SiGe and CMOS technologies with and of 150 GHz and beyond has brought down the cost of such driver-assist technology and with it, widespread adoption.