A 94GHz 3D-image radar engine with 4TX/4RX beamforming scan technique in 65nm CMOS

Millimeter-Wave and sub-THz imaging sensors have been demonstrated in CMOS technology recently. Mechanical scanners are still required to capture the whole image, making the systems bulky and costly. The limited resolution of the third-dimension (z-direction) also leads to a vague 3D picture. Other 2D solutions need not only focal lens, but large chip area to accommodate more pixels. This paper presents a 94GHz 3D image radar with electronic scanning. Using a 4TX/4RX beamforming technique and a modulated time-of-flight (ToF) algorithm, this prototype achieves ±28° scanning range, 2m maximum distance, and 1mm depth resolution with 960mW of power.