UCLA researchers in the Department of Electrical and Computer Engineering have developed a frequency-modulated continuous wave radar system that extends chirp bandwidth, leading to higher axial radar resolutions.
There is an increasing demand for simple, high performance silicon mm-wave radar systems for use within the automotive industry. The global automotive sensor market is expected to increase by 21% between 2018 and 2023, with increased need for cruise control, anti-collision detection, and autonomous driving navigation. Frequency-modulated continuous wave (FMCW) systems are the most popular in the automotive radar space because they require lower transmit power compared with alternative approaches. Directly chirped FMCW architecture synthesizers simplify the transmitter and receiver chain while providing an extremely linear and low distortion frequency chirp. Directly chirped synthesizer architecture, however, imposes chirp bandwidth constraints, thus limiting the radar resolution. Therefore, there is a need for FMCW sensors with increased chirp bandwidth that are simple to implement.
UCLA researchers have developed a FMCW radar system that employs a synchronously switched digitally controlled artificial dielectric (DiCAD) to extend the FMCW chirp bandwidth. The DiCAD is synchronously switched at key moments in the reference chirp sequence, which allows the voltage-controlled oscillator to digitally adjust its analog tuning range mid-chirp, therefore providing a wider chirp bandwidth. The invention has been successfully prototyped and demonstrated 3-fold increase in chirp bandwidth with the possibility of further increase in bandwidth compared to existing FMCW systems. The entire radar chip is compact (occupying 2.5 x 1.7 mm of silicon area) and has low power consumption (320 mW of DC power).
Radar W-Band Chirp Extension, Radar Resolution, Chirp Bandwith, Frequency-modulated continuous wave (FMCW) systems, directly chirped synthesizers, Synchronously switched digitally controlled artificial dielectric (DiCAD)