Millimeter-wave range radars have gained huge attention last few years due to its wide variety of applications. IMEC with ETRO-VUB students has designed automotive radars operating at 79 GHz and is now extending its application to the indoor environment. The indoor radars can be utilized not only for industrial applications but also for human-oriented detections such as presence of people in a room, detection of heartbeat and gesture recognition.
The waveform of the modern mm-wave radar is a modulated continuous wave. By using constant-envelope modulation such as frequency or phase modulation, the peak-to-average power ratio of the time-domain waveform becomes low, which is opt for a highly efficient transmitter. The time delay and doppler shift from the received signal provide a distance and speed information of targets, respectively. The angular information can be achieved with the help of multiple antennas steering the antenna pattern. The range resolution of the radar is determined by the bandwidth as the resolution is equal to c/BW/2. The existing ISM band from 57 GHz to 66 GHz together with the recently opened spectrum range from 64 GHz to 71 GHz for unlicensed use enable 14 GHz bandwidth corresponding to 1 cm resolution.
The goal of this PhD research is to make a CMOS-based mm-wave radar operating at 57-71 GHz range. The design focus is on the RF and analog circuitry of the transmitter. As the transmitter consumes more power than receiver, the emphasis is placed on the highest efficiency and lowest power consumption, while fully exploiting the required bandwidth of 57-71 GHz.