A 77-81 GHz FMCW MIMO Radar with Linear Virtual Array Enabling 3D Target Localization by Use of Frequency-Steered TX Antennas

In this paper, an FMCW MIMO radar is presented which is capable of determining the three-dimensional location of targets even though it has a linear virtual array. The compact system is based on two cascaded radar transceiver ICs, which provide a total of 48 virtual channels. With these channels, a direction of arrival estimation is performed to determine the azimuth angle. To overcome the spatial limitation of the linear array, frequency-steered TX antennas are used which vary their main beam direction during the frequency chirp, allowing the elevation angle to be determined. In this paper, the system’s concept and the corresponding signal processing is presented. The ability to separate adjacent targets in both the azimuth and elevation planes is investigated by various measurements.