A 223-GHz FMCW Imaging Radar With 360° FoV and 0.3° Azimuthal Resolution Enabled by a Rotationally Stable Fan-Beam Reflector

A mechanically scanned high-resolution 2-D imaging radar system with full 360° field of view (FoV) is presented. The system is composed of a multifunction 222–228-GHz frequency-modulated continuous-wave (FMCW) radar and a moment of inertia optimized 3-D-printed offset reflector antenna. The reflector geometry is made from an
elliptic toroidal
surface which is shown to produce a high-gain fan beam with an 11:1 aspect ratio. The reflector is rotated at speeds up to 10 Hz for high-throughput imaging. The wobble generated by the high-speed rotation is suppressed by optimizing the mass distribution of the reflector body. It is fabricated in-house using a low-cost table-top fused deposition modeling (FDM) 3-D printer. The reflecting surface is metallized with a silver-coated copper paint and processed using simple steps to ensure smoothness and accuracy. The reflector achieves beamwidths of 4.6° in elevation and 0.42° in azimuth, with a peak gain of 38.7 dBi. The 3-dB azimuthal resolution of the radar two-way beam is measured to be 0.3°. The system is tested in real-world scenarios, and the resulting images and videos are of unprecedented quality due to the large area of coverage, high resolution, high speed, and excellent dynamic range. To the best of our knowledge, this is the first demonstration of a compact radar system that is comparable in resolution, speed, and angular coverage to lidars, while offering higher dynamic range and immunity to severe weather and lighting conditions.