Distance Measurement Using mmWave Radar: Micron Accuracy at Medium Range

This work provides a proof-of-concept for linear-position sensor using an ultrawideband (UWB) frequency-modulated continuous wave (FMCW) radar system operating at 126–182 GHz. It is the first to show environmental compensated and calibration-free distance measurements with micron accuracy medium range millimeter-wave (mmWave) technology. We addressed hardware imperfections, parameter estimation, free-space path, i.e., refractive index near-field effects. The proposed signal processing chain robust interference of low computational cost. Experiments reveal systematic error $\pm 1~\mu \text{m}$ over 4.8 m (0.8–5.6 m), random minimum 30 nm, providing very high sensitivity.