A 5.8-GHz Short-Range PMCW Radar with a Sub-Bit Super-Resolution Correlator for Enhanced Range Estimation

Short-range radars at 5.8 GHz ISM band have only 150 MHz licensed bandwidth, which corresponds to 100 cm wide range bins. In this work, we propose a phase-modulated continuous wave (PMCW) radar with a sub-bit super-resolution correlator that shifts the reference code sequence by 0.2 bit to generate a 5-times oversampled range profile. In addition, we develop a target-fitting algorithm to further improve range estimation properties. In the proof of concept design, we demonstrate a 5.8 GHz radar with a 40-MS/s 255-bit pseudorandom binary phase shift keying (BPSK) code sequence. The radar can estimate the target from 0 to 3.75 m range with 15 cm wide range bins, which has been downsized by a factor of 25 compared to the conventional PMCW radars.