FMCW Radar Post Processing Method for Small Displacement Detection

A conventional Frequency Modulated Continuous Wave (FMCW) radar needs a large bandwidth in detecting a small displacement with millimeter scale. Phase data processing usually was implemented to avoid the needs of large bandwidth in radar system. Many implementations of phase detection in FMCW, generally utilized the IQ demodulation that placed at radio frequency (RF) circuit which a significant change is needed in RF circuit part. This paper proposes a method of advance post processing method in FMCW radar for small displacement detection. In the proposed method, IQ demodulation is performed at computation domain to minimize the change in RF hardware meanwhile the beat frequency detection using Fast Fourier Transform (FFT) still elaborate in the proposed post processing to detect the initial position of the target. Theoretical and simulation analysis has performed to investigate the ability of proposed method and the results show that the proposed method is able to detect a small displacement in millimeter scale without increasing the FMCW bandwidth and modification in RF hardware.