Calibration of the Self-Radar-Cross-Section of Continuous-Wave Radars

This article presents a calibration method to eliminate measurement errors introduced by the own radar cross section (self-RCS) of continuous-wave (CW) radar systems, which focus on the measurement of relative target motions. By measuring the radar response of an unknown target located at known positions, the proposed procedure retrieves the calibration constants. They allow for eliminating the systematic errors associated with the multiple reflections between the radar device and the target, an effect initiated by the self-RCS. This improves the linearity of the overall transfer function, which enhances measurement accuracy and mitigates nonlinear distortion effects for vibration-sensing applications. The calibration approach is successfully validated by measurements in different conditions. In contrast to conventional techniques that implicitly neglect the self-RCS, the proposed technique achieves a superior and robust accuracy reaching one-thousandth of the operating wavelength.