Research on Automatic Calibration Method of Transmission Loss for Millimeter-Wave Radar Testing System in Intelligent Vehicle

The millimeter wave radar test system has been widely used to test the performance of vehicle radar, but the test system has transmission loss caused by the radio frequency cables and the free space, and is required to calibrate the transmission loss of the millimeter-wave radar test system regularly to ensure accuracy and reliability of the radar performance measurement. An automatic calibration method for transmission loss of millimeter wave radar test system is proposed based on the combination of antenna substitution method and virtual instrument control technology in this paper. A calibration system is established based on LabVIEW to verify the proposed automatic calibration method. The frequency range of the calibration system is up to (76 ~ 81) GHz, and the frequency space is up to 10MHz. The calibration results show that the automatic calibration method saves 73 % of the test time-consuming compared with the traditional manual calibration method, which can satisfy the calibration requirements of MMW-RTS with the full frequency range of vehicle MMW radar, and verify that the automatic transmission loss calibration method based on the combination of antenna substitution method and virtual instrument control is a reasonable, feasible, efficient calibration method.