Abstract: In order to meet the requirement of antenna calibration accurately with frequency range (110~170)GHz,An antenna plane near-field measurement system based on robot automatic scanning is designed.The system is composed of a vector network analyzer,spread spectrum modules,mechanical arm scanning frame,small optical platform and a scanning probe etc.Parameters of measurement setting and scanning trajectory control of manipulator are realized by testing software.The amplitudes and phases of test points on the scanning surface are collected by software,which is calculated using Fourier near-far field transformation algorithm.Then the antenna gain directivity pattern is obtained.A standard gain horn as an antenna under test is tested by the antenna planar near-field measurement system.The results are very consistent with those measured in far-field method and the maximum deviation of the main lobe pattern is 0.25 dB.

Key words: Plane near-field measurement, Antenna directivity pattern, Mechanical arm