An Automatic Antenna Near-Field Measurement System for Narrow Beam Array Antennas

Directivity Pattern and gain of narrow beam array antennas which have electric large size are hard to be tested in far-field method for almost impossible alignment. In order to solve the problem, an antenna testing system is built. At this system, a probe antenna is loaded on a robotic arm with six dimensions, and the arm is used as an antenna scanning support to drive the probe antenna to move according to the specific trajectory. During the process of moving, amplitudes and phases of aperture-field distribution of AUT (Antenna under Test) are collected by the probe. Then amplitudes and phases of sampling points at the near-field plane are transformed in FFT (Fast Fourier Transform) algorithm method and the pattern of AUT can be obtained. Several array antennas are tested with the system for verification experiments and the system can be proved good for narrow beam antennas measurement.