Research And Design Of Source Field Measurement System For Array Antennas

With the development of the mobile communication network applications, base-station antennas widely use multi-systems antenna and MIMO array antenna, and the number of mobile communication array antenna unit is increasing. So it’s more and more difficult to design the base-station antennas. Moreover, the performances of antenna must be assessed and verified by pattern measurement. Accordingly, the antenna measurements will be increasingly complicated. While the source field measurement equipment needed is simpler, the measurement site needed is smaller, and the radiating element can be checked easilier, so research and design of such measurement system is significant.This paper reviews the history of development of antenna measurements since 19 th century and introduces the research situation both in China and abroad, then discusses the basic principle and key technology of the source field measurement system. In case of the best performance between the dipole and the probe, we designs the dual-frequency source field probe, and improve the performance of the probe further. Due to the little literature of source field probe specification, a verification experiment on the detection principle is designed.Then the pattern array factors are extracted by the probe, and we extract the simulated element pattern in an array to draw the array antenna pattern. Comparing the differences of the measured pattern between the far-field and source field, we make a simple analysis in this paper, and it is proved that this system can realize the high efficiency and accurate measurement on the antenna pattern measurement.At last, the paper analyzes three main error sources in the source field system in detail such as the assemblage error between the dipole and the probe, the amplitude and phase error outgoing wave coefficient and the interference error of test fixture. Through the simulation and experiment, the effects of three main error to the source field measurement results are analyzed, and come to some useful conclusions.