Design and realization of a planar near field antenna measurement system

Determination of the radiation pattern is one of the major issues in antenna characterization. Radiation pattern is a far field parameter and it must be measured at a point where wave trains are propagating in same phase. Although this range can be obtained inside a laboratory for isotropic antennas, in case of high gain directive antennas it can well extend to several tens of meters. Radiation pattern measurement using near field approach is possible for the latter case, even inside a small-scale laboratory. Nevertheless, since the design and the realization of near field antenna measurement systems require detailed engineering activities compared to that of far field systems, their costs are fairly high. In order to obtain a low-cost, maintainable and native near field antenna measurement system, an engineering study was conducted in TUBITAK BILGEM UEKAE EMC Laboratory and a near field measurement system was developed. In this article, antenna patterns measured by the developed system are presented.