Research on automatic extraction method of quiet zone index in anechoic chamber

Anechoic chamber is an indispensable measurement environment for antenna, electromagnetic scattering and electromagnetic compatibility measurement. The quiet zone of the anechoic chamber is an important indicator for evaluating the uniformity of the field, which directly affects the performance of the anechoic chamber. Compared with the measurement method used to search the quiet zone, it is a low-cost implementation method to determine the range of the quiet zone of the anechoic chamber by numerical simulation. However, most of the widely used methods are based on the prior knowledge of researchers. Specifically, the approximate range of the quiet zone in the anechoic chamber is first estimated, and then a large amount of planar grid data within this range are calculated to determine the accurate quiet zone. However, this method is time consuming, and the results obtained can only be presented in the form of a two-dimensional plane. In order to overcome these problems, this paper proposes an extraction method based on regional growth algorithm to efficiently and accurately extract the three-dimensional space of the quiet region of the anechoic chamber. The numerical results show that the proposed method can automatically determine the three-dimensional spatial range of the static zone without the needs of prior knowledge, which greatly shortens the solution time of the quiet zone compared with the conventional planar grid based extraction method.