Equivalent Test Method of Low-frequency Strong Magnetic Field on Underground Space

Urban underground space facilities contain a large number of electronic information equipment, which is easily to be interfered by low frequency pulse of strong magnetic field. In this paper, the method of continuous wave equivalent test is proposed to evaluate the influence strong magnetic field affected on underground space, and the scheme of wire antenna close to the ground is adopted. The magnetic field formula of radiation field in underground space is deduced, then the influence of the antenna length, geological conditions and other factors on radiation characteristics are studied. The sample antenna is manufactured by using the layout of symmetrical array, and the radiation characteristics of the antenna in 100m underground space are studied based on the FDTD method.