TECHNIQUE FOR ESTIMATING ELECTROMAGNETIC-FIELD DISTRIBUTIONS IN AND AROUND BUILDINGS USING WIRE-GRID APPROXIMATION

The technology to derive analytically the electromagnetic field distri bution inside and outside a building by the electromagnetic interferen ce caused by electronic equipment and from external illegal CB has bee n an important subject of study for establishment of the protection of damages to equipment. In this paper, the building as a complex config uration is approximated by a wire-grid model considering its steel fra me construction. The electromagnetic field distribution inside and out side the model is analyzed numerically by the moment method so that th e distribution of the electromagnetic interference around the building is derived. First, for a model of a simple building, the calculated a nd measured electric field intensity values are compared. They agree w ithin a maximum deviation of 3 dB in the frequency range of 30 MHz to 1 GHz. The effectiveness of the calculation method and the resonance c haracteristics of the building model have become clear. Next, an actua l building (Telecommunication Center Building) was modeled and the cal culated and measured values of the electric field intensity in the mod el were compared, The calculated and measured results agreed within a maximum deviation of 5 dB in the Frequency range of 30 to 200 MHz so t hat the validity of the present estimation method was confirmed. Also, the frequency characteristics of an actual building have become clear .