Analysis of site attenuation for spherical dipole antenna and its application

Spherical dipole antenna has been used to evaluate EMC performance because it can consider small dipole source. In this paper, site attenuation of spherical dipole antenna is calculated using wire grid model. It is also measured in semi-anechoic chamber for 3m distance, and the result indicates the deviation between calculation and measurement result is within 4dB from 30 MHz to 1000 MHz. The site attenuation distribution is measured in a small semi-anechoic chamber and compared with the measured one. The result indicates that the large reflection loss absorber is effective to improve the performance of the site and the site attenuation is improved when transmitting and receiving antenna place at line unsymmetrical position.