The applications of the visual anechoic chamber technique in EMI testing

The application of the visual anechoic chamber system was discussed. A test was designed to validate the effects of the system used in EMI testing. The results were shown that the average level of the ambient cancelled mode was 11.323 dBmuV / m and the effects were influenced by the distance between the device antenna and the background antenna. The coherence of the two antennas may be another factor. When it comes to the background signals whose amplitudes are near to those of the device signals, the effects will become worse. The source localization mode can distinguish the signals having the same frequency but not coming from the same source. By through the coherence coefficient, the spectrum contents of a device can be received and the leaking area of it can be localized.