Switching device used on digital and inverter circuits such as a stabilizer of fluorescent lamp is one of main sources of electromagnetic noise. To make such noise characteristics clear, using a simple printed line model with a TTL IC as a switching device, electric far field noise radiating from that model is measured in an anechoic chamber. It is shown typical results and that noise characteristics can be evaluated by comparing the spectrum and spectrum change of the harmonics of 3 MHz switching pulse using the same switching device. And the characteristics of the electric field noise with PCB thickness and strip line width changed are compared with the magnetic near-field noise measured by a small shielded loop antenna. The results indicate that the electric field noise strength, on the case where the width is 7 mm and the thickness is 0.51 mm, is larger than that on other cases in the range from 50 to 150 MHz. And it is confirmed that the magnetic near-field noise increases as the loop antenna approaches the IC and varies depending on the PCB thickness and the line width. However, the spectral profile of the electric field noise is different from the magnetic near-field noise.
|ジャーナル||IEICE Transactions on Communications|
|出版ステータス||Published - 1997 1月 1|
ASJC Scopus subject areas
- コンピュータ ネットワークおよび通信