Immunity of a twisted-wire pair above the perfectly conducting ground plane is developed. Line equations for externally excited two-wire lines are derived for balanced and unbalanced modes. By the use of equivalent representations for externally excited transmission lines, the effects of external electromagnetic fields to the twisted-wire pair are described : these effects decrease with decreasing twist-pitch for balanced mode, though, no advantage for unbalanced mode.
The major cause of the interference, occurring in the Kyushyu and the Sanin districts, by TV or FM broadcast wave from the southern part of Korea is discribed in this report. According to the analysis of meterological data near the propagation path and to the obserbation of interference level at Dazaifu city in Fukuoka prefecture, reflection at refractive index boundaries is the main reason of the interference in these areas. Some methods to forecast the interference are also included.
1984 International Symposium on Electromagnetic Compatibility was held on Oct. 16-18 at Hotel Pacific, Tokyo, jointly sponsored by the Thechnical Group on EMC of the IECE, the IEE of Japan and the EMCS, the EMCS Tokyo Chapter of the IEEE. Five hundred and twelve specialists came from 23 countries attended this Symposium. Many discussions and exchange of information were made not only in the session rooms but also at the lobby outside. The first Symposium on EMC held in Japan was thought to be very successful. At the same time, 31 companies exhibited many measuring equipments, parts, and materials relating to EMC.