Method of Predicting Disturbance to TV Signal Reception Caused by Information Technology Equipment(Special Issue on Recent Progress in Electromagnetic Compatibility Technology)

A method of predicting disturbances to TV signal reception hasbeendeveloped inorderto workout countermeasures for interference caused by unwanted emissions from information technology equipment (lTE). The prediction parameters were determined by measuring theemission levels fromITEat an opentest site, propagation characteristics of unwanted emissions fromITEin a building, the output power of the TV transmitting station, the propagation characteristics of theTV radio waves, and the directivity of theTVreceiving antenna. Thepossibility of disturbances occurring in the Kanto areawaspredicted and theresults showthat,in the worst case,a disturbance willappearin about II % of the areaswithin 30 m of a building containingsuch equipment. This also shows that the disturbance can be suppressed by improving the shielding of the equipment or building by as littleas 10dB. key UJora.s: EMC, emission, TV disturbance