Method of predicting disturbance to TV signal reception caused by information technology equipment

摘要

A method of predicting disturbances to TV signal reception has been developed in order to workout countermeasures for interference caused by unwanted emissions from information technology equipment (ITE). The prediction parameters were determined by measuring the emission levels from ITE at an open test site, propagation characteristics of unwanted emissions from ITE in a building, the output power cf the TV transmitting station, the propagation characteristics of the TV radio waves, and the directivity of the TV receiving antenna. The possibility of disturbances occurring in tl-ie Kanto area was predicted and the results show that, in the worst case, a disturbance will appear in about 11 % of the areas within 30 m of a building containing such equipment. This also shows that the disturbance can be suppressed by improving the shielding of the equipment or building by as little as 10 dB.