Abstract:
According to requirement of electromagnetic compatibility in European Norm EN 301 489-1, mine-used personnel location system must pass radiation emission test when it is applied in foreign countries. For the requirement, radiation emission test for mine-used personnel location system was carried out, and causes of radiation noise was analyzed. The following rectification scheme was put forward: for the radiation emission caused by the clock signal, shorten the length of clock signal line during PCB routing, reduce the number of vias, increase the alignment width and line spacing, and laying ground wire on both sides to shield, so as to reduce return area of clock line; for different clock circuits, low-pass filter, common mode suppression and other measures were adopted to reduce radiation signal transmission. Tests results show that the maximum peak frequency power of the personnel location system after the rectification is 13.086 dB lower than requirement of EN 55032 standard CLASS A and 3.086 dB lower than the requirement of EN 55032 standard CLASS B, which can meet the export requirements.