Influence of electrode approach speed in variation characteristics of the impulsive ESD noise

Impulsive electromagnetic noise is caused by ESD. Especially, micro gap discharge of less than 1kV produces GHz band width electromagnetic noise. It is thought ESD noise has possibility that affects to various electrical systems. To solve EMC problems, we elucidated a mechanism which ESD noise occurs. We found out the amplitude of electromagnetic noise depended on the size of electrode and applied voltage of the electrode in a previous study. Therefore, we mainly measured the amplitude of electromagnetic noise when we changed the approach speed of electrode by this experiment. Then, the average amplitude and the dispersion of the amplitude tended to increase with the approach speed became fast. On the other hand, the difference between the intermediate value of the amplitude and the average value tended to decrease with the approach speed of electrode became fast. Furthermore, we discovered these changes make logarithmic change by approximating them.