Measurement and analysis of electromagnetic pulses due to indirect ESD

Abstract

Abstract Electrostatic discharge (ESD) usually is accompanied by two phenomena: the injection of discharge current, and the radiation of electromagnetic pulses. The discharge phenomenon can cause transient electrical interference of electronic equipment and the time‐domain measurement of radiated fields associated with ESD is a difficult task because of the very fast and wide‐band waves involved. This paper describes measurement and analytical results of ESD pulses. ESD pulses were measured by three EMI‐type antennas (a loop antenna, a biconical antenna, and a double‐ridged guide antenna) in the time domain. It is shown that the electromagnetic pulses can be evaluated by the energy spectrum without using the phase information of antenna factors. Based on the measurement of waveforms of the known electromagnetic pulses, it is shown that the waveform can be evaluated with an accuracy of 2 to 6 dB. As a result, it was found that radiated ESD energy does not always increase in proportion to discharge voltage and that ESD pulses produced by low‐voltage ESD can cause strong electromagnetic interference.