Lightning Attachment Behavior of Metamaterial Plate From Lightning and Switching Impulse Discharge Tests

Electromagnetic metamaterials have excellent electromagnetic properties, and can be widely used in radome, which, however, might suffer from damage by lightning in thunderstorm days. Here, using lightning and switching impulse discharge tests, we investigate the lightning attachment behavior of the equivalent plate for radome. We examine the influence of the metamaterial type, the spacing of diverter strips, polarity and waveform of the impulse on the lightning attachment behavior by observing the streamer development and statistics of the lightning attachment counts. As expected, the lightning protection effectiveness of diverter strips for metamaterial plates is worse than that for conventional dielectric plates, and the protection effectiveness decreases as the spacing of diverter strips increases. Unexpectedly, the lightning attachment behavior do not differ too much between metamaterial plates with diverse metal microstructure units. Moreover, the polarity of the impulse and the voltage waveform are found to have a remarkable influence, suggesting that the impulses with a positive polarity or longer durations are more likely to attach to the metamaterial plates. The results offer theoretical insights into optimizing the lightning protection for metamaterial radomes.