Miniaturized Designing of a High Current Symmetric High Altitude Electromagnetic Pulse (HEMP) Filter

Abstract

In this study, the world's smallest symmetric high current (1,250 A) high-altitude electromagnetic pulse (HEMP) filter was fabricated and its performance was demonstrated. The filter was separated from all lines and made of a non-magnetic material to prevent the proximity effect and Joule heat caused by eddy current. The size of the filter was miniaturized by designing the core with a material with low residual magnetic flux. In the case of the shielding effectiveness (SE) test, 100 dB was attenuated from 400 MHz to 18 GHz and measurement of insertion loss, the\ MIL-STD-188-125-1 standard was met from 10 kHz to 1 GHz. The pulse current injection (PCI) short pulse test met MIL-STD-188-125-1 with a residual current of 6.04 A, maximum current arrival time of 6.00×10 5 A/s, and root action of 4.18×10 −2 A   , and the intermediate pulse test also showed no damage or performance degradation in filter performance. Finally, in the load test, the average temperature rise of the bus bar was 45.5 K until it was saturated by applying 1,250 A, proving its performance.