Research in Electromagnetic Shielding Theory. Part 2. EMP (Electromagnetic Pulse) Simulation Using Small Loops

摘要

The feasibility of an EMP simulator consisting of a high voltage pulse generator driving a small loop antenna is investigated. It is shown that such a simulator could be used to make direct time domain measurements of the shielding effectiveness of small enclosures like the S280C tactical electronics shelter using a method analogous to the frequency domain technique employed in the small loop test described in MIL-STD-285 and IEEE-299. Specifications are given for a simulator that would reproduce the waveform, structure, and polarization of an EMP field over a 4 m2 plane surface with a peak field of 2.7 A/m. The simulator consists of a 2 MV generator with a 0.755 pf storage capacitor and a resistance of 331 ohms driving a 0.3 m square loop formed from conductors with 1 cm radii. In operation, the loop is oriented with its plane perpendicular to the surface of the enclosure and its center 2.5 m from that surface.