Simulation of the EMP Coupling to Circuits inside a Shielding Box by a Wire Penetrated with an Aperture

The finite difference time domain (FDTD) method is used to simulate the electromagnetic pulse (EMP) induced interference current in circuits inside a shielding box by a wire penetrated with an aperture. Results show that penetrative wire can make the induced interference current in circuits increase greatly, the wire's length and incidence angle of the EMP both have significant influence on the interference current. We also proposed a simple method that using a metal ferrule for suppressing the interference current'.

1 Introduction

With the incessant development of the electronic technology, the integrated level of the circuits is increasing and its working voltage is lower and lower, which increase the sensitivity of the circuit to EMI and thus requires better anti-interference working environment. Generally, sensitive electronic apparatus and circuits are usually shielded the external interference EMP with a metal shielding box.