电磁脉冲对数字电路的辐照效应研究

为研究电磁脉冲对数字电路的辐照耦合规律,介绍了雷电电磁脉冲的模拟装置并以某装备上信息处理的串行数据分配电路为试验研究对象,研究了电磁脉冲辐射场对数字电路的辐照效应,通过改变场的强度、极性、被试器件的类型等试验条件,探讨了电磁脉冲对数字电路的耦合规律。试验结果表明:影响电磁脉冲对电路的辐照耦合的因素有场的强度、接收天线形状、器件电路的内部结构与阻抗特性、设备或系统在电磁场中的方向、以及线上的信号(即高或低电平信号)等。

Study on Radiation Effects of EMP on Digital Circuits

Lightning EMP (LEMP) is a type of natural source of electromagnetic disturbance. EMP can couple in electronic system and devices by electric lines and circuits, and such disturbances reach device terminals in form of transient voltages or currents. Devices can't normally work due to these disturbances, these disturbances even make devices latent failure or hard damage. So this paper studies coupling rules of LEMP to digital circuits. At first, the LEMP simulation setup is introduced. The simulation setup is composed of lightning surge generator and parallel plate transmission cell (PPTC). A serial data-distributing circuit is taken as an experimental object, and the coupling of EMP to digital circuits is studied. A signal line in digital circuit is made in rectangular shape to receive radiation disturbances, and the disturbances are generated by a NAND-gate device. By changing strength and polarity of EMP field, direction and position of object in field and NAND-gate type in radiation experiments, coupling rules of EMP to digital circuits are discussed. The experimental results show that the voltage wave gained by the NAND-gate device is an attenuation oscillating wave, which is relative with the rise-time of field pulse and field strength, etc. The rise-time of field pulse is shorter, or the field strength is higher, the oscillating amplitude of coupling voltage is higher. The coupling voltage is also influenced by input impedance of devices. The input impedance is higher; the voltage device received is higher, so different devices receive different coupling voltage. When signal on the input port is in different status (high level or low level), coupling voltage is different. The induced voltage is higher when signal is in low level. The factors which influence on the radiation coupling of LEMP on digital circuits also include shape and size of equivalent antenna, equipment direction in fields, and so on.