Research On Effect Of Cable Coupling Of NEMP

Nuclear electromagnetic pulse (NEMP) is a very high intensity, very short duration, wide-band frequency radio electromagnetic pulse, coupling to electronic equipments through a variety of ways such as slots, cables, antennas to make them out of order or even get permanent damaged, and therefore, the research of coupling mechanism of NEMP and protection against NEMP is one of hot spots. In this paper, the theory of NEMP coupling and the theory of electromagnetic simulation are introduced. Then the mechanism of cable coupling of NEMP, which is one of the most important coupling ways that NEMP have impact on electronic equipment, is researched in detail by simulation and then verified by experiments.First of all, this paper discusses the theory of nuclear electromagnetic pulse coupling: We describe nuclear electromagnetic pulse waveform of time-frequency domain, and describe the coupling ways and harm of nuclear electromagnetic pulse, then choose the idea of time-domain finite integral algorithm for its advantage to solve the problem of cable coupling.Based on the above theory and algorithm, through modeling and simulation, we analyze the discipline of the cross-wires coupling of nuclear electromagnetic pulse. The results show that: In the case of cross-wires coupling, the energy coupling through cables will be the largest when the direction of electronic field is parallel to cables; the coupling energy is in direct proportion with the length of exposed cable. The energy coupling through slots will be the largest when the direction of electromagnetic waves is parallel to the direction of normal line of slots; the coupling energy is in direct proportion with the area of slots; The energy coupling to cable terminal is inversely proportional to the thickness, the conductivity of the out conductor of cable and the angle between coaxial cable and electric field, and then directly proportional to the resistance value of the cable terminal.After modeling and simulation, we set up the experimental platform for cable coupling of NEMP, and record the voltage data of different length of cable, different resistance value of cable terminal, different angle between the direction of cable and the direction of electronic field. The experimental results show that: The coupling energy of cable terminal is directly proportional to the length of cable and resistance value of cable terminal, and inversely proportional to the angle between the direction of electronic field and the direction of cable. Experimental conclusions and simulation conclusions are mostly the same, except for the amplitude of the voltage on cable terminal and the proportion of high-frequency component. Then, we put forward necessary explain.At last, based on the results of simulation and experiments, we present various protections against the coupling energy from different coupling ways, and especially analyze the protection against the energy coupling from cables.