HPEM protection on HF transmission lines

摘要

Traditional protection concepts against electromagneticinterferences are combinations of nonlinear elementslike spark gaps, varistors or suppressor diodes. Dueto parasitic capacitances and inductivities and the general behaviorof the elements, a trade off has to be made between thefrequency bandwidth and the energy absorption capability ofthe protection circuit. For high frequency applications withsignal frequencies above about 500MHz a sufficient protectioncan not be given without changing the transmitted signalsitself. Additionally this kind of protection concept is designedand optimized against transient interferences with risetimes down to some nanoseconds, for example the LEMP, theNEMP or the ESD. Current researches focus on transient interferenceswith rise times in the picosecond range and pulsewidths of a few nanoseconds, the so called ultra wideband(UWB) pulses, combined with a significant voltage amplitudeof some kilovolts. In this paper investigations on nonlinearprotection elements and linear filters against line-coupledUWB pulses with high voltage amplitudes will be done withspecial focus on the protection of high frequency data-lines.