High power microwave susceptibility of IT network components

As an illustration of the threat of high power microwaves (HPM) to critical civil infrastructure we show electromagnetic susceptibility tests of commercial IT network components with HPM pulses in the frequency range between 150 MHz and 3.4 GHz. In our facility field strengths up to 1 kV/m can be achieved at the position of the test objects for pulse lengths between 250 ns and 10 µs and pulse repetition rates between 1 Hz and 10 kHz. The test setup consists of two PCs connected with twisted pair cable over a hub or a switch as typical IT network components. Network traffic is realized by file transfer between both PCs. As an option, a part of the data connection is implemented with fibre optic cable and media converters. The main coupling of fields to network components takes place via attached cabling and is most effective for the lowest frequencies. For the majority of tested equipment failures can be induced already at fields of some 100 V/m for frequencies above 200 MHz and at some 10 V/m below 200 MHz. The use of shielded cables clearly reduces the malfunctions. The media converter can be identified as another important source of failure. Our results give hints on protection measures of IT infrastructure against the HPM threat.