HPEM and HEMP susceptibility assessments of computer equipment

This paper provides a summary of two susceptibility assessments conducted by the QinetiQ EMC group. The first assessment attempted to understand the susceptibility threshold of commercial off the shelf (COTS) computer equipment to a high power electromagnetic (HPEM), or high intensity radiated field (HIRF) environment. This environment was produced using the mode stirred reverberation chamber technique. The second assessment evaluated the susceptibility threshold of COTS computer network equipment to a high altitude electromagnetic pulse (HEMP) environment produced within the QinetiQ HEMP bounded wave simulator. These assessments have focused on the threshold of susceptibility of computer equipment and networks with variation in technology maturity. Technology trends are established where possible. The impact of EMC compliance on computer equipment immunity is also discussed. It is considered that the data presented in this paper will be informative to those seeking to protect systems and infrastructures from intentional and unintentional electromagnetic interference (EMI).