Mitigation method/Results/Conclusion At this installation, the lightning struck the antenna tower; the surge current flowed into E0 earthing through the wave guide and building structures, and the DC power feeding line. The potential of E0 and also of the DC power feeding lines rose. The surge current penetrated ISM and flowed into E0, and then the ISM packages were damaged. To solve this problem, it was required to change the feeding routes as shown in Figure 2.4-2. Radio tower 2F CSM PDF CLK line Wave guide DC+ DC power feeding line F-SSF ISM DC+ F-SSF 1F ISM-0E TR DC+ DC BF EN-48-TH-RF MR-48-R2-RF DC+ DC+ DC+ Miti(08)_F2.4-2 E0 Figure 2.4-2 – Mitigation configuration References Recs ITU-T K.27, ITU-T K.35, ITU-T K.40, ITU-T K.56; Annex C. Case study 2.4 – 2 –