Simulation results are shown in Figure 12. It can be seen
the envelope shapes of resonance attenuation of UHF PF
signals are basically identical with or without shielding
electrodes; the attenuation of signal amplitude occurs
somewhat with shield electrodes, while the frequency spectrum
without shielding electrodes is smooth. However, the case
when only one pair of shielding electrodes is used is
investigated in this study. In practice, several shielding
electrodes might be installed at the conductor joints, corners,
the two sides of isolation insulator of GIS, with their influence
on the propagation of electromagnetic waves being nonnegligible.