Low-Frequency Shielding Properties of Conducting Cylindrical Shells of Arbitrary Cross Section

The shielding properties of general, two dimensional, finitely conducting shells with vanishingly thin walls are analyzed by the integral-equation method. For the circular cylinder case, a field plot throughout the shield interior reveals that, at the ´no shielding´ frequencies found by Schieber, fields are attenuated greatly, except near the center. The influence of slots in the shell walls is also assessed for both circular and rectangular cylinders. Due to focusing effects, the field at the shield center is even stronger than the incident field at certain resonant frequencies for the slotted cylindrical shells.