Low-Frequency Shielding Resonance

A low-frequency resonance in the 5- to 200-kHz range has been discovered in typical shielding enclosures. It is due to unequal phase shifts in wave transmission to a receiving point via two or more parallel paths: one through the shielding material itself and others through leakage paths such as seams. Theoretical and experimental results are shown to be in close agreement and indicate a new approach to the design of shielding enclosures.