Electromagnetic leakage through slot configurations in a shielded enclosure

Abstract

The electromagnetic leakage through a seam or gasketed joint for any given frequency is directly proportional to the voltage across the seam (or gasketed joint), where the voltage is the result of currents which cross the seam. This is true for both the E and H fields. Testing has been performed to illustrate the relationship by use of a shielded enclosure with a 450 mm long by 2 mm wide slot. The E field and H field, one meter from the slot, are measured and documented over the frequency range of 10 kHz through 50 MHz. Two-methods are used to drive current across the seam for three conditions. These conditions are: (1) the 450 mm slot; (2) the 450 mm slot with 10 mm long gaskets at 150 mm spacing; and (3) the 450 mm slot with 10 mm long gaskets at 75 mm spacing.<>