As we learned above, currents flow in the shielding barrier as a
function of the radiated field being impinged on the barrier. When
the current crosses a seam in
the barrier (created by maintenance covers, etc.), a voltage is created across the
seam, where the value of the
voltage is equal to the current times the impedance of
the seam. The seam then
becomes a radiating antenna
where the impedance and
pattern is similar to that of a
slot antenna. EMI gaskets are used to reduce the impedance of the
seam and subsequent power radiating from the seam.