METHOD AND APPARATUS FOR REDUCING ESD-INDUCED EMI RADIATING FROM I/O CONNECTOR APERTURE

PROBLEM TO BE SOLVED: To provide a method and an apparatus to solve the problem of I/O card fault caused by the ESD-induced EMI in an area near the opening of chassis. SOLUTION: Conductive boots 10L, 10R are provided covering an I/O cable 3. The boots 10L, 10R are physically mounted to the chassis 4 at one end thereof, are at least AC coupled, and are formed to become narrower toward the small aperture at the far end for allowing passing of the I/O cable 3. The aperture at the far end is considerably smaller than the aperture at the chassis 4. The smaller aperture becomes an antenna of lower efficiency for the frequency in question and is further moved from the parts working as the receiving antenna. Interposing length of the conductive boots 10L, 10R also functions as a waveguide low-frequency shield and also functions as a filter for shielding the passing of spurious RF energy of reduced amount which is still radiated towards the I/O card from the small aperture. The boots may be formed of a metal material or a plastic material, of which internal surface is shielded with a conductive coating material.