| 摘要 |
A printed circuit board having a plurality of spaced apart scrap border support tabs along the perimeter. The board surfaces including the edges are coated with a conductive shielding material, except that each tab presents an uncoated, unshielded surface at the point of severance created by detachment of a scrap border subsequent to the coating application. The printed circuit board includes a plurality of spaced apart elongated apertures adjacent the perimeter, with each aperture being inwardly coincident to a respective one of each support tabs, each aperture defining an inner surface adjacent to the corresponding support tab with a portion of the inner surface being substantially parallel to adjacent perimeter portions of the circuit board, the inner surface of each aperture also being coated with the conductive shielding material with the latter being attached to the conductive shielding material of the board surface. A waveguide configuration is created which serves to attenuate electromagnetic emissions entering into or leaving the printed control board at the corresponding uncoated unshielded surface portions of the support tab during use of the printed circuit board. Frequencies in excess of 40 gigahertz may be attenuated.
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