Patent ID: 6147299
Filing Date: 2000-11-14
Classification: H05K

Abstract:
A device for improving shielding effectiveness of an enclosure from electromagnetic interference (EMI), said device comprising:a housing which has an inner surface and an outer surface;a disc with an aperture, said disc being attached to said inner surface of said housing to define a first inner space adapted to receive an electrical component and a second inner space; anda ferrite core with an aperture, said ferrite core being fit into said second inner space wherein said disc aperture is circularly shaped, and a depth of said housing and a diameter of said circular disc aperture are governed by the equation: ##EQU9## where SE represents the shielding effectiveness of said housing, t represents the depth of said housing, d represents the diameter of said circular disc aperture, and f represents the frequency of the EMI being shielded.