Claims
- 1. A combination air and EMI filter for a vented area having a surrounding surface, said combination air filter and EMI filter comprising: a portion of the surrounding surface defining a dimple, said dimple having a surface which is offset from the remainder of the surrounding surface and having a ventilating port provided therethrough, said ventilating port having a dimension which is sized to minimize the amount of EMI leakage from the vented area; and a non-woven material covering at least a portion of said dimple and covering said ventilating port, said non-woven material allowing the passage of gases through said ventilating port and substantially preventing the passage of liquid and particulate through at least a portion of said dimple and through said ventilating port, the surface area of said non-woven material which covers at least a portion of said dimple and covers said ventilating port defining a dimension which is different than said dimension of said ventilating port for maximizing the effective surface area of the filtration provided by said non-woven material.
- 2. A combination air and EMI filter as defined in claim 1, wherein said non-woven material is attached to the surrounding surface.
- 3. A combination air and EMI filter as defined in claim 2, wherein said non-woven material is attached to the surrounding surface by adhesive.
- 4. A combination air and EMI filter as defined in claim 1, wherein said non-woven material is expanded polytetraflouroethylene material.
- 5. A combination air and EMI filter as defined in claim 1, wherein said non-woven material has a plurality of open areas therethrough to allow the passage of gases therethrough and to substantially prevent the passage of liquid and particulate therethrough, wherein the total surface area of the open areas approximately equals the surface area of said ventilating port.
CROSS-REFERENCE
This patent application claims the priority of provisional application Ser. No. 60/038,632, filed on Feb. 19, 1997 and entitled "Tuned Electromagnetic Interference Air Filter".
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