EBG designs for mitigating radio frequency interference

• US 10,403,973 B2
• Filed: 04/22/2014
• Issued: 09/03/2019
• Est. Priority Date: 04/22/2014
• Status: Active Grant

• Current Assignee: Apple Inc.
• Original Assignee: Intel Corporation
• Inventors: Chen, Chung-Hao
• Primary Examiner(s): Duong, Dieu Hein T
• Assistant Examiner(s): Jegede, Bamidele A
• Application Number:
  US14/258,683
• Publication Number:
  US 20150303562A1
• Time in Patent Office: 1,960 Days
• Field of Search: 343842, 174382, 361719, 361818
• CPC Class Codes: H01Q 1/242 specially adapted for hand-held use
• CPC Class Codes: H01Q 1/52 Means for reducing coupling between antennas; Means for reducing coupling between an antenna and another structure absorbing means H01Q17/00
• CPC Class Codes: H01Q 1/526 Electromagnetic shields
• CPC Class Codes: H01Q 15/008 said selective devices having Sievenpipers' mushroom elements

Abstract

An apparatus for electromagnetic interference shielding is described herein. The apparatus includes an electromagnetic bandgap (EBG) structure. The EBG structure is attached to a surface of the apparatus such that noise propagation is mitigated. The apparatus may be a chassis of an electronic device, and the EBG structure may be attached to one surface of the chassis. Further, the apparatus may be a heat sink, and the EBG structure can be attached to one surface of the heat sink.

Claims

1. An apparatus for electromagnetic interference shielding, comprising:

an electromagnetic bandgap (EBG) structure;

a surface of the apparatus, wherein the EBG structure is disposed onto the surface and in between an interference generating source and an antenna, wherein the EBG structure is to provide isolation to the antenna from an electromagnetic interference band comprising an operating frequency of the antenna generated by the interference generating source coupled to an opposing surface of a printed circuit board from the surface of the apparatus, the apparatus comprising a chassis enclosing the printed circuit board, the antenna, and the interference generating source, wherein the printed circuit board, the antenna, and the interference generating source are attached to the chassis, wherein the chassis comprises a metal enclosure that serves as a propagation path for the electromagnetic interference band from the interference generating source and the EBG structure prevents propagation of the electromagnetic interference band to the antenna.

2. The apparatus of claim 1, wherein the EBG structure is integrated into one surface of the chassis.

3. The apparatus of claim 1, comprising a heat sink, wherein a second EBG structure integrated into to one surface of the heat sink.

4. The apparatus of claim 1, comprising a heat pipe, wherein a second EBG structure is integrated into one surface of the heat pipe.

5. The apparatus of claim 1, comprising a heat spreader, wherein a second EBG structure is integrated into one surface of the heat spreader.

6. The apparatus of claim 1, wherein the EBG structure is a mushroom type EBG structure.

7. The apparatus of claim 1, wherein a second EBG structure is attached to the surface of the apparatus using an adhesive such that the second EBG structure is an EBG adhesive tape.

8. The apparatus of claim 1, wherein the EBG structure comprises a combined plurality of types of EBG structures, wherein the plurality of types of EBG structures comprises a spiral EBG structure, a wide band EBG structure, a planar EBG structure, or any combination thereof.

9. The apparatus of claim 1, wherein a metal coating or a metal foil of the chassis can be positioned along with the EBG structure in order to direct any electromagnetic interference away from antennas within the chassis.

10. A method for constructing an electronic device with electromagnetic interference shielding, comprising:

forming an enclosure of the electronic device, where an electromagnetic bandgap (EBG) structure is disposed onto an inner surface of the enclosure;

locating an antenna and a plurality of interference generating sources within the enclosure to block noise from the plurality of interference generating sources from the antenna, wherein the EBG structure is implemented in between the interference generating sources and the antenna to provide isolation to the antenna from an electromagnetic interference band comprising an operating frequency of the antenna generated by a component of the plurality of interference generating sources coupled to an opposing surface of a printed circuit board from the surface of the apparatus, the enclosure comprising a chassis enclosing the printed circuit board, the antenna, and the interference generating source, wherein the printed circuit board, the antenna, and the interference generating source are attached to the chassis, wherein the chassis comprises a metal enclosure that serves as a propagation path for the electromagnetic interference band from the interference generating source and the EBG structure prevents propagation of the electromagnetic interference band to the antenna.

11. The method of claim 10, wherein the EBG structure is a mushroom type EBG structure.

12. The method of claim 10, wherein EBG structure is integrated with the enclosure.

13. The method of claim 10, wherein an arrangement of the EBG structure on the enclosure is generated during an industrial design of the enclosure.

14. The method of claim 10, wherein the interference generating sources include at least a central processing unit (CPU), platform controller hub (PCH), memory device, panel timing controller, motherboard layout, or any combination thereof.

15. The method of claim 10, wherein the EBG structure is selected to mitigate a frequency band of the electromagnetic interference, to block a selective frequency of the electromagnetic interference.

16. The method of claim 10, wherein the enclosure includes a metallic coating that directs the electromagnetic interference away from the antenna.

17. The method of claim 10, wherein a metallic coating directs the electromagnetic interference from the interference generating sources throughout the enclosure.

18. A method for fitting an electronic device for electromagnetic interference shielding, comprising:

attaching an electromagnetic bandgap (EBG) adhesive tape comprising an electromagnetic bandgap (EBG) structure to a surface in between an antenna and an interference generating source within the electronic device to prevent noise generated by the interference generating source from interfering with the operation of the antenna, wherein the EBG structure is to mitigate an electromagnetic interference band comprising an operating frequency of the antenna, and wherein the interference generating source is coupled to an opposing surface of a printed circuit board from the surface of a chassis of the electronic device, the chassis enclosing the printed circuit board, the antenna, and the interference generating source, wherein the printed circuit board the antenna, and the interference generating source are attached to the chassis, wherein the chassis comprises a metal enclosure that serves as a propagation path for the electromagnetic interference band from the interference generating source and the EBG structure prevents propagation of the electromagnetic interference band to the antenna.

19. The method of claim 18, wherein the surface is a housing of the electronic device.

20. The method of claim 18, wherein the EBG adhesive tape includes a conductive adhesive layer.

21. The method of claim 18, wherein the EBG adhesive tape includes a mushroom type EBG structure.

22. The method of claim 18, wherein the surface is a portion of a housing of the electronic device.

23. The method of claim 18, wherein the surface is a heat sink, and the EBG adhesive tape is attached to one surface of the heat sink.

24. The method of claim 18, wherein the surface is a heat pipe, and the EBG adhesive tape is attached to one surface of the heat pipe.

25. The method of claim 18, wherein the surface is a heat spreader, and the EBG adhesive tape is attached to one surface of the heat spreader.