WO2017123236A1

WO2017123236A1 - Electromagnetic interference shield for optical connectors

Info

Publication number: WO2017123236A1
Application number: PCT/US2016/013520
Authority: WO
Inventors: John Norton; Kevin B. Leigh; Sunil Ganta
Original assignee: Hewlett Packard Enterprise Development Lp
Priority date: 2016-01-15
Filing date: 2016-01-15
Publication date: 2017-07-20

Abstract

An example electromagnetic interference (EMI) shield for optical connectors is provided herein. The EMI shield includes a connector cage and a fastening member. The connector cage is formed of a conductive material to cover an optical connector. The fastening member holds the connector cage in place.

Description

ELECTROMAGNETIC INTERFERENCE SHIELD FOR OPTICAL

CONNECTORS

BACKGROUND

[0001] In an electronic system, bezels and covers surround electronic components. Bezels may include openings for connections to electronic components, such as, power, networking, and other connectors. For example, a thru bezel optical connector fits into an opening in the input/output faceplate of switches to allow optical ferrules and lenses to mate and align.

BRIEF DESCRIPTION OF THE DRAWINGS

[0002] Non-limiting examples of the present disclosure are described in the following description, read with reference to the figures attached hereto and do not limit the scope of the claims. In the figures, identical and similar structures, elements or parts thereof that appear in more than one figure are generally labeled with the same or similar references in the figures in which they appear. Dimensions of components and features illustrated in the figures are chosen primarily for convenience and clarity of presentation and are not necessarily to scale. Referring to the attached figures:

[0003] FIG. 1 illustrates a block diagram of an electromagnetic

interference (EMI) shield according to an example;

[0004] FIG. 2 illustrates a schematic view of the EMI shield of FIG. 1 according to an example;

[0005] FIG. 3 illustrates a cross-sectional view of the EMI shield of FIG. 2 according to an example; [0006] FIG. 4 illustrates a schematic view of an EMI shield of FIG. 1 according to an example;

[0007] FIG. 5 illustrates a cross-sectional view of an EMI shield of FIG. 4 according to an example;

[0008] FIG. 6 illustrates a cross-sectional view of an EMI shield of FIG. 1 according to an example;

[0009] FIG. 7 illustrates a schematic view of the EMI shield of FIG. 1 according to an example;

[0010] FIG. 8 illustrates a cross-sectional view of the EMI shield of FIG. 7 according to an example;

[0011] FIG. 9 illustrates a block diagram of an assembly to reduce EMI leakage according to an example;

[0012] FIG. 10 illustrates a block diagram of a system to reduce EMI leakage according to an example; and

[0013] FIG. 1 1 illustrates a schematic view of the system of FIG. 10 according to an example.

DETAILED DESCRIPTION

[0014] In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is depicted by way of illustration specific examples in which the present disclosure may be practiced. It is to be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure.

[0015] Thru bezel optical connectors are inserted into an opening in bezels to allow optical ferrules and lenses to mate and align. The bezel opening is not sealed against electromagnetic interference (EMI) and as input/output speeds increase the allowable orifice size shrinks. A current method to seal the opening is to make the optical connector out of metal instead of plastic. Using metal increases the cost of the optical connectors and although the metal contains some EMIs, EMI leakage may still occur through the optical ferrule, which is not conductive. [0016] Practices to address EMI leakage through optical connectors center around changing the material from plastic to die cast metal. This increases component cost and will not prevent leakage at higher speeds, such as 25 Gigabits/second. For example, low cost plastic optical thru bezel connectors, e.g., multi-fiber push on (MPO) adapters, that are used in high speed I/O applications and the inherent material properties of optical ferrules allow for EMI leakage. In examples, an EMI shield for optical connectors is provided. The EMI shield includes a connector cage and a fastening member. The connector cage formed of a conductive material to cover an optical connector. The fastening member to hold the connector cage in place. EMI shields according to the examples reduce the EMI leakage and provide a reduced cost alternative that use lower cost plastic optical connectors.

[0017] FIG. 1 illustrates a block diagram of an EMI shield 100 according to an example. The EMI shield 100 includes a connector cage 120 and a fastening member 140. The connector cage 120 is formed of a conductive material, such as sheet metal, to cover an optical connector on one side of a bezel, such as an MPO optical connector or hot pluggable optical transceivers. The conductive material to ground the connector cage 120. The fastening member 140 to hold the connector cage 120 in place and adjacent to the bezel.

[0018] Referring to FIGS. 2-8 examples of EMI shields 100 are illustrated. FIG. 2 illustrates a schematic view of the EMI shield 100 of FIG. 1 according to an example. FIG. 3 illustrates a cross-sectional view of the EMI shield 100 of FIG. 2 according to an example. Referring to FIGS. 2-3, the EMI shield 100 illustrated includes the connector cage 120 with a connector enclosure 220 to surround the optical connector 230 that may be connected to a plastic adapter 235. The connector cage 120 may enclose optical connector 230, the optical connection ferrule 210, and a portion of the plastic adapter 235. The EMI shield 100 may also include an alignment member 222 to allow the connector cage 120 to enclose the optical connector 230 and clear the optical cable 215 that optically couple the optical connector 230 to the optical transceiver 217. For example, the optical transceiver 217 is connected to a substrate 219. The substrate 219 is connected to an interposer board 213 that is connected to a system board 21 1 . The alignment member 222 is illustrated as an opening that allows the connector enclosure 220 to be placed over the optical connector 230. The opening illustrated is one way to position the connector enclosure 220 and enable the connector enclosure 220 to be placed over the optical connector 230 while the optical cable 215 is connected to the optical connector 230 and the optical connector 230 is mounted to a bezel 250, such as an input/output bezel. The connector cage 120 may also be used to retain the optical cable 215 at the connection point. The EMI shield 100 also includes the fastening member 140 illustrated as a clip 240 that attaches to the bezel 250 and holds the connector enclosure 220 in place. The fastening member 140 illustrated includes a latching mechanism that secures the connector cage 120 to the optical connector 230 and to a bezel 250. The latching mechanism is illustrated to include a base 242 and two side walls. The base 242 is formed of a planar member that includes a fastening aperture 243 to align the fastening member 140 over the connector cage 120 when the optical connector 230 is connected to the bezel 250. A first side wall 244 includes a first lip 245 and a second side wall 246 includes a second lip 247. The first and second lips 245, 247 are formed on the fastening member 140 to engage with hooks 255, 257 on the bezel 250.

[0019] FIG. 4 illustrates a schematic view of an EMI shield 100 of FIG. 1 according to an example. The connector cage 120 is illustrated as a protective cover that includes a sleeve 420 formed to encase the optical connector 230, and the fastening member 140 is illustrated as tabs 440 extending from the sleeve 420 and formed to attach to the bezel 250 using an adhesive. For example, the sleeve 420 may be formed of a conductive fabric or foil that wraps around the optical cable 215. The sleeve 420 includes an alignment opening 422 to allow the optical cable 215 to pass through. The sleeve 420 is grounded to the bezel 250 using a conductive adhesive. FIG. 5 illustrates a cross- sectional view of an EMI shield 100 of FIG. 4 according to an example. As illustrated in FIG. 5, the sleeve 420 encases or surrounds the optical connector 230 and a portion of the optical cable 215. The fastening member 140 as illustrated include tabs 440 extending from the sleeve 420 and connected to the bezel 250.

[0020] FIG. 6 illustrates a cross-sectional view of an EMI shield 100 of FIG. 1 according to an example. Referring to FIG. 6, a variation of the EMI shield 100 described with reference to FIGS. 4-5 are illustrated. As illustrated in FIGS. 4-5, the connector cage 120 includes a protective cover that includes a sleeve 420 formed to encase the optical connector 230, and the fastening member 140 include tabs 440 extending from the sleeve 420 and formed to attach to the bezel 250 using an adhesive. In contrast to FIGS. 4-5 where the EMI shield 100 is on an interior portion 452 of the bezel 250, FIG. 6 illustrates an alternative arrangement that covers a portion of the optical connector 230 on an exterior portion 652 of the bezel 250. The EMI shield 100 encases an external optical cable (not shown) installed on the optical connector 230. The sleeve 420 may be formed to wrap around the external optical cable or formed to include an alignment opening 422, e.g. , a slot that allows the external optical cable to pass through.

[0021] FIG. 7 illustrates a schematic view of the EMI shield 100 of FIG. 1 according to an example. FIG. 8 illustrates a cross-sectional view of the EMI Shield 100 of FIG. 7 according to an example. The EMI shield 100 of FIGS. 7-8 encloses the optical components, such as the input/output optical connectors, while allowing air flow via ventilation apertures 726 to reach temperature sensitive components, such as optical transceivers. As illustrated, the connector cage 120 includes a connector frame 720 that covers two optical connectors 230. The connector cages 120 illustrated are examples of connector cages 120. Each connector cage 120 illustrated may be formed to cover one optical connector 230 as illustrated in FIGS. 2-6 or multiple optical connectors 230 as illustrated in FIGS. 7-8. The connector frame 720 connects to the bezel 250 via engagement members 840 that slide into the bezel 250 and retain the connector frame 720 therein. The connector frame 720 may be used alone to form the connector cage 120 or in combination with the connector enclosure 220 or sleeve 420 to provide additional protection against EMI leakage. The EMI shield 100 illustrated in FIGS. 7-8 extends between an optical connector 230 and an optical component module 760 with ventilation apertures 726 to allow air flow to the optical component module 760. For example, the EMI shield 100 may include a module cage 722 to connect to the connector cage 120 and extend over a portion of an optical component module 760. The module cage 722 may be integrated into the connector cage 120 as a unitary member or as a separate member attached to the connector cage 120. The module cage 722 may include ventilation apertures 726.

[0022] FIG. 9 illustrates a block diagram of an assembly to reduce EMI leakage according to an example. The assembly 950 includes a connector cage 120, a fastening member 140, and a module cage 722. The connector cage 120 is formed of a conductive material to cover or encase an optical connector 230 and an optical connection ferrule 210, such as an enclosure to surround the optical connector 230, as illustrated in FIGS. 2-8. The fastening member 140 to hold the connector cage 120 in place and adjacent to the bezel. For example, the fastening member 140 to extend across the enclosure and secure the enclosure to the bezel 250. The fastening member 140 is illustrated in FIGS. 2-3 as clip 240, in FIGS. 4-6 as tabs 440, and in FIG. 8 as engagement members 840. The module cage 722 to cover a portion of an optical component module 760 connected to the optical connector 230 using the modular cage 722. For example, the module cage 722 may be connected to a connector cage 120 that encases the optical connector 230. The module cage 722 may then extend from the connector frame and cover a portion of optical component module 760. The optical component module 760 may include for example, the optical transceiver 217, substrate 219, and interposer 213. FIGS. 7-8 illustrate examples of the connector cage 120 and the module cage 722 used together. Moreover, FIG. 8 illustrates an assembly with two connector cages 120. A first connector cage 820 that encases the optical connector 230, and a second connector cage, such as connector frame 720, that surround the first connector cage 820. The use of two connector cages 120 provides additional EMI shielding and further reduces EMI leakage.

[0023] FIG. 10 illustrates a block diagram of a system 1000 to reduce EMI leakage according to an example. The system 1000 includes a bezel 250 and an EMI shield. FIG. 1 1 illustrates a schematic view of the system 1000 of FIG. 10 according to an example. The bezel 250 to receive an optical connector 230. Examples of bezels 250 include a bezel for a switch system and a bezel for switch line cards, but other bezels may also be used. The EMI shield 100 includes a connector cage 120 formed of a conductive material to cover the optical connector 230 on one side of the bezel 250 and a fastening member 140 to hold the connector cage 120 in place against the bezel 250. The connector cage 120 illustrated connects to the bezel 250 on an interior portion 452 of the bezel 250, which is adjacent to the optical component module 760 that is attached to a system board 21 1 . The connector cage 120 covers the optical connector 230 between the bezel 250 and the optical connection ferrule 210. The connector cage 120 may alternatively connect to an exterior portion 652 of the bezel 250. The connector cage 120 may connect to the bezel 250 using a fastening member 140 that connect lips 245, 247 to hooks 255, 257 on the bezel 250 as illustrated in FIGS. 2-3, an adhesive as illustrated in FIGS. 4-6, and/or engagement members 840 as illustrated in FIGS. 7-8.

[0024] The present disclosure has been described using non-limiting detailed descriptions of examples thereof and is not intended to limit the scope of the present disclosure. It should be understood that features and/or operations described with respect to one example may be used with other examples and that not all examples of the present disclosure have all of the features and/or operations illustrated in a particular figure or described with respect to one of the examples. Variations of examples described will occur to persons of the art. Furthermore, the terms "comprise," "include," "have" and their conjugates, shall mean, when used in the present disclosure and/or claims, "including but not necessarily limited to."

[0025] It is noted that some of the above described examples may include structure, acts or details of structures and acts that may not be essential to the present disclosure and are intended to be examples. Structure and acts described herein are replaceable by equivalents, which perform the same function, even if the structure or acts are different, as known in the art. Therefore, the scope of the present disclosure is limited only by the elements and limitations as used in the claims.

Claims

CLAIMS WHAT IS CLAIMED IS:

1 . An electromagnetic interference (EMI) shield comprising:

a connector cage formed of a conductive material to cover an optical connector and an optical connection ferrule; and a fastening member to hold the connector cage adjacent to a bezel.

2. The EMI shield of claim 1 , further comprising an alignment member to allow the connector cage to enclose the optical connector and clear an optical cable that optically couple the optical connector to an optical transceiver.

3. The EMI shield of claim 1 , wherein the fastening member comprises a latching mechanism to secure the connector cage to the optical connector.

4. The EMI shield of claim 1 , further comprising a module cage to extend over a portion of a module.

5. The EMI shield of claim 4, wherein the module cage comprises ventilation apertures.

6. The EMI shield of claim 4, wherein the connector cage connects to the module cage to extend between the optical connector and the module.

7. The EMI shield of claim 1 , wherein the connector cage comprises a sleeve formed to encase the optical connector.

8. The EMI shield of claim 1 , wherein the connector cage comprises a connector enclosure to surround the optical connector and the fastening member comprises a clip to attach to the bezel and hold the connector enclosure in place.

9. A system to reduce electromagnetic interference (EMI) leakage, the system comprising:

a bezel to receive an optical connector; and

an EMI shield including:

a connector cage formed of a conductive material to cover the optical connector on one side of the bezel, and

a fastening member to hold the connector cage against the bezel.

10. The system of claim 9, wherein the connector cage connects to the bezel on an interior portion of the bezel.

1 1 . The system of claim 9, wherein the connector cage connects to the bezel on an exterior portion of the bezel.

12. The system of claim 9, wherein the bezel comprises hooks to engage with the fastening member.

13. An assembly to reduce electromagnetic interference (EMI) leakage, the assembly comprising:

a connector cage formed of a conductive material to encase an optical connector and an optical connection ferrule; a fastening member to hold the connector cage against a bezel; and

a module cage to cover a portion of a module connected to the optical connector.

14. The assembly of claim 13, wherein the module cage comprises a first and a second connector cage, the first connector cage to encase the optical connector and the second connector cage to surround the first connector cage.

15. The assembly of claim 13, wherein the module cage to extend from the connector cage and cover a portion of the module.