Patent Application
20150072561
The subject matter described and/or illustrated herein relates generally to receptacle assemblies, and more particularly to the metal cages of receptacle assemblies.
Various types of fiber optic and copper based electrical connector assemblies that permit communication between host equipment and external devices are known. These electrical connector assemblies typically include a pluggable module that is received within a receptacle assembly, which includes a receptacle connector that pluggably connects to the pluggable module. Receptacle assemblies typically include a metal cage having an internal compartment that receives the pluggable module therein. The receptacle connector is held in the cage for connection with the pluggable module as the module is inserted into the cage. The pluggable modules are constructed according to various standards for size and compatibility, for example the Quad Small Form-factor Pluggable (QSFP) module standard and the XFP standard.
One particular concern regarding receptacle assemblies is reducing electromagnetic interference (EMI) emissions. Due to government regulations, there is a need not only to minimize the EMI emissions of the electrical connector assembly, but also to contain the EMI emissions of the host system in which the electrical connector assembly is mounted, regardless of whether a pluggable module is plugged in to the receptacle. In at least some known receptacle assemblies, EMI shielding is achieved using the metal cage. However, due to increasing signal speeds being transmitted through the electrical connector assemblies, the EMI shielding provided by conventional cages is proving to be inadequate.
Accordingly, there is a need for an electrical connector assembly that reduces EMI emissions.
In an embodiment, a cage is provided for a receptacle assembly that includes a receptacle connector. The cage includes a body having an upper wall, a lower wall, and side walls that extend from the upper wall to the lower wall. The body has a lower side along which the lower wall extends, a front end, and an internal compartment. The internal compartment is configured to hold the receptacle connector therein. The internal compartment is configured to receive a pluggable module therein through the front end. The cage is configured to be mounted to a printed circuit along the lower side. The lower side includes a connector opening. An electromagnetic interference (EMI) absorber extends over at least a portion of the lower wall. The EMI absorber is configured to absorb EMI.
In an embodiment, a receptacle assembly is provided for mating with a pluggable module. The receptacle assembly includes a receptacle connector, and a cage that includes a body having an upper wall, a lower wall, and side walls that extend from the upper wall to the lower wall. The body has a lower side along which the lower wall extends, a front end, and an internal compartment. The receptacle connector is held within the internal compartment. The internal compartment is configured to receive the pluggable module therein through the front end. The cage is configured to be mounted to a printed circuit along the lower side. The lower side includes a connector opening. The cage includes an electromagnetic interference (EMI) absorber that extends over at least a portion of the lower wall. The EMI absorber is configured to absorb EMI.
In an embodiment, a cage is provided for a receptacle assembly that includes a receptacle connector. The cage includes a body having an upper wall, a lower wall, and side walls that extend from the upper wall to the lower wall. The body has a lower side along which the lower wall extends, a front end, and an internal compartment. The internal compartment is configured to hold the receptacle connector therein. The internal compartment is configured to receive a pluggable module therein through the front end. The cage is configured to be mounted to a printed circuit along the lower side. The lower side includes a connector opening. The cage includes an electromagnetic interference (EMI) absorber that is configured to absorb EMI. The EMI absorber extends along a perimeter of the lower wall.
The electrical connector assembly 10 includes one or more pluggable modules 12 configured for pluggable insertion into a receptacle assembly 14 that is mounted on a host circuit board 15 (
The pluggable module 12 is configured to be inserted into the receptacle assembly 14. Specifically, the pluggable module 12 is inserted into the receptacle assembly 14 through the panel opening such that a front end 22 of the pluggable module 12 extends outwardly from the receptacle assembly 14. The pluggable module 12 includes a housing 24 that forms a protective shell for a circuit board 26 that is disposed within the housing 24. The circuit board 26 will be referred to herein as a “module circuit board” and carries circuitry, traces, paths, devices, and/or the like that perform transceiver functions in a known manner. An edge 28 of the module circuit board 26 is exposed at a rear end 30 of the housing 24. In the illustrated embodiment, the module circuit board 26 of the pluggable module 12 directly mates with a receptacle connector 34 (
In general, the pluggable module 12 and the receptacle assembly 14 may be used in any application requiring an interface between a host system and electrical and/or optical signals. Each pluggable module 12 interfaces to the host system through the receptacle assembly 14 via the corresponding receptacle connector 34 of the receptacle assembly 14, which is located within an electrically conductive cage 36 (which is sometimes referred to as a “receptacle guide frame” or a “guide frame”) of the receptacle assembly 14. As illustrated in
Each pluggable module 12 interfaces to one or more optical cables (not shown) and/or one or more electrical cables (not shown) through a connector interface 50 at the front end 22 of the module 12. Optionally, the connector interface 50 comprises a mechanism that cooperates with a fiber or cable assembly (not shown) to secure the fiber or cable assembly to the pluggable module 12. Suitable connector interfaces 50 are known and include adapters for the LC style fiber connectors and the MTP/MPO style fiber connectors offered by TE Connectivity (Harrisburg, Pa.).
Although the cage 36 is shown as including a plurality of internal compartments 42 and a plurality of ports 40 for electrically connecting a plurality of pluggable modules 12 to the host circuit board 15, the cage 36 may include any number of internal compartments 42 and ports 40, arranged in any pattern, configuration, arrangement, and/or the like (such as, but not limited to, any number of rows and/or columns), for electrically connecting any number of pluggable modules 12 to the host circuit board 15. Optionally, an electromagnetic interference (EMI) gasket 52 extends circumferentially about one or more of the ports 40. The EMI gasket 52 is configured to block EMI from leaking through an interface between the front end 38 of the cage 36 and the panel (not shown) to which the cage 36 is mounted.
As will be described in more detail below, the cage 36 includes an electromagnetic interference (EMI) absorber 100 that extends along the lower side 46 of the cage 36 and over at least a portion of a lower wall 76 of the cage 36. The EMI absorber 100 is configured to absorb EMI.
The receptacle 54 of the receptacle connector 34 receives the edge 28 of the module circuit board 26 of the pluggable module 12 therein. The receptacle connector 34 includes electrical contacts (not shown) that extend within the receptacle 54 and engage corresponding electrical contacts (not shown) on opposite sides 60 and 62 of the module circuit board 26 to establish an electrical connection between the module circuit board 26 of the pluggable module 12 and the host circuit board 15 through the receptacle connector 34.
The upper wall 74 extends along, and defines at least a portion of, the upper side 72 of the body 82. The lower wall 76 extends along, and defines at least a portion of, the lower side 46 of the body 82. In the illustrated embodiment, the cage 36 includes a generally rectangular cross-sectional shape, defined by the walls 74, 76, 78, and 80, such that the cage 36 generally has the shape of a parallelepiped. But, the cage 36 may include any other shape.
In the illustrated embodiment, the side walls 78 and 80 and the rear wall 84 of the cage body 82 are each integrally formed as a single, unitary piece with the upper wall 74, while the lower wall 76 is a discrete component (of the cage body 82) relative to the upper wall 74, the rear wall 84, and the side walls 78 and 80. The lower wall 76 is mechanically connected to each of the side walls 78 and 80 using any suitable connection structure, means, type, and/or the like that enables a mechanical connection between the lower wall 76 and the side walls 78 and 80. In the illustrated embodiment, the lower wall 76 includes one or more mounting clips 92 that engage one or more corresponding mounting tabs 94 on the side walls 78 and 80 with a snap-fit connection to mechanically connect the lower wall 76 to the side walls 78 and 80. In addition or alternatively to being integrally formed with the upper wall 74 and/or the rear wall 84, the side walls 78 and/or 80 may be integrally formed with the lower wall 76. Moreover, the rear wall 84 may be a discrete component of the cage body 82 relative to the upper wall 74 and/or the side walls 78 and/or 80, and each of the side walls 78 and/or 80 may be a discrete component of the cage body 82 relative to the upper wall 74, the rear wall 84, and/or the lower wall 76.
The divider walls 86 of the cage body 82 are discrete components of the cage body 82 relative to the upper wall 74 and the lower wall 76 in the illustrated embodiment. Each divider wall 86 is mechanically connected to the upper wall 74 and the lower wall 76 using any suitable connection structure, means, type, and/or the like that enables a mechanical connection therebetween. In the illustrated embodiment, the divider walls 86 are mechanically connected to the upper wall 74 via one or more mounting tabs 94 that are received within one or more corresponding slots 96 that extend within the upper wall 74, as can be seen in
The lower wall 76 includes a perimeter 104, which is defined by a front edge 106, a rear edge 108, and opposite side edges 110 and 112 of the lower wall 76. A surface area A of the lower wall 76 is defined between the edges 106, 108, 110, and 112. The lower wall 76 includes a plurality of interior segments 114 that are spaced apart from the edges 106, 108, 110, and 112. Optionally, a plurality of spring fingers 116 extend outward from the rear edge 108 to facilitate grounding the lower side 46 of the cage body 82 to the host circuit board 15 (
The rear wall 84 includes an edge 120. The side walls 78 and 80 include respective edges 122 and 124. The edges 106, 110, 112, 120, 122, and 124 define a portion of the lower side 46 of the cage body 82. Specifically, the edges 106, 110, 112, 120, 122, and 124 define a perimeter 126 of the lower side 46 of the cage body 82. As can be seen in
The sheet of material 130 of the EMI absorber 100 may extend over any amount of, and location(s) along, the lower side 46 of the cage 36. In the illustrated embodiment, the sheet of material 130 extends along the perimeter 126 of the lower side 46, over the lower wall 76, and between adjacent connector openings 48 for absorbing EMI along the perimeter 126, along the lower wall 76, and between adjacent connector openings 48. For example, segments 140, 142, and 144 of the sheet of material 130 extend along the perimeter 126. In some embodiments, the sheet of material 130 may extend along an approximate entirety of the perimeter 126. For example, the sheet of material 130 may include a segment (not shown) that extends along the front edge 106 of the perimeter 126.
The sheet of material 130 of the EMI absorber 100 extends over the lower wall 76. Specifically, in the illustrated embodiment, the sheet of material 130 extends over the interior segments 114 of the lower wall 76 and along the perimeter 104 of the lower wall 76. The segments 140 and 144 and a segment 150 of the sheet of material 130 extend along the perimeter 104 for absorbing EMI along the perimeter 104. The sheet of material 130 extends over a majority of the surface area A of the lower wall 76 in the illustrated embodiment. But, the sheet of material 130 of the EMI absorber 100 may extend over any amount of, and location(s) along, the lower wall 76 of the cage 36. For example, the sheet of material 130 may extend over less than a majority of the surface area A of the lower wall 76. Moreover, and for example, the sheet of material 130 may extend along an approximate entirety of the perimeter 104. For example, the sheet of material 130 may include a segment (not shown) that extends along the front edge 106 of the perimeter 104. As shown in
The sheet of material 130 includes one or more openings 156. Each opening 156 is at least partially aligned with a corresponding opening 48 of the lower side 46 of the cage 36. The at least partial alignment between the corresponding openings 156 and 48 enables the corresponding receptacle connector 34 (
In the illustrated embodiment, the sheet of material 130 of the EMI absorber 100 extends along the perimeter 128 of each of the openings 48 of the lower side 46 for absorbing EMI along the perimeters 128. Although shown as extending along an approximate entirety of the perimeters 128, the sheet of material 130 may extend along only a portion of one or more of the perimeters 128. The sheet of material 130 may not extend along any of the perimeters 128 or may extend along only one or some of the perimeters 128 in other embodiments. Optionally, the sheet of material 130 includes segments 158 that extend between adjacent openings 48.
The EMI absorber 100 is optionally secured to the lower side 46 of the cage 36. The EMI absorber 100 may be secured to the lower side 46 of the cage 36 using any suitable method, structure, means, and/or the like, such as, but not limited to, using an interference fit (e.g., between the openings 152 and the tines 154), using an adhesive, using a tab, using a clip, and/or the like.
As briefly described above, the EMI absorber 100 is configured to absorb EMI. Specifically, the EMI absorber 100 has a relatively high permeability to absorb EMI. The EMI absorber 100 may be fabricated from any materials that provide the EMI absorber 100 with the relatively high permeability to absorb EMI, such as, but not limited to, a magnetic elastomer, rubber, nitrile, silicone, carbonal iron, a ferrite-based material, a ferrite material in a binder (e.g., a polymer binder), Viton® fluoroelastomer, neoprene, Hypolan® elastomer, urethane, an elastomeric material, and/or the like. The EMI absorber 100 may have magnetic fillers included within an elastomeric material, such as, but not limited to, a carbonyl iron powder, an iron silicide, other magnetic fillers, and/or the like. The type of material(s) within the EMI absorber 100 may be selected to target EMI at different frequencies. In some embodiments, the EMI absorber 100 includes a Q-Zorb™ material, commercially available from Laird Technologies.
Referring again to
As described above, the EMI absorber 100 has a relatively high permeability to absorb EMI. The EMI absorber 100 is thus configured to absorb EMI emitted along the lower side 46 of the cage 36. By absorbing EMI emitted along the lower side 46 of the cage 36, the EMI absorber 100 may reduce or eliminate EMI leakage from an interface 160 between the lower side 46 of the cage 36 and the host circuit board 15. For example, the EMI absorber 100 may reduce or eliminate EMI leakage from the interface 160 along the perimeter 126 (
The embodiments described and/or illustrated herein may provide an electrical connector assembly that reduces EMI emissions.
It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. Further, the limitations of the following claims are not written in means-plus-function format and are not intended to be interpreted based on 35 U.S.C. §112, sixth paragraph, unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.
