Patent Publication Number: US-9425562-B2

Title: Cable connector having a shielding insert

Description:
BACKGROUND OF THE INVENTION 
     The subject matter herein relates generally to cable connectors. 
     Various types of fiber optic and copper based connectors that permit communication, such as between host equipment and external devices, are known. These connectors can be pluggably connected to other connectors to provide flexibility in system configuration. These connectors are generally constructed to established standards for size and compatibility. For example, the connector may conform to a Small Form-factor Pluggable (SFP), a derivative thereof, or similar standard, such as, SFP+, XFP, CFP, GBIC, QSFP, XENPAK, PON, X2. These various standards have data transmission requirements. For example, the XFP and QSFP standards require that the electronic connectors be capable of transmitting data at high rates, such as 10 Gbps (Gigabits per second). As the signal transmission rates increase, the circuitry and/or the wiring within the connector generates larger amounts of electromagnetic radiation at shorter wavelengths and higher energy. The high-energy electromagnetic radiation increases the likelihood that electromagnetic radiation may escape through openings in the connector. For example, the connector may include an opening at one end to allow a cable to pass therethrough. Electromagnetic radiation may escape through such an opening. Adjacent connectors, and/or other foreign electrical components outside of the electrical connector, such as the host equipment and the external devices, may experience interference as a result of the electromagnetic radiation. This electromagnetic interference (EMI) can degrade the quality and/or performance of the electrical components or the connector. 
     A need remains for a cable connector having reduced leakage of electromagnetic radiation. 
     BRIEF DESCRIPTION OF THE INVENTION 
     In one embodiment, an electrical connector is disclosed. The electrical connector comprises a shell having a mating end and a cable end. The shell has a cavity with at least one conductor therein. The at least one conductor is arranged at the mating end for termination to a mating connector. The shell has a cable extending from the cavity through the cable end being electrically connected to the at least one conductor. The electrical connector also includes a shielding insert received proximate to the cable end. The shielding insert circumferentially surrounds the cable and is configured to block transmission of electromagnetic radiation through the cable end. 
     In one embodiment, an electrical connector is disclosed. The electrical connector comprises a shell having a mating end and a cable end. The shell has a cavity with at least one conductor therein. The at least one conductor is arranged at the mating end for termination to a mating connector. The shell has a cable extending from the cavity through the cable end being electrically connected to the at least one conductor. The shell defines a pocket in the cavity proximate to the cable end with the cable passing through the pocket. The electrical connector also includes a shielding insert received in the pocket. The shielding insert circumferentially surrounds the cable and is configured to block transmission of electromagnetic radiation through the cable end. The shielding insert includes a front segment and a rear segment. The front segment is formed from a first material. The rear segment is formed from a second material that is different than the first material. The first material has a higher electromagnetic radiation absorbing characteristic than the second material. 
     In one embodiment, an electrical connector is disclosed. The electrical connector comprises a shell having a mating end and a cable end. The shell has a cavity with at least one conductor therein. The at least one conductor is arranged at the mating end for termination to a mating connector. The shell has a cable extending from the cavity through the cable end being electrically connected to the at least one conductor. The shell defines a pocket in the cavity proximate to the cable end with the cable passing through the pocket. The electrical connector also includes a shielding insert received in the pocket. The shielding insert circumferentially surrounds the cable and is configured to block transmission of electromagnetic radiation through the cable end. The shielding insert includes a front segment and a rear segment. The front segment is formed from a first material. The rear segment is formed from a second material that is different than the first material. The first material is conductive and the second material is non-conductive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of an electrical connector system in accordance with an embodiment. 
         FIG. 2  is a partial exploded perspective view of a connector in accordance with an embodiment. 
         FIG. 3  is a perspective view of a portion of a connector showing a shielding insert outside of a pocket in accordance with an embodiment. 
         FIG. 4  is a cross sectional view of a shielding insert configured to absorb electromagnetic radiation in accordance with an embodiment. 
         FIG. 5  is a cross sectional view of a shielding insert configured to reflect electromagnetic radiation in accordance with an embodiment. 
         FIG. 6  is an exploded perspective view of a shielding insert in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a perspective view of an electrical connector system  100  in accordance with an embodiment. The electrical connector system  100  includes one or more connectors, such as a cable connector  102  that may be plugged into a receptacle assembly  104 . The receptacle assembly  104  may be mounted on a circuit board  106  of a host device. The circuit board  106  may be any circuit board, such as, for example, a motherboard in the host device. For example, the host device may be any electrical device, such as but not limited to, a computer, router, network switch, hub, and/or the like. 
     The cable connector  102  includes a shell  108  having a cable end  110  opposite a mating end  112 . A cable  114  is terminated to the cable connector  102  at the cable end  110 . The cable  114  may be electrically connected to an electrical device  116 . When the cable connector  102  is received within the receptacle assembly  104 , the electrical connector system  100  connects the electrical device  116  to the circuit board  106  as discussed below. The cable connector  102  includes components to reduce interference caused by electromagnetic radiation. 
     The receptacle assembly  104  is illustrated as having four ports, although the invention may be used with a receptacle assembly having only a single port or any number of ports. The receptacle assembly  104  includes a guide frame  118  positioned on the circuit board  106  and configured to receive the cable connector  102 . The guide frame  118  houses a plurality of receptacle connectors (not shown) positioned therein and configured to electrically connect the cable connector  102  to the circuit board  106 . The guide frame  118  has a plug end portion  120  through which the cable connector  102  is installed. The plug end portion  120  is configured to be mounted or received within an opening of a panel (not shown) that is adjacent to the circuit board  106 . For example, the panel may be a wall of a housing encapsulating the host device. In such an example, the cable connector  102  which is initially outside the housing can be received in the receptacle assembly  104  to be electrically connected to the circuit board  106  which is behind the panel and contained within the host device. 
     The guide frame  118  extends between the plug end portion  120  and an opposite rear end portion  122 . In the illustrated embodiment, the guide frame  118  has a generally rectangular cross section and includes an upper wall  124 , a lower wall  126 , side walls  128  and  130 , and a rear wall  132 . The guide frame  118  includes an internal chamber  134  that is subdivided into a plurality of internal bays or compartments  136 . In the illustrated embodiment, the guide frame  118  includes divider walls  138   a ,  138   b , and  138   c  that divide the internal camber into the compartments  136 . Each of the compartments  136  are configured to receive and secure the mating end  112  of one of the cable connector  102  therein. Although the guide frame  118  is shown as including four compartments  136  arranged in a single row, the guide frame  118  may include any number of compartments  136 , arranged in any number of rows and/or columns, for receiving any number of connectors. 
     Each of the compartments  136  includes a respective receptacle connector (not shown) housed therein. The receptacle connector is electrically connected to the circuit board  106 . When the cable connector  102  is inserted into one of the compartments  136 , the receptacle connector electrically connects the cable connector  102  to the circuit board  106 . As discussed above, the cable connector  102  is terminated to the cable  114  that terminates to the electrical device  116 . Accordingly, the electrical device  116  may be electrically coupled to the circuit board  106  of the host device via the cable connector  102 . 
       FIG. 2  is a partial exploded perspective view of the cable connector  102  in accordance with an embodiment. In the illustrated embodiment, the cable connector  102  includes the cable end  110  and the mating end  112 . But other configurations are possible in various embodiments, for example, the cable connector  102  may include a second cable end. In the illustrated embodiment, the cable connector  102  is shown as a small form-factor pluggable (SFP) connector, however, the cable connector  102  may be any type of pluggable electrical component. 
     The cable connector  102  includes a shielding insert  140 . The shielding insert  140  is configured to block transmission of electromagnetic radiation. The shielding insert  140  is situated proximate to the cable end  110 . As discussed below, the shielding insert  140  circumferentially surrounds the cable  114 . In this manner, the shielding insert substantially blocks or eliminates the transmission of electromagnetic radiation through the cable end  110 . 
     The shell  108  has a top cover  142  and a base  144  that are secured together to form a cavity  146  therebetween. The cavity  146  may be selectively sized and shaped to house a connector circuit board  148 , one or more conductors  150 , and/or the cable  114 , among other components. The top cover  142  and the base  144  may be made of any suitable material, such as, for example, a metal, a polymer, or other suitable material. The top cover  142  and the base  144  may be secured to one another using any means commonly known in the art for joining the housing pieces, such as, but not limited to, a snap fit, a friction fit, the use of a threaded fastener (for example, screws) and/or the like. 
     One or more of the conductors  150  define transmission lines extending through the cavity  146  between the cable end  110  and the mating end  112 . The conductors  150  may be any type of electrical conductor configured to be connected to a mating component, such as the receptacle connector housed within the guide frame  118  (shown in  FIG. 1 ). The conductors  150  may be terminated to the circuit board  148  on a proximal end, and may be terminated to wires  152  within the cable  114  on a distal end. The wires  152  may comprise at least a portion of the conductors  150 . For example, in the illustrated embodiment, the cable  114  includes wires  152   a ,  152   b ,  152   c , and  152   d  housed therein. The wires  152  may extend beyond a terminal end  154  of the cable  114 . The wires  152  may extend to and through the shielding insert  140  received in a pocket  156  (also shown in  FIG. 3 ) in the cavity  146 , as is described below. In various embodiments, the conductors  150  may include traces of the connector circuit board  148 . Other types of conductors may form part of the transmission lines defining the conductors  150 . 
     The connector circuit board  148  may be any circuit board, for example, the connector circuit board  148  may be a circuit board configured to perform transceiver functions. The wires  152  may terminate to wire contact pads  158  on the connector circuit board  148 . The wire contact pads  158  may then electrically connect to contact pads  160  arranged along an edge portion  162  of the connector circuit board  148 . For example, the connector circuit board  148  may include traces to electrically connect the wire contact pads  158  to the contact pads  160 . The contact pads  160  may define the electrical interface of the cable connector  102 . When the cable connector  102  is fully loaded into one of the compartments  136  (shown in  FIG. 1 ), the contact pads  160  electrically connect with corresponding terminal contacts (not shown) within the electrical connector housed within the guide frame  118 . 
       FIG. 3  is a perspective view of a portion of the cable connector  102  showing the shielding insert  140  outside of the pocket  156 . In an exemplary embodiment, the shielding insert  140  is molded in place in the pocket  156  around the cable  114 , and as such would remain positioned in the pocket  156  as opposed to being removable from the pocket  156 . However, in alternate embodiments, the shielding insert  140  may be pre-formed and may be separately loaded into the pocket  156 . The pocket  156  is a portion of the cavity  146  in the base  144  and/or the top cover  142  (shown in  FIG. 2 ). The pocket  156  may be selectively sized and shaped to ensure that the shielding insert  140  remains in position in the base  144 . The pocket  156  may be located proximate to the cable end  110 . A portion of the cable  114  passes through the pocket  156  and the shielding insert  140 . 
     In an exemplary embodiment, the shielding insert  140  circumferentially surrounds the cable  114  and/or the wires  152  (shown in  FIG. 2 ) to restrict movement of the conductor  150  (shown in  FIG. 2 ). The shielding insert  140  provides strain relief for the wires  152 . By molding in place in the pocket  156  around the cable  114 , the cable  114  is stabilized by the shielding insert  140 . The shielding insert  140  restricts movement of the cable  114  and/or the conductors  150  within the pocket  156  to provide strain relief for the cable  114  and/or the wires  152 . For example, the shielding insert  140  may limit movement of the cable  114  and/or the wires  152  in a longitudinal direction D. Additionally, the shielding insert  140  may limit the amount of transverse deflection of the cable  114  (for example, bending of the cable perpendicular to the direction D). Additionally, the shielding insert  140  may provide torsional strain relief by limiting rotational movement of the cable  114 . 
     The shielding insert  140  conforms to the contours of the pocket  156  such that a relatively tight fit may be achieved in the base  144 . The shielding insert  140  includes flanges  164  and  166  diametrically opposed along the body of the shielding insert  140 . The flanges  164 ,  166  abut against stops  168 ,  170 , respectively, in the pocket  156 . For example, the flange  164  may abut against the stop  168  such the stop  168  limits movement of the shielding insert  140  in the direction D. Similarly, the flange  166  may abut against the stop  170  such that the stop  170  limits movement of the shielding insert  140  in the direction D. In the illustrated embodiment, the flanges  164 ,  166  are shown as being integrally formed with the shielding insert  140 . However, in other embodiments, the flanges  164 ,  166  may be separate components that are secured to the shielding insert  140 . Optionally the shielding insert  140  may be compressible between the top cover  142  and the base  144  to provide a seal between the top cover  142  and the base  144 . No gaps exist between the top cover  142  and the base  144  at the cable end  110 . 
     The shielding insert  140  provides electromagnetic shielding and the relatively tight fit of the shielding insert  140  in the shell  108  limits transmission of electromagnetic radiation through the cable end  110 . The conductors  150  and/or wires  152  may transmit electrical signals at high frequencies and may emit electromagnetic radiation. For example, the connector circuit board  148  and/or the wires  152  may radiate electromagnetic radiation into the cavity  146  and the electromagnetic radiation may escape through openings or gaps at the cable end  110 , the mating end  112 , and/or seams (not sown) between the top cover  142  and the base  144  of the shell  108 . The electromagnetic radiation may detrimentally interfere with signals carried in the cable  114 , thus reducing the performance of the electrical cable connector  102 . Additionally, the electromagnetic radiation may cause electromagnetic interference (EMI) and may disrupt or otherwise degrade the operation of other electrical devices and/or other electrical components in the vicinity of the cable connector  102 . For example, the EMI may degrade the performance of the host device and/or the electrical device  116  (shown in  FIG. 1 ). Embodiments of the shielding insert  140  substantially suppress, reduce, or eliminate the transmission of the electromagnetic radiation through the cable end  110 . In another exemplary embodiment, the shielding insert  140  is manufactured from a material to absorb and/or reflect the electromagnetic radiation. 
       FIG. 4  is a cross sectional view of the shielding insert  140  configured to absorb electromagnetic radiation in accordance with an embodiment. In the illustrated embodiment, the cable  114  is shown passing through the shielding insert  140 , however, in other embodiments, such as the embodiment illustrated in  FIG. 2 , only the conductors  150  may pass through the shielding insert  140 . In various embodiments, the shielding insert  140  is manufactured from electromagnetic radiation absorbing material  172  configured to absorb substantially all of the electromagnetic radiation before the electromagnetic radiation exits the cable end  110  (shown in  FIG. 1 ) of the shell  108  (shown in  FIG. 1 ). The electromagnetic radiation absorbing material  172  is a material configured to suppress the propagation of electromagnetic radiation or waves. For example, the shielding insert  140  may be manufactured from a material having high electromagnetic radiation absorbing characteristic, such as, for example, a low magnetic permeability factor or a low electric permittivity factor. In various embodiments, the composition and/or density of the shielding insert  140  may be based on the desired amount of electromagnetic radiation absorption. 
       FIG. 5  is a cross sectional view of the shielding insert  140  configured to reflect electromagnetic radiation in accordance with an embodiment. In the illustrated embodiment, the cable  114  and the conductors  150  are shown passing through the shielding insert  140 . In various embodiments, the shielding insert  140  may be configured to reflect, trap, and/or guide the electromagnetic radiation into the shell  108  (shown in  FIG. 1 ) to prevent the transmission of electromagnetic radiation through the cable end  110  (shown in  FIG. 1 ). The shielding insert  140  is manufactured from a conductive impregnated dielectric material  174 . The conductive impregnated dielectric material  174  dissipates substantially all of the electromagnetic radiation exiting the cable end  110  by reflecting (for example, scattering, diffusing, or guiding) the electromagnetic radiation into the shell. The conductive impregnated dielectric material  174  includes a dielectric base or substrate  176  and conductive particles or flakes  178  embedded throughout the dielectric substrate  176 . For example, the conductive flakes  178  may comprise metal fibers or flakes, such as silver particles. The dielectric substrate  176  may be the electromagnetic radiation absorbing material  172  (shown in  FIG. 4 ). Although shown having a nearly uniform random distribution in the illustrated embodiment, the conductive flakes  178  may be selectively distributed throughout the dielectric substrate  176 . For example, the conductive flakes  178  may be in close, touching proximity such that conductive paths created through the shielding insert  140  allow the radiation to be transmitted into the shell  108 . The conductive flakes  178  are electrically connected to the shell  108  to direct the electromagnetic radiation into the shell  108 . The conductive impregnated dielectric material  174  is then electrically grounded to the shell  108 . 
       FIG. 6  is an exploded perspective view of the shielding insert  140  in accordance with an embodiment. In an exemplary embodiment, the shielding insert  140  may be formed by joining a front segment  180  and a rear segment  182 . The front and rear segments  180 ,  182  may be formed of different materials. For example, the front segment  180  may be formed of less expensive dielectric material while the rear segment  182  is formed of the electromagnetic radiation absorbing material  172  (shown in  FIG. 4 ) or the conductive impregnated dielectric material  174  (shown in  FIG. 5 ). The second material of the rear segment  182  has a higher electromagnetic radiation absorbing characteristic than the first material of the front segment  180 . 
     The front and rear segments  180 ,  182  may be overmolded over the cable  114  and/or the conductors  150  (shown in  FIG. 2 ) in a split-shot overmold as a multi-stage molding process. The first shot of the split-shot overmold is accomplished with a first material, while the second shot of the split-shot overmold is accomplished with a second material different than the first material. For example, the first shot of the split-shot overmold may be accomplished with the electromagnetic radiation absorbing material  172  or the conductive impregnated dielectric material  174 . The second shot of the split-shot overmold may be a non-conductive (for example, electrically insulative) hot melt configured to provide strain relief and structural rigidity. The second shot may be a less expensive material than the first material. Enough of the first material is used in the first shot to provide the desired amount of radiation absorbing or dissipation and the remainder of the insert  140  is formed with the molding of the second material in the pocket  156 . In an exemplary embodiment, the second shot is molded in situ against the first shot. 
     The first and the second shot of the overmold conform to the contours of the pocket  156  (shown in  FIG. 2 ). The split-shot overmold reduces manufacturing costs by reducing the amount of electromagnetic radiation absorbing material  172  or the conductive impregnated dielectric material  174  required to form the shielding insert  140 . The split-shot overmold also allows the electromagnetic radiation absorbing material  172  or the conductive impregnated dielectric material  174  to be situated near the cable end  110  and/or near the cable shield of the cable. 
     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. §102(f), unless and until such claim limitations expressly use the phrase “means for” followed by a statement of function void of further structure.