[0001] The present invention is directed to a cable assembly which controls impedance. In particular, the invention is directed to a cable assembly which utilizes a dielectric clamshell component to control cable termination impedance.

[0002] Maintaining signal integrity in communications is always desired. Factors that affect signal integrity include cable design and the process that is used to terminate or attach a cable. Cables are typically made of at least one plated, or unplated, center conductor covered by a dielectric and a braid and/or foil shield protector with an overall non-conductive jacket. The termination of the braid onto a device, such as a printed circuit board (PCB) or a connector, can significantly affect cable performance.

[0003] Various methods are known to terminate shield, components, including soldering the end of the wire onto a PCB/connector termination, laser terminating parallel gap resistance welding. Another comment method of termination is to use a ferrule. One significant problem with a ferrule is that crimping the wire to apply the ferrule tends to crush the cable dielectric. Another problem with existing methods of terminating a braid is that they can tend to rearrange the placement of the differential pair within the cable jacket. Both problems can affect impedance and other electrical parameters, which affect signal integrity.

[0004] The problem to be solved is to provide a cable assembly which controls impedance, and which does not damage or rearrange the conductors. In particular, it would be beneficial to a cable assembly which utilizes a dielectric clamshell component to control cable termination impedance.

[0005] This problem is solved by a connector for controlling impedance for use in a connector assembly, the connector has a housing with a first conductor receiving opening and a second conductor receiving opening. The first conductor receiving opening and the second conductor receiving opening are dimensioned to receive exposed conductors of a cable. The first conductor receiving opening and the second conductor receiving opening have conductor receiving portions, the conductor receiving portions extending at an angle relative to a longitudinal axis of the housing. The first conductor receiving opening and the second conductor receiving opening have conductor spacing portions which extend from the conductor receiving opening. The conductor spacing portions extend in a direction which is essentially parallel to the longitudinal axis of the housing. The spacing portions are spaced apart by a distance. The distance the spacing portions are spaced apart being selected to match the impedance of the cable.

[0006] The invention will now be described by way of example with reference to the accompanying drawings in which:

[0007] FIG. 1 is an exploded perspective view of a cable assembly according to the present invention.

[0008] FIG. 2 is a cross sectional view of the cable taken along line 2-2 of FIG. 1.

[0009] FIG. 3 is an enlarged perspective view of a clamshell connector of the cable assembly.

[0010] FIG. 4 is an enlarged perspective view of conductors position in a first portion of the clamshell connector, with a second portion of the clamshell connector exploded therefrom.

[0011] FIG. 5 is an enlarged perspective view of the clamshell connector fully inserted onto the conductors.

[0012] FIG. 6 is a perspective view of the cable assembly fully assembled.

[0013] FIG. 7 is a cross sectional view of the cable assembly of FIG. 6, taken along line 7-7. [0014] A cable 10 is illustrated in FIGS. 1 and 6. The cable 10 can transfer data between and among storage devices, switches, routers, printed circuit boards (PCBs), analog to digital converters, connectors, and other devices. In various embodiments, the cable 10 can support data transfer rates of 100 Mbps and higher. In some embodiments, the cable 10 can support data transfer rates of approximately 4.25 Gbps to approximately 25 Gbps. The cable 10 also can be used with data transfer rates above or below these exemplary rates. As shown in FIG. 2, the cable 10 has a cable jacket 12, a braided shield 16, a metalized foil 14 and two center conductors 18, 20. The conductors 18, 20 are spaced from each other and extend essentially parallel to each other. The conductors 18, 20 are surrounded by braided metal shield 16, such as, but not limited to braided copper shielding. The center conductors 18, 20 may also be surrounded by individual dielectrics 22, 23.

[0015] As shown in FIGS. 1 and 7, an end of the cable 10 has the cable jacket 12 removed. A portion 24 of the cable 10 may include a ferrule 26 provided proximate the end thereof. In such applications, the braided shield 16 would be folded back over the ferrule 26. The dielectrics of the conductors 18, 20 are also removed, thereby exposing a portion of the conductors 18, 20.

[0016] With the conductors 18, 20 exposed, terminals 30 are positioned on the ends of the conductors 18, 20. As shown in FIG. 4, wire terminating portions 32 of the terminals 30 are crimped to the conductors 18, 20. However, other methods of terminating the terminals 30 to the conductors 18, 20 may be used. In the illustrative embodiment shown, the terminals 30 are male terminals with pin portions 34 extending from the wire terminating portions 32. However, other configurations of terminals, including, but not limited to, female socket terminals, may be used.

[0017] With the terminals 30 properly terminated to the conductors 18, 20, the exposed portions of the conductors 18, 20 are aligned into a clamshell connector or housing 44. The clamshell connector 44 is made of a dielectric material. As shown in FIG. 3, the clamshell connector 44 has a first or bottom portion 42 and a second or top portion 46.

[0018] As shown in FIGS. 3 and 4, the bottom portion 42 has conductor receiving recesses 40 for receiving the conductors 18, 20 therein. The conductor receiving recesses 40 have conductor receiving portions 41 and conductor transition or spacing portions 43. The conductor receiving portions 41 extend at an angle relative to a longitudinal axis 45 of the housing 44 to receive and space apart the conductors 18, 20 as the conductors 18, 20 exit the cable 10. The conductor spacing portions 43 extend in a direction which is essentially parallel to the longitudinal axis 45 of the housing 44. The spacing portions 43 are spaced apart by the distance 47.

[0019] The bottom portion 42 has conductor receiving recesses 40 for receiving the conductors 18, 20 therein. The conductor receiving recesses 40 extend to terminal receiving recesses 58 which are dimensioned to receive the wire terminating portions 32 of the terminals 30 therein. A latch receiving opening 60 is positioned between the conductor receiving recesses 40. The latch receiving opening 60 has latching shoulders 61 extending from sidewalls thereof. A latch receiving recess 62 is positioned between the terminal receiving recesses 58. The latch receiving recess 62 has a latching shoulder 63 extending from a sidewall thereof.

[0020] The top portion 46 has conductor receiving recesses 48 for receiving the conductors 18, 20 therein. The conductor receiving recesses 48 have conductor receiving portions 49 and conductor transition or spacing portions 51. The conductor receiving portions 49 extend at an angle relative to the longitudinal axis 45 of the housing 44 to receive and space apart the conductors 18, 20 as the exit the cable 10. The conductor spacing portions 51 extend in a direction which is essentially parallel to the longitudinal axis 45 of the housing 44. The spacing portions 51 are spaced apart by the distance 47.

[0021] The conductor receiving recesses 48 extend to terminal receiving recesses 50 which are dimensioned to receive the wire terminating portions 32 of the terminals 30 therein. Latches 52, 54 extend from the top portion 46 and are positioned between the conductor receiving recesses 48. The latches 52, 54 have latching shoulders 53, 55. A latch 56 extends from the top portion 46 and is positioned between the terminal receiving recesses 50. The latch 56 has a latching shoulder 57. In the illustrative embodiment shown, the latches 52, 54, and 56 have similar configurations. However, other configurations of the latches may be used.

[0022] As shown in FIG. 5, the bottom portion 42 and top portion 46 are configured to be secured together to enclose the exposed portions of the conductors 18, 20. When secured, the exposed portions of the conductors 18, 20 are positioned in a first and second conductor receiving openings 66 (FIG. 7) formed by the conductor receiving recesses 40, 48. The conductor receiving openings 66 include first and second conductor transition or spacing portions 65 which are formed by the first conductor transition or spacing portions 43 and second conductor transition or spacing portions 51 when the bottom portions 42 is mated to the top portion 46. The conductor receiving openings 66 also include first and second conductor receiving portions 67 which are formed by first conductor receiving portions 41 and second conductor receiving portions 49 when the bottom portions 42 is mated to the top portion 46. The wire terminating portions 32 of the terminals 30 are positioned in first and second terminal receiving openings 68 (FIG. 7) formed by the terminal receiving recesses 50, 58.

[0023] The bottom portion 42 and the top portion 46 are retained in the closed position by the cooperation of the latching shoulders 53, 55 of the latches 52, 54 with the latching shoulders 61 of the latch receiving opening 60 and the latching shoulder 57 of the latch 56 with the latching shoulder 63 of the latch receiving recess 62.

[0024] The positioning of the exposed portions of the conductors 18, 20 in the first and second conductor receiving portions 67 of the first and second conductor receiving opening 66 of the clamshell connector 44 maintains the proper positioning and desired spacing of exposed portions of the conductors 18, 20 to allow mating to a mating connector. In the illustrative embodiment, the exposed portions of the conductors 18, 20 in the first and second conductor receiving portions 67 extend substantially parallel to each other and in substantially the same plane. As the housing 44 surrounds the exposed portions of the conductors 18, 20, the housing provides protection to the exposed portions of the conductors 18, 20, preventing damage to the exposed portions of the conductors 18, 20, thereby maintaining the integrity of the exposed portions of the conductors 18, 20 and the signal path provided thereby.

[0025] As the spacing and dimension of the first and second conductor receiving portions 67 of the first and second conductor receiving openings 66 of the clamshell connector 44 are controlled during the manufacture of the clamshell connector 44, the spacing of the exposed portions of the conductors 18, 20 are also controlled when the conductors are positioned in the first and second conductor receiving portions 67 of the first and second conductor receiving openings 66. Consequently, by properly selecting the dielectric material used for the clamshell connector 44 and properly determining the spacing between the first and second conductor receiving portions 67 formed by the first conductor receiving portions 41 and second conductor receiving portions 49, the impedance of the clamshell connector 44 can be tailored to match or approximately match the impedance of the cable 10.

[0026] The positioning of the exposed portions of the conductors 18, 20 in the first and second conductor transition or spacing portions 65 of the first and second conductor receiving opening 66 of the clamshell connector 44 provides a controlled transition with a controlled transition angle 71 between the conductor 18, 20 provided in the cable 10 and the exposed conductors 18, 20 positioned in the first and second conductor receiving portions 67 of the first and second conductor receiving openings 66. The transition angle 71 is the angle as measured between a longitudinal axis 45 of the housing 44 and the surface of the transition portions 65.

[0027] As the transition angle 71 , spacing and dimension of the first and second conductor receiving openings 66 of the clamshell connector 44 are controlled during the manufacture of the clamshell connector 44, the transition angle 71 and spacing of the exposed portions of the conductors 18, 20 are also controlled when the conductors are positioned in the first and second conductor transition or spacing portions 65 of the first and second conductor receiving openings 66. Consequently, by properly selecting the dielectric material used for the clamshell connector 44 and properly determining the transition angle 71 and spacing between the first and second conductor transition or spacing portions 65 formed by the first conductor transition or spacing portions 43 and second conductor transition or spacing portions 51 , the impedance of the clamshell connector 44 can be tailored to match or approximately match the impedance of the cable 10.

[0028] With the clamshell connector 44 properly positioned on the exposed portions of the conductors 18, 20 and the wire terminating portions 32 of the terminals 30, a terminal housing 70 (FIG. 7) is provided to provide stability to free ends of contacts 30.

[0029] An outer metallic shield member 72 of the cable assembly 74 is secured to the cable 10. As shown in FIGS. 6 and 7, a securing portion 76 of the outer metallic member 72 is positioned over a portion of the cable 10 and the ferrule 26. The securing portion 76 is then secured, for example by crimping, crimped to retain the outer metallic member 72 on the cable 10. A necked down portion 78 of the outer metallic member 72 is positioned over the clamshell connector 44 to provide additional shielding and to maintain the clamshell connector 44 in position. In the embodiment shown, the outer metallic member 72 has two pieces which are mechanically and electrically connected by latches, adhesive, or other know methods of attachment.

[0030] The cable assembly 74, and in particular, the clamshell connector 44, provides impedance control and does not damage or rearrange the conductors 18, 20. By properly selecting the dielectric material used for the clamshell connector 44 and properly determining the spacing between the recesses 40, 48, the conductors 18, 20 are properly positioned and the impedance of the clamshell connector 44 can be tailored to match or approximately match the impedance of the cable 10, thereby optimizing the performance of the cable 10 and the cable assembly 74.