Patent Publication Number: US-RE48230-E

Title: High speed bypass cable assembly

Description:
REFERENCE To RELATED APPLICATIONS 
     The Present DisclosureThis application is a reissue continuation of U.S. application Ser. No. 15/271,903, which is a reissue of U.S. Pat. No. 9,011,177, which issued on Apr. 21, 2015 from U.S. application Ser. No. 13/987,296, which is a continuation-in-part of International Application No. PCT/US2010/022738, filed Feb. 1, 2010, entitled “High Speed Interconnect Cable Assembly,” filed 01 Feb. 2010 with the U.S. Patent And Trademark Office (USPTO) as Receiving Office for the Patent Cooperation Treaty. The &#39;738 Application claims priority of prior-filed U.S. Provisional Application No. 61/145,685, entitled “High Speed Interconnect Cable Assembly,” filed 30 Jan. 2009 also with the USPTO. The contents of each of the above Applications are fully incorporated in their entireties herein. 
    
    
     BACKGROUND OF THE PRESENT DISCLOSURE 
     The Present Disclosure relates generally to cable interconnection systems, and more particularly, to bypass cable interconnection systems for transmitting high speed signals at low losses. 
     Conventional cable interconnection systems are found in electronic devices such as routers and servers and the like, and are used to form a signal transmission line that extends between a primary chip member mounted on a printed circuit board of the device, such as an ASIC, and a connector mounted to the circuit board. The transmission line typically takes the form of a plurality of conductive traces that are etched, or otherwise formed on or as part of the printed circuit board. These traces extend between the chip member and a connector that provides a connection between one or more external plug connectors and the chip member. Circuit boards are usually formed from a material known as FR-4, which is inexpensive. However, FR-4 is known to promote losses in high speed signal transmission lines, and these losses make it undesirable to utilize FR-4 material for high speed applications (10 GHz and above). Custom materials for circuit boards are available that reduce such losses but the price of these materials severely increase the cost of the circuit board and, consequently, the electronic devices in which they are used. Additionally, when traces are used to form the signal transmission line, the overall length of the transmission line typically may well exceed 10 inches in length. These long lengths require that the signals traveling through the transmission line be amplified and repeated, thereby increasing the cost of the circuit board, and complicating the design inasmuch as additional board space is needed to accommodate these amplifiers and repeaters. In addition, the routing of the traces of such a transmission line in the FR-4 may require multiple turns and the transitions which occur at terminations affect the integrity of the signals transmitted thereby. It becomes difficult to route transmission line traces in a manner so as to achieve consistent impedance and a low signal loss therethrough. 
     The Present Disclosure is therefore directed to a high speed, bypass cable assembly that defines a transmission line for transmitting high speed signals, 10 GHz and greater that removes the transmission line from on the circuit board and which has low loss characteristics. 
     SUMMARY OF THE PRESENT DISCLOSURE 
     Accordingly, there is provided an improved high speed bypass cable assembly that defines a signal transmission line useful for high speed applications at 10 GHz or above and with low loss characteristics. 
     In accordance with an embodiment as described in the disclosure, an electrical connector assembly is disclosed. The electrical connector assembly comprises a printed circuit board, a chip member, a termination member, a first connector member, a bypass cable member and a second connector member. The chip member and the termination member are mounted on the printed circuit board, with the termination member mounted toward the end of the printed circuit board. The first connector member is in electrical communication with the chip member at a first end, and the bypass cable member electrically connects the first connector member, where it is coupled at a second end thereof, and the termination member, at a first end. The second connector member, disposed at a second end of the termination member, is in electrical communication with the termination member. Generally, the electrical connector is capable of the transmission of high speed signals. As the chip member is located a long length from the board connector, the bypass cable provides a transmission line therebetween that has a consistent geometry and structure that resists signal loss and maintains the system impedance at a consistent level without discontinuities. 
     In accordance with a second embodiment of the disclosure, the cable bypass assembly provides a transmission line that is separate from the circuit board, and may include one or more associated signal wire pairs, such as is found in “twin-ax” cable. The wires of the bypass cable are configured at their opposite ends in two fashions. At a first end of the bypass cable, the wires are configured for a direct termination to a board mounted connector, and are arranged in a manner such that the conductors of the signal wires extend in alignment with terminal termination ends, or feet, of the board mounted connector. The shielding of the signal wires are rolled back upon the insulative coating of the wires and exterior shield extensions are preferably provided to ensure that the signal wire conductor leads are effectively shielded through the connection. In this manner of connection, the terminal tails need not be attached to the circuit board, either as surface mount or through hole tails, thereby significantly reducing losses and the impedance discontinuity that occurs in the tail to board mounting transition. 
     At the second end of the bypass cable the signal wires are terminated in a fashion so that they can either be connected directly to the chip member or to the board in close proximity to the chip member. In this regard, and as disclosed in this second embodiment, the signal wire conductors are terminated to associated tail portions that are aligned with the conductors, similar to the termination which occurs at the first end. These tails are maintained in a desired spacing and are further completely shielded by a surrounding conductive enclosure to provide full EMI shielding and reduction of cross talk. The termination of the ends of the bypass cable assembly are done in a manner such that to the extent possible, the geometry of the conductors in the bypass cable is maintained through the termination of the cable to the board connector and/or the chip. 
     These and other objects, features and advantages of the Present Disclosure will be clearly understood through a consideration of the following detailed description. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       The organization and manner of the structure and operation of the Present Disclosure, together with further objects and advantages thereof, may best be understood by reference to the following Detailed Description, taken in connection with the accompanying Figures, wherein like reference numerals identify like elements, and in which: 
         FIG. 1  illustrates a perspective view of one embodiment of a high speed interconnect cable assembly, developed in accordance with the Present Disclosure; 
         FIG. 2  illustrates a perspective view of another embodiment of a high speed interconnect cable assembly, developed in accordance with the Present Disclosure; 
         FIG. 3  illustrates a perspective view of another embodiment of a high speed interconnect cable assembly, developed in accordance with the Present Disclosure; 
         FIG. 4  illustrates a perspective and inset view of the via transfer connector of the interconnect cable assembly of  FIG. 3 ; 
         FIG. 5  illustrates a perspective and inset view of the first connector member of the interconnect cable assembly of  FIG. 3 ; 
         FIG. 6  is a perspective view of a second embodiment of a cable bypass assembly constructed in accordance with the Present Disclosure; 
         FIG. 7  is a top plan view of the cable bypass assembly of  FIG. 6 ; 
         FIG. 8  is an exploded view of the assembly of  FIG. 6 , illustrating in greater detail the board connector to which the cable bypass assembly is terminated; 
         FIG. 9  is a perspective view of the board mounted connector of  FIG. 8 , with the first ends of the bypass assembly attached thereto; 
         FIG. 10  is a partially exploded view of  FIG. 9 ; 
         FIG. 11  is a top plan view of  FIG. 9 , with the EMI shield removed for clarity; 
         FIG. 11A  is a side elevational view of  FIG. 11 ; 
         FIG. 12  is perspective view of four pairs of signal wires terminated to the board connector terminal assembly and with one set of the shielding extensions removed for clarity; 
         FIG. 12A  is the same view as  FIG. 12 , but taken from the rear thereof; 
         FIG. 12B  is a end view of two pairs of signal wires with an associated shielding extension in place, illustrating the relative alignments of the signal conductors with each other and to the shielding of the cables; 
         FIG. 13  is a perspective view of one manner of terminating the ends of the cables of the cable bypass assembly which is opposite that of the termination to the board mounted connector; 
         FIG. 13A  is the same view as  FIG. 13 , but with one of the exterior shielding components removed for clarity; 
         FIG. 13B  is the same view as  FIG. 13A  but with the lower shielding component removed and the terminal support in place on the terminals attached to the second end of the cable; 
         FIG. 13C  is the same view as  FIG. 13B  but with the terminal support removed for clarity; 
         FIG. 13D  is the same view as  FIG. 13C , but taken from the other end thereof; 
         FIG. 13E  is a sectional view of  FIG. 13 ; 
         FIG. 14  is an embodiment of a termination structure for direct connection to a chip member; 
         FIG. 14A  is an exploded view of  FIG. 14 ; 
         FIG. 14B  is an enlarged detail view of  FIG. 14A . 
         FIG. 15  is a partially exploded view of an extent of flexible circuitry which may be used as a signal transmission line in cable bypass assemblies of the disclosure; and, 
         FIG. 16  is a graph comparing the losses between 12-inch lengths of signal transmission lines incorporated on a circuit board made from FR-4 material and a cable bypass assembly constructed in accordance with the principles of the disclosure. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     While the Present Disclosure may be susceptible to embodiment in different forms, there is shown in the Figures, and will be described herein in detail, specific embodiments, with the understanding that the disclosure is to be considered an exemplification of the principles of the Present Disclosure, and is not intended to limit the Present Disclosure to that as illustrated. 
     In the embodiments illustrated in the Figures, representations of directions such as up, down, left, right, front and rear, used for explaining the structure and movement of the various elements of the Present Application, are not absolute, but relative. These representations are appropriate when the elements are in the position shown in the Figures. If the description of the position of the elements changes, however, these representations are to be changed accordingly. 
     While the Present Disclosure may be susceptible to embodiment in different forms, there is shown in the Figures, and will be described herein in detail, specific embodiments, with the understanding that the disclosure is to be considered an exemplification of the principles of the Present Disclosure, and is not intended to limit the Present Disclosure to that as illustrated. 
       FIGS. 1-5  provide various perspective views of some basic components of a high speed interconnect cable assembly, developed in accordance with the teachings and tenets of the Present Disclosure. 
     Referring more specifically to  FIG. 1 , high speed interconnect cable assembly  10  generally comprises chip member  12  mounted on printed circuit board member  14 , first connector member  16  interfacing between chip member  12  and bypass cable member  18 , and termination member  20  interfacing between bypass cable member  18  and second connector member  22  disposed at the edge of printed circuit board member  14 . 
     Preferably, chip member  12  may comprise a PHY Chip, or any other surface-mounted, physical layer device, known in the art, from which a high speed signal is generated, such as an ASIC and transmitted to a cable assembly. Chip member  12  is mounted to any currently-known printed circuit board, using preferably any of the various currently-known mounting means. Preferably, an FR-4 type printed circuit board is used, in an effort to take advantage of its low cost and wide usage. For purposes of the Present Disclosure, the generated high speed signal may be any type of signal, but typically a data signal, generally having a frequency of 5 GHz and above, and most preferably and is a data signal having a frequency of 10 GHz or more. 
     Bypass cable member  18  is connected to chip member  12  by means of first connector member  16 . First connector member  16  is capable of transmitting a signal greater than 10 GHz between chip member  12  and bypass cable member  18 . The interface between first connector member  16  and chip member  18  may be by any known means, including, for example, a plug-receptacle connection, a friction-based connection or the like. It is preferred that the interface be removable. First connector member  16  is preferably capable of receiving the high speed signal generated by the chip member and transmitting it to the bypass cable member without need for a repeater or an amplifier, and without having to use the conductive properties of printed circuit board  14 . 
     Bypass cable member  18  comprises a flexible circuit member, such as a cable, extending from first connector member  16  to termination member  20 . Preferably, bypass cable member  18  is capable of receiving and carrying signals above 10 GHz. Preferably, bypass cable member  18  includes one or more wire pairs that transmit differential signals at high speeds. Each such wire pair may have a ground, or drain, wire associated with it. Further, the pairs may be enclosed within bypass cable member  18  and within an associated cable shield. Like first connector member  16 , bypass cable member  18  is preferably capable of receiving the high speed signal generated by first connector member  18  and transmitting it to termination member  20  without need for a repeater or an amplifier, and without having to use the conductive properties of printed circuit board  14 . 
     Termination member  20  is electrically connected to bypass cable member  18 , and receives the signal from bypass cable member  18 . Like all other elements in interconnection assembly  10 , termination member  20  is capable of receiving signals greater than 10 GHz. Preferably, termination member  20  is located at or near the edge of printed circuit board  14 . Termination member  20  may be mounted to the edge of printed circuit board  14 . Alternatively, termination member  20  may be “freestanding,” and not connected to any aspect of assembly  10 . Termination member  20  may receive bypass cable member  18  though any methods and means as currently described in the art. 
     Second connector member  22  preferably provides one end of a male-female relationship with termination member  20  (with termination member  20  providing the second end). It is not imperative that second connector member  22  (or termination member  20 ) be specifically relegated to the male or female end, as the teachings of the Present Disclosure will nevertheless be realized. 
     Second connector member  22  is preferably not disposed on any other aspect of interconnection assembly  10  of the Present Disclosure, i.e., second connector member  22  is not mounted on printed circuit board  14 . Second connector member  22  receives the signal from termination member  20 , and transmits the signal to its next or final destination. 
     The discussion above focused on a single interconnection assembly. Nevertheless, a plurality of interconnection assemblies may be used on a single printed circuit board, each generally comprising the above-referenced elements. A plurality of assemblies is generally illustrated in  FIG. 1 . Further, in a second embodiment, which is illustrated in  FIG. 2 , lamination member  24  may encompass all or part of multiple bypass cable members  18  for ease in assembly, as well as to maintain order on printed circuit board  14  and reduce the cost of assembly  10 . Preferably, lamination member  24  may comprise a rigid, formable polymer material that can be molded over both first connector member  16  and bypass cable member  18 . 
     Further, in another embodiment, a plurality of interconnection assemblies, used on a single printed circuit board, may be channeled to a single termination member  26  for transmission of signals beyond the printed circuit board. As illustrated in  FIG. 3 , bypass cable members  18  extend from chip members  12 , via first connector member  16 , towards first via transfer connectors  28 . Each via transfer connector  28  allows the signal being carried in bypass cable members  18  to pass through holes (or vias) in the printed circuit board where they connect with termination member  26 . 
       FIG. 4  illustrates a perspective close up of the connection of via transfer connectors  28  to termination member (not shown in  FIG. 4 ). As illustrated, each via transfer connector  28  houses the termination of bypass cable members  18 . Individual wires  30  extending from bypass cable members  18  are mounted within connector housing  32 . Connector housing  32 , along with individual wires  30  and a portion of bypass cable members  18 , are overmolded with terminal housing  34 . Terminal housing  34  is then inserted into the via hole of the printed circuit board, where it couples to termination member. 
       FIG. 5  illustrates a perspective close up of first connector member  16 . As illustrated, each first connector  16  houses the termination of bypass cable members  18 . Individual wires  36  extending from bypass cable members are overmolded with terminal housing  38 . Terminal housing  38  is then coupled to chip member  12 . 
       FIGS. 6-13E  illustrate another embodiment of a bypass cable assembly  100  constructed in accordance with the principles of the Present Disclosure. As shown in  FIG. 6 , a circuit board  101  that is used in an electronic device (not shown) has mounted thereon a chip member  104 , such as an ASIC, at one location and a shielding cage  102  mounted to the circuit board at another location, remote from the one location. The shielding cage  102  houses a receptacle connector assembly  110  that includes a receptacle connector  112  configured to receive the mating blade (typically the leading edge of a circuit card) of an opposing, mating connector (not shown) in a elongated card-receiving slot  113 . The connector  112  may also include a channel  114  disposed underneath the card slot  113  to receive a polarizing member of the mating connector. The connector  112  is accessible through an opening  103  at one end of the shielding cage  102 . A portion of the shielding cage  102  extends past the edge of the circuit board  101  and out of the enclosure which houses the circuit board  101 . This opening  103  permits access to the connector  112  from the exterior of the device and permits the insertion of a mating connector, typically in the form of a plug connector, therein in order to connect the device to another device and permit the transfer of signals between them. 
     A bypass cable assembly  105  is provided to connect together, the connector  112  and the chip member  104 , in order to form a signal transmission line extending therebetween for transmitting signals at high speeds of approximately 5 GHz and greater and preferably of approximately 10 GHz and greater. The cable assembly  105  includes a preselected length of cable  107  that has at a first end  107 a thereof, a first termination assembly and at a second and opposite end  107 b thereof, a second termination assembly. As shown best in  FIG. 12B , each cable  107  may be of the “twin-ax” type, in which a pair of signal conductors  144 A,  144 B are positioned in spaced-apart relationship within an insulative body  142 . This cable body  142  is surrounded by an outer conductive shielding layer  148  that is located underneath an exterior, insulative covering  140  and all of the cable elements may be formed as the single component illustrated. The structure of this particular type of twin-ax cable lends itself to uniformity throughout its length so that a consistent impedance profile is attained for the length of the cable. The cable assemblies  105  of this disclosure may include as few as one or two cables, or they may include greater numbers, such as the eight cables shown in  FIGS. 6, 9 &amp; 11 . 
     In order to avoid losses that normally occur in the use of signal transmission lines in the circuit board  101  using FR-4 as the board material, the cables  107  are used as the signal transmission lines. As noted above, the cables  107  are made in a manner that controls their size, thickness and the position and spacing of the signal conductors  144 A,  144 B so as to define a constant impedance profile throughout the lengths of the cables. Accordingly, twin-ax type of cable is desirable as well as flexible circuitry where positioning of the conductors and insulators may be controlled to a high degree of tolerance. Problems with impedance profiles typically occur at the termination points of cables where the geometry of the cable disrupted in order to effect a termination. One such solution to this problem is disclosed in U.S. Pat. No. 6,454,605, issued Sep. 24, 2002 and assigned to the assignee of the Present Disclosure and which is hereby incorporated by reference, in its entirety. 
     The cable assemblies of the Present Disclosure are terminated at their opposite ends  107 A,  107 B in a manner that seeks to reduce the modification of the cable geometry in order to reduce the magnitude of the aforementioned discontinuities and to prevent to the extent possible excessive loss, noise and crosstalk. Returning to the drawings and in particular  FIGS. 12 &amp; 12A , it can be seen that the terminals  120  of the receptacle connector  112  have tail portions  132  that extend outwardly from the rear face of the terminal assembly supports  118 A,  118 B and contact portions  130  that extend forwardly within the card-receiving slot  113  of the body of the receptacle connector  112 . The terminal contact and tail portions  130 ,  132 a,  132 b, extend in a continuous, generally horizontal extent through the connector without any vertical terminal extents that would provide an interruption of the horizontal extent. Consequently, as used herein, the term uninterrupted means a generally horizontal extent without any vertical portions. Similarly, “generally horizontal extent” also means that there are no vertical portions of the terminals that change the levels of the terminal contact and tail portions as would be found in terminals configured for surface mounting such as the low speed, power and status terminals  134  that are interposed between the high speed terminal sets. These non-high speed terminals  134  may be positioned with the use of a tail aligner block  116  or the like. In order to provide strain relief and to facilitate assembly, two cables may be held together by a block  106  applied to the cables  107  downstream of the termination areas. 
     In this manner, a “direct connection” is effected between the cable first end  107 A and the connector  112 , in a manner such that the signal terminal tail portions  132 a,  132 b are aligned with the exposed leads of the cable conductors  144 A,  144 B so that the exposed leads may be placed on the flat surfaces which the terminal tail portions  132 a,  132 b preferably provide. The inner shielding  148  of each cable  107  is pulled back over the exposed end of the cable and a shield extension  146  is provided for engaging these cable ends. The extension  146  is shown as a dual extension that can accommodate two cables. The shield extension  146  has what may be considered a cup portion  145  that is formed in a configuration that is generally complementary to the exterior configuration of the cable  107 , and it is provided with contact feet  146 a-c for contacting the associated terminal tail portions  132 c of ground terminals in the receptacle connector  112 . 
     The dual shield extension  146  shown in the drawings has two such cup portions  145  and three contact feet. Two contact feet  146 a,  146 b are formed along the outer edges of the cup portion  145 , while the third contact foot  14 c is formed between the cup portions  145 . The contact surfaces  147  formed on the bottom of the contact feet are preferably aligned with each other along a common plane, shown as “H” in  FIG. 12B . The conductors  144 A,  144 B of the cable  107  are also preferably aligned with the contact feet, along H as illustrated best in  FIG. 12B . In this manner a “direct” connection is effected between first ends  107 A of the cables  107  and the board mounted connector  112 , thereby eliminating the need for surface mounting or through hole mounting of the connector high speed terminal tails, all of which contribute to loss, noise and crosstalk at high speeds. Terminals of the connector  112  for which high speed performance is not an issue, such as low speed signal terminals and/or power and status terminals  134 , may be terminated in conventional manners mentioned above and they are shown in  FIGS. 12 &amp; 12A  as surface mounted, and such terminals may be disposed between sets of high speed terminals as illustrated for additional separation between the high speed terminal sets. Removing the high speed signals of the receptacle connector from attachment directly to the board, reduces the cost in formation and manufacture of the circuit board  102 . Additionally, the termination style shown in the drawings mirrors the geometry of the cable and provides generally complete shielding at the direct connection. 
     The shield extensions  146  provide as close as can be attained complete shielding at the direct termination to the board connector and they extend forwardly to completely cover the exposed ends of the cable signal conductors  144 A,  144 B as shown in  FIG. 11 . The shield extension mounting feet  146 a-c thereof are spaced apart and contact opposing tail portions of ground terminals of the first connector  112 . The shield extension feet  146 a-c and the conductors  144 A,  144 B of the cables  107  can be soldered or welded in their attachment to the connector terminals and the shield extensions  146  may be attached to the cables  107  by contact, a conductive adhesive, soldering or other suitable means. In this manner, the cable geometry is closely replicated in the termination area and more effective shielding is provided than just an ordinary ground wire to ground terminal connection. An EMI housing  109  may be utilized to provide an enclosure, in combination with the shielding cage  102  about the cable termination area. 
       FIGS. 13A-D  illustrate one form of termination that may be applied to the second ends of the cables  107 , which may be either connected directly to the chip member or to the circuit board  101  in close proximity thereto. As illustrated in  FIGS. 13B-D , the exposed leads of the cable conductors  144 A,  144 B are attached to signal terminals  160 , shown as a pair of signal terminals  160 A,  160 B. These terminal preferably have flat tail portions  163  and through hole contact portions  162 . The flat tail portions  163  preferably provide a flat surface to which the exposed conductors  144 A,  144 B may be contacted and attached via solder, welding or the like. The signal terminal  160  may be held in by an insulative support  156  that as shown is molded over body portions of the terminal  160 , leaving the tail and contact portions  163 ,  162  exposed for termination purposes. A shield collar  152  is provided that houses the signal terminal support  156  and substantially encloses the signal terminals with a conductive shield. The shield collar  152  has a shield extension  153 B that is similar in configuration to cable first end shield extensions  146  in that is has a cup portion  145  that contacts and receives the cable  107  and its inner shielding  148  therein. A cap member  153  is also provided and the cap member includes a block portion  154  that preferably abuts the terminal support  156  and which further preferably engages the shield collar  152  by way of tabs  156  that engage like holes  157  in the walls of the collar  152 . 
       FIGS. 14-14B  illustrate another embodiment of a manner or termination to a second connector. In this embodiment, the second connector  200  is one that is used to attach directly to the chip member  104 , and typically to a top surface thereof. In this regard, the second connector  200  has a housing  202  that receives a plurality of cables  204 , and the type of cables illustrated are of a different twin-ax structure, namely one in which each cable  204  contain a pair of signal wires  205  and a drain (ground) wire  206 . The signal wires  205  have signal conductors  207  running their length and surrounded by an outer insulative covering  208  and an outer covering  209  is provided that encloses a pair of the signal wires  205  and an associated drain wire  206 . A perforated base portion  210  of the housing  202  has a plurality of slots, or cavities  211 , each of which is configured to receive a single terminal  212  therein. LGA-style terminals are illustrated and each such terminal  212  includes a body portion  213  that engages the housing cavity  211 , a tail portion or mounting stub  214  that extends out of the cavity  211  and into contact with an exposed conductor  207  of the signal wires  205 , and a contact portion  215  that extend out of the opposite end of the cavity  211 . The second connector  200  also includes second cavities  216  that receive ground terminals (not shown) that are connected at their upper ends to the drain wires  206  and at their lower ends to the chip member  104 . The termination arrangement of this connector  200  also maintains, to the extent possible the geometry of the cables  204  through the connector termination, in the sense that the triangular arrangement of the three wires of each cable is maintained until the point where the drain wire is attached to the ground terminal and then the extent of the ground terminal is spaced from the ends of the signal wire terminals  212  as evidenced by the pattern of the first and second terminal cavities  211 ,  216 . 
       FIG. 15  illustrates an alternate construction for use as a signal transmission line in accordance with the disclosure and takes the form of an extent of flat flexible circuitry  300 . The extent includes a pair of signal conductors  302  that are spaced apart from each other and which run lengthwise between opposite ends of the cable  300 . The conductors  302  are surrounded on their top and bottom surfaces and sides by insulative portions  304 ,  305 . Ground shields  306  are provided to enclose the signal conductors  302 , and although shown only as above and below the signal conductors  302 , it will be understood that they may be disposed alongside of the signal conductors. With this sort of structure, the signal conductors may be exposed and aligned with terminal tails, while the ground shield extended to cover the termination areas in a manner similar to that shown above. 
       FIG. 16  is a graph comparing the loss between two 12-inch lengths of signal transmission lines, with one of the transmission lines comprising a pair of circuit traces formed in or on FR-4 circuit board material and the other transmission line comprising cables of the Present Disclosure. It can be seen from  FIG. 16  that the use of the cable of the Present Disclosure leads to a very low loss transition that only breaks past the 5 dB mark at approximately the 20 GHz frequency. Within the range of testing error, we believe that the cables of the Present Disclosure have low loss characteristics of no greater than between about 5 dB and about 8 dB at frequencies greater than about 19 Ghz. 
     While a preferred embodiment of the Present Disclosure is shown and described, it is envisioned that those skilled in the art may devise various modifications without departing from the spirit and scope of the foregoing Description and the appended Claims.