WO2013074149A1 - Câble à paire mixte à large pas - Google Patents

Câble à paire mixte à large pas Download PDF

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Publication number
WO2013074149A1
WO2013074149A1 PCT/US2012/039236 US2012039236W WO2013074149A1 WO 2013074149 A1 WO2013074149 A1 WO 2013074149A1 US 2012039236 W US2012039236 W US 2012039236W WO 2013074149 A1 WO2013074149 A1 WO 2013074149A1
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WO
WIPO (PCT)
Prior art keywords
conductor
cable
conductors
shielding films
pinched
Prior art date
Application number
PCT/US2012/039236
Other languages
English (en)
Inventor
Douglas B. Gundel
Original Assignee
3M Innovative Properties Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 3M Innovative Properties Company filed Critical 3M Innovative Properties Company
Priority to CN201290000978.2U priority Critical patent/CN204257280U/zh
Publication of WO2013074149A1 publication Critical patent/WO2013074149A1/fr

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B11/00—Communication cables or conductors
    • H01B11/18—Coaxial cables; Analogous cables having more than one inner conductor within a common outer conductor
    • H01B11/20—Cables having a multiplicity of coaxial lines
    • H01B11/203—Cables having a multiplicity of coaxial lines forming a flat arrangement
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B7/00—Insulated conductors or cables characterised by their form
    • H01B7/08—Flat or ribbon cables
    • H01B7/0838—Parallel wires, sandwiched between two insulating layers

Definitions

  • the present disclosure relates generally to shielded electrical cables, systems, and methods.
  • Coaxial cables generally include an electrically conductive wire surrounded by an insulator. The wire and insulator are surrounded by a shield, and the wire, insulator, and shield are surrounded by a jacket.
  • a shielded electrical cable comprising one or more insulated signal conductors surrounded by a shielding layer formed, for example, by a metal foil. To facilitate electrical connection of the shielding layer, a further un-insulated conductor is sometimes provided between the shielding layer and the insulation of the signal conductor or conductors.
  • Some embodiment involve an electrical cable comprising one or more pairs of conductors extending along a length of the cable and spaced apart from each other along a width of the cable.
  • Each of the pairs includes a first conductor and a second conductor.
  • Each of the first and second conductors includes a conductor wire and surrounded by conductor insulation.
  • First and second shielding films are disposed on opposite sides of the electrical cable. The first and second shielding films including cover portions and pinched portions arranged such that, in transverse cross section, the cover portions of the first and second films in combination substantially surround each of the first and second conductors, and the pinched portions of the first and second films in combination form a pinched portion of the cable on at least one side of each of the first and second conductors.
  • the center-to-center spacing between the first and second insulated conductors is greater than about 1.2D when the cable is laid flat.
  • a maximum separation between the cover portions of the first and second shielding films is D and a minimum separation between the pinched portions of the first and second shielding films is d, where the ratio d/D is less than about 0.5.
  • a difference between a propagation delay for the first conductor and a propagation delay for the second conductor is less than about 20 picoseconds/meter.
  • Each of the pairs comprises a first conductor and a second conductor, each of the first and second conductors comprising a conductor wire and surrounded by conductor insulation.
  • First and second shielding films are disposed on opposite sides of the electrical cable, the first and second shielding films including cover portions and pinched portions arranged such that, in transverse cross section, the cover portions of the first and second films in combination substantially surround each of the first and second conductors, and the pinched portions of the first and second films in combination form at least one pinched portions of the cable between the first and second conductors.
  • a maximum separation between the cover portions of the first and second shielding films is D and a minimum separation between the pinched portions of the first and second shielding films is d, d/D being less than about 0.5.
  • the system includes a first signal propagating along the first conductor and a second signal propagating along the second conductor, wherein the first and second signals are complementary signals.
  • the electrical cable includes one or more pairs of conductors extending along a length of the cable and spaced apart from each other along a width of the cable. Each of the pairs comprises a first conductor and a second conductor, each of the first and second conductors comprising a conductor wire and surrounded by conductor insulation.
  • First and second shielding films are disposed on opposite sides of the electrical cable, the first and second shielding films including cover portions and pinched portions arranged such that, in transverse cross section, the cover portions of the first and second films in combination substantially surround each of the first and second conductors, and the pinched portions of the first and second films in combination form at least one pinched portions of the cable between the first and second conductors.
  • a maximum separation between the cover portions of the first and second shielding films is D and a minimum separation between the pinched portions of the first and second shielding films is d, d/D being less than about 0.5.
  • a first signal is propagated along the first conductor and a second signal is propagated along the second conductor, wherein the first and second signals are complementary signals.
  • Fig. 1 is a perspective view of an exemplary embodiment of a shielded electrical cable
  • Figs. 2A and 2B are transverse cross sectional views of cables according to some embodiments;
  • Fig. 3A depicts a cable termination configuration in which the center-to-center spacing of the termination connections substantially matches the center-to-center spacing of the conductors of the twin axial cable of Fig. 3B;
  • Fig. 3B is a cross sectional view of a twin axial cable;
  • Fig 3C depicts a cable termination configuration in which the center-to-center spacing of the termination connections is greater than the center-to-center spacing of the conductors of the twin axial cable of Fig. 3B;
  • Fig. 3D depicts a cable termination configuration in which the center-to-center spacing of the termination connections substantially matches than the center-to-center spacing of the conductors of a pair of coaxial conductors of a cable in accordance with some embodiments;
  • Figs.4- 1 1 depict various cable configurations in accordance with embodiments discussed herein;
  • Fig. 12 is a block diagram of an electrical system having complementary signals propagating in conductors of conductor pairs of a cable in accordance with various embodiments;
  • Figs. 13A-13C show bundled cable configurations
  • Fig. 14 depicts a bundled cable configuration for a multiple pair cable
  • Fig. 15 depicts a bundled cable having an external covering
  • Figs. 16A - 16C illustrates a method of fabricating cables according to various embodiments
  • Figs. 17A and 17B are cross sectional views of test cables
  • Fig. 18 illustrates a set up used to test the test cables
  • Fig. 19 shows differential insertion loss of the test cables
  • Fig. 20 shows differential-to-common mode conversion of the test cables
  • Fig. 21 shows time domain skew of the test cables.
  • Differential signaling may be implemented to transmit information over a pair of conductors, wherein one of the conductors carries a signal that is
  • complementary signals may be about 180 out of phase for substantially all of the length of the cable.
  • Differential signaling can provide some degree of noise immunity because, at the receiving end, the differential signals carried by the conductor pair are subtracted from one another, which reduces the effect of noise between each conductor to ground.
  • Shielding is used in some electrical cables to reduce interactions between signals carried by neighboring conductors. Differential pairs in a cable have been arranged in close proximity and shielded together to provide some degree of noise immunity from signals carried by neighboring conductor pairs in the cable.
  • the spacing of conductors in cables that include differential conductor pairs placed in close proximity and/or shielded together may need to be increased at the point wherein the conductors of the cable are attached to a terminating connector. For example, if the spacing of the connector terminals is greater than the conductor spacing, then the conductor spacing is increased to align with the connector terminal spacing.
  • increasing the conductor spacing at the termination point can lead to changes in impedance and/or intrapair signal skew at the termination point and/or can make it more difficult for mass termination of the cable conductors.
  • cables described herein can be arranged in a generally flat configuration, and include multiple conductors that extend along a length of the cable with electrical shielding films disposed on opposite sides of the cable.
  • the cables may be arranged in various folded configurations as discussed below. Pinched portions of the shielding films may be disposed between adjacent conductors.
  • An insulative jacket can be disposed around the conductive shield. Cables described herein can be configured with a conductor spacing that reduces misalignment between the conductors and termination connections at the termination point of the cable, while also being suitable to provide the noise immunity associated with differential signaling.
  • Figure 1 illustrates an exemplary shielded electrical cable 2 that depicts two pairs 4 of conductors 6 spaced apart from each other along a width, w, of the cable 2 and extending along a length, L, of the cable 2.
  • the conductors 6 include electrically conductive wires 6a surrounded by insulation 6b.
  • the cable 2 may be arranged generally in a planar configuration as illustrated in Fig. 1 or may be folded at one or more places along its length into a folded configuration. In some implementations, some parts of cable 2 may be arranged in a planar configuration and other parts of the cable may be folded.
  • the conductors 6 of the cable 2 may be arranged substantially parallel along all or a portion of the length, L, of the cable 2.
  • Two shielding films 8 are disposed on opposite sides of the cable 2.
  • the first and second shielding films 8 are arranged so that, in transverse cross section, cable 2 includes cover regions 14 and pinched regions 18.
  • cover portions 7 of the first and second shielding films 8 in transverse cross section substantially surround each conductor 6.
  • cover portions 7 of the shielding films may collectively encompass at least 75%, or at least 80, or at least 85% or at least 90% of the perimeter of any given conductor.
  • Pinched portions 9 of the first and second shielding films form the pinched regions 18 of cable 2 on each side of each conductor 6.
  • one or both of the shielding films 8 are deflected, bringing the pinched portions 9 of the shielding films 8 into closer proximity.
  • both of the shielding films 8 are deflected in the pinched regions 18 to bring the pinched portions 9 into closer proximity. These configurations are referred to herein as symmetrical configurations.
  • one of the shielding films may remain relatively flat in the pinched regions 18 when the cable is in a planar or unfolded configuration, and the other shielding film on the opposite side of the cable may be deflected to bring the pinched portions of the shielding film into closer proximity. These configurations are referred to herein as asymmetrical configurations.
  • the cable 2 may include one or more optional ground or drain wires 12 which may be disposed, for example, between the conductor pairs.
  • the ground/drain wires may be insulated or un-insulated wires and may be electrically coupled with one or both of the shielding films 8.
  • the ground/drain wires 12 may be in direct DC electrical contact with the shielding films 8.
  • the ground/drain wires 12 may be AC (capacitively) coupled to the shielding films 8.
  • the ground/drain wires 12 may be coupled to the circuit ground or in some cases may be coupled to the circuit power rail.
  • ground/drain wires may not be connected to ground, may not provide a drain, and/or may be coupled in a circuit to carry various signals, but are referred to as ground/drain wires herein for naming convenience.
  • Ground/drain wires 12 can be spaced apart from and extend in substantially the same direction as insulated conductors 6. In some cases, as shown in Fig. 1, ground/drain wires 12 are disposed between each differential pair 4, although other configurations are possible, some of which are discussed herein.
  • the cable 2 may optionally include an adhesive layer 10 disposed between shielding films 8 at least between the pinched portions 9.
  • the adhesive layer 10 bonds at least the pinched portions 9 of the shielding films 8 to each other in the pinched regions 18 of the cable 2.
  • the optional adhesive layer 10 may bond shielding films 8 to each other in the pinched regions 18.
  • the adhesive layer 10 may also be present in the cover region 14 of the cable 2. In the cover region 14, the adhesive layer 10 may bond the shielding films to the conductor insulator.
  • the conductor wires and/or ground/drain wires may comprise any suitable conductive material and may have a variety of cross sectional shapes and sizes.
  • the conductor wires and/or ground/drain wires may be circular, oval, rectangular or any other shape.
  • One or more conductor wires and/or ground/drain wires in a cable may have one shape and/or size that differs from other one or more conductors and/or ground wires in the cable.
  • the conductor wires and/or un-insulated wires may be solid or stranded wires. All of the conductor wires and/or ground/drain wires in a cable may be stranded, all may be solid, or some may be stranded and some solid.
  • Stranded conductor wires and/or ground/drain wires may take on different sizes and/or shapes.
  • the conductor wires and/or ground/drain wires may be coated or plated with various metals and/or metallic materials, including gold, silver, tin, and/or other materials.
  • the material used for the insulation may be any suitable material that achieves the desired electrical properties of the cable.
  • the insulation used may be a foamed insulation which includes air to reduce the dielectric constant and the overall thickness of the cable.
  • One or both of the shielding films may include a conductive layer and a non-conductive polymeric layer.
  • the shielding films may have a thickness in the range of 0.01 mm to 0.05 mm and the overall thickness of the cable may be less than 2 mm or less than 1 mm.
  • the conductive layer may include any suitable electrically conductive material, including but not limited to copper, silver, aluminum, gold, and alloys thereof.
  • the cable may include a jacket, e.g., of an electrically insulating material, surrounding the shielding films 8.
  • a coaxial conductor is formed by the conductor wire 6a surrounded by the insulator 6b which in turn is substantially surrounded by the shielding film cover portions 7.
  • Each pair 4 includes two coaxial conductors 6.
  • Each pair 4 or can be configured as a differential signaling conductor pair configured to carry complementary signals, as indicated by the "+" and "-" signs in Fig. 1.
  • FIG. 2A and 2B illustrate cables 200a, 200b according to some embodiments.
  • Cable 200a includes a single coaxial conductor pair 204, whereas cable 200b exhibits the same general configuration as cable 200a in a multiple coaxial pair version.
  • cables 200a and 200b show one conductor pair and two conductor pairs, respectively, it will be appreciated that a cable can include any number of conductor pairs.
  • the cables 200a, 200b illustrate one or more pairs 204 of conductors 206 and one or more ground/drain wires 212 which in this implementation are spaced apart from the conductors 206.
  • the conductors 206 include electrically conductive wires 206a surrounded by insulation 206b.
  • cables 200a and 200b include cover regions 221 and pinched regions 225.
  • the shielding films 208 include first cover portions 222 that cover the conductors 206.
  • the cover portions 222 in combination, substantially surround a conductor 206.
  • each of the shielding films 208 includes a pinched portion 226 that is deflected to bring the shielding films 208 into closer proximity in the pinched region 225.
  • Ground/drain wires 212 are spaced apart from and extend in substantially the same direction as insulated conductors 206.
  • the ground/drain wires 212 may electrically contact at least one of shielding films 208.
  • Conductors 206 and ground/drain wires 212 can be arranged so that they lie generally in a plane as illustrated in Figs. 2A and 2B.
  • the cables 200a, 200b include cover regions 223 in which the shielding films 208 include cover portions 224 that cover the ground/drain wires.
  • Pinched regions 227 are disposed between a conductor 206 and a ground/drain wire 212. In the pinched regions 227, pinched portions 228 of each of the shielding films 208 are deflected, bringing the shielding films 208 into closer proximity in the second pinched regions 227.
  • An optional adhesive layer 210 may bond the shielding films 208 to each other in the pinched regions 225 between the conductors 206 and/or the pinched regions 227 between a conductor 206 and a ground/drain wire 212.
  • the adhesive layer can extend or be disposed in one or both of the conductor cover regions 221 and/or the ground/drain wire cover regions 223, bonding the conductor insulation 206b and/or the ground/drain wires 212 to the shielding film 208.
  • the adhesive used may be a conductive adhesive to facilitate electrical connection between the ground/drain wires 212 and the shielding film 208.
  • each shielding film cover portion 222 can include a concentric portion 222a that is substantially concentric with the conductor 206 and transition portions 222b at the transition between the cover portion 222 and the pinched portions 226, 228 of the shielding film 208.
  • transition portions 222b may be positioned on both sides of the conductor 206 as illustrated by cable 200a, however, in some embodiments, it is possible for a transition portion to be positioned on only one side of the conductor.
  • the transition portions 222b of the shielding films 208 may provide a gradual transition between concentric portions 222a and pinched portions 226 of the shielding films 208.
  • a gradual or smooth transition such as, e.g., a substantially sigmoidal transition, provides strain and stress relief for shielding films 208 in the region of the transition portions 222b and helps to prevents damage to shielding films 208 (e.g., such as fractures and/or debonding of the shielding film) when shielded electrical cable 200a is in use, e.g., when laterally or axially bending shielded electrical cable 222a.
  • gap 250 may be substantially filled with air.
  • adhesive e.g., from the adhesive layer
  • the gap volume may comprise substantially no air, or may comprise a small amount of air, e.g., less than 20%, 10%, 5% or less than 1% air.
  • acceptable electrical properties can be achieved by reducing the electrical impact of the transition portions, e.g., by reducing the size of the transition portions and/or carefully controlling the configuration of the transition portions along the length of the shielded electrical cable. Reducing the size of the transition portions reduces the capacitance deviation and reduces the required space between multiple conductor sets, thereby reducing the conductor set pitch and/or increasing the electrical isolation between conductor sets. Careful control of the configuration of the transition portions along the length of the shielded electrical cable contributes to obtaining predictable electrical behavior and consistency, which provides for high speed transmission lines so that electrical data can be more reliably transmitted. Careful control of the configuration of the transition portions along the length of the shielded electrical cable is a factor as the size of the transition portion approaches a lower size limit.
  • Each insulated conductor 206 and cover portions 222 of the shielding films 208 are effectively arranged in a coaxial cable configuration.
  • Each pair 204 of coaxial conductors 206 can be used together as a differential pair configured to carry complementary signals, as indicated by the "+" and "-" signs.
  • the center-to-center spacing between the conductors 206 in a pair 204 is designated as w c . c which can be determined as the distance from the center point a first conductor wire 206a in a conductor pair 204 and the center point of a second conductor wire 206a in the pair 204. In various embodiments, w c .
  • c can have any value equal to or greater than D, and exemplary values for w c . c could range from about 1.2D to about 10D. In some cases, w c . c , may be greater than 10D.
  • the center-to-edge spacing between a conductor 206 and an adjacent ground/drain wire 212 is designated as H> e-g , which can be determined as the distance from the center point of a conductor wire 206a to an edge of a ground/drain wire 212.
  • w c . g may be greater than or about equal to 0.5D, with exemplary values for w c . g ranging from about 0.5D to about 10D. In some implementations, w c . g may be greater than 10D.
  • the center-to-center spacing, w p . p , between conductor pairs 204 is determined as the distance from the center point of a first conductor pair to a center point of an adjacent conductor pair.
  • exemplary values for w p . p range from about 2.5D to about 20D, or may even be greater than 20D.
  • w c . c , w c . g , and/or w p . p can vary along the transverse direction in the cable, e.g., w c . c , for a first conductor pair may not be equal to the w c . c of an adjacent conductor pair in the cable.
  • the electrical length of a cable is its length measured in wavelengths and is related to the frequency of the signal and the velocity with which the signal propagates along the cable.
  • the electrical length of the cable may be expressed:
  • / is the physical length of the cable, /is the frequency of the signal, V F is the velocity factor of the cable, and a is a constant.
  • the velocity factor of the cable is the speed at which a signal passes through the cable:
  • the series inductance, L s , and parallel capacitance, C P , of a coaxial cable depend on the physical and material properties of the cable.
  • the characteristic impedance, and thus the electrical length and/or propagation delay may depend on factors including the dielectric constant of the material between the conductor wires, the diameter of the conductor wires, the distance between the conductor wires and the shield, which is related to the distance, D, and/or the center-to-center spacing between the conductor wires, w c . c .
  • Conductors that have different electrical lengths may have different signal propagation times for a signal of a given frequency.
  • Conductors of a conductor pair may exhibit skew between the signals carried on the conductors, which is the difference in propagation time between signals carried by the two conductors in a pair.
  • the physical and material properties of the conductor can be adjusted to change the electrical length of the conductor.
  • Cable embodiments described herein can have coaxial conductor pairs, as illustrated by the first and second conductors 206 of the coaxial pairs 204 in Figs. 2A and 2B, having a d/D ratio of less than 0.5, c _ c may be greater than D, e.g., 1.2D to 10D, or even greater than 10D, wherein the coaxial conductors have substantially equal propagation delay times and/or electrical lengths.
  • the difference between propagation times for signals propagating one meter in each of the conductors 206 of a conductor pair 204 is less than 1% and/or less than about 20 picoseconds or even less than about 10 picoseconds.
  • the length of wire that is free from the shield (which offers impedance control) is longer. Because the impedance in the span where the conductor wire is free from the shield is not the same as the impedance in the cable or the impedance in the connector card, an impedance difference results, which can degrade signal integrity. The larger the impedance difference and the longer the span of this impedance difference, the greater the degradation of signal integrity. Furthermore, in cases where w c . c is less than the spacing of the termination connections, termination of the cable to the connector, e.g., connector printed circuit board, is more difficult because the wires need to be manipulated after the shield is stripped.
  • FIG. 3A depicts a cable termination configuration 301 in which the center-to-center spacing of the termination connections 310 substantially matches the center-to-center spacing of the conductors 316 of the twin axial cable 391, which is shown in cross section in Fig. 3B.
  • the twin axial cable 391 includes two insulated electrical conductors 316 that together are substantially surrounded by shielding films 318 disposed on either side of the conductors 316.
  • Figure 3C depicts a cable termination configuration 302 in which the spacing of the termination connections 310 is wider than the spacing of the conductors 316 of the twin axial cable 391 illustrated in Fig. 3B.
  • the spacing mismatch between the termination connections 310 and the conductors 316 in the termination configuration 302 of Fig. 3C causes the shield 318 in configuration 302 to be stripped back farther when compared to configuration 301 of Fig 3A.
  • the conductors 316 of configuration 302 are further separated at the point of termination when compared to the conductors 316 of termination configuration 301.
  • the termination configuration 302 of Fig. 3C is suboptimal when compared to configuration 301.
  • FIG. 3D depicts a termination configuration 303 that includes a cable that is similar to cable 200a of Fig. 2A.
  • the cable of configuration 303 includes dual coaxial conductors 306 that may be operated as a differential pair.
  • the cable has shielding layers 308 disposed on either side of the conductors 306.
  • the spacing, w c . c , between conductors 306 substantially matches the spacing of the termination connections 310.
  • the shield in configuration 303 can remain relatively close to the termination connections 310 and the separation between the conductors 306 at the termination connections 310 does not have to be substantially increased from the spacing, w c . c to match the spacing of the termination connections 310.
  • the termination configuration 303 is provides more robust noise performance, the electrical length and/or propagation delays of the conductors are substantially equal, and the skew between conductors is reduced. Cost may be reduced because it is easier to produce and/or assemble the cables.
  • Figures 4- 1 1 provide single pair and multiple pair examples of cables 400a, 400b, 500a, 500b, 600a, 600b, 700a, 700b, 800a, 800b, 900, 1000, 1100 in accordance with various embodiments.
  • the conductors and the shielding films are arranged so that deflection of the shielding films in the cover regions of each of the conductors substantially surrounds the conductors and effectively provides a coaxial cable configuration.
  • Each pair of coaxial conductors can be used together as a differential pair configured to carry complementary signals, as indicated by the "+" and "-" signs on the conductors.
  • the cover regions there is a maximum separation, D, between the cover portions of the shielding films, and there is a minimum separation, d, between the pinched portions of the shielding films.
  • the ratio d/D is less than about 0.5.
  • the spacing between the conductors in a pair, w c . c can have any value equal to or greater than D. Exemplary values for w c . c could range from about 1.2D to about 10D, however, in some cases, w c . c may be greater than 10D.
  • w c . g The center-to-edge spacing between a conductor and an adjacent ground/drain wire is designated as w c . g , which can be determined as the distance from the center point a conductor wire to an edge of a ground/drain wire.
  • w c . g may be greater than or about equal to 0.5D, with exemplary values for w c . g ranging from about 0.5D to about 10D. In some cases, w c . g could be greater than 10D.
  • the center-to-center spacing, w p . p , between conductor pairs is determined as the distance from the center point of a first conductor pair to a center point of an adjacent conductor pair.
  • exemplary values for w p . p range from about 2.5D to about 20D, or may even be greater than 20D.
  • the coaxial conductors of a conductor pair can have substantially equal propagation delay times and/or electrical lengths. In some embodiments, the difference between propagation times for signals propagating one meter in each of the conductors in a conductor pair is less than 1% and/or less than about 20 picoseconds or even less than about 10 picoseconds.
  • the transverse cross sectional views of Figs. 4A and 4B illustrate cables 400a, 400b have some similarity to cables 200a, 200b, except that cables 400a include ground/drain wires between conductors of a conductor pair and ground/drain wires are not disposed between conductor pairs, as in cables 200a, 200b.
  • Cable 400a includes a single coaxial conductor pair 404, whereas cable 400b exhibits the same general configuration as cable 400a in a multiple coaxial pair version.
  • cables 400a and 400b include cover regions 421 and pinched regions 425.
  • the shielding films 408 include cover portions 422 that cover the conductors 406. In transverse cross section, the cover portions 422, in combination, substantially surround a conductor 406.
  • the pinched regions 425 of the cable 400a, 400b are located between conductors 406 of adjacent pairs 404.
  • each of the shielding films 408 includes pinched portions 426 that are deflected to bring the shielding films 408 in the pinched regions 425 into closer proximity.
  • Each shielding film 408 includes cover regions 423 and pinched regions 427.
  • cover regions 423 cover portions 424 of the shielding film 408 are disposed around the ground/drain wires 412.
  • pinched portions 428 of the shielding film 408 are disposed between a conductor 406 and a ground/drain wire 412.
  • the pinched portions 427 of each of the shielding films 408 are deflected, bringing the shielding films 408 into closer proximity in the pinched regions 427.
  • Figs. 5A and 5B illustrate cables 500a, 500b have some similarity to cables 200a, 200b and 400a, 400b except that in cables 500a, 500b ground drain wires 512 are disposed between conductors 506 of each conductor pair 504 and ground/drain wires 512 are disposed conductor pairs 504.
  • cables 500a and 500b include cover regions 521 and pinched regions 527.
  • the shielding films 508 include cover portions 522 that cover the conductors 506. In transverse cross section, the cover portions 522, in combination, substantially surround a conductor 506.
  • the pinched regions 527 of the cable 500a, 500b are located between conductors 506 and ground/drain wires 512.
  • each of the shielding films 508 includes pinched portions 528 that are deflected to bring the shielding films 508 in the pinched regions 527 into closer proximity.
  • FIG. 6A and 6B illustrate cables 600a, 600b according to some embodiments.
  • Cable 600a includes a single coaxial conductor pair 604, whereas cable 600b exhibits the same general configuration as cable 600a in a multiple coaxial pair version.
  • Cables 600a, 600b illustrate configurations in which a ground/drain wire 612 is in close proximity with a conductor 606. In these close-proximity configurations in which a ground/drain wire is grouped with a conductor, an outer surface of the ground/drain wire may contact the outer surface of the conductor insulator. The ground/drain wire may be as close to the conductor as the shielding films.
  • Cover portions 632 of the shielding films 608 cover both each group of a conductor 606 and a ground/drain wire 612 in these embodiments.
  • Cables 600a and 600b include cover regions 631 and pinched regions 633.
  • the shielding films 608 include cover portions 632 that cover conductors 606 and a ground/drain wire 612. In transverse cross section, the cover portions 632, in combination, substantially surround a conductor 606 and the ground/drain wire 612.
  • Pinched regions 633 of the cable 600a, 600b are located between conductors 606 of a conductor pair 604.
  • each of the shielding films 608 includes pinched portions 634 that are deflected to bring the shielding films 608 in the pinched regions 633 into closer proximity.
  • Each shielding film 608 also includes pinched regions 639.
  • pinched portions 640 of the shielding film 608 are disposed between a two ground/drain wires 612. As illustrated in Figs. 6A and 6B, the pinched portions 640 of each of the shielding films 608 are deflected, bringing the shielding films 608 into closer proximity in the pinched regions 639.
  • cables 700a, 700b have some similarity to cables 600a, 600b except that in cables 700a, 700b two ground drain wires 712 are in close proximity with a conductor 706.
  • Cables 700a and 700b include cover regions 733 and pinched regions 739.
  • the shielding films 708 include cover portions 734 that cover each conductor 706 and two ground/drain wires 712.
  • the cover portions 733 in combination, substantially surround a conductor 706 and ground/drain wires 712.
  • the pinched regions 739 of the cable 700a, 700b are located between two ground/drain wires 712.
  • each of the shielding films 708 includes pinched portions 740 that are deflected to bring the shielding films 708 in the pinched regions 739 into closer proximity.
  • cables 200a, 200b, 400a, 400b, 500a, 500b, 600a, 600b, 700a, 700b discussed above are referred to as symmetrical cables because the two shielding films are symmetrical with respect to the transverse axis.
  • the cables may have asymmetrical shielding films as illustrated by cables 800a and 800b in Figs 8 A and 8B.
  • Cable 800a includes a single coaxial conductor pair 804, whereas cable 800b exhibits the same general configuration as cable 800a in a multiple coaxial pair version.
  • Cables 800a and 800b include cover regions 841 and pinched regions 845, 847.
  • the shielding films 808 include cover portions 842t, 842b that cover the conductors 806. In transverse cross section, the cover portions 842t, 842b, in combination, substantially surround a conductor 806.
  • the pinched regions 845 of the cable 800a, 800b are located between conductors 806 of a pair 804.
  • the shielding films 808 include pinched portion 846t, 846b. The pinched portion 846t of one of the shielding films 808 is deflected to bring the shielding films 808 in the pinched regions 845 into closer proximity.
  • the pinched portion 846b of the opposing shielding film 808 may be substantially undeflected or may be deflected by a lesser amount than the pinched portion 846t.
  • Each shielding film 808 includes pinched regions 847. In the pinched regions 847, pinched portions 848t, 848b of the shielding film 808 are disposed between a conductor 806 and a ground/drain wire 812 which in this implementation is spaced apart from the conductor. In the implementation illustrated in Figs. 8A and 8B, the pinched portions 848t, 848b of each of the shielding films 808 are deflected, bringing the shielding films 808 into closer proximity in the pinched regions 847. In some embodiments, in pinched regions between a conductor and a ground/drain wire, only one of the shielding films pinched portions is deflected and the other pinched portion is substantially undeflected, or is deflected a lesser amount.
  • Fig. 9 illustrates cable 900 in which ground/drain wires
  • Cable 900 includes a single coaxial conductor pair 904, although a cable may include more than one conductor pair. Cable 900 illustrates a configuration in which the ground/drain wires 912 are disposed in close proximity to a conductor 906. Cover portions 953 of the shielding films 908 cover both the conductors 906 and two ground/drain wires 912 in this embodiment.
  • Cables 900a includes cover regions 953 and pinched regions 959.
  • the shielding films 908 include cover portions 954t, 954b that cover a conductor 906 in close proximity with two ground/drain wires 912. In transverse cross section, the cover portions 953, in combination, substantially surround a grouped conductor 906 and ground/drain wires 912.
  • the pinched regions 959 of the cable 900 are located between the conductor- ground/drain wire groups.
  • the shielding films 908 include pinched portion 960t, 960b.
  • the pinched portion 960t of one of the shielding films 908 is deflected to bring the shielding films 908 in the pinched regions 959 into closer proximity.
  • the pinched portion 960b of the opposing shielding film 908 may be substantially undeflected or may be deflected by a lesser amount than the pinched portion 960t.
  • the transverse cross sectional view of Fig. 10 illustrates cable 1000 in which one ground/drain wire 1012 is located in close proximity, with conductor 1006.
  • Cable 1000 includes a single coaxial conductor pair 1004, although a cable may include more than one conductor pair 1004.
  • cover portions 1052t, 1052b of the shielding films 1008 cover the grouped conductor 1006 and ground/drain wire 1012.
  • the cover portions 1053t, 1052b in combination, substantially surround a grouped conductor 1006 and the ground/drain wire 1012.
  • Pinched regions 1057 of the cable 1000 are located between the conductor 1006 and ground/drain wire 1012 groups.
  • the shielding films 1008 include pinched portion 1058t, 1057b.
  • the pinched portion 1058t of one of the shielding films 1008 is deflected to bring the shielding films 1008 in the pinched regions 1057 into closer proximity.
  • the pinched portion 1058b of the opposing shielding film 1008 may be substantially undeflected or may be deflected by a lesser amount than the pinched portion 10581
  • the conductor spacing between coaxial pairs is not consistent from coaxial pair to coaxial pair along the width (the transverse direction) of the cable. These implementations facilitate termination to termination connections that have inconsistent pair to pair spacing.
  • the conductors 1106 of a first coaxial conductor pair 1104 are separated by a first spacing, w c-c i.
  • the conductors 1106 of a second coaxial conductor pair 1105 are separated by a second spacing, w c-C 2 that is different from the first spacing.
  • the conductor spacing between conductors of a pair and/or between conductor pairs varies along the cable length (the longitudinal direction of the cable).
  • Conductor spacing that varies along the cable length is illustrated by cable 1100b of FIG. 1 IB.
  • the conductor-to-conductor spacing of a conductor pair, w c . c3 at one end or longitudinal position of the cable 1100b, is less than the conductor-to-conductor spacing of the conductor pair, w c . C4 , at another or longitudinal position of the cable.
  • Figure 12 illustrates an electrical system 1200 that includes a cable 1220 that comprises at least one coaxial pair, such as any of the cables 400a, 400b, 500a, 500b, 600a, 600b, 700a, 700b, 800a, 800b, 900, 1000, 1100.
  • the cable includes at least two conductors 1221a, 1221b and shield 1222.
  • the conductors 1221a, 1221b of cable 1220 are terminated at the source side to termination connections 1235a, 1235b of a first printed circuit (PC) board 1230 and are terminated at a target side to termination connections 1245a, 1245b of a second PC board 1245.
  • the termination connections 1205a, 1205b have substantially the same spacing as the spacing between conductors 1221a, 1221b of the coaxial conductor pairs of cable 1220.
  • the system 1200 includes a source which is configured to generate two
  • complementary signals that are substantially 180 degrees out of phase.
  • One of the complementary signals is carried by a first conductor 1221a of the coaxial conductor pair and another of the complementary signals is carried by a second conductor 1221b of the coaxial conductor pair.
  • the complementary signals propagate through the conductors 1221a, 1221b of the cable 1220 from the source to the target. At the target, the complementary signals are subtracted by differential circuit element 1250 which produces a differential output signal at trace 1255.
  • An electrical characteristic that is often considered for cable conductors is the characteristic impedance as previously discussed. Any impedance changes along the length of a conductor may cause power to be reflected back to the source instead of being transmitted to the target. Ideally, the conductor line will have no impedance variation along its length, but, depending on the intended application, variations up to 5- 10% may be acceptable.
  • Another electrical characteristic that is often considered in conductors used in a differential signaling configuration is skew or unequal transmission speeds of the two conductors of a differential pair along at least a portion of their length. Skew produces conversion of the differential signal to a common mode signal that can be reflected back to the source, reduces the transmitted signal strength, creates electromagnetic radiation, and can dramatically increase the bit error rate, in particular jitter.
  • conductors of a differential pair will have no skew, i.e., propagation delays that are substantially the same.
  • a differential S-parameter SCD21 or SCD12 value (which is a measure of skew as the differential-to common mode conversion from one end of the transmission line to the other) of less than -15 to -30 dB up to a frequency of interest, such as, e.g., 6 GHz, may be acceptable.
  • Skew can be measured in the time domain.
  • the coaxial pairs used in differential mode of the electrical cables described herein may achieve skew values of less than about 20 picoseconds/meter (psec/m) or less than about 10 psec/m at data transfer speeds up to about 10 Gbps, for example.
  • Signal loss or attenuation is another important consideration for many electrical cable applications.
  • One typical loss specification for high speed I/O applications is that the cable have a loss of less than -6dB at, for example, a frequency of 5 GHz. (In this regard, the reader will understand that, for example, a loss of -5dB is less than a loss of -6dB.)
  • Such a specification places a limit on attempting to miniaturize a cable simply by using thinner wires for the insulated conductors of the conductor sets and/or for the drain wires. In general, with other factors being equal, as the wires used in a cable are made thinner, cable loss increases.
  • wire sizes may be feasible in other high speed applications, and advances in technology can also be expected to render smaller wire sizes acceptable.
  • Twinaxial cables include configurations such as cable 391 illustrated in FIG. 3B and the more conventional cables having braided or wrapped shields.
  • cables comprising coaxial pairs as described in various embodiments herein are bundled, e.g., folded along the cable transverse axis so that the cable conductors are pushed closer together.
  • the cable bundle may be wrapped, e.g., to maintain the bundled configuration and/or to provide additional shielding.
  • the cable bundle can be put in an external wrap or an extruded jacket with an external shield or braid, etc. as needed.
  • Bundling the cables reduces the spacing between conductors of a conductor pair, providing a smaller and more manageable profile, but with possibly superior electrical performance when compared with twinaxial cables.
  • Bundling the cables can also provide enhanced flexibility when compared to a twinaxial cables since the conductors of the bundled cables according to embodiments described herein can separate and still maintain good electrical properties.
  • FIGURES 13A - 13C depict bundled cables 1300a, 1300b, 1300c, which if laid flat, would have some similarity to cable 200a of FIG. 2A.
  • the distance between the conductor wires of the conductor pair illustrated in each of the cables 1300a, 1300b, 1300c is less than the w c _ c spacing of the cables 1300a, 1300b, 1300c, where w c _ c is the spacing between conductors of a conductor pair when the cable is laid flat.
  • the distance between conductors of cable 1300a is smaller than the distance between conductors of cable 1300b which is smaller than the distance between conductors of cable 1300c. Cables having multiple conductor pairs can also be bundled.
  • FIGURE 14 illustrates bundled cable 1400.
  • Cable 1400 if laid flat, would have some similarity to cable 200b of FIG. 2B.
  • Cable 1400 includes two conductor pairs, wherein the bundling of cable 1400 pushes the conductors of each pair closer together and also pushed the conductor pairs closer together, when compared to the spacing of the conductors and conductor pairs in a flat arrangement of cable 1400.
  • the bundled cable 1500 may include an additional covering 1510, such as an additional insulative jacket and/or an additional shield.
  • the additional covering 1510 may be wrapped, as illustrated in FIG. 15 or in some cases may be braided or extruded.
  • FIGURES 16A- 16C illustrate an exemplary method of making a shielded electrical cable that may be substantially the same as the cable shown in FIG. 1.
  • insulated conductors 6 are formed using any suitable method, such as, e.g., extrusion, or are otherwise provided. Insulated conductors 6 may be formed of any suitable length. Insulated conductors 6 may then be provided as such or cut to a desired length. Ground/drain wires 12 (see FIG. 16C) may be formed and provided in a similar fashion.
  • one or more shielding films 8 are formed.
  • a single layer or multilayer web may be formed using any suitable method, such as, e.g., continuous wide web processing.
  • Each shielding film 8 may be formed of any suitable length.
  • the shielding film 8 may then be provided as such or cut to a desired length and/or width.
  • the shielding film 8 may be pre-formed to have transverse partial folds to increase flexibility in the longitudinal direction.
  • One or both of the shielding films 8 may include a conformable adhesive layer 10, which may be formed on the shielding film 8 using any suitable method, such as, e.g., laminating or sputtering.
  • a plurality of insulated conductors 6, ground conductors 12, and shielding films 8 are provided.
  • a forming tool 24 is provided.
  • Forming tool 24 includes a pair of forming rolls 26a, 26b having a shape corresponding to a desired cross-sectional shape of the shielded electrical cable 2, the forming tool also including a bite 28.
  • Insulated conductors 6, ground conductors 12, and shielding films 8 are arranged according to the configuration of desired shielded electrical cable 2, such as any of the cables shown and/or described herein, and positioned in proximity to forming rolls 26a, 26b, after which they are concurrently fed into bite 28 of forming rolls 26a, 26b and disposed between forming rolls 26a, 26b.
  • the forming rolls 26a, 26b include ridges 27 that compress the layers of the cable to form the pinched regions 9 and grooves 28 between the ridges.
  • Forming tool 24 forms shielding films 8 around conductor sets 4 and ground conductor 12 and bonds shielding films 8 to each other on both sides of each conductor set 4 and ground conductors 12. Heat may be applied to facilitate bonding. Although in this embodiment, forming shielding films 8 around conductor sets 4 and ground conductor 12 and bonding shielding films 8 to each other on both sides of each conductor set 4 and ground conductors 12 occur in a single operation, in other embodiments, these steps may occur in separate operations. During fabrication of the conductor, a conformable adhesive layer may optionally be disposed on the shielding films.
  • the shielding films are formed around insulated conductors and/or ground/drain wires and are bonded to each other. Initially, the adhesive layers disposed on the shielding films still have their original thickness. As the forming and bonding of shielding films proceeds, the conformable adhesive layers conform to achieve desired mechanical and electrical performance characteristics of shielded electrical cable.
  • the spacing between conductors w c _ c is illustrated as being constant along the length of the cable.
  • the w c _ c spacing varies along the cable length.
  • Methods for fabricating cables with longitudinally varying w c _ c spacing may involve the use of forming rolls with grooves that vary in spacing circumferentially around the forming rolls.
  • the conductors can be arranged between the shielding films in a non-parallel arrangement to achieve the desired w c _ c spacing difference between opposite ends of the finished cable.
  • the ridges between the varying width grooves compress the shielding films around the conductors in the non-parallel arrangement.
  • cables with w c _ c spacing that is constant or varies longitudinally may be made using two flat plates that have grooves and ridges arranged according to the desired configuration of the cable.
  • the spacing of the grooves could be constant, to produce a cable with constant w c _ c along the length.
  • the grooves would vary across the plates. After conductors and shielding films are arranged between the plates, the plates are pressed together, and may be heated, causing the shielding films to conform to the shape of the conductors.
  • FIGURES 17A and 17B show cross sectional diagrams and spacing of the test cables.
  • each of the cables tested included four coaxial conductor pairs with ground wires disposed between each of the cable pairs, similar to the cable illustrated in Figs. 2A and 2B.
  • FIG. 17B shows the dimensions for a conductor pair.
  • the characteristic impedance of the conductors was about 91 ohms.
  • FIG. 18 is a block diagram of the test set up used for the cable tests. Both ends of the cables 1810 were soldered to custom PC boards 1820. The connections on the PC boards 1820 were probed with a Cascade Microtech ACP40-GSSG-250 microprobe 1430. S-parameters of the cables were tested during a first test sequence. During this test sequence, the circuit analyzer 1840 used was a Agilent 43.5GHz 4-Port PNA-X - Model N5244A-400 network analyzer. Probes and PCB were not de-embedded from the measurements.
  • Figure 19 is a graph showing the insertion loss (SDD12) of the eight coaxial conductor pairs tested. Each of the 8 coaxial conductor pairs had SDD12 values less than -5dB at a signaling frequency of at 6 GHz.
  • Figure 20 shows the differential-to-common mode conversion, as measured by SDC21 , for the test coaxial conductor pairs. At frequencies up to about 6 GHz, all eight pairs tested achieved an SDC21 value of less than about -15 dB; seven of eight pairs tested achieved an SDC21 value of less than -20dB; and three of eight channels achieved an SCD21 value of less than -25 dB.
  • Time domain transmissometry was used to measure the time domain skew characteristics of the cables. Measurements were performed using the test set up illustrated in Fig. 18 with a Tektronix 50 GHz Scope Tek 02 - Model CSA8000 in the place of the circuit analyzer 1740. The rise time of the pulse used was 35 picoseconds and skew was measured at 20% of the rise. All eight coaxial conductor pairs tested achieved skew less than 10 picoseconds and seven of eight coaxial conductor pairs tested achieved skew less than 5 picoseconds as shown in Fig. 21.
  • Cables including twin axial conductor pairs disposed between shielding films have been constructed such that a pair of signal conductors are included together in a single pocket of shield material.
  • the optimal spacing of the locations to which the cable is terminated is the same as the signal conductor spacing in the cable. This provides ease of termination since the wires do not have to be manipulated after stripping to match the termination spacing, and also provides the optimal signal integrity since the wires are maintained at their same spacing thereby minimizing impedance changes resulting from separating them or moving them closer together.
  • the termination spacing is larger than the spacing of the wires in the twinax pair, the length of wire that is free from the shield (which offers impedance control) is longer. Since the impedance is not the same in this span as in the cable or in the card, it represents an impedance difference, which can degrade signal integrity. The larger the impedance difference and the longer the span of this impedance difference, the greater the degradation of signal integrity. Furthermore, in these cases the termination is more difficult since the wires need to be manipulated after stripping.
  • the shielding films for multiple coaxial conductors can be removed in one step, the shielding films and the conductor insulation of multiple conductors can be simultaneously removed, the length of the two wires is substantially the same which limits skew, there is no attenuation resonance, and/or the cables are cost -effective to produce and assemble into cable assemblies.
  • Some embodiments involve conductors comprising insulated wires that are spaced apart from each other and the two shields surround each conductor. There may also be separate ground/drain wires that are in direct DC contact with the shielding films, or are in AC contact with the shielding films through capacitive coupling.
  • each coaxial conductor wire does not have a close proximity wire or return path to be connected to a termination point at the cable end.
  • each of the conductor wires acts as the return path for the other conductor wire and therefore separate close proximity ground or return wires are not required. Reducing the need for separate ground/drain wires saves cost by reducing the number of wires in the construction.
  • the embodiments described herein provide reduced impedance mismatch, greater ease of termination and/or reduced skew when compared to other twin axial or separately shielded dual coaxial configurations.
  • separately shielded coaxial cables even if provided in the same ribbon so the lengths can be maintained more easily
  • the coax shields are not tied together and do not carry the same noise, and therefore common mode noise can interfere with the differential signal integrity.
  • cables 600a, 600b, 700a, 700b, 900, 1000 use a close
  • ground/drain wires can be terminated at the termination location and they can be in direct DC electrical contact with the shield or shields, or can be in AC (capacitive) contact with the shield or shield.
  • This construction is distinguished from two separately shielded coaxial conductors in that the cables discussed herein can be terminated in a single step while also providing alignment with the mating connections at the termination point.
  • Item 1 is a shielded electrical cable, comprising:
  • each of the pairs comprising a first conductor and a second conductor, each of the first and second conductors comprising a conductor wire surrounded by conductor insulation;
  • first and second shielding films disposed on opposite sides of the electrical cable, the first and second shielding films including cover portions and pinched portions arranged such that, in transverse cross section, the cover portions of the first and second films in combination substantially surround each of the first and second conductors, and the pinched portions of the first and second films in combination form at least one pinched portion of the cable between the first and second conductors, a center-to-center spacing between the first and second insulated conductors being greater than about 1.2D when the cable is laid flat, a maximum separation between the cover portions of the first and second shielding films being D, a minimum separation between the pinched portions of the first and second shielding films being d, d/D being less than about 0.5, wherein for equal lengths of the first and second conductors, a difference between a propagation delay for the first conductor and a propagation delay for the second conductor being less than about 20 picoseconds/meter.
  • Item 2 is the shielded electrical cable of item 1, further comprising a ground/drain wire between each pair of conductors.
  • Item 3 is the shielded electrical cable of item 2, wherein center-to-center spacing between the ground/drain wires and a nearest conductor is greater than about 0.5D.
  • Item 4 is the shielded electrical cable of item 2, wherein an outer surface of the ground/drain wires touches an outer surface of a nearest conductor or a distance between an outer surface of the ground/drain wires and a nearest conductor is about equal to a distance between the shielding films and the nearest conductor.
  • Item 5 is the shielded electrical cable of item 1 , wherein the conductor pairs have a
  • differential- to-common mode conversion of less than about -20dB at a signaling frequency of about 6 GHz.
  • Item 6 is the shielded electrical cable of item 1, wherein a center-to-center spacing between the first and second conductors varies along a width of the cable.
  • Item 7 is the shielded electrical cable of item 1, wherein a center-to-center spacing between the first and second conductors varies along a length of the cable.
  • Item 8 is an electrical system comprising:
  • a shielded electrical cable comprising:
  • each of the pairs comprising a first conductor and a second conductor, each of the first and second conductors comprising a conductor wire surrounded by conductor insulation;
  • first and second shielding films disposed on opposite sides of the electrical cable, the first and second shielding films including cover portions and pinched portions arranged such that, in transverse cross section, the cover portions of the first and second films in combination substantially surround each of the first and second conductors, and the pinched portions of the first and second films in combination form at least one pinched portion of the cable between the first and second conductors, a maximum separation between the cover portions of the first and second shielding films being D, a minimum separation between the pinched portions of the first and second shielding films being d, d/D being less than about 0.5; a first signal propagating along the first conductor; and
  • Item 9 is the electrical system of item 8, wherein for equal lengths of the first and second conductors, a difference between a propagation delay for the first conductor and a propagation delay for the second conductor being less than about 20 picoseconds/meter.
  • Item 10 is the electrical system of item 8, further comprising a differential circuit component configured to subtract the first signal from the second signal after the signals exit the first and second conductors.
  • Item 1 1 is the electrical system of item 8, wherein the cable further comprises a ground/drain wire between each pair of conductors, wherein the ground/drain wire is electrically coupled to one or both of the shielding films.
  • Item 12 is the electrical system of item 10, wherein a center-to-center spacing between the ground/drain wire and a nearest conductor of a conductor of a nearest conductor pair is greater than about 0.5D.
  • Item 13 is the electrical system of item 8, wherein a center-to-center spacing between the first and second conductors is at least about 2D.
  • Item 14 is the electrical system of item 8, further comprising a connector having connections, wherein the first and second conductors are attached to the connections, and a center-to-center spacing of between the connections is substantially the same as a center-to-center spacing between the first and second conductors.
  • Item 15 is the electrical system of item 8, wherein the electrical cable is arranged in a bundled configuration so that a center-to-center spacing between the first and second insulated conductors in the bundled configuration is less than a center-to-center spacing between the first and second insulated conductors when the cable is laid flat.
  • Item 16 is a method, comprising:
  • the shielded electrical cable comprises:
  • each of the pairs comprising the first conductor and the second conductor, each of the first and second conductors comprising a conductor wire surrounded by conductor insulation;
  • first and second shielding films disposed on opposite sides of the electrical cable, the first and second shielding films including cover portions and pinched portions arranged such that, in transverse cross section, the cover portions of the first and second films in combination substantially surround each of the first and second conductors, and the pinched portions of the first and second films in combination form at least one pinched portion of the cable between the first and second conductors, a maximum separation between the cover portions of the first and second shielding films being D, a minimum separation between the pinched portions of the first and second shielding films being d, d/D being less than about 0.5
  • Item 17 is the method of item 16, propagating the first and second signals comprises propagating the first and second signals having a difference between a propagation delay for the first conductor and a propagation delay for the second conductor less than about 20 picoseconds/meter for equal lengths of the first and second conductors.
  • Item 18 is the method of item 16, wherein propagating the first and second signals comprises propagating the first and second signals with a differential- to-common mode conversion of less than about -20dB at a signaling frequency of about 6 GHz.
  • Item 19 is the method of item 16, wherein the cable includes ground/drain wires that are spaced apart from the conductors by at least 0.5D.
  • Item 20 is the method of item 16, further comprising:
  • Item 21 is the method of item 16, further comprising simultaneously removing the shielding films and the conductor insulation from the first and second conductors.

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  • Insulated Conductors (AREA)

Abstract

Selon la présente invention, un système électrique comprend un câble électrique armé (200a) comprenant une ou plusieurs paires (204) de conducteurs (206) s'étendant le long d'une longueur du câble et espacées les unes des autres le long d'une largeur du câble. Des premier et second films de protection (208) sont disposés sur des côtés opposés du câble électrique, les premier et second films de protection (208) comprenant des parties recouvrement (222) et des parties pincées (226) disposées de sorte que, dans la coupe transversale, les parties recouvrement (222) des premier et second films (208) en combinaison entourent sensiblement chacun des premier et second conducteurs (206), et que les parties pincées (226) des premier et second films (208) en combinaison forment au moins une partie pincée (225) du câble entre les premier et second conducteurs (206). Une séparation maximale entre les parties recouvrement (222) des premier et second films de protection (208) est D et une séparation minimale entre les parties pincées (226) des premier et second films de protection (208) est d, d/D étant inférieur à 0,5 environ. Un premier signal se propage le long du premier conducteur et un second signal se propage le long du second conducteur, les premier et second signaux étant complémentaires.
PCT/US2012/039236 2011-11-14 2012-05-24 Câble à paire mixte à large pas WO2013074149A1 (fr)

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US10665366B2 (en) 2017-12-21 2020-05-26 3M Innovative Properties Company Electrical ribbon cable

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JP6614017B2 (ja) * 2016-04-28 2019-12-04 株式会社オートネットワーク技術研究所 電磁シールド具及びワイヤーハーネス
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US10665366B2 (en) 2017-12-21 2020-05-26 3M Innovative Properties Company Electrical ribbon cable
US10892069B2 (en) 2017-12-21 2021-01-12 3M Innovative Properties Company Conductor set and ribbon cable
US11495371B2 (en) 2017-12-21 2022-11-08 3M Innovative Properties Company Electrical ribbon cable

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