Patent Publication Number: US-11646131-B2

Title: Electrical cable with structured dielectric

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage filing under 35 U.S.C. 371 of PCT/IB2019/056837, filed Aug. 12, 2019, which claims the benefit of provisional Application No. 62/718,103, filed Aug. 13, 2018, the disclosure of which is incorporated by reference in its/their entirety herein. 
    
    
     BACKGROUND 
     Electrical cables for transmission of electrical signals are well known. One common type of electrical cable is a coaxial cable. Coaxial cables generally include an electrically conductive wire surrounded by an insulating material. The wire and insulator are surrounded by a shield, and the wire, insulator, and shield are surrounded by a jacket. Another common type of electrical cable is a shielded electrical cable that includes one or more insulated signal conductors surrounded by a shielding layer formed, for example, by a metal foil. 
     SUMMARY 
     In some aspects of the present description, an electrical cable is described, including a plurality of substantially parallel conductors extending along a length of the cable and generally lying in a plane of the conductors, and a dielectric film including a plurality of pairs of structures and folded upon itself along a longitudinal fold line so that the structures in each pair of structures face, and are aligned with, each other, each conductor of the plurality of conductors disposed between the structures in a corresponding pair of structures. 
     In some aspects of the present description, an electrical cable is described, including a plurality of substantially parallel conductors extending along a length of the cable and generally lying in a plane of the conductors, a first dielectric film including a first plurality of structures, and a second dielectric film including a second plurality of structures. The second dielectric film is disposed on and substantially co-extensive with the first dielectric film, such that each structure in the first plurality of structures faces and is substantially aligned with a corresponding structure in the second plurality of structures to create pairs of structures, each conductor of the plurality of conductors disposed between the structures in each pair of structures, where the structures in each pair of structures, in combination, cover at least 40% of a periphery of the conductor. 
     In some aspects of the present description, a ribbon cable is described, including a plurality of conductor sets extending along a length of the ribbon cable and generally lying in a plane of the ribbon cable, a first bonding film disposed on a top side of the plurality of conductor sets, and a second bonding film disposed on a bottom side of the plurality of conductor sets. The first bonding film is bonded to the second bonding film such that the conductor sets are captured between and substantially surrounded by the first bonding film and second bonding film. Each conductor set includes a plurality of substantially parallel conductors extending along a length of the conductor set and generally lying in a plane of the conductors, and a dielectric film including a plurality of pairs of structures, and folded upon itself along a longitudinal fold line so that the structures in each pair of structures face, and are aligned with, each other, each conductor of the plurality of conductors disposed between the structures of a single corresponding pair of structures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a cross-sectional view of an electrical cable; 
         FIG.  2    is a cross-sectional view of an electrical cable; 
         FIG.  3    is a perspective view of a structured dielectric film; 
         FIG.  4    is a perspective view of a structured dielectric film; 
         FIG.  5    is a perspective view of a structured dielectric film; 
         FIG.  6    is a perspective view of a structured dielectric film; 
         FIGS.  7 A- 7 C  present cross-sectional views of the support structures of a structured dielectric film; 
         FIG.  8 A  is a side view of the support structures of a structured dielectric film; 
         FIG.  8 B  is a side view of the support structures and longitudinal ribs of a structured dielectric film; 
         FIG.  9    illustrates how various spacings and support lengths can be used in a structured dielectric film; 
         FIG.  10    illustrates a ribbon cable featuring multiple conductor sets; 
         FIG.  11    illustrates various embodiments of a ribbon cable featuring multiple conductor sets; 
         FIG.  12    is a cross-sectional view of an electrical cable illustrating a heat bondable surface coating on the conductors; 
         FIG.  13    is a cross-sectional view of an electrical cable; 
         FIG.  14    is a cross-sectional view of an electrical cable; 
         FIG.  15    is an exploded, cross-sectional view of an electrical cable; and 
         FIGS.  16 A- 16 B  are cross-sectional views of an electrical cable with top and bottom structured dielectric films. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description, reference is made to the accompanying drawings that form a part hereof and in which various embodiments are shown by way of illustration. The drawings are not necessarily to scale. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present description. The following detailed description, therefore, is not to be taken in a limiting sense. 
     According to some aspects of the present description, electrical cables incorporating the layers and structures described herein have been found to provide improved performance over conventional cables. For example, the electrical cables may have one or more of a reduced impedance variation along the cable length, lower skew, lower propagation delay, lower insertion loss, increased crush resistance, reduced cable size, increased conductor density, and improved bend performance compared to conventional cables. In addition, manufacturing processes for the construction of electrical cables such as those described herein have been found to be simplified and/or more cost effective when compared to manufacturing processes used in the production of conventional cables. 
     In some embodiments, an electrical cable is constructed by creating a structured dielectric that maintains a geometrical structure and arrangement of a set of electrical conductors to achieve certain improvements in performance. These improvements may include, but are not limited to, maintaining a consistent impedance along the cable length, incorporating air into the structure of the electrical cable to decrease size and increase density, as well as to decrease the dielectric constant of the cable, and providing a high mechanical resistance to local impedance change with externally applied force and strains like bending. Specifically, since the primary bending plane of the cable is the same as the wire plane with a portion of the wires occupying the neutral axis, there can be optimum configurations that allow air inclusion in some of the structure, while providing deformation resistance in bending. The design of the electrical cable herein also provides a means to create the structures and apply them to the conductors and complete the construction with an outer conductive shield surrounding the cable. 
     In some embodiments, a ribbon cable is constructed including a plurality of conductor sets extending along a length of the ribbon cable and generally lying in a plane of the ribbon cable, a first bonding film disposed on a top side of the plurality of conductor sets, and a second bonding film disposed on a bottom side of the plurality of conductor sets. The first bonding film may be bonded to the second bonding film such that the plurality of conductor sets is captured between and substantially surrounded by the first bonding film and second bonding film to create a ribbon cable. Each conductor set in the ribbon cable may include a plurality of substantially parallel conductors extending along a length of the conductor set and generally lying in a plane of the conductors, and a dielectric film. The dielectric film may include a plurality of pairs of structures, and the dielectric film may be folded upon itself along a longitudinal fold line so that the structures in each pair of structures face, and are aligned with, each other. Each conductor of the plurality of conductors is disposed between the structures of a single corresponding pair of structures. 
     In some embodiments, the structured dielectric may be a created as a microreplicated film including a series of pairs of structures which extend along the length of the dielectric film. The structured dielectric film may then be folded upon itself along one or more longitudinal fold lines such that it substantially surrounds and encloses a set of electrical conductors. The structures in each pairs of structures face each other and are aligned with each other, such that each conductor in the set of electrical conductors is disposed between the corresponding structures in a single pair of structures. The shape and size of the structures are such that the structures of a single pair of structures cradle a conductor and prevent any lateral movement of the conductors. 
     For the purposes of this specification, microreplication shall refer to the process of replicating a pattern of microscale structures onto a substrate. In some embodiments, the microscale structures may be precisely-sculpted microscopic shapes placed on a substrate or backing layer to form cells or air voids. In other embodiments, the microscale structures may be molded or formed into an insulative layer using microreplication techniques and/or micromolds to create support structures or air voids. 
     The structured dielectric film described herein may have a low dielectric constant and/or low dielectric loss (e.g., low effective loss tangent). For example, the arrangement, size, and spacing of the structures on the dielectric film may be such that the resulting electrical cable has an air content of greater than 40%. In some embodiments, the dielectric film may have an effective dielectric constant of less than about 2, or less than about 1.7, or less than about 1.6, or less than about 1.5, or less than about 1.4, or less than about 1.3, or less than about 1.2. In some embodiments, an effective dielectric constant of an electrical cable constructed using the structured dielectric film described herein for at least one pair of adjacent conductors driven with differential signals of equal amplitude and opposite polarities is less than about 2.5, or less than about 2.2, or less than about 2, or less than 1.7, or less than about 1.6, or less than about 1.5, or less than about 1.4, or less than about 1.3, or less than about 1.2. 
     The conductors used in the electrical cable may include any suitable conductive material, such as an elemental metal or a metal alloy (e.g., copper or a copper alloy), and may have a variety of cross sectional shapes and sizes. For example, in cross section, the conductors may be circular, oval, rectangular or any other shape. One or more conductors in a cable may have one shape and/or size that differs from other one or more conductors in the cable. The conductors may be solid or stranded wires. All the conductors in a cable may be stranded, all may be solid, or some may be stranded and some solid. Stranded conductors and/or ground wires may take on different sizes and/or shapes. The conductors may be coated or plated with various metals and/or metallic materials, including gold, silver, tin, and/or other materials. 
     In some embodiments, an electrically conductive shield may be layered, wrapped, or otherwise placed around the structured dielectric film and conductors. The shield may include an electrically conductive shielding layer disposed on an electrically insulative substrate layer. In some embodiments, the shield may include a first shield disposed on a top side of the electrical cable and a second shield disposed on a bottom side of the electrical cable. 
       FIG.  1    is a cross-sectional view of an electrical cable in accordance with an embodiment of the present description. An electrical cable  100  is shown in an unfolded state, including a dielectric film  10 , and a plurality of substantially parallel conductors  40  extending along a length (e.g., in the x-direction of  FIG.  1   , extending into the page) of the cable  100  and generally lying in a plane of the conductors  40 . The dielectric film  10  includes a plurality of structures  20  arranged in pairs of structures  22 . Please note that the reference designator  22  without a corresponding letter shall be used to refer generally to pairs of structures within the text of the specification, but each pair of structures shall be shown in the figures with a corresponding letter to refer to a specific pair of structures. For example, referring to  FIG.  1   , components  22   a  and  22   a ′ are used to designate a specific pair of structures. Similarly,  22   b  and  22   b ′, and  22   c  and  22   c ′ are used to designated two additional specific pairs of structures. When the dielectric film  10  is folded along a longitudinal fold line  15 , the structures  20  in each pair of structures  22  face, and are aligned with, each other, and each conductor  40  of the plurality of conductors  40  is disposed between the structures  20  in a corresponding pair of structures  22  (for example, structure  22   c ′ will be positioned directly above structure  22   c  when the dielectric film  10  is folded along line  15 . This will be described in additional detail in  FIG.  2   . Returning to  FIG.  1   , in some embodiments, the electrical cable  100  further includes a conductive shield  50 , which may be disposed on a surface of the dielectric film  10 . In some embodiments, the dielectric film  10  and/or structures  20  may be made of a material which has a low effective dielectric constant and/or a low dielectric loss. For example, the dielectric film  10  and structures  20  may have a high air content to provide the low effective dielectric constant. For example, the dielectric material may be a single-layer or multi-layer film, or may be a foam material. Air voids may be engineered, machined, formed, or otherwise included within the dielectric material to decrease the dielectric constant of the resulting cable. In some embodiments, the dielectric film  10  and structures  20  may be formed in a single manufacturing process from the same material, while in other embodiments, the dielectric film  10  and structures  20  may be made in separate manufacturing processes and/or made of different materials. 
       FIG.  2    is a cross-sectional view of the electrical cable of  FIG.  1   , now in its final, folded form. An electrical cable  100  includes a dielectric film  10 , and a plurality of substantially parallel conductors  40  extending along a length (e.g., in the x-direction of  FIG.  2   , extending into the page) of the cable  100  and generally lying in a plane of the conductors  40 . The dielectric film  10  includes a plurality of structures  20  arranged in pairs of structures  22 . The dielectric film  10  has been folded upon itself along longitudinal fold line  15 , causing the structures  20  in each pair of structures  22  to face, and be aligned with, each other. Each conductor  40  of the plurality of conductors  40  is disposed between the structures  20  in a corresponding pair of structures  22 . For example, one conductor  40  is disposed between structure  22   c  and  22   c ′, and another conductor  40  is disposed between structure  22   b  and  22   b ′. In the folded form of  FIG.  2   , the dielectric film  10  has a pinched portion  30  on one lateral side of the cable, and the longitudinal fold line  15  on an opposite lateral side of the cable  100 . In some embodiments, the electrical cable further includes an adhesive layer  35 , which may be disposed within the pinched portion  30 . In some embodiments, the electrical cable  100  further includes a conductive shield  50 , which may be disposed on a surface of the dielectric film  10 , to form the exterior layer of the folded electrical cable  100 . 
       FIGS.  3 - 6    provide perspective views of embodiments of a dielectric film such as the dielectric film  10  of the electrical cable  100  of  FIGS.  1  and  2   .  FIG.  3    illustrates an example embodiment where the structures  20  in each pair of structures  22  (including pairs  22   a / 22   a ′,  22   b / 22   b ′, and  22   c / 22   c ′) extend substantially the length (e.g., in the x-direction of  FIG.  3   ) of the dielectric film  10 . In the example of  FIG.  3   , a single pair of structures  20  is sufficient to support each conductor ( 40 ,  FIG.  2   ), allowing the electrical cable to have structural integrity (e.g., crush resistance) while still allowing a high air content within the cable. 
       FIG.  4    illustrates an example embodiment of the dielectric film  10  where each structure in each pair of structures (such as pair of structures  22  of  FIG.  3   ) includes a plurality of structure segments  20   a  separated by air gaps  24  along the length of the dielectric film  10 . The spacing of air gaps  24  may be a regular or an irregular spacing. The inclusion of air gaps  24  can be used to increase the air content of the electrical cable while still maintaining sufficient cable integrity. 
       FIG.  5    illustrates an example embodiment of the dielectric film  10  where the air gaps of  FIG.  4    further include longitudinal ribs  25  disposed between successive structure segments  20   a . In some embodiments, the longitudinal ribs  25  provide additional structural support under externally applied loads, such as bending of the cable, but may be smaller than full-length structures  20  such as those of  FIG.  3    to allow for increased air content. 
       FIG.  6    illustrates an example embodiment of the dielectric film  10  of  FIG.  5   , where the dielectric film  10  further includes lateral ribs  28  extending between adjacent longitudinal ribs  25 . In some embodiments, such as the embodiment of  FIG.  3    including full-length structures  20 , lateral ribs  28  may also extend between adjacent structures  20 . The inclusion of lateral ribs  28  can further increase the structural integrity of an electrical cable. 
       FIGS.  7 A- 7 C  illustrate cross-sectional views of the support structures  20  of a structured dielectric film  10 , showing how variations in the surface of the structures  20  can increase the air content in the areas immediately adjacent to the conductors.  FIGS.  7 B and  7 C  illustrate two different, example embodiments where at least one structure  20  in at least one pair of structures  22  includes a substructure  37  designed to increase an air content of the at least one structure  20 . The shape of the substructure  37  may be any appropriate shape designed to introduce air into the structure  20 , including but not limited to triangular notches, square channels, rounded channels, rectangular slots, and/or holes of any appropriate shape. 
       FIG.  8 A  is a side view of the support structures  20  of a structured dielectric film  10 , in both an unbent (top of  FIG.  8 A ) and bent (bottom of  FIG.  8 A ) configuration. In the embodiment of  FIG.  8 A , a plurality of air gaps  24  has been incorporated into the structures  20 . As described elsewhere, these air gaps  24  may increase the air content of the resulting electrical cable, but an additional purpose may also be achieved in some embodiments. The design of the air gaps  24  is such as to create a uniform bend radius for the resulting cable, which may result in a more uniform electrical performance under bending conditions. In the example of  FIG.  8 A , the design of air gaps  24  is of a triangular notch, but any appropriate shape or design may be used for air gaps  24  to achieve the desired bend radius. 
       FIG.  8 B  is a side view of the support structures  20  and air gap  24  including longitudinal ribs  25  of a structured dielectric film  10 , in both an unbent (top of  FIG.  8 B ) and bent (bottom of  FIG.  8 B ) configuration. Longitudinal ribs  25  are disposed within air gaps  24 . In the embodiment shown, air gaps  24  are a first set of air gaps, and the longitudinal ribs  25  include a second set of air gaps  27 . Second set of air gaps  27  is introduced into the longitudinal ribs  25 . The design of the second set of air gaps  27  is such as to create a uniform bend radius for the cable, which may result in a more uniform electrical performance under bending conditions. The design of second set of air gaps  27  is shown as a triangular notch in  FIG.  8 B , but any appropriate shape or design may be used for air gaps  27  to achieve the desired bend radius. 
     One potential performance artifact of creating a regular pattern of structure segments and air gaps is that the repeated dielectric structure could give rise to unwanted resonance that could interfere with transmitting the high-speed data signal. If this occurred, certain design strategies may provide mitigation of the resonance effect, in some embodiments. For example, varying the support size (e.g., the length of the support segments in the longitudinal dimension of the electrical cable), or varying the spacing of the support segments may help mitigate resonance effects. In addition, if the support segment and the air gaps between them are designed to be smaller relative to the effective wavelength of the signal, the effect may be minimized or eliminated. 
       FIG.  9    illustrates how various spacings and support segment lengths can be used in a structured dielectric film, both to manage the air content in a cable and to mitigate resonance issues.  FIG.  9    shows four example dielectric films  10   a ,  10   b ,  10   c , and  10   d , each using different lengths and spacing schemes for support segments  20   a . In the example of dielectric film  10   a , a spacing of the structure segments along the length of the cable is a regular spacing, and the length of the support segments  20   a  (e.g., the length of support segments  20   a  in the X direction of  FIG.  9   ) is consistent throughout the length of film  10   a . In the example of dielectric film  10   b , the length of the support segments  20   a  remains consistent, but the spacing of the structure segments  20   a  along the length of the cable is a random or pseudorandom spacing. In example  10   c , both the spacing and length of the structure segments  20   a  is random or pseudorandom. In example  10   d , the length of the support segments  20   a  and air gaps  24  is kept relatively small to help mitigate resonance effects. 
       FIG.  10    is an exploded view of an embodiment of a ribbon cable featuring multiple conductor sets. A ribbon cable  300  includes a plurality of conductor sets  200  extending along a length of the ribbon cable and generally lying in a plane of the ribbon cable, a first bonding film  60  disposed on a top side of the plurality of conductor sets  200 , and a second bonding film  60  disposed on a bottom side of the plurality of conductor sets  200 , the first bonding film  60  bonded to the second bonding film  60  such that the plurality of conductor sets  200  is captured between and substantially surrounded by the first bonding film  60  and second bonding film  60 . In some embodiments, conductor set  200  may be electrical cable  100  of, for example,  FIG.  2   . Each conductor set  200  may include a plurality of substantially parallel conductors  40  extending along a length (e.g., direction X as shown in  FIG.  10   , extending into the page) of the conductor set  200  and generally lying in a plane of the conductors, and a dielectric film  10  comprising a plurality of pairs of structures  20  and folded upon itself along a longitudinal fold line so that the structures in each pair of structures face, and are aligned with, each other. Each conductor  40  of the plurality of conductors  40  is disposed between the structures  20  of a single corresponding pair of structures  22  (for example, pair  22   c / 22   c ′). In some embodiments, the first bonding film  60  and the second bonding film  60  are constructed of a dielectric material. In some embodiments, the first bonding film and the second bonding film may further include a conductive shield  50 . In some embodiments, ribbon cable  300  may further include at least one single conductor  40   a  not part of the plurality of conductor sets  200 . Single conductors  40   a  may or may not be individually insulated and/or shielded. 
       FIG.  11    illustrates various embodiments of a ribbon cable featuring multiple conductor sets.  FIG.  11    provides three example embodiments of a ribbon cable,  300   a ,  300   b , and  300   c . In the example of ribbon cable  300   a , the first bonding film  60  (disposed on a top side of ribbon cable  300   a ) and the second bonding film  60  (disposed on a bottom side of ribbon cable  300   a ) form pinched portions  80  in ribbon cable  300   a  between adjacent conductor sets  200 . In some embodiments, the pinched portions  80  may serve to isolate the conductor sets  200  from each other. In the example of ribbon cable  300   b , the first bonding film  60  ( top ) and the second bonding film  60  (bottom) provide sections containing air voids  85  in ribbon cable  300   b  between adjacent conductor sets  200 , which may contribute to a decrease in the dielectric constant of ribbon cable  300   b . As shown in the example of ribbon cable  300   c , a combination  80   a  of pinched portions and air voids can be used to create ribbon cables  300   c  with the desired electrical and structural properties. 
       FIG.  12    is a cross-sectional view of various embodiments of an electrical cable where the conductors include a heat bondable surface coating.  FIG.  12    presents three different electrical cable embodiments,  100   a ,  100   b , and  100   c . Each example embodiment shows four conductors  40 , although any appropriate number of conductors  40  may be used, including, but not limited to, 1, 2, 4, 6, 8, 12, and 20. Each configuration  100   a - 100   c  illustrates a surface coating  70  on two of the conductors  40 . In some embodiments, this surface coating  70  may be a heat bondable insulator that is applied prior to passing the electrical cables  100  through a lamination or folding process. In some embodiments, the surface coating  70  is designed to create a bond between the conductors  40  and the structured dielectric film  10 , and, in particular, between the supports  20  and the conductors  40 . The surface coating  70  may be a single layer, or it may be any appropriate number of layers, including, but not limited to, 2, 4, and 6 layers. In some embodiments, the surface coating  70  is a heat bondable insulator, and a bond is created during assembly of the electrical cable  100  through heat seal bonding or another appropriate means. In some embodiments, the surface coating  70  may be applied only to certain conductors  40 , while other conductors  40  may remain uncoated. For example, the surface coating  70  may have insulating properties which may isolate the coated conductors  40  electrically and protect the conductors  40  from environmental exposure. Conductors  40  may use insulation for a variety of purposes, including electrically isolating a conductor from another conductor or surface, protection against environmental threats (such as moisture), protection against physical damage, resisting electrical leakage, etc. In some example embodiments, a first set of conductors may be insulated, while a second set of conductors may be uninsulated. 
       FIG.  12    also illustrates that a variety of shapes and sizes may be used in the design of the structures  20 . For example, electrical cables  100   a  and  100   c  show examples where a single, continuous structure  20  may be used for two or more conductors  40 , such as the two central, insulated conductors  40  in each example. In the example of  100   c , the shape of the central structure  20  holding the two central, insulated conductors  40  is essentially flat, and lateral movements are prevented more from the heat bondable surface coating  70  than due to the shape or configuration of the structures  20 . 
       FIGS.  13 - 14    illustrate cross-sectional views of three example embodiments of an electrical cable  100 . Turning to  FIG.  13   , example embodiments  100   d  and  100   e  feature larger supports  20 , where the supports  20  extend down and up between the centermost conductors  40  until they contact each other. In some embodiments, an adhesive layer  35  is applied at the point between conductors  40  where the upper and lower structures  20  come in contact. The embodiment shown in example  100   e  substantially surrounds conductors  40  with dielectric material from structures  20  of dielectric film  10 , while example  100   d  leaves air voids within the electrical cable  100   d .  FIG.  14    is a cross-sectional view of an example embodiment of an electrical cable  100   f , where at least one structure  20  in at least one pair of structures  22  (for example, pair  22   b / 22   b ′ in  FIG.  14   ) includes a mechanical interference feature  90 . In some embodiments, the purpose of the mechanical interference feature  90  is to more firmly connect the upper structure  20  to the lower structure  20  and to further prevent relative lateral movements of the conductors  40  and structures  20 . As with examples  100   d  and  100   e  of  FIG.  13   , an adhesive layer  35  may be disposed between one or more contacting surfaces of structures  20 , or between structures  20  and one or more conductors  40 . 
       FIG.  15    is a cross-sectional view of an electrical cable, along with exploded, cross-sectional views of an alternate embodiment of a structured dielectric film  10  including structures  20 . In the embodiment shown in  FIG.  15   , the dielectric film  10  exhibits a first longitudinal fold line  15   a  located on one lateral side of the dielectric film  10 , and a second longitudinal fold line  15   b  on the opposite lateral side of the dielectric film  10 . That is, when assembled (i.e., folded), there is a first longitudinal fold line  15   a  located on one lateral side of the cable  100 , and the dielectric film  10  is further folded upon itself along a second longitudinal fold line  15   b  on an opposite lateral side of the cable  100 . This example design has the effect of creating a more symmetrical final electrical cable  100 , avoiding the one-sided pinched portion such as that shown in the example embodiment of  FIG.  2   . As with other designs, an adhesive layer  35  may be disposed between contacting surfaces of structures  20 , or between structures  20  and at least one conductor  40 . 
       FIGS.  16 A- 16 B  are cross-sectional views of an electrical cable with top and bottom structured dielectric films. Looking at  FIGS.  16 A and  16 B  together, a cable includes a plurality of substantially parallel conductors  40  extending along a length of the cable (e.g., direction X in  FIGS.  16 A and  16 B , extending into the page) and generally lying in a plane of the conductors, a first dielectric film  10   a  comprising a first plurality of structures  20 , and a second dielectric film  10   b  comprising a second plurality of structures  20 . The second dielectric film  10   b  is disposed on and substantially co-extensive with the first dielectric film  10   a , such that each structure  20  in the first plurality of structures  20  faces and is substantially aligned with a corresponding structure  20  in the second plurality of structures  20  to create pairs of structures  22 , each conductor  40  of the plurality of conductors  40  disposed between the structures  20  in each pair of structures  22 , where the structures  20  in each pair of structures  22 , in combination, cover at least 40% of a periphery of the corresponding conductor  40 . For example, the structures  20  of pair  22   c / 22   c ′ may together cover at least 40% of the conductor  40  disposed between them. When assembled, as shown in  FIG.  16   b   , a pinched portion  30  may appear on both lateral sides of electrical cable  100 , and no longitudinal fold lines are present. 
     The structures  20  in each pair of structures  22 , in combination, substantially prevent any lateral movement of the conductor  40  in relation to the structures  22 . This may be achieved by designing structures  20  with features (e.g., grooves or channels) which conform to the periphery of conductors  40 , through the use of an adhesive layer (not shown) disposed between corresponding structures  20  or between structures  20  and conductors  40 , by mechanical friction (i.e., for example, pressure provided by pair of structures  22   b / 22   b ′ to the surface of the conductor  40  disposed between them), or by any appropriate means. In some embodiments, the first dielectric film  10   a  may be thermally bonded to the second dielectric film  10   b . In some embodiments, at least one of the first dielectric film  10   a  and the second dielectric film  10   b  are thermally bonded to at least one of the conductors  40 . In some embodiments, the cable  100  may further include an adhesive layer (not shown) disposed between the first dielectric film  10   a  and the second dielectric film  10   b , or between conductors  40  and the first dielectric film  10   a  and second dielectric film  10   b . In some embodiments, the electrical cable  100  may further include a conductive shield  50  which substantially surrounds and encloses cable  100 . In some embodiments, the conductive shield may consist of a first conductive shield layer  50   a  and a second conductive shield layer  50   b.    
     Terms such as “about” will be understood in the context in which they are used and described in the present description by one of ordinary skill in the art. If the use of “about” as applied to quantities expressing feature sizes, amounts, and physical properties is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, “about” will be understood to mean within 10 percent of the specified value. A quantity given as about a specified value can be precisely the specified value. For example, if it is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, a quantity having a value of about 1, means that the quantity has a value between 0.9 and 1.1, and that the value could be 1. 
     Terms such as “substantially” will be understood in the context in which they are used and described in the present description by one of ordinary skill in the art. If the use of “substantially equal” is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, “substantially equal” will mean about equal where about is as described above. If the use of “substantially parallel” is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, “substantially parallel” will mean within 30 degrees of parallel. Directions or surfaces described as substantially parallel to one another may, in some embodiments, be within 20 degrees, or within 10 degrees of parallel, or may be parallel or nominally parallel. If the use of “substantially aligned” is not otherwise clear to one of ordinary skill in the art in the context in which it is used and described in the present description, “substantially aligned” will mean aligned to within 20% of a width of the objects being aligned. Objects described as substantially aligned may, in some embodiments, be aligned to within 10% or to within 5% of a width of the objects being aligned. 
     All references, patents, and patent applications referenced in the foregoing are hereby incorporated herein by reference in their entirety in a consistent manner. In the event of inconsistencies or contradictions between portions of the incorporated references and this application, the information in the preceding description shall control. 
     Descriptions for elements in figures should be understood to apply equally to corresponding elements in other figures, unless indicated otherwise. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.