Differential signaling cable, transmission cable assembly using same, and production method for differential signaling cable

• US 9,660,318 B2
• Filed: 07/06/2015
• Issued: 05/23/2017
• Est. Priority Date: 10/14/2009
• Status: Active Grant

• Current Assignee: Hitachi Metals (Thailand) Ltd.
• Original Assignee: Hitachi Metals (Thailand) Ltd.
• Inventors: Sugiyama, Takahiro, Ishimatsu, Yosuke, Nounen, Hideki, Kumakura, Takashi
• Primary Examiner(s): Nguyen, Chau N
• Application Number:
  US14/792,360
• Publication Number:
  US 20160036112A1
• Time in Patent Office: 687 Days
• Field of Search: 174113 R, 174115, 174117 F
• CPC Class Codes: H01B 11/1025 composed of a helicoidally wound tape-conductor
• CPC Class Codes: H01B 11/1033 composed of a wire-braided conductor
• CPC Class Codes: H01B 11/1091 with screen grounding means, e.g. drain wires
• CPC Class Codes: H01B 11/20 Cables having a multiplicity of coaxial lines
• CPC Class Codes: H01B 7/0823 Parallel wires, incorporated in a flat insulating profile
• CPC Class Codes: H01P 11/001 Manufacturing waveguides or transmission lines of the waveguide type
• CPC Class Codes: H01P 3/02 with two longitudinal conductors

Abstract

A differential signaling cable includes a pair of signal conductors provided in parallel, longitudinally within the differential signaling cable, an insulator covering a periphery of the pair of signal conductors as a whole, wherein only the insulator is between the pair of signal conductors, and a shield conductor provided on an outer periphery of the insulator. An interval between the pair of signal conductors is set so that an even-mode impedance of the pair of signal conductors having the interval fixed by embedment within the insulator and covered by the shield conductor, is in a range from 1.5 to 1.9 times an odd-mode impedance for improved skew and differential mode insertion loss experienced during a transmission of high-speed signals of at least 10 Gbps.

Claims

1. A differential signaling cable, comprising:

a pair of signal conductors provided in parallel, longitudinally within the differential signaling cable;

an insulator covering a periphery of the pair of signal conductors as a whole, wherein only the insulator is between the pair of signal conductors; and

a shield conductor provided on an outer periphery of the insulator,

wherein an interval between the pair of signal conductors is set so that an even-mode impedance of the pair of signal conductors having the interval fixed by embedment within the insulator and covered by the shield conductor, is in a range from 1.67 times to 1.88 times an odd-mode impedance for improved skew and differential mode insertion loss experienced during a transmission of high-speed signals of at least 10 Gbps, the improved skew and differential mode insertion loss being in comparison both to skew experienced with below 1.67 times the odd-mode impedance and differential mode insertion loss experienced with above 1.88 times the odd-mode impedance, and

wherein the pair of signal conductors includes the even-mode impedance in a range from 75Ω

to 95Ω

.

2. The differential signaling cable according to claim 1, wherein a length of the insulator in a width direction of the insulator in which the pair of signal conductors is arranged, is longer than a length in a thickness direction of the insulator perpendicular to the width direction, and

wherein the pair of signal conductors is disposed at a center of the thickness direction of the insulator.

3. The differential signaling cable according to claim 2, wherein a ratio of the length of the insulator in the width direction to the length in the thickness direction is 2:

1.

4. The differential signaling cable according to claim 2, further comprising:

a drain wire longitudinally disposed on an end on one side or ends on both sides of the insulator in the width direction, the drain wire being provided between the insulator and the shield conductor, the drain wire being electrically connected to the shield conductor.

5. The differential signaling cable according to claim 4, wherein the drain wire and the signal conductors are linearly disposed along the width direction of the insulator.

6. The differential signaling cable according to claim 4, wherein each of the drain wires is disposed on the ends on both sides of the insulator in its width direction,

wherein both of the drain wires are linearly disposed along the width direction of the insulator, and

wherein both of the drain wires are disposed in locations deviating from the center of the thickness direction of the insulator.

7. The differential signaling cable according to claim 4, wherein the drain wire is engaged with an engagement groove formed on the end on one side or the drain wires are engaged with engagement grooves formed on the ends on both sides of the insulator in the width direction.

8. A transmission cable assembly, wherein at least two or more of differential signaling cables according to claim 1 are bundled,

wherein a batch-covering shield conductor is provided on a periphery of the bundled cables as a whole, and

wherein an outer periphery of the batch-covering shield conductor is covered with a jacket comprising an insulator.

9. The differential signaling cable according to claim 1, further comprising:

a jacket for cable protection provided on an outer periphery of the shield conductor.

10. The differential signaling cable according to claim 1, wherein the insulator comprises a monolithic insulator.

11. The differential signaling cable according to claim 1, wherein the pair of signal conductors comprises a pair of signal wires.

12. The differential signaling cable according to claim 1, wherein the interval between the pair of signal conductors is set such that the even-mode impedance of the pair of signal conductors, having the interval fixed by embedment within the insulator and covered by the shield conductor, is about 1.67 times of the odd-mode impedance.

13. The differential signaling cable according to claim 1, wherein the pair of signal conductors is configured such that a differential impedance of the pair of signal conductors is about 100Ω

.

14. A production method for a differential signaling cable, the production method comprising:

providing a pair of signal conductors in parallel longitudinally within the differential signaling cable;

covering a periphery of the pair of signal conductors as a whole with an insulator; and

covering an outer periphery of the insulator with a shield conductor,

wherein each conductor of the pair of signal conductors is disposed such that an interval therebetween is set so that an even-mode impedance of the pair of signal conductors having the interval fixed by embedment within the insulator and covered by the shield conductor, is in a range from 1.67 times to 1.88 times an odd-mode impedance for improved skew and differential mode insertion loss experienced during transmission of high-speed signals of at least 10 Gbps, the improved skew and differential mode insertion loss being in comparison both to skew experienced with below 1.67 times odd-mode impedance and differential mode insertion loss experienced with above 1.88 times odd-mode impedance,

wherein the insulator is formed in a batch on the periphery of the pair of signal conductors by an extrusion molding, such that only the insulator is disposed between the pair of signal conductors, and

wherein the pair of signal conductors includes the even-mode impedance in a range from 75Ω

to 95Ω

.

15. The production method according to claim 14, wherein the pair of signal conductors comprises a pair of signal wires.

16. The production method according to claim 14, wherein the insulator comprises a monolithic insulator.

17. The production method according to claim 14, wherein the interval between the pair of signal conductors is set such that the even-mode impedance of the pair of signal conductors, having the interval fixed by embedment within the insulator and covered by the shield conductor, is about 1.67 times of the odd-mode impedance.

18. The production method according to claim 14, wherein the pair of signal conductors includes a differential impedance of the pair of signal conductors is about 100Ω

.

19. A differential signaling cable, comprising:

a pair of signal conductors provided in parallel, longitudinally within the differential signaling cable;

an insulator covering a periphery of the pair of signal conductors as a whole, wherein only the insulator is between the pair of signal conductors; and

a shield conductor provided on an outer periphery of the insulator,

wherein an interval between the pair of signal conductors is set so that an even-mode impedance of the pair of signal conductors having the interval fixed by embedment within the insulator and covered by the shield conductor, is in a range from 1.67 times to 1.88 times an odd-mode impedance, and

wherein the pair of signal conductors includes the even-mode impedance in a range from 75Ω

to 95Ω

.

20. A differential signaling cable, comprising:

a pair of signal conductors provided in parallel, longitudinally within the differential signaling cable;

an insulator covering a periphery of the pair of signal conductors as a whole, wherein only the insulator is between the pair of signal conductors; and

a shield conductor provided on an outer periphery of the insulator,

wherein an interval between the pair of signal conductors is set so that an even-mode impedance of the pair of signal conductors having the interval fixed by embedment within the insulator and covered by the shield conductor, is in a range from 1.67 times to 1.88 times an odd-mode impedance for improved skew and differential mode insertion loss experienced during a transmission of high-speed signals of at least 10 Gbps, the improved skew and differential mode insertion loss being in comparison both to skew experienced with below 1.67 times the odd-mode impedance and differential mode insertion loss experienced with above 1.88 times the odd-mode impedance.