Shielded Cable Assembly Impedance Control for High-Speed Data
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current coaxial cables cannot support data transfer rates above 5 Gb/s, and while fiber optic and twisted pair cables can, fiber optics are fragile and expensive, making them unsuitable for cost-sensitive applications requiring high data rates and electromagnetic interference immunity, especially in automotive and aerospace industries.
Innovation Solution
A shielded wire cable assembly with a pair of conductors and a dielectric structure maintaining consistent radial spacing between the conductors and the shield, eliminating the need for a drain wire and twisting, which reduces manufacturing costs and allows for high data transfer rates up to 5 Gb/s while maintaining electromagnetic interference immunity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If fiber optic cable is used to achieve high data transfer rates (up to 100 Gb/s) and electromagnetic interference immunity, then data transfer rate and reliability are improved, but cost and fragility increase significantly
Solution Approach 1:
The patent replaces expensive fiber optic cables with a cost-effective shielded twisted pair cable construction that achieves comparable electromagnetic interference immunity and data transfer rates (up to 10 Gb/s). The shielded cable assembly with braided shield and dielectric structure provides the necessary protection against electromagnetic interference without the high cost and fragility of fiber optics, making it suitable for cost-sensitive applications like automotive and consumer electronics.
2Reliability
If coaxial cable is used to achieve good electromagnetic interference immunity and support data rates up to 10 Gb/s, then reliability is improved, but data transfer rate capability above 5 Gb/s is limited
Solution Approach 1:
The patent modifies the cable construction parameters by using a shielded twisted pair configuration with specific impedance control (95 ohms differential impedance), optimized conductor spacing, and a braided shield structure. These parameter changes enable the cable to support data transfer rates up to 10 Gb/s while maintaining electromagnetic interference immunity, exceeding the capabilities of conventional coaxial cables which are limited to 5-10 Gb/s.
3Speed
If twisted pair cable with multiple pairs is used to achieve data rates above 5 Gb/s, then data transfer rate is improved, but cable mass and complexity increase
Solution Approach 1:
The patent extracts the essential functionality of high-speed data transmission by using a single shielded twisted pair configuration instead of multiple twisted pairs. The shielded construction with controlled impedance and optimized geometry allows a single pair to achieve data transfer rates up to 10 Gb/s, eliminating the need for multiple pairs and thereby reducing cable mass, complexity, and flexibility requirements while maintaining the required data transfer capability.
4Reliability
If shielded cable construction is used to achieve electromagnetic interference immunity and controlled impedance, then reliability is improved, but manufacturing complexity increases due to drain wire and twisting requirements
Solution Approach 1:
The patent merges the functions of the drain wire and shield into a unified braided shield construction that is in direct electrical contact with the ground. The braided shield serves both as the electromagnetic shield and as the reference ground path, eliminating the need for a separate drain wire. This integration simplifies the manufacturing process while maintaining controlled impedance and electromagnetic interference immunity through the optimized braided structure and dielectric spacing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The cable assembly achieves data transfer rates of up to 5 Gb/s with low insertion loss and intra-pair skew, meeting USB 3.0 and HDMI 1.4 specifications, and is cost-effective and flexible enough for automotive and aerospace applications.
Implementation Method 1
a dielectric structure configured to maintain a first predetermined spacing between the first inner conductor and the second inner conductor and a second predetermined spacing between the first inner conductor and the second inner conductor and the shield
Implementation Method 2
The shield includes an inner shield conductor at least partially enclosing the dielectric structure, thereby establishing a characteristic impedance of the wire cable, and an outer shield conductor at least partially enclosing the inner shield conductor
Data Source
Figure 1
Figure 2~3
Figure 4
AI summary
A shielded cable assembly 100 capable of transmitting signals at speeds of 3.5 Gigabits per second (Gb/s) or higher without modulation or encoding over a single pair of conductors (102b, 104b). The cable 100 has a characteristic impedance of 95 Ohms and can support transmission data according to either USB 3.0 or HDMI 1.4 performance specifications. The wire cable (100f) includes a pair of conductors, a shield (116, 124) surrounding the conductors, and a dielectric structure (113) configured to maintain a first predetermined spacing between the conductors and a second predetermined spacing between the conductors (102b, 104b) and the shield (116, 124). The shield includes an inner shield (116) conductor enclosing the dielectric structure (113) and an outer shield (124) conductor enclosing the inner shield (116) conductor.