PCIe High-speed Interconnect New Solution: Application Analysis of Extremely Thin Coaxial Cable Arrays

In the era of high-speed computing and data center interconnectivity, PCIe (PCI Express) has become a high-speed bus for connecting core devices such as CPUs, GPUs, SSDs, and AI acceleration cards. With PCIe 5.0/6.0 speeds reaching 32~64GT/s, the requirements for signal integrity, transmission loss, and wiring structure are becoming increasingly strict. Against this backdrop, ultra-thin coaxial cable assemblies (Micro Coaxial Cable Assembly) have emerged as a key solution for high-frequency and high-speed transmission, thanks to their high shielding, precise impedance control, and small, flexible design.

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Why PCIe high-speed signals require extremely thin coaxial cable bundles

PCIe signals are high-speed differential signals with frequencies up to tens of GHz. When the rate exceeds 16Gbps, any impedance mismatch or poor shielding can lead to signal reflection, eye diagram collapse, and increased error rates. Extremely fine coaxial cable bundles have each conductor with an independent shielding layer, providing excellent electromagnetic interference isolation (EMI performance), and maintaining strict geometric consistency to keep the differential impedance stable within the 100Ω or 90Ω range. This design ensures the synchronization and integrity of high-speed signals in multi-channel, multi-interface environments, making it very suitable for PCIe Gen4/5/6 applications.

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Part 2: The Harness Challenges Brought by PCIe High-Speed Technology

With the rate increasing to 32Gbps and above, the signal frequency enters the tens of GHz range, posing high requirements for attenuation, crosstalk, insertion loss, and return loss. Traditional twisted pair cables, FFC, or FPC are difficult to balance high bandwidth and compact wiring. However, ultra-thin coaxial cable bundles, with independent shielding and precise impedance control, effectively reduce signal reflection and loss. At the same time, their high flexibility design is suitable for complex structures such as high-density AI servers, GPU modules, and FPGA expansion boards, meeting the dual needs of high-speed transmission and wiring flexibility.

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Thermal Management of High-Speed Signal Lines in PCIe Systems

In AI servers, edge computing equipment, and GPU expansion systems, ultra-fine coaxial cable bundles are widely used for PCIe extenders, backplane interconnects, adapter modules, and FPGA test interfaces. For example, in GPU multi-card interconnects or PCIe expansion boxes, the cable length can reach 30~50cm, but still needs to ensure low loss and low error rate at speeds above 32Gbps. Micro coax with silver-plated copper conductors, woven shielding, and high-frequency dielectric materials (such as PTFE, ePTFE) can achieve a signal bandwidth of up to 40GHz and stable transmission, meeting the high-speed interconnect needs of complex application scenarios.

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The extremely fine coaxial cable bundle, with its high-frequency low-loss, precise impedance control, excellent shielding performance, and high flexibility, has become the ideal solution for PCIe Gen4/5/6 high-speed interconnects, providing reliable and high-speed signal transmission for AI servers, high-performance computing platforms, and data centers.

I amSuzhou Huichengyuan Electronic TechnologyLong-term focus on the design and customization of high-speed cable harnesses and ultra-thin coaxial cables, committed to providing customers with stable and reliable high-speed interconnection solutions. If you have related needs or want to learn more, welcome to contactManager Zhang: 18913228573 (same as WeChat)。