High-Speed Bulk Cable Design Presents Multiple Challenges, Luxshare-Tech Mitigates Risks Through Early Simulation and Validation

Amid the wave of AI computing clusters expanding to ten-thousand-card scales, the leap in single-channel data transmission rates to 224G/448G has become an inevitable trend. As the core transmission medium, the performance stability and environmental adaptability of high-speed bulk cables directly impact the operational efficiency of the entire system. In the realm of ultra-high-speed transmission, challenges such as excessive signal attenuation, performance fluctuations in complex environments, and reliability degradation after installation bending pose significant hurdles for the design and manufacturing of high-speed bulk cables.

At the recent SuperNode Interconnect Technology Innovation Conference, Yan Huanzhong, Senior Product Design Engineer at Luxshare-Tech, delivered a keynote presentation titled “Simulation Design and Reliability Validation for 224G & 448G Bulk Cables.” He shared a critical solution to high-speed bulk cable design challenges, integrating simulation design throughout the entire process, from material selection and structural optimization to process control, paired with rigorous reliability validation. This approach eliminates potential application risks during the design and testing phases, ultimately delivering the Optamax series of high-speed bulk cables meeting 224G/448G transmission requirements.

I. Simulation First: Mitigating Performance Risk at the Source

In 224G/448G high-frequency transmission scenarios, excessive signal attenuation and inadequate SI performance represent core technical challenges. Luxshare-Tech abandoned traditional trial-and-error R&D, adopting simulation-driven design as the core approach. This enables precise performance prediction during material selection, proactively mitigating risks.

For signal line conductors, Luxshare-Tech compared the conductivity and material properties of metals A, B, and C alongside plating materials through simulation. Considering factors like the skin effect, Material A emerged as the preferred choice. Simulation results are illustrated below:

For insulation materials, the innovative Material A exhibits a significantly lower loss factor (df) than Material B. Simulation results indicate 86GHz attenuation is 12.32% lower than Material B. Considering cost and application scenarios, multiple material options are available. Simulation results are shown below:

For the shielding layer, the simulation confirms Material B as the optimal solution. At 86GHz, its attenuation is 3.85% lower than Material A's shielding material, and its weldability aligns with subsequent processing requirements. Simulation results are shown below:

II. Structural Simulation Optimization: Proactively Addressing Installation and Compatibility Challenges

In practical applications, data centers frequently encounter issues such as “limited space hindering cabling” and " performance degradation after bending." Through iterative structural simulation, Luxshare-Tech resolves these challenges during the design phase.

After simulation optimization, Luxshare-Tech's Optamax bulk cable eliminates dual-side ground planes, adopting either a central flat ground plane or a ground-free structure. It incorporates an innovative insulating layer (with extremely low df and dk) and employs a tightly coupled structure, reducing width by over 15%. At 86GHz, attenuation is reduced by 9.25% compared to traditional designs, meeting high-density routing demands while ensuring stable performance after bending. Simulation results are illustrated below:

III. Process Simulation Control: Mitigating Mass Production Consistency Risks

In industrial applications, “sample compliance versus mass production variability” remains a critical barrier to large-scale deployment. Luxshare-Tech extended simulation into manufacturing processes, establishing precise control standards by predicting critical parameter impacts.

Simulation revealed significant performance degradation linked to core concentricity—SCD21 parameters deteriorated markedly when concentricity dropped from 100% to 80%. Consequently, Luxshare-Tech prioritized monitoring conductor OD and core concentricity during production, maintaining concentricity above 95%. For the 13.28GHz-56GHz frequency band, measured attenuation values deviated no more than 0.22dB/m from simulation results, ensuring mass production consistency. 

IV. Rigorous Reliability Validation: Proactive Elimination of Environmental Adaptability Risks 

After deployment, high-speed bulk cables face complex environments like high temperatures and bending. Luxshare-Tech employs testing exceeding industry standards to simulate extreme scenarios, validating stability and preemptively eliminating failure risks.

High-Temperature Test SI Curve

Temperature ramp testing at 25°C-45°C-65°C-85°C-105°C (2-hour dwell per stage) showed no oscillation in the attenuation curve. The SCD21 curve exhibited high consistency. At 105°C, the attenuation change rate at 53.12GHz remained <20%, meeting high-temperature stability requirements.

Static Bending + Torsion Test: At a 2.5mm bending radius, subjected to 360°/720° bending and torsion. The attenuation change rate during bending < 1.5%@53.12GHz. Attenuation curve exhibits no resonance and remains smooth. Meets practical installation bending requirements.

Static Bending + Torsion Test Diagram Bending-Torsion Pre- and Post-Attenuation Test Graph

V. Full-Process Closed-Loop: Delivering Highly Reliable Products Through Simulation and Validation

From material selection and structural design to process control and reliability testing, Luxshare-Tech integrates simulation throughout the entire high-speed bulk cable R&D process, forming a closed-loop system of “simulation prediction - optimization adjustment - validation implementation.” Optamax high-speed bulk cables not only meet ultra-high-speed transmission requirements in electrical performance but also satisfy critical application needs for high-speed copper interconnect systems in cost, installation compatibility, and environmental adaptability.

Looking ahead, as transmission speeds advance toward 800G and beyond, Luxshare-Tech will continue to prioritize simulation-driven design. We will explore new materials and processes while proactively preparing for next-generation high-speed interconnect R&D. Through our “end-to-end simulation + rigorous validation” approach, we will deliver more reliable products to accelerate the growth of AI and data center industries.