High-speed Analysis of DisplayPort 2.1: The Key Role of Thin Coaxial Cables

In recent years, with the widespread use of high-resolution displays, VR devices, and professional workstations, video interface standards have continued to evolve. The advent of DisplayPort 2.1 has raised the bandwidth capacity to an unprecedented level, especially supporting UHBR20 (20 Gbps per channel), which puts higher requirements on the entire signal chain. In this ultra-high-speed transmission environment, the importance of cable structure becomes increasingly prominent. The extremely fine coaxial cable束 (micro coaxial cable) has become a key choice for ensuring signal integrity and system reliability due to its excellent high-speed transmission performance and anti-interference ability.
This article will analyze the high-speed challenge of DP2.1, the characteristics of extremely fine coaxial cables, and their value in practical applications from three aspects.

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High-speed Challenge between DP2.1 and UHBR20

The DisplayPort 2.1 standard introduces three speed grades: UHBR10, UHBR13.5, and UHBR20, with UHBR20's total bandwidth reaching 80 Gbps. Such high-speed data transmission places extremely high requirements on signal integrity, cable loss, and anti-interference performance. Any minor reflections, crosstalk, or impedance mismatches can lead to a decline in signal quality, thereby affecting image stability and refresh rate performance. To this end, VESA has launched the DP80 certified cable to ensure reliable transmission in UHBR20 mode. However, actual tests show that as cable length increases or frequency rises, signal loss will significantly increase, so high-speed transmission not only depends on the interface chip but also on the cable's own structure and performance.

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The characteristics of extremely fine coaxial beam

Extremely fine coaxial cable束 is a miniature coaxial structure wire material, usually using conductors as fine as AWG 40 or finer, with extremely low loss, excellent shielding characteristics, and precise impedance control. It can minimize high-frequency loss to the maximum extent, with each signal line having an independent shielding layer, effectively reducing EMI and crosstalk. At the same time, its outer diameter is extremely thin, making it very suitable for high-density wiring in space-limited devices such as laptops and VR headsets. Its frequency response is stable, and it can maintain excellent signal integrity even at transmission rates of several tens of Gbps. Compared with traditional twisted pair cables or ordinary cable bundles, extremely fine coaxial cables have significant advantages in high-speed and high-frequency environments, making them the ideal choice to ensure DP2.1 UHBR20 performance.

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Is DP2.1 mandatory to use ultra-fine coaxial cable?

Although ultra-fine coaxial cables are not the only choice, they are almost essential in scenarios where the highest performance of DP2.1 is pursued. For example, when delivering uncompressed output at 8K@60Hz or 4K@240Hz, ultra-fine coaxial cables can significantly reduce high-frequency loss, improve signal integrity, and ensure the system passes the DP80 or future DP80LL certification. For systems operating in UHBR10 or UHBR13.5 modes, with shorter cables or less interference, ordinary high-quality cables can also meet the requirements. However, if the device is expected to have higher signal margin and future expandability, ultra-fine coaxial cables are still the preferred choice. They can ensure signal stability and reliability in high-speed, high refresh rate, and high-resolution states, and are a safe design strategy for high-bandwidth and high-reliability equipment.

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In the DisplayPort 2.1 UHBR20 transmission environment, the ultra-thin coaxial cable bundle is not the only choice, but it is almost the optimal solution in terms of performance. It can significantly reduce signal attenuation and interference during high-speed transmission, allowing devices to maintain stable and reliable performance in high refresh and high-resolution states, while also meeting the high-density wiring requirements in limited spaces. For equipment manufacturers pursuing high performance, high reliability, or future expandability, adopting the ultra-thin coaxial cable bundle is a sound and efficient design strategy.

I amSuzhou Huichengyuan Electronic TechnologyLong-term focus on the design and customization of high-speed cable harnesses and ultra-fine coaxial cable harnesses, committed to providing stable and reliable high-speed interconnect solutions. For inquiries, please contactManager Zhang: 18913228573 (WeChat same number)。