In high-speed interconnect applications, signal stability directly affects device performance. Camera modules, display modules, 5G devices, and various high-speed transmission systems impose strict requirements on high-speed data links. However, in actual application environments, high-frequency signals are prone to various interference, leading to data errors, image distortion, and even system malfunctions. The extremely fine coaxial cable harness (Micro Coaxial Cable Harness) is widely used in high-speed transmission due to its compact structure and excellent electrical performance. This paper will analyze the types of interference that may occur in extremely fine coaxial cable harnesses and effective countermeasures in common application scenarios.
One, crosstalk problem
Crosstalk is one of the most common interference types in extremely thin coaxial cable bundles. When the electromagnetic fields between the cables within a bundle or between adjacent bundles couple too strongly, a signal from one channel may "leak" into another. In high-speed multi-channel applications, excessive crosstalk can lead to a decrease in signal integrity, thereby affecting transmission speed and system stability.
Effective measures: Rational planning of cable arrangement, maintaining impedance consistency, and enhancing the integrity of the shielding layer are effective methods to reduce crosstalk.
Second, electromagnetic interference (EMI) and radio frequency interference (RFI)
In high-speed transmission, ultra-fine coaxial cable bundles can operate in frequency bands reaching hundreds of MHz even several GHz. Under these conditions, external electromagnetic radiation or radio frequency signals are prone to interfere with the signal chain, increasing the error rate.
Solution measures: By optimizing the shielding structure, such as increasing the density of weaving layers or using foil composite shielding, and ensuring the shielding transition at the connector port is complete, the impact of EMI/RFI on the system can be effectively reduced.
Three, reflection interference caused by impedance mismatch
Impedance mismatch can cause reflections at discontinuities in interfaces or cables, superimposed on the original signal, leading to eye diagram closure and signal distortion.
Control measures: Strictly control the characteristic impedance of ultra-fine coaxial cable束 (commonly 50Ω or 100Ω differential), maintain the impedance continuity of the entire link, thereby reducing reflection interference.
Four, common mode interference caused by poor grounding and shielding
In portable devices or small modules, due to limited space, the grounding design is imperfect or the shielding layer grounding is insufficient, which can cause common mode interference, reducing the overall anti-interference ability of the system, and making it susceptible to external noise.
Optimize the grounding path, ensure that the shielding layer has a low-impedance grounding, and use common-mode chokes to improve the overall anti-interference performance when necessary.
Extremely thin coaxial cable bundles have significant advantages in high-speed signal transmission, but their high-frequency characteristics and compact structure are also prone to interference such as crosstalk, EMI/RFI, impedance mismatch, and poor grounding. Engineers need to combine cable parameters, impedance control, shielding layout, and system-level electromagnetic compatibility design during design and selection to achieve stable and reliable high-speed signal transmission. Through scientific design and reasonable protection, micro coax not only ensures the integrity of the high-speed signal chain but also meets the comprehensive requirements of modern electronic equipment for thinness, high performance, and anti-interference capability.
I am
[Suzhou Huichengyuan Electronic Technology]Long-term focus on the design and customization of high-speed signal cable harnesses and ultra-fine coaxial cable harnesses, committed to providing stable and reliable high-speed interconnect solutions. For more information or customization needs, please contact:
Manager Zhang 18913228573 (WeChat same number)。
