From structure to anti-interference: How ultra-fine coaxial cable bundles help high-speed equipment pass EMC tests

In high-speed, miniaturized electronic devices, extremely thin coaxial cable束 (Micro Coaxial Cable) is a key signal transmission medium. It not only supports high-frequency, high-speed data transmission but is also closely related to the EMI/EMC (Electromagnetic Interference and Electromagnetic Compatibility) test results of the devices. Below, from aspects such as structural characteristics, test performance, and design challenges, the important role of this cable in high-speed electronic systems will be analyzed.

Unique structure of extremely fine coaxial beam
Extremely thin coaxial cables are usually composed of a central conductor, insulating layer, metallic shielding layer, and an outer sheath. Although their size is much smaller than that of traditional coaxial cables, they still possess excellent impedance consistency and signal transmission performance. Especially the application of the shielding layer, which makes them excel in resisting external electromagnetic interference and reducing their own radiation. This "double-layer protection" structure allows the extremely thin coaxial cables to have higher reliability and stability in EMI/EMC tests compared to ordinary parallel cables.
The advantages of ultra-fine coaxial cables in EMI/EMC testing
(1) Suppression of electromagnetic emission: In the transmission test, extremely thin coaxial cables can effectively reduce the leakage of high-frequency signals, prevent the cables from acting as "antennas," thereby reducing the risk of exceeding the electromagnetic radiation standard.
(2) Enhanced anti-interference capability: In anti-interference tests, its shielding layer can resist external electromagnetic noise and maintain internal signal stability, which is particularly crucial for high-speed interfaces and RF modules.
(3) Maintain signal integrity: Under GHz-level high-frequency transmission, extremely thin coaxial cables have low loss and precise impedance control, which can effectively maintain the clarity of signal waveforms, reduce reflection and distortion.

Challenges in Design and Application
Although ultra-fine coaxial cable束 has outstanding electromagnetic compatibility performance, it may also become a hidden danger of EMC problems if not designed properly:
(1) Discontinuity shielding: If the connector terminals or grounding design is poor, the shielding layer may have "break points," causing interference leakage.
(2) Insufficient mechanical reliability: The wire is soft and the diameter is small. If it is frequently bent or subjected to improper force, it is easy to cause damage to the shielding layer, affecting the EMI/EMC test results.
（3） Poor impedance matching: If there is an impedance mismatch between the harness and the PCB or connector, it will cause signal reflection, increasing the risk of radiation.
Therefore, in the product design and selection stage, it is necessary to consider factors such as shielding grounding methods, impedance matching, and structural protection simultaneously to fully utilize its electromagnetic compatibility performance.

Four, typical application scenarios
Extremely fine coaxial cable束 is widely used in mobile phone camera modules, notebook screens, AR/VR devices, drones, and high-speed data interfaces. These products generally have the characteristics of compact structure and high signal rate. Micro coaxial cable, with its miniaturization and high shielding efficiency, allows devices to maintain excellent electromagnetic compatibility performance in limited spaces and pass tests smoothly.

In general, ultra-fine coaxial cable束, with its exquisite structure, efficient shielding performance, and stable high-frequency characteristics, provides reliable support for EMI/EMC compliance of modern electronic equipment. However, it is not a "one-size-fits-all" solution—ideal results require careful consideration of materials, connections, wiring, and testing coordination during the design phase to achieve electromagnetic compatibility optimization at the system level.
We are[Suzhou Huichengyuan Electronic], focusing on the design and customization of high-speed cable harnesses and ultra-fine coaxial cables, committed to providing customers with high-quality high-speed interconnection solutions. If you have relevant needs or wish to learn more, please contact:Manager Yin 18913280527 (WeChat number the same)。