Why do high-speed cameras from mobile phones to cars all rely on Micro Coax?

In smart phones, vehicle systems, robots and other devices, camera resolution is becoming higher and frame rates are getting faster, while the internal space of the motherboard is becoming more compact. In order to achieve stable transmission of high-speed image signals in limited space, the CSI interface (Camera Serial Interface) has become one of the mainstream solutions.
In this high-speed system, there is a seemingly insignificant but extremely critical role – the ultra-fine coaxial cable bundle (Micro Coaxial Cable).

What is a "micro coaxial bundle"?
So-called "ultra-fine coaxial cable bundle" is a high-frequency signal cable with an extremely small diameter and a complete shielding structure.
Its typical structure includes: central conductor, insulation layer, shielding layer, and outer sheath—to achieve high-density wiring, stable impedance, and excellent anti-interference ability within a small size.
Compared to traditional coaxial cables, the diameter of Micro Coax lines can be as small as AWG42 or even smaller, making them light and flexible, capable of withstanding repeated bending, and very suitable for high-speed applications with limited space, such as smartphones, camera modules, and automotive imaging systems.
Between the CSI camera module and the mainboard, it has become the preferred harness solution that balances performance and space efficiency.

Why can't the CSI interface do without the extremely thin coaxial cable bundle?
CSI interface is essentially a high-speed serial data transmission channel.
Taking MIPI CSI-2 and CSI-3 as examples, their transmission rates usually reach several Gbps. If FPC or thin ribbon cables are still used, problems such as signal reflection, crosstalk, and bit errors are likely to occur. The structure of extremely thin coaxial cables can exactly solve these pain points.
Its advantages are mainly reflected in the following aspects:
Impedance control accuracy
Coaxial structures naturally have good impedance continuity in geometry, with minimal signal reflection. For CSI interfaces, the stability of impedance is directly related to frame rate of the image and signal integrity.
Strong anti-interference ability
The outer shielding layer can effectively isolate electromagnetic interference, especially in complex electromagnetic environments such as in vehicles or robots, which can significantly improve the image signal quality and system reliability.
High space utilization rate
The Micro Coax cable is very slender, soft, and flexible, allowing for easy passage through narrow areas such as hinges and shell gaps, providing more space for structural design.
Excellent high-frequency performance
With the increase in image resolution and frame rate, the data frequency is getting higher and higher. The extremely fine coaxial cable's low loss and wide bandwidth characteristics make it capable of easily handling high-speed signal transmission of up to 10Gbps and even higher.

Three, key points of design and use
When using extremely thin coaxial cables in CSI system design, the following points need to be paid special attention to:
Impedance matching must be complete
Cables must control impedance, and connectors, solder points, transition boards, etc., must maintain continuity. It is usually paired with micro high-speed connectors such as I-PEX, Hirose, etc., to ensure system signal integrity.
The length of the wire and the bending radius should be reasonable.
The longer the line, the more obvious the signal attenuation; sharp bends may destroy the integrity of the shielding layer. Design should control the length and bending radius, and follow the specification layout.
Bonding grounding must be complete
The shielding layer, if not properly grounded, will significantly reduce the anti-interference performance. Especially in multi-module systems, it is necessary to ensure continuous and stable grounding.
Focus on environmental and durability parameters
The harnesses used in high-stress scenarios such as cars, drones, and robotic arms should pay special attention to their high-temperature resistance, vibration resistance, and bend fatigue life indicators.

Four, typical application scenarios
Mobile phone/laptop camera
Space-saving and complex wiring, Micro Coax can achieve high-speed transmission in a very small space.
Vehicle-mounted camera and ADAS system
Maintains signal stability in high-temperature and strong-vibration environments, ensuring reliable imaging.
Industrial vision and robot systems
With high durability and consistency, it is suitable for long-term operation and dynamic motion scenarios.

In general, ultra-fine coaxial cable束 is a signal transmission solution designed for high speed, miniaturization, and complex environments.
It has a compact structure, strong anti-interference capability, and flexible wiring, which not only guarantees the high-speed stability of the CSI interface but also meets the assembly requirements of various miniaturized devices.
With the popularization of high-bandwidth systems such as in-car imaging, robots, AR/VR, the application fields of Micro Coax cables will continue to expand.
It may not be the most prominent component, but it is a key link for the stable operation of the high-speed imaging system.
I amSuzhou Huichengyuan Electronic, Long-term focus on the design and customization of high-speed signal cable harnesses and ultra-fine coaxial cable harnesses, committed to providing customers with high-performance and highly reliable interconnection solutions.
Welcome to contact us if you have any related needs or wish to learn more.Manager Zhang 18913228573 (WeChat number the same)。