Challenges of隐形 transmission at high speeds: reasons for attenuation of ultra-thin coaxial cables and improvement ideas

In modern electronic devices, **micro coaxial cables** are almost everywhere.
Whether it's a smartphone, laptop, drone, or high-precision medical equipment, it undertakes the important task of high-speed signal transmission. Its advantage lies in being able to achieve high-speed and low-noise transmission in an extremely limited space, while maintaining lightness and flexibility.
However, behind these advantages, **signal attenuation** remains a technical challenge that engineers must face. Understanding its formation mechanism and optimization direction is crucial for ensuring system performance.

The main reasons for signal attenuation
1.1 Conductor Loss:
The inner conductor of extremely fine coaxial cables is usually made of silver-plated copper or tin-plated copper to improve conductivity.
But due to the extremely small wire diameter, a significant skin effect (Skin Effect) occurs when the signal frequency increases—the current concentrates in the conductor surface, the equivalent cross-sectional area decreases, leading to an increase in resistance, and thus an increase in high-frequency losses.
1.2 Dielectric Loss:
Insulating medium (such as PTFE or FEP) inside cables will experience dielectric polarization loss at high frequencies.
The higher the frequency, the greater the medium loss factor (Df), and energy is dissipated in the form of heat, causing the signal strength to衰减 as the distance increases.
1.3 Shielding layer attenuation:
Very fine coaxial cables usually adopt a woven shielding or a combination of foil + woven structures.
However, due to the wire diameter and manufacturing process, the thickness of the shielding layer and the weaving density are limited. When the shielding efficiency is insufficient, external electromagnetic noise (EMI) will be superimposed on the signal path, further weakening the effective signal.
1.4 Connector and bend loss:
In miniature devices, cables often need to be routed and bent in narrow spaces.
If the bending radius is too small, it will cause impedance discontinuity and induce reflection loss; at the same time, an unreasonable connector design may also cause the contact resistance to increase, resulting in increased transmission attenuation.

Part Two: Engineering Optimization Approach
In order to minimize signal attenuation and improve the transmission performance of the system, engineers usually adopt the following measures during design and manufacturing:
2.1 Optimize conductor material
Select high-conductivity materials such as silver-plated copper or pure copper to reduce high-frequency resistance loss.
2.2 Use low-loss medium materials
Insulation materials with low dielectric constant and low loss factor, such as PTFE and LCP, effectively reduce dielectric loss.
Enhance the design of the shielding structure
By increasing the weaving layer density and adopting double-layer or multi-layer shielding structures, the interference resistance and signal purity are significantly improved.
2.4 Optimize Wiring and Mechanical Structure
Control the bending radius of cables to avoid excessive bending and stretching; at the same time, choose high-precision connectors to reduce contact resistance.
In summary, the signal attenuation of ultra-fine coaxial束 is mainly caused by multiple factors including the conductor, medium, shielding, and mechanical structure.
Only by optimizing the whole process from materials, design, manufacturing to application can the signal integrity and system stability be maximized.
Therefore, in the design of high-speed signal chains, choosing and using high-quality Micro Coax cables correctly has become a crucial step in enhancing equipment performance.

I amSuzhou Huichengyuan ElectronicFocusing on the design and customization of high-speed signal cable harnesses and ultra-fine coaxial cable harnesses, committed to providing high-performance, low-loss high-speed interconnection solutions. If you have any related needs or wish to learn more, please contact:Manager Zhang 18913228573 (WeChat same number)。