The core role of the ultra-fine coaxial cable束 insulation layer: material, structure, and high-speed performance analysis

Under the continuous development of high-speed signal transmission and equipment miniaturization, extremely thin coaxial cable束 has become an indispensable interconnection method for devices such as smartphone camera modules, VR/AR display modules, medical probes, and industrial cameras. Although the insulation layer occupies the smallest volume in the coaxial structure, it is a key link that determines impedance, loss, speed, and reliability. This article will systematically analyze the core value of the insulation layer in extremely thin coaxial cable束 from the aspects of structural principle, material properties to future trends, providing reference for engineers in design and material selection.

Insulation structure and core function in ultra-fine coaxial cable束
Extremely thin coaxial cable bundles are usually composed of a central conductor, an insulating dielectric layer, a shielding layer, and a sheath. The insulating layer is located between the conductor and the shielding and is the core for maintaining impedance, capacitance, and signal stability. As the cable diameter continues to shrink, the thickness, geometric uniformity, and dielectric properties of the insulating layer have a more significant impact on signal integrity. Even small deviations can cause impedance fluctuations, increased reflections, and higher losses. Therefore, although the insulating layer is thin, it is a key structural factor determining whether a high-speed link can operate stably.

The key properties and common types of insulating materials
High-quality insulating materials should have low dielectric constant, low dielectric loss, high voltage resistance, good geometric uniformity, and stable environmental tolerance. Otherwise, it may cause signal distortion, increased attenuation, or inconsistent transmission delay. Common materials include solid PE (performance stability, low loss), foamed materials (lower dielectric constant but higher manufacturing difficulty), fluoroplastic PTFE/PFA (suitable for high-frequency and high-speed applications), and air structures with near-ideal dielectric properties (but insufficient mechanical stability). Engineers need to choose the appropriate material based on the application frequency, spatial constraints, bending life, and temperature environment.

The influence of insulation on high-speed performance and future technological trends

The insulating layer determines the impedance matching, signal attenuation, propagation speed, and long-term reliability of coaxial cables, directly affecting the system performance of high-speed links. A high-quality insulating layer can maintain stable performance under high bending, temperature and humidity changes, and long-term use. With the continuous increase in demand for high-speed interfaces, lightweight, and flexible applications, the future insulating materials will develop towards being thinner, lower in loss, higher in consistency, and stronger in reliability to meet the requirements of more stringent applications such as 8K display, VR ultra-high-speed links, and medical miniature probes.


Insulation plays a core role in maintaining impedance, reducing losses, enhancing speed, and improving reliability in extremely fine coaxial cable bundles, which is the fundamental factor for the stability of high-speed signal transmission. Understanding material properties, structural consistency, and environmental tolerance is crucial for designing high-performance and highly reliable micro coaxial cables. With the increasing demand for high-speed, high-frequency, and miniaturized devices, insulation material innovation and precision manufacturing processes will become an important support for future high-speed interconnect technology.

I amSuzhou Huichengyuan Electronic TechnologyCommitted to the design and customization of high-speed signal cable harnesses and ultra-thin coaxial cable harnesses, we strive to provide customers with stable and reliable high-speed interconnection solutions. For technical consultation or more information, please contact:Yin Manager18913280527 (WeChat number)）。