关键词: 柔性编织同轴线缆, 结构设计, 电气性能, 线缆材料

Abstract: In recent years, the market for smart wearable devices has witnessed rapid growth, with a continuous emergence of various products such as smart watches, smart bracelets, and smart clothing. People's requirements for their functions and performance have also been increasing, including demands for high-speed data transmission, precise positioning, and health monitoring. This has led to a growing need for high-performance antenna connection feeders. To improve the comfort and convenience of wearing, smart wearable devices are increasingly trending towards miniaturization and flexibility. Traditional rigid coaxial cables can no longer meet the usage requirements under bending, folding, and other conditions. As a result, flexible coaxial cables have emerged, which can better adapt to various shapes and motion states of wearable devices. With the development of wireless communication technologies such as 5G and even future 6G, the frequency of signal transmission is increasing, placing higher demands on the the transmission performance of antenna connection feeders, such as low loss, high shielding effectiveness, and stable impedance characteristics. Flexible coaxial cables need to continuously improve their performance to meet the needs of high-frequency signal transmission. Researchers are exploring the use of novel conductive materials to improve the performance of flexible coaxial cables. For example, some nanometallic materials such as silver nanowires and copper nanowires exhibit excellent conductivity and flexibility, but issues such as cost and stability still need to be solved. Researchers are optimizing the multi-layer structure design of flexible coaxial cables to improve their performance. For instance, by adjusting the thickness, material, and relative positional relationships of the inner conductor, insulation layer, outer conductor, and shielding layer, better impedance matching, reduced signal loss, and improved shielding effectiveness can be achieved. However, there is still a challenging balance between structural changes and performance. In the field of smart wearables, flexible coaxial cables used as antenna connection feeders need to develop towards textile integration and flexible intelligence. By combining novel conductive yarns with high-performance, low-loss insulating yarns, it is necessary to improve the tensile strength, bending resistance, and wear resistance of the cables to ensure their stable and reliable operation over long-term use. With continuous advancements in materials science, manufacturing processes, and wireless communication technologies, flexible coaxial cables have achieved significant improvements in both performance and functionality. However, they still face some challenges, such as the optimization of large-scale production processes and integration with wearable devices. In the future, it is necessary to further strengthen interdisciplinary collaborative research, and continue to explore and innovate, so as to develop flexible coaxial cables with better performance, lower costs and greater suitability for the needs of smart wearable devices to drive the continuous development of smart wearable technology. This paper provides a comprehensive review of the textile materials, structural design classifications, performance testing methods and evaluation indicators of flexible coaxial cables, offering technical reference for the textile design and preparation of flexible coaxial cables. Additionally, it outlines the development trends and technical challenges of flexible coaxial cables.

Key words: flexible braided coaxial cables, structural design, electrical properties, cable material