Development of the UTP Cable for 10 Gbps Transmission

摘要

Local-area network (LAN) cables used for data communications systems have been evolving to provide transmission speeds of up to 1 Gbps. This study aims to achieve data transmissions at even higher frequencies using unshielded twisted pair (UTP) cables. The most important key to achieving this goal is to improve crosstalk, and it turned out that maintaining transmission in the TEM mode is effective for reducing crosstalk. To maintain the TEM mode, each pairs of category 6 (CAT6) twisted pair cables were circularly covered with a thin insulator. The trial cables with this construction exhibited a crosstalk of 60 dB (at 300 MHz for 100 m), remarkably increasing the frequency band compared with the conventional cables. This paper describes the cable construction and transmission characteristics based on an electromagnetic field analysis and experiments and indicates that the construction proposed by this study has a high possibility of achieving 10 Gbps transmission with UTP.