Investigation of the influence of twisting methods multi-pair LAN cables on their electrical transmission characteristics

The need to study the infuence of twisting methods of cable core of multi-pair LAN cables on their main electrical transmission characteristics is justifed. Experimental studies of the electrical transmission characteristics of multi-pair LAN cables of category 5e in the frequency range up to 100 MHz have been conducted. The results of experimental studies of low-frequency and high-frequency electrical transmission characteristics of these LAN cables are presented. A detailed analysis of the results of experimental studies is carried out. It has been found that high-frequency transmission characteristics such as wave resistance and return losses are most afected by cable core twisting methods. Frequency behavior of these transmission characteristics is analyzed. It was shown that high geometric and structural uniformity of isolated cores, as well as the use of modern high-speed specialized equipment for twisting the pairs provide high transmission parameters of a four-pair LAN cable of category 5e. It was found that SZ twisting technology is unacceptable due to the introduction of geometric inhomogeneities in the manufacture of multi-pair cables. It is recommended to use unidirectional twisting bow-type stranders to minimize geometric inhomogeneities.