Study at the Influence of Different Paring Method and Their Effect on Coupling Attenuation

摘要

In the design of LAN cables there are many ways that can be used for pairing the insulated cooper wire. The different pairing methods directly effects on performance requirements such as return-loss, attenuation and Crosstalk. In this context, Shielding Effectiveness properties like transfer impedance and coupling attenuation can influence on the performance of larger band LAN cable such as CAT 6A, CAT 7, CAT 8. As already shown by other studies, shielding effectiveness is affected by many different aspects of the cable as different average lay-length where you can gain or lose margin depending on the lay-length used. From [2], it is possible to conclude that if you have a different average lay length you gain some margin on shielding, at the same time, it is possible that, due to the same process condition, the back-twisting factor can reduce the crosstalk on the cable and improve margin on shielding effectiveness testing. The results show that the backtwist mode influence on pairs depending on the lay length, for high lay length the use of backtwist (75%) you get around 2 dB from the next better pair. For lower lay length the use of backtwist (50%) you get around 1 dB from the next better pair.