Analysis of Signal Integrity Performance of Twinax Cable under Bending Conditions

In this paper, the signal integrity performance of high-speed twinax cable under different bending conditions are studied. Test results show that vertical bending has little effect on SI performance, while horizontal bending will cause deterioration of insertion loss, differential to common mode conversion, effective intra-pair skew, as well as variation in the signal propagation time. Studies on such impacts are carried out from various aspects including low level contact resistance measurement, mechanical simulation and destructive physical analysis. Results show that, the degradation of SI performance is mainly induced by the asymmetric deformation of the shielding foil and dielectric insulator. It is highly suggested that twinax cable under horizontal bending should be avoided in application.