What issue commonly causes high return loss?

• A. Excessive cable length
• B. Impedance mismatches due to poor terminations or damaged connectors
• C. Shielded cabling in low-EMI environments
• D. Using Category 6 cable instead of Category 5e

Answer: (B)

Impedance matching along the cable is what keeps reflections from bouncing back toward the source. When terminations are poor or connectors are damaged, the impedance changes abruptly at those points. That mismatch causes part of the transmitted signal to reflect back, which shows up as return loss and degrades the overall link performance. The other options don’t typically create the abrupt impedance change that drives reflections: extra cable length mainly adds attenuation over distance, shielded cabling is about EMI rather than impedance continuity, and using a different category cable is a factor only if the transmission path isn’t terminated to the correct impedance. The key idea is that poor terminations and damaged connectors introduce the impedance discontinuities that generate the reflections measured by return loss.