What defines cable impedance, its measurement unit, and critical factors influencing this parameter in high-frequency applications?

Cable impedance—denoted by the symbol "Z" and measured in Ohms—represents the total opposition to alternating current flow in conductive systems. At elevated frequencies, this electrical property is primarily determined by three interdependent factors: conductor cross-sectional dimensions, dielectric material composition, and insulation thickness. Proper impedance matching (e.g., aligning 100Ω system specifications with compatible cabling) prevents signal degradation through reflection minimization, directly impacting return loss performance in bidirectional transmission scenarios where mismatched impedances generate error-inducing waveform distortions.