What are the primary causes of coaxial cable line losses at RF frequencies?

Coaxial cable line losses at RF frequencies primarily arise from wire resistance and reactance.

When an RF signal travels through coaxial cable, it encounters resistance due to the conductive materials used in the inner conductor and the shield. This resistance can cause power dissipation in the form of heat, leading to a loss of signal strength. Additionally, coaxial cables exhibit reactance, which includes both inductive and capacitive effects related to the cable's physical characteristics and the frequency of the signal. These reactance effects can also contribute to the overall impedance seen by the RF signal, which influences how efficiently the signal is transmitted and can lead to further losses.

In summary, wire resistance and reactance are critical factors that impact the efficiency of RF signal transmission through coaxial cables, resulting in line losses that must be considered in high-frequency applications.