What causes coaxial cable line losses at RF frequencies?

Losses in coaxial cable at radio frequency (RF) are primarily attributed to the combination of wire resistance, capacitive reactance, and inductive reactance.

When RF signals travel through a coaxial cable, the conductor (usually copper or aluminum) experiences resistance, which leads to power loss in the form of heat. This is a fundamental concept in electrical engineering where all conductors have some level of resistance, which can be more pronounced at higher frequencies due to skin effect, where the current tends to flow on the surface of the conductor rather than through its entire cross-section.

Additionally, capacitive and inductive reactance plays a significant role in signal integrity. At RF frequencies, the capacitance created by the insulation between the inner and outer conductors, along with the inductance of the cable, can create impedance mismatches and reflections. These reactances can lead to attenuation of the signal as well.

This interaction of resistance, capacitance, and inductance at RF frequencies is crucial in understanding the overall performance of coaxial cables and helps in designing systems for minimal signal loss.

In contrast, signal interference primarily affects the quality of the received signal rather than the inherent line losses due to the physical properties of the cable itself. Low bandwidth,