Why might signal levels vary in coaxial cables at higher frequencies?

Signal levels in coaxial cables can vary at higher frequencies primarily due to cable attenuation characteristics. As frequency increases, coaxial cables inherently experience more loss. Attenuation refers to the reduction in signal strength as it travels through the cable, and this loss can be influenced by various factors including the cable design, materials used, and the frequency of the signal.

At higher frequencies, signal energy can be absorbed more by the dielectric material and can also be reflected at various points along the cable due to impedance mismatches. This results in a decrease in the effective signal strength as it reaches the end of the cable. Understanding these characteristics is vital for ensuring that signals maintain their integrity over longer distances or at higher bandwidths.

While factors such as increased cable length, capacitance variations, and temperature fluctuations can play a role in signal degradation, the most direct and significant impact at higher frequencies comes from the attenuation characteristics of the coaxial cable itself.