Ham Radio General Class Test 2025 – 400 Free Practice Questions to Pass the Exam

As frequency increases, the attenuation of coaxial cable typically increases due to several factors. At higher frequencies, the electromagnetic waves interact with the materials within the coaxial cable, such as the dielectric and conductor. This interaction results in more signal loss, which manifests as attenuation.

One major contributor to this increase in attenuation is the skin effect, which causes RF currents to flow primarily on the surface of the conductor at higher frequencies, effectively reducing the conductor's cross-sectional area and increasing resistance. Additionally, dielectric losses in the insulating material can become more pronounced at higher frequencies, further contributing to the overall attenuation.

This relationship highlights the importance of considering the frequency when designing and selecting coaxial cables for specific applications, as higher frequency signals will experience more loss than lower frequency signals.