RF signal propagation that is generally considered "line-of-sight" primarily operates in which frequency range?

The frequency range typically associated with "line-of-sight" RF signal propagation is UHF, which stands for Ultra High Frequency. This range encompasses frequencies from 300 MHz to 3 GHz. Signals in this frequency range can travel directly between the transmitter and receiver without needing to follow the curvature of the Earth or bounce off the ionosphere, making them ideal for applications where a clear path is present, such as in mobile communications, television broadcasts, and two-way radio.

Line-of-sight propagation is particularly effective in this range because higher frequencies tend to have shorter wavelengths, allowing for a more direct transmission without obstacles causing significant interference. Solutions employed in UHF systems often include antennas designed to optimize reception and transmission within these parameters.

In contrast, other frequency bands like VHF (Very High Frequency) and HF (High Frequency) are less associated with line-of-sight due to their longer wavelengths which can be affected by obstacles, terrain, and atmospheric conditions. SHF (Super High Frequency), while also capable of line-of-sight propagation, is often used in different applications, particularly for radar and satellite communications, but UHF is more commonly recognized for terrestrial line-of-sight communication systems.