Why do lower frequencies bend around terrain better?

Lower frequencies tend to bend around terrain more effectively due to their longer wavelengths. When a radio wave encounters an obstacle, whether it be a building, a hill, or any irregularity in terrain, longer wavelengths can "diffract" or bend around these obstacles more easily than shorter wavelengths can. This ability allows lower frequencies to maintain better communication even in environments where line-of-sight is obstructed.

The principle lies in how electromagnetic waves interact with objects. As the frequency of the wave decreases, the wavelength increases, and this increase in wavelength allows the wave to navigate around barriers more smoothly. Consequently, signals that operate at these lower frequencies are often less affected by physical obstructions, providing better coverage in urban, hilly, or forested areas where higher frequencies might be blocked or reflected.

Understanding this property is crucial for effective communication planning in various terrain types, as it influences the choice of operating frequencies based on environmental conditions.