mmWave propagation: path loss, foliage, rain fade, blockage

mmWave Path Loss Characteristics

Millimeter wave frequencies between 24 and 100 GHz experience dramatically higher free-space path loss compared to sub-6 GHz bands. At 28 GHz, path loss is approximately twenty-two dB greater than at 3.5 GHz for the same distance, following the Friis transmission equation. This fundamental physics constraint limits mmWave cell radius to a few hundred meters in most practical deployments. Additionally, mmWave signals have minimal diffraction capability around obstacles, meaning even small obstructions like a human body can attenuate the signal by twenty to thirty dB, creating deep shadow zones…