Refractive Multipath Model for Line-of-Sight Microwave Relay Links

A major source of propagation outages on microwave line-of-sight (LOS) links is multipath fading caused by steep negative refractive index gradients. This paper develops a complete transfer function characterization of refractive multipath on LOS links. The results clearly show the dependence of discrete path amplitudes and delays on receiver height, transmitter height, refractive index gradient, layer height and ground range.