Characterization of propagating waves through Leafy vegetation

An assessment of the environmental impact on a communication link is imperative to wireless network planning. In this paper simulations have been carried out to find out the behavior of an electromagnetic wave propagating through a leafy vegetation layer. A communication link is assumed where the leafy vegetation medium comes in the line of sight of the receiver and the transmitter. This vegetation medium could be several kilometers long. The transmitting and receiving antennas have high gain of around 30 db. Hence the propagating wave is largely confined within the vegetation medium. It is found that the propagating wave does not attenuate monotonically. It decays rapidly over a certain distance but beyond this distance the rate of the decay decreases. A simple model is assumed to estimate the macroscopic effective dielectric constant. This model assumes that multiple reflections within the vegetation medium is absent. Since the attenuation of the fields are not monotonic, the calculated effective dielectric constant varies with the medium distance in a non linear fashion.