A method of estimating antenna effective gain in land mobile communication environments

A method for estimating the average effective gain of mobile antennas in a multipath propagation environment is discussed. The effective gain is defined as the ratio of the average received power of mobile antennas to the sum of the incident power of the vertically polarized (VP) waves and the horizontally polarized (HP) waves. This is called the average field gain (AFG). The expression for the AFG is derived by introducing a statistical model in which incident plane waves are distributed uniformly in azimuth and described by a Gaussian distribution in elevation. It is confirmed through 900-MHz-band measurements carried out in an urban area that the average distributions of incident waves can be approximated with this theoretical model. It is shown that the theoretical gain characteristics of half-wavelength dipole antennas inclined from the vertical closely agree with the experimental results. It is concluded that this method is useful in estimating the effective gain of mobile antennas in various mobile communication environments