Frequency Characteristics of Diffracted Waves Considering Transition Region of GTD Shadow Boundary

In order to have an effective utilization of the radio wave resources, it is important to estimate propagation path in the urban area. In our previous work, we have examined the diffracted fields by two edges with an arbitrary angle which are in different and same heights. In this paper, we consider the frequency characteristics of the diffracted fields not only outside but also inside the transition region by two horizontal edges of a building rooftop. The numerical calculations are carried out for two wedges of a building rooftop on perfect conductor and concrete wedges and for two cases: with parapets or without parapets. The numerical results confirm our analytical results that single, double and slope diffraction components are inverse proportional with the square root of frequency, frequency, and square of frequency outside the transition region, respectively. But these components are almost constant near the shadow boundary.