On the possibility of estimating the multiple-diffraction losses of a rectangular obstacle at mm-wave frequencies from the corresponding double knife-edge results

The possibility of estimating the multiple-diffraction attenuation caused by a rectangular obstacle, when illuminated from a low source (i.e., the transmitter height is smaller than the obstacle height), from the results obtained when considering the corresponding double knife-edge configuration is hereby analyzed, at millimeter-wave frequencies. The theoretical analysis shows that the rectangular obstacle propagation losses can be predicted by the addition of a proper offset to the double knife-edge case attenuation values. Numerical results are carried out, for both vertical and horizontal polarization, as a function of the angle of incidence, the distance between the transmitter and the obstacle, the width of the obstacle, and the distance between the obstacle and the receiver.