Evaluation of the Effect of Radius of Curvature on the Rounded Edge Diffraction Loss Computed by Hacking Method for a Plateau

Abstract

Abstract:In this paper, the effect of the radius of curvature on the diffraction loss of rounded edge obstruction is presented.The study is conducted for C-band microwave link with a plateau in its path. The plateau has flat to that spans about 1922 m. Two different approaches are used to determine the radius of curvature of the rounded edged fitted to the plateau top. Among the two methods employed, the ITU-R 526-13 method overestimated the radius (about 12,374,693.37 m) as against 59,031.42 m estimated by the second method at the same C-band frequency of 4 GHz. Also, high radius of curvature by the ITU-R 526-13 method gave very high diffraction loss value for the plateau. Furthermore, with the ITU-R 526-13 method, the radius of curvature does increase with increase in frequency. In all, the results indicate that the ITU-R 526-13 method is not particularly suitable for estimating the radius of curvature for the rounded edge when applied to a plateau. In addition, a more accurate method is required to estimate the radius of curvature for computing rounded edge diffraction loss.