| 摘要 |
PURPOSE:To reduce the effect on communication lines due to wind, by making the main beam within a vertical plane broad, through the folding of a reflection plate used for reflection plate relaying horizontally and the forming of a bent plane plate tilted toward the front, respectively. CONSTITUTION:A main reflection plate is constituted that a plane reflection plate 4 is folded at a horizontal center postion O and upper and lower halves, reflection plates 8, 9 are tilted toward the front by an angle PHI by setting the position O as a center, respectively. This tilted angle PHI is selected so that asin PHI lines between lambda/12 and lambda/8, where lambda is a wavelength in use. The directivity within the vertical plane when this reflected plate is displaced by bending and vibration caused by a strong wind and an earthquake, is much improved in comparison with the characteristic curve 1 of the plane plate, as shown in curves 10 and 11. Curves 10, 11 show the case where the maximum displacement of the plates 8, 9 is respectively lambda/8 and lambda/12 and curve 12 indicates the maximum displacement for lambda/4. |
