| 摘要 |
PURPOSE:To attain ease of manufacture, to improve the strength of an antenna and the safety by deforming plastically a disc board so as to form an elliptic reflecting plate of an offset type antenna. CONSTITUTION:An aluminum or the like being a material for the reflecting plate of the offset type antenna is formed to a circular disc 11. The elliptic reflecting board 12 is formed by deforming plastically the disc 11 by means of a press machine or a metallic die. The elliptic reflecting board 12 is formed with a curved part 13 and a foldback 14 curled outward. A part 14a folded largely is produced to the foldback 14. Further, the foldback 14 is formed with a curl 15. Since the disc 11 is subjected to press processing, the orientation of a raw material is eliminated and the disc is manufactured easily. Further, the part 14a folded largely is produced, then the strength is increased. Moreover, the curl 15 is formed, then the safety for the worker is improved. |
