| 摘要 |
The antenna element includes a ground plane (1) and a conical support (2) of dielectric material. Four radiation elements (3-6) are symmetrically arranged around the support to provide conical helical antenna elements. The radiation elements are attached to the ground plane at their exterior, lower ends. At their upper ends they are provided with an individual microwave signal through an individual coaxial cable (8,9) so that two orthogonally polarized radiation patterns, pref. circular, are generated. A distribution network (15) is arranged for dividing the signal incoming for transmission into four sub-signals which are offset in phase relation to each other. Each one is provided to the first to fourth radiation elements. Adaption elements (11-14) adapt the output impedance of the distribution network to the input impedance of the radiation element. |
