| 摘要 |
In the case of a reflector antenna having three polar diagrams (A, B, C) lying side-by-side, the two outer polar diagrams are arranged to be in antiphase, in order to achieve a polar diagram in a sector form, in each case by reflection of two primary emissions, which run with their beam directions (b, c) initially opposing one another and orthogonally with respect to the main beam direction (a), on in each case one flat lateral reflector (5, 7) which is bent towards the main beam direction and acts as a deflection mirror. The lateral reflectors are arranged symmetrically with respect to a rearward reflector (4) and a common exciter (E) which is seated in front and is used both for direct production of the central polar diagram (A) and for the two primary emissions. The width of the rearward reflector (4) is in this case selected to be so large that, while exclusively energising the reflector antenna by means of the two lateral primary emissions, the second null point of the polar diagram of the reflector antenna coincides with half the beam angle phi 0 of the polar diagram in sector form. The common exciter consists of a central Yagi antenna (1) pointing in the main beam direction (a) and two lateral Yagi antennas (2, 3), which are arranged with their beam directions (b, c) orthogonal thereto and opposing one another, and are supplied in-phase by a common dipole which is arranged at the intersection of the beam directions (a, b, c) which abut in a T-shape. <IMAGE>
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