| 摘要 |
1290358 Aerials THOMSON-CSF 17 Dec 1969 [18 Dec 1968] 61493/69 Heading H4A An aerial comprises a primary source 1, Fig. 1, which directs linearly polarized waves towards a grid of parallel conductive wires 3 in a radome 2. As described, the radome is of parabolic form, and the wires are horizontal. Spherical waves with horizontal polarization are received from the source, and are reflected back as plane waves, to be received by a network of re-radiating sources 4. Each of said sources effects an orthogonal transformation of polarization between its input and its output, which are connected together by variable phase shifting means. Consequently, the re-radiated plane waves are vertically polarized, so that they pass through the wires 3, and they may be scanned in elevation, or in azimuth and elevation, by suitably varying the phase shifting means. A source 4 may comprise crossed dipoles, or a rectangular horn (Fig. 2, not shown). The phase shifting means 7 may comprise semi-conductor diodes, or ferrites. In another embodiment, a non- parabolic radome is used, so that the waves received by the re-radiating sources are non- planar. However, by suitably adjusting the phase shifting means, the re-radiated waves may be made planar, with reduced side lobes. |
