| 摘要 |
970,274. Aerials. COMPAGNIE FRANCAISE THOMSON-HOUSTON. July 25, 1961 [July 26, 1960], No. 26911/61. Heading H4A. An aerial feeder comprises a pair of rectangular horns, the extremities of the adjacent wall of each horn being inside the other horn. These extremities are reflective to waves propagated by their respective horns, but transparent to waves propagated by horn into which they penetrate. Horns 2 and 3 radiate waves polarized parallel and perpendicular to the plane of Fig. 1, respectively. The overlapping portions 4, 6 of the walls have sections 13, 14, Figs. 2a and 2b comprising parallel rods or slots which are transparent to radiation from horns 3 and 2 and reflective to radiations from horns 2 and 3 respectively. The horns may be made symmetrical by the inclusion of further semi-transparent panels 7, 8, 11 and 12. The horns may radiate different wavelengths rather than different polarizations. An array of two or more overlapping horns may feed a reflector and may be combined with non-overlapping horns providing a cosec<SP>2</SP> pattern. The feeder and reflector may be rotated about a vertical axis for scaning and the horns may be energized alternately for beam switching. Specification 864,324 is referred to. |
