GB889611A - Electrically steerable horn antenna system - Google Patents

Abstract

889,611. Aerials. ANTENNA SYSTEMS Inc. May 9, 1960, No. 16389/60. Class 40(7). An aerial of which the direction of the major lobe can be varied comprises a horn radiator mounted at the open end of a rectangular waveguide, the guide being excited by a pair of probes which are connected to radio apparatus, and there being means for varying the relative phases of the signals passing between the radio apparatus and the two probes. In a first embodiment, Fig. 1, the probes 15, 16 are mounted in opposite walls of the waveguide, which has a metal partition 12 extending along the guide in the H plane. The probes are connected through matching pads 21, 23 to radio apparatus 19, and the relative phasing between the probes is varied by means of a phase shifter 25. Variation of the degree of phase shift causes the main lobe to move in a plane perpendicular to that of the partition 12. In a second embodiment, Fig. 3 (not shown), in which the beam variation is in a direction perpendicular to that produced by the first embodiment, both probes are mounted in the same wall of the guide, and there is no partition. Scanning of the beam in both directions is obtained by combining the first two embodiments as in Fig. 5. Pairs of probes 53, 54 and 63, 64 are mounted in opposite walls of the guide which has a central partition 52. A phase shifter 59, 67 is required between the probes of each pair and a further phase shifter 60 is required between the pairs of probes.