GB579763A - Improvements in or relating to directive antenna structures - Google Patents

Abstract

579,763. Directive wireless, signalling. SPERRY GYROSCOPE CO., Inc. Feb. 3, 1943, No. 1834. Convention date, Feb. 4, 1942. [Class 40 (v)] A directive antenna structure comprises a reflector, a wave-guide, and a deflector in front of the mouth of the wave-guide for transferring energy between the wave-guide, and the reflector. The deflector, the reflector, or the termination of the wave-guide may be arranged asymmetrically so that if one or more of these elements is rotated continuously, the axis of the radiation pattern rotates about the surface of a cone whose apex is at the antenna, as shown in Figs. 3 and 4. In Fig. 1, the waveguide '2 passes through the reflector 1 and terminates in an inclined part 11 carried by arms 12 on a disc 13 rotated by a motor 15. The waves emitted by the guide 2, 11 are reflected by the disc 13 to the main reflector 1. The disc 13 may have a rotatable central part and a stationary outer part, Fig. 2 (not shown). In Fig. 5, the rotating disc 23 is inclined to the axis of the guide and, to reduce windage and vibration, may be mounted within a cylinder of insulating material, Fig. 6 (not shown). In Fig. 7, the guide 27 terminates in a rotatable looped portion 32 with its end 35 inclined to the axis of the guide. A complementary dummy portion 33 balances the loop 32. In Fig. 8, the guide 27<1> terminates in a rotatable cylindrical portion 29<1> coupled to a rectangular portion 42 by a coupling element or rod 39 projecting into the parts 29<1>, 42. The extension 44 of the rectangular guide projects through the reflector 51 which rotates with the guide, energy being reflected to the main reflector 51 by a cylindrical member 49, Fig. 11 (not shown), or by a flat disc, Fig. 12 (not shown). The wave-guide may have a solid dielectric projecting within the reflector and carrying a fixed or rotating deflector, Figs. 14 to 17 (not shown). The dielectric may be tapered and pass through the deflector to provide an " end-fire array." Other slight modifications are described.