GB320425A - Improvements in or relating to aerials for use in wireless telegraphy and telephony - Google Patents

Abstract

320,425. Franklin, C. S., and Green, E. July 17, 1928. Aerials ; directive signalling. - In directive aerials of the type described in Specifications 242,342 and 285,106, the intermediate folded portions of the wire are now so arranged that they radiate effectively in the same direction as the straight portions. As shown in Fig. 2, a straight half-wave portion A is followed by a reversed or folded half-wave porton B, and then by a straight length C, a reversed length D, and so on. The phase relation of the currents in successive half-wave lengths is indicated by the dotted lines, the reversed sections B, D, F adding to the effective fieldstrength due to the straight wire sections A, C. E. Reflection from the upper end Y of the aerial may be prevented by employing the method described in Specification 281,762, [Class 118 (ii), Signals]. A series of such radiators may form a beam aerial system arranged vertically, horizontally. or otherwise, and backed by reflectors. By varying the distances between the centres of adjacent half-wave sections, the direction of the predominat radiation may be changed angularly. In Fig. 4, the amount of reversed wire is increased so as to give a greater field strength than in Fig. 2 for the same input. In Fig. 6 the straightwire portions A, C, E are paralleled. In another arrangement the wires are arranged along the edges of a vertical hexagonal prism.