GB579773A - Improvements in or relating to directive antenna systems - Google Patents

Abstract

579,773. Wave guides ; directive wireless systems. WESTERN ELECTRIC CO., Inc. Oct. 20, 1943, No, 17308. Convention date, June 11, 1942. [Class 40 (v)] A directive system for ultra-high frequency waves comprises a plurality of parallel open-ended wave-guides of different lengths arranged side by side for transmission or reception in an endon direction, their transverse dimensions being critically related to their lengths so that the wave energies are substantially in phase and the transmission or reception is of maximum intensity in the said direction. Figs. 1 and 2 are side and end views of a system using two rectangular guides 5, 6 connected at their inner ends by a tapered guide 3 to the transmitter or receiver 1, and having their outer or open ends 7 displaced a distance f in the direction 9 of wave propagation. The two guides are of the same depth a in the direction of the electric field of the waves, but their widths ba, bn are so related to each other and to the lengths d and d+f of the respective guides that transmitted waves are in phase where they merge in the wave front 11. The Specification describes a system having a large number of rectangular guides, each being half a wavelength longer than its neighbour on one side, and each having the same transverse dimension a. The b dimension is, however, varied from guide to guide in such a way that all waves are in phase at the end of the longest guide (Figs. 4 and 5, not shown). The resultant beam is narrow both in the a and b directions (Figs. 6 and 7, not shown). The guides may be of square or circular section and may be dielectrically loaded. Their lengths may be non-uniformly graded.