GB675164A - Improvements in or relating to omni-directional aerial systems - Google Patents

Abstract

675,164. Aerials. MARCONI'S WIRELESS TELEGRAPH CO., Ltd. March 25, 1948 [Sept. 1, 1947], No. 24105/47. Class 40 (vii). An aerial system having a substantially circular radiation pattern comprises a plurality of capacity loaded loop aerials side by side in juxta-position and angularly displaced with respect to one another in the planes in which they lie. It is stated that with a known capacity loaded loop such as that of Fig. 1, the current in the radiators drops to 0.924 of its maximum value at each end of the radiators causing non-uniformity in the field pattern particularly close to the loop. If, however, a second loop angularly displaced by 45 degrees be placed side by side with the first and both energized the resultant pattern is more nearly circular, a larger number of aerials with regularly spaced angular relationships will give still better omnidirectional results. A three-loop system, Fig. 4, comprises three loop sections 9, 10 and 11, with oppositely dispersed gaps 12 and 15 cut diagonally to provide angular displacement between the loops. Capacity loading is introduced at 13 and 14. In a development of this arrangement a large number of turns of wire are wound on a cylindrical former to provide a corresponding number of loops, inclined gaps are cut across the loops for the connection of the feeders and capacity loading elements in the form of triangular plates, Figs. 5 and 6 (not shown).