GB1211725A - Loop antenna - Google Patents

Abstract

1,211,725. Aerials. LTV ELECTROSYSTEMS Inc. 3 Nov., 1967 [9 Dec., 1966], No. 24663/70. Divided out of 1,211,723. Heading H4A. A crossed-loop type aerial comprises an aerial 21, Fig. 3, of the type shown in Fig. 1, in which a closed core 1 of ferromagnetic material consists of core sections 2, 3 with end-pieces 4, 5. Coils 6, 7 are wound on the said core sections and they are so connected that magnetic fluxes due to incident radio waves produce voltages which are additive, whereas the magnetic fluxes induced by a current flowing in the coils are opposed. As shown, the coils 6, 7 are of opposite hands, and their finish ends are connected together. Alternatively, as shown in Fig. 2, coils of the same hand may be wound on core sections 12, 13 (which are adjoined by end-pieces 14, 15) and the finish end t1 of the coil 16 connected to the start end t2 of the coil 17. The core sections on which the coils are wound may be in the form of elongate rods, and the said coils may be distributed over their entire lengths, and have equal numbers of turns. A transverse loop aerial 22, Fig. 3, is wound over the end-pieces of the aerial 21 and over a plurality of ferromagnetic frames 23, such as ferrite rings, which are disposed around the aerial 21 and at intervals along it. The aerials 21, 22 may be utilized to give omnidirectional reception.