GB1321734A - Electromagnetic detection systems comprising separate transmitting and receiving antennas - Google Patents

Abstract

1321734 Aerials; duplex radio signalling THOMSON-CSF 18 May 1971 [20 May 1970] 15636/71 Headings H4A and H4L In a radio system which comprises separate side-by-side transmitting and receiving aerials, one or more centrally situated electrical conductors are provided near said aerials. One extremity of each conductor receives energy from the transmitting aerial, and the other extremity radiates towards the received. The amplitude and phase of the energy so coupled may be arranged so as to compensate for the energy which is directly coupled between the aerials. As described, an aerial assembly comprises co-linear transmitting and receiving portions 3, 4, Fig. 1, with respective conical end portions 5, 6 which serve both as supports and reflectors. Two compensating elements are provided, each comprising probes 7, 8 and a transmission line 9. These elements, which may be formed from lengths of coaxial cable which are stripped back at each end, are mounted at their centres 10 on the supports 5, 6. In a second embodiment, a cylindrical radome encloses the aerial assembly and conductors are provided around its centre (Fig. 2, not shown). They may be made of metal foil, or metallized dielectric material, and be secured by an adhesive. Alternatively, they may be produced by printed circuit techniques. Each may be shaped as a horizontal V, or a horizontal U, or a Z or X &c. In a third embodiment, for use in a proximity fuse, a transmitting aerial portion comprises a slotted waveguide 31, Fig. 3, between double conical reflectors 30, and a receiving aerial portion 32 constituted by an array of slots in a co-linear member. A conical radome 34 encloses the aerial assembly. Two diametrically positioned horizontal V conductors 33 are provided on the radome between the two aerial portions.