GB840850A - Improvements relating to high frequency aerial-arrangements - Google Patents

Abstract

840,850. Aerials. TELEFUNKEN G.m.b.H. July 19, 1956 [July 19, 1955], No. 22386/56. Class 40(7). A dipole aerial comprises a plastic tube 5 in which are embedded conductive rings 6, 6a, 6b, and 6c. Between the rings 6 and 6a extend a plurality of thin conductors 7 wound spirally on non-conductive cores and embedded in the tube 5, these form the upper quarter wave element of the dipole and are connected at point 11 to the inner conductor of the feeder 10. Conductors 7a, similarly arranged to conductors 7 and embedded in the tube 5 between rings 6b and 6c, form the lower quarter wave element and the ring 6b is connected at 12 to the outer conductor of feeder 10. Over the lower end of the tube 5 is fitted a cast-iron ring 8 which can be moved to tune the quarter-wave isolating line formed between the coaxial cable outer and the lower aerial element. Instead of each of the conductors 7, 7a being spiralled about its own individual axis all of them may be spiralled about the central axis of the aerial (Figs. 3a and 3b, both not shown). Such an arrangement enables the physical length of the aerial to be shortened. The plastic supports for the dipole elements may be conical or barrel-shaped instead of circular-cylindrical and strengthening strands of glass or synthetic fibres can be incorporated. The conductors and non-conductive strands may be formed into a woven hose before being moulded into the tubular support.