GB596614A - Antenna structure - Google Patents

Abstract

596,614. Aerials; radio directionfinding. STANDARD TELEPHONES & CABLES, Ltd. July 20, 1945, No. 18710. Convention date, July 22, 1944. [Class 40 (v)] An antenna providing a radiation pattern consisting of crossed figures of eight, consists of four symmetrical loops 1-4 in the same plane and forming a closed geometrical pattern around a central point ; each loop is open at the central point and opposite pairs of loops 1 and 3, 2 and 4, are connected in parallel by connecting links 23-26 and to respective dual feeders 29-30, 27-28. The loops may consist of concentric line and be arranged as shown, the adjacent sides 7-14, 8-9, 10-11, 12-13 having their outer conductors soldered together and enclosed in a metallic sheath 20. The inner ends of the sheaths are attached to a junction-box 21 containing the loop connections and feeder junctions and the outer ends are terminated in junction-boxes 22. Gaps 37-40 are symmetrically arranged in the outer conductors of each loop in order to energize the antenna and because of the symmetrical arrangement of these gaps the box 21 can be mounted directly on top of a metallic mast without insulation. The feeders may be led down inside the mast and connected to the field coils of a goniometer 32, 33 the search coil 34 being connected to a translator 35 and a signal device 36. This arrangement may be used in direction-finding apparatus or in a radio beacon. The antenna of Fig. 1 has a radiation pattern which is horizontally polarized, by adding dipoles arranged as shown in Fig. 3 a similar but vertically polarized pattern may also be produced.