GB887555A - Improvements relating to wide band aerials - Google Patents

Abstract

887,555. Aerials. TELEFUNKEN G.m.b.H. Feb. 19, 1958 [Feb. 19, 1957], No. 5473/58. Class 40(7). A wide-band aerial comprises at least two coplanar aerial elements, each element being divided into at least two sections connected by an impedance. The elements are spaced apart in the direction of propagation or reception, and the impedances are such that at low frequency the aerial elements are excited predominantly by standing waves, while at high frequency they are excited predominantly by travelling waves. In a first embodiment, Fig. 1, the elements 1, 2 and 7, 8 are divided by the impedance units 5, 11. The aerial is directive in the direction of the arrow but may be designed to become substantially omnidirectional at certain frequencies. In other embodiments the aerial is made symmetrical, as in Fig. 2, to form a multiple V arrangement. The angle between the pair of elements forming a V may differ from that between the neighbouring elements, Figs. 4a, 4b, 8a, 8b (all not shown). The electrical length of the conductors 13, 14 between the elements may be modified, for example by the insertion of an inductance or the embedding of the conductors in a dielectric. The feeder 15, 16 to the radio apparatus may be connected to an aerial element, or pair of elements as in Figs. 1 and 2, or to a point on the feeder 13, 14. This point may be variable. The aerials may be stacked, the planes in which component aerials lie being parallel. The sections of each aerial element need not be collinear, and an aerial of this type may be mounted as in Fig. 9. In this instance, the angles that the various sections make with the horizontal is varied by adjustment of the -tension in ropes 60, 61, or by loading the elements at suitable points along them. Specification 629,986 is referred to.