GB993561A - Improvements relating to aerials for ultra short waves - Google Patents

Abstract

993,561. Aerials. COMPAGNIE FRANCAISE THOMSON-HOUSTON. Sept. 8, 1961 [Sept. 8, 1960], No. 32355/61. Heading H4A. An aerial assembly for use with ultra short waves comprises a plurality of radiating elements arranged in groups adjacent to each other, each group having its own feeder system and at least one of the elements being common to each adjacent pair of groups; the assembly may be associated with a common reflector. In one arrangement, Fig. 1, five vertically stacked horns 2-6 and their associated wave guides 10-14 comprise two groups 7 and 8, the horn 4 being common to each group and the waveguide 12 connected to the horn 4 being coupled to waveguides 11 and 13 by a T-junction 16 and coupling 9 and 15. Switches 24, 19 and 20 are provided for causing the two groups to transmit or receive alternately at the same or different frequencies, each of the switches 19 and 20 comprising a semi-circular vane 25, 26 attached to a rotating spindle 29 synchronized with the switch 24 so that when the switch 24 supplies the guide 22, the vane 26 opens the arm 18 of the junction 16 as shown and energy is fed along the guide 22 to guides 12, 13 and 14 and thence to horns 4, 5 and 6, i.e. to group 8. In a further arrangement, Fig. 2, again comprising five horns 32-36 arranged in two groups 37, 38 one group transmits or receives horizontally polarized waves while the other group transmits or receives vertically polarized waves, the common horn 34 emitting or receiving either. In this arrangement the groups act simultaneously to supply signals to or receive signals from apparatus coupled to feeders 44 and 48.