GB1323384A - Cylindrical array antenna - Google Patents

Abstract

1323384 Aerials HAZELTINE CORP 30 June 1971 [27 Nov 1970] 30552/71 Heading H4A In an aerial array radiating elements are arranged along a path, which may be circular, and possibly shaped to fit the fuselage of an aircraft. The elements may be dipoles, or vertically stacked dipole arrays. A set of signals having a selected phase distribution is developed, and is applied to a corresponding group of aerial elements in a predetermined order. The beam radiated by the array is steered in coarse increments by selecting different groups of elements along the path, the predetermined order of illumination being maintained, and is steered in fine increments by selecting different phase distributions for the signals. As described, 32 consecutive elements of a circular array 11, Fig. 3, of 128 dipoles a 1 to a 128 are simultaneously energized by a signal applied to the sum port of a hybrid 16. A divider network 18 provides 32 signals from the two outputs of the hybrid 16. These signals may be symmetrically tapered in amplitude distribution and have fixed phase differences (obtained by inserting lengths of transmission line) to compensate for the curvature of the array. The outputs of the divider network 18 are coupled to the inputs of a coupling means 14 through phase shifters 19, which are of the electronically controlled digital type, giving eight selectable values of linear phase distribution across the group of radiating elements, for fine steering. The coupling means 14 comprises a switching matrix of 80 individually selectable double pole change-over switches (Fig. 3a), which enables any input signal to be connected to any one of its output terminals. The said output terminals are each connected to the input of one of 32 single pole four throw switches of a bank 22. Each of said switches is coupled to a respective set of four radiating elements which are spaced 90 degrees apart, and by operating appropriate switches any group of 32 consecutive radiating elements may be selected. A control means comprising logic circuitry is also described (Fig. 4, not shown).