GB1393081A - Antenna system having a reflector with a substantially open construction - Google Patents

Abstract

1393081 Aerials HAZELTINE CORP 21 Feb 1974 [25 June 1973] 7847/74 Heading H4A An aerial system comprises one or more radiating elements linearly polarized in a particular direction, such as the array of dipoles 10, arranged in rows and columns, shown in Fig. 1, a reflector made up of conductive columns 11 with interspersed collinear arrays 12 of tuned elements 13, said columns and said arrays being parallel to the direction of polarization, and supporting means for said radiating elements, columns and arrays. The purpose of the collinear arrays 12 of tuned reflective elements is to suppress radiation leakage between the reflective columns 11. In the ease of a planar reflector, back lobe formation is thereby largely prevented (Fig. 4, not shown). As described, the supporting means comprises a frame 14, between two opposite sides of which the columns 11 and the arrays 12 extend, the spacing between adjacent columns being less than one wavelength at the operating frequency of the system. The dipoles 10 are mounted on the columns 11 and are fed by cables which run therein, Fig. 2, not shown. The reflective elements 13 may be lengths of conductive tube mounted on insulating rods and a protective outer tube of insulating material may be provided (Figs. 3a, 3c, not shown). The lengths of, and the spacings between, said reflective elements are made such that each element is effectively a half-wavelength long at the operating frequency of the system. To this end, fixed capacitors may be provided between adjacent reflective elements (Fig. 3b, not shown), of the arrays.