Abstract: A circulator having integrally formed conductors (20, 21, and 22) which may be folded to form overlaying conductors of a circulator. The circulator includes a lens (44) for shaping a biasing magnetic field distribution to compensate for non-uniformity of magnetic field strength caused by irregularities of a magnetic circuit or the shape of a magnet (45) or ferrite (40, 41). The characteristics of ferrite discs (40,41) are preferably correlated with the characteristics of a permanent magnet (45) so that variations of permeability of the ferrite (40, 41) are minimized over a specified temperature range.

Abstract: A radiating element for dual polarised operation in a linear antenna array is disclosed. The radiating element is a dual polarised radiating patch element consisting of a ground plane, a lower patch, an upper patch and parasitic elements. The lower patch and upper patch are stacked above the ground plane in a spaced apart relationship. The parasitic elements lie in the same plane as the lateral edges of the lower patch. Supports are used to hold the patches and the parasitic elements in a spaced apart relationship. The parasitic elements are fed from a central area of the lower patch by microstrips. The ground plane has apertures which are of a dumbbell shape to achieve the same effective length as long apertures. Orthogonally disposed strip type driven elements span across the central portions of the apertures and the length of these strips is selected to achieve the desired matchings.

Abstract: An antenna control system enabling the remote variation of antenna beam tilt. A drive means (5, 30) continuously adjusts phase shifters (1, 2, 3; 36, 39, 40) of a feed distribution network to radiating elements to continuously vary antenna beam tilt. A controller (80) enables the beam tilt of a number of antenna at a site to be remotely varied.

Abstract: A circulator having integrally formed conductors (20, 21, and 22) which may be folded to form overlaying conductors of a circulator. The circulator includes a lens (44) for shaping a biasing magnetic field distribution to compensate for non-uniformity of magnetic field strength caused by irregularities of a magnetic circuit or the shape of a magnet (45) or ferrite (40, 41). The characteristics of ferrite discs (40, 41) are preferably correlated with the characteristics of a permanent magnet (45) so that variations of permeability of the ferrite (40, 41) are minimized over a specified temperature range.