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 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 variable differential phase shifter is provided. The device provides a continuous variation in phase between two outputs derived from a single input. The device is suitable for application at signal frequencies around 900 MHz, and is constructed in the form of an inner (38) and outer (37) sleeve capacitively coupled to an inner conductive rod (24) and outer conductive tube (26) respectively, wherein the inner (38), and outer (37) sleeves are connected to an input and can be moved in fixed relative relation thereby varying the phase relationship between the two outputs which are connected to the inner rod (24) and outer tube (26). A dielectric layer (25 and 27) may be provided around the inner rod (24) and outer tube (26). An unequal power division version of the device is provided for by the inclusion of a dielectric tube surrounding a portion of the inner rod.

Abstract: A dipole having radiating elements (9, 14) which taper from the proximal end (1) of the radiating element to the distal end (2) of the radiating element. Electrical coupling is provided between adjacent lateral edges of the radiating elements by means of spaced apart tabs (10, 11, 12, 13). Cut-away portions (5, 5a) are provided between the proximal end (1) and the tabs (3, 4). By adjusting the distance between and the extent to which the tabs (10, 11, 12, 13) overlap the real part of the impedance of the dipole may be adjusted. The dipole may thus be configured to be directly driven from a feed-line without requiring matching components. This results in reduced complexity and losses. The dipole also exhibits reduced impedance variation, increasing the bandwidth of the dipole.