GB1298281A - Improvements in or relating to y-junction circulators - Google Patents

Abstract

1298281 Circulators WESTERN ELECTRIC CO Inc 30 Jan 1970 [3 Feb 1969 7 Oct 1969] 4540/70 Heading H1W A Y-circulator comprises overlapping radiallyextending strip conductors, the capacitance between the conductors being arranged to resonate with the inductance of the conductors at a frequency within the operating band. As described, the circulator comprises a disc 20 of gyromagnetic material bearing, on one side, a ground plane and, on the other, a pattern of strip conductors, e.g. as shown in Figs. 1, 4. A further disc and ground plane may be added to form a "sandwich" construction. As shown in Fig. 1, three radial strip conductors 11, 12, 13 are grounded by conductive pins 14, 15, 16 at one end and are provided with divided central portions which intermesh at insulated crossing points. Further overlapping is provided by sets of interdigitated fingers, e.g. as shown at 21. In one embodiment (Fig. 7, not shown), the overlapping of the central portions is alone relied upon to provide the necessary capacitance. This may be increased by insertion of thin dielectric spaces between the intersecting conductors. The pattern of intersection is symmetrical, i.e. it is identical for each strip conductor. In another embodiment (Fig. 4), the conductors 31, 32, 33 are connected at their ends to a circular conductive strip 39 which is recessed into the gyromagnetic disc so as to afford three insulated intersections 31a, 32a, 33a with the radial conductors. The circular strip 39 is grounded at the intersections by pins 34, 35, 36. Air or solid dielectric spacing may be used. The pattern of conductors and dielectric spacers may be built up using a photolithographic process.