Waveguide circulators

Claim 2

A three-port microwave junction circulation for use with a waveguide, including a junction member defining three ports, a gyromagnetic element within the junction member and having one surface only in electrical contact therewith, means for applying a magnetic field to traverse the gyromagnetic element in a predetermined direction, and at least one dielectric element aligned with the gyromagnetic element in the said direction, the overall dimension in the said direction of the gyromagnetic and dielectric elements taken together being substantially equal to an odd number of quarters of a wavelength, for propagation in the gyromagnetic and dielectric elements, at the centre frequency of a working range of frequencies of the circulator.

Claim 3

A circulator according to claim 1 including a further gyromagnetic element within the junction member, aligned with other gyromagnetic element in the said direction and having one surface only in electrical contact with the junction member, and at least one further dielectric element aligned with the said further gyromagnetic element in the said direction, the overall dimension in the said direction of the said further elements taken together being substantially equal to either a quarter of a wavelenth or an odd number of quarters of a wavelength, for propagation in the said further elements, at the said centre frequency.

Claim 4

A circulator according to claim 1 wherein the gyromagnetic element is positioned in a region of the junction member where the magnetic field is, in operation, substantially a maximum, the three ports have centres in a plane generally transverse to the said direction, with imaginary lines from the said centres to the point of intersection of the plane and the axis of the magnetic field, in operation, within the junction member, forming three equal angles in the plane.

Claim 5

A circulator according to claim 3 wherein the junction member has parallel conductive walls normal to the said direction, and the circulator includes at least one electrically conductive element positioned between the gyromagnetic element and one of the conductive walls, and in electrical contact with the said wall, the gyromagnetic element being mounted with that surface thereof which is in electrical contact with the junction member abutting the electrically conductive element.

Claim 6

A circulator according to claim 3 wherein the gyromagnetic and dielectric elements are triangular in cross-section in planes parallel to the said plane, and the axes of the gyromagnetic and dielectric elements normal to the said planes pass substantially through the said point of intersection.

Claim 7

A three-port microwave junction circulator for use with a waveguide, including a cylindrical gyromagnetic element, a junction member containing the gyromagnetic element and defining three ports, each port having its centre in a plane generally transverse to the axis of the gyromagnetic element, with imaginary lines from the point of intersection of the axis of the gyromagnetic element and the said plane forming three equal angles in the plane, one end surface only of the gyromagnetic element being in electrical contact with the junction member, means for applying a magnetic field to the gyromagnetic element in the axis direction, and a cylindrical dielectric element associated with and coaxial with the gyromagnetic element, the overall axial length of the gyromagnetic and dielectric members taken together being substantially equal to one quarter of a wavelength for propagation in the gyromagnetic and dielectric elements, at the centre frequency of a working range of frequencies of the circulator.

Claim 8

A three-port microwave junction circulator for use with a waveguide, including a cylindrical gyromagnetic element, a junction member containing the gyromagnetic element and defining three ports, each port having its centre in a plane generally transverse to the axis of the gyromagnetic element, with imaginary lines from the point of intersection of the axis of the gyromagnetic element and the said plane forming three equal angles in the plane, one end surface only of the gyromagnetic element being in electrical contact with the junction member, means for applying a magnetic field to the gyromagnetic element in the axis direction, and a cylindrical dielectric element associated with and coaxial with the gyromagnetic element, the overall axial length of the gyromagnetic and dielectric members taken together being substantially equal to one quarter of a wavelength for propagation in the gyromagnetic and dielectric elements, at the centre frequency of a working range of frequencies of the circulator.

Claim 9

A circulator according to claim 6 wherein the diameter of the gyromagnetic element and the dielectric element is substantially equal to half a wavelength for propagation in the said elements at the centre frequency of the said working range.

Claim 10

A circulator according to claim 7 including a further cylindrical gyromagnetic element within the junction member, axially aligned with the other gyromagnetic element and having one end surface only in electrical contact with the junction member, and a further cylindrical dielectric element associated with and coaxial with the said further gyromagnetic element, the axial length of the said further elements taken together being substantially equal to one quarter of a wavelength, for propagation in the said further elements, at the said centre frequency.

Claim 11

A circulator according to claim 8 wherein the gyromagnetic elements are ferrite discs.

Claim 12

A circulator according to claim 9 wherein the dielectric elements are disc shaped and each is mounted with one of its plane surfaces in contact with one of the plane surfaces of a different ferrite disc, each dielectric disc having the same diameter as that of the ferrite disc to which it is mounted.

Claim 13

A circulator according to claim 9 wherein the junction member has parallel conductive walls normal to the axis of the ferrite discs, and the circulator includes at least two electrically conductive cylindrical elements each associated with a different ferrite disc, each conductive element being positioned between the associated ferrite disc and one of the conductive walls, and in electrical contact with the said one wall, each ferrite disc being mounted with that end surface thereof which is in electrical contact with the junction member abutting one end surface of its associated conductive member.

Claim 14

A circulator according to claim 9 wherein the dielectric elements are at least partially hollow and each contains the associated gyromagnetic element, and it is the overall diameters of the gyromagnetic and the dielectric elements, and of the further gyromagnetic and further dielectric elements, which are each substantially equal to the said half wavelength.

Claim 15

A circulator according to claim 7 wherein the gyromagnetic element is a ferrite disc.

Claim 16

A circulator according to claim 13 wherein the dielectric element is disc shaped with the same diameter as the ferrite disc and is mounted with one of its plane surfaces in contact with one of the plane surfaces of the ferrite disc.

Claim 17

A circulator according to claim 14 wherein the junction member has parallel conductive walls normal to the axis of the ferrite disc, and the circulator includes at least one electrically conductive cylindrical element positioned between the ferrite disc and one of the conductive walls, and in electrical contact with the said wall, the ferrite disc being mounted with that end surface thereof which is in electrical contact with the junction member abutting one end surface of the electrically conductive member.

Claim 18

A circulator according to claim 13 wherein the dielectric element is at least partially hollow and contains the gyromagnetic element, and it is the overall diameter of the gyromagnetic and dielectric elements, which is substantially equal to the said half wavelength.