Dielectric resonators and circuits made therefrom
A dielectric resonator having variable cross-section, preferably varying monotonically, and, most preferably, the resonator being in the shape of a truncated cone. Such shapes displace the H 11 mode from the TE mode in the longitudinal direction of the cone. Truncating the cone to eliminate the portion of the cone where the H 11 mode exists, virtually eliminates the H 11 mode. A circuit comprising a plurality of these resonators may be arranged in an enclosure with each resonator longitudinally inverted relative to adjacent resonator(s) to provide a compact design with enhanced coupling and adjustability. A spiral coupling loop provides high magnetic flux in a small physical volume for coupling energy into or out of the circuit. Alternately, the resonator can coupled to a microstrip by placing the resonator upside-down near the microstrip, whereby the TE mode is immediately above the microstrip, providing enhanced coupling there between.
1. A dielectric resonator formed of a dielectric material adapted to resonate electromagnetically in response to electromagnetic excitation, said dielectric resonator including a longitudinal through hole, said dielectric resonator varying monotonically in cross-sectional area perpendicular to said longitudinal direction as a function of said longitudinal direction, wherein said dielectric resonator comprises a cone.
2. The dielectric resonator of claim 1 wherein said dielectric resonator comprises a truncated cone.
3. The dielectric resonator of claim 1 wherein said dielectric material is barium titanate.
4. The dielectric resonator of claim 1 wherein said dielectric material has a dielectric constant of greater than about 45.
5. The dielectric resonator of claim 1 wherein said dielectric resonator comprises a cylindrical bottom portion and a conical upper portion.
6. The dielectric resonator of claim 1 wherein said dielectric resonator comprises a stepped cone.
7. A dielectric resonator formed of a dielectric material, said dielectric resonator including a longitudinal through hole, said dielectric resonator varying monotonically in cross-sectional area perpendicular to said longitudinal direction as a function of said longitudinal direction, wherein said dielectric resonator comprises at least two discontinuous truncated cones.
8. A dielectric resonator formed of a dielectric material adapted to resonate electromagnetically in response to electromagnetic excitation, said dielectric resonator body including a longitudinal through hole, said dielectric resonator body varying monotonically in cross-sectional area perpendicular to said longitudinal direction as a function of said longitudinal direction, wherein said dielectric resonator comprises a plurality of sloped planar side walls.
9. The dielectric resonator of claim 8 wherein said dielectric resonator comprises a pyramid.
10. The dielectric resonator of claim 8 wherein said dielectric resonator comprises a hexagonal pyramid.
11. A dielectric resonator comprising a body formed of a dielectric material, said body including a longitudinal through hole, said body comprising a plurality of sequentially stacked annular portions, each annular portion having a diameter smaller than the diameter of a preceding annular portion in said sequence wherein said annular portions are torroidal in shape.
12. A dielectric resonator comprising a body formed of a dielectric material and adapted to resonate in response to electromagnetic excitation with a TE 01δ mode as the fundamental mode, said TE 01δ mode having electric field lines oriented in a transverse direction around said dielectric resonator body, said body including a through hole in a longitudinal direction perpendicular to said TE 01δ mode, said body varying monotonically in cross-sectional area perpendicular to said longitudinal direction as a function of said longitudinal direction, wherein said body comprises a cone.
13. The dielectric resonator of claim 12 wherein said body comprises a truncated cone.
14. The dielectric resonator of claim 12 wherein said dielectric material has a dielectric constant of greater than about 45.
15. A dielectric resonator comprising a body formed of a dielectric material and adapted to resonate in response to electromagnetic excitation with a TE 01δ mode as the fundamental mode, said TE 01δ mode having electric field lines oriented in a transverse direction around said dielectric resonator body, said body including a longitudinal through hole, said body varying monotonically in cross-sectional area perpendicular to said longitudinal direction as a function of said longitudinal direction, wherein said body comprises at least two discontinuous truncated cones.
16. A dielectric resonator circuit comprising:
an enclosure;
an input coupler;
an output coupler; and
at least one dielectric resonator having a body formed of a dielectric material and adapted to resonate in response to electromagnetic excitation with a TE 01δ mode as the fundamental mode, said TE 01δ mode having electric field lines oriented in a transverse direction around said dielectric resonator body, said body including a through hole in a longitudinal direction perpendicular to said TE 01δ mode, said body varying monotonically in cross-sectional area perpendicular to said longitudinal direction as a function of said longitudinal direction, wherein said body comprises a cone.
17. The dielectric resonator of claim 16 wherein said body comprises a truncated cone.
18. The dielectric resonator of claim 16 wherein said dielectric material has a dielectric constant of greater than about 45.
19. A dielectric resonator circuit comprising:
an enclosure;
an input coupler;
an output coupler; and
at least one dielectric resonator having a body formed of a dielectric material and adapted to resonate in response to electromagnetic excitation with a TE 01δ mode as the fundamental mode, said TE 01δ mode having electric field lines oriented in a transverse direction around said dielectric resonator body, said body including a longitudinal through hole, said body varying monotonically in cross-sectional area perpendicular to said longitudinal direction as a function of said longitudinal direction, wherein said body comprises at least two discontinuous truncated cones.