Choked dielectric loaded tip dipole microwave antenna

1. A microwave antenna assembly, comprising:

a feedline including an inner conductor, an outer conductor and an inner insulator disposed therebetween;

a radiating section coupled to the feedline, the radiating section including:

a dipole antenna including a proximal portion and a distal portion and a gap defining a feed point therebetween, wherein the feed point includes a dielectric material; and

a tubular dielectric loading disposed about at least a portion of the dipole antenna including the dielectric material of the feed point, wherein a dielectric permittivity of the tubular dielectric loading is higher than a dielectric permittivity of the dielectric material of the feed point; and

a choke disposed around at least a portion of the feedline, the choke including an inner dielectric layer and an outer conductive layer, wherein a distal end of the inner dielectric layer is disposed between a distal end of the outer conductive layer and the gap.

2. The microwave antenna assembly according to claim 1 , wherein the tubular dielectric loading is formed from a material selected from the group consisting of titanium oxide and alumina.

3. The microwave antenna assembly according to claim 2 , wherein the material of the tubular dielectric loading is deposited onto the radiating section via a method selected from the group consisting of spray coating, atomic layer deposition and vapor layer deposition.

4. The microwave antenna assembly according to claim 1 , wherein the dielectric permittivity of the dielectric material of the feed point is higher than a dielectric permittivity of the outer insulator.

5. The microwave antenna assembly according to claim 4 , further comprising:

a housing that defines a chamber therein, the chamber being dimensioned to house the feedline and the radiating section and configured to circulate a dielectric coolant fluid therethrough.

6. The microwave antenna assembly according to claim 5 , wherein a dielectric permittivity of the dielectric coolant fluid is higher than the dielectric permittivity of the dielectric material of the feed point.

7. A microwave antenna assembly, comprising:

a feedline including an inner conductor, an outer conductor and an inner insulator disposed therebetween;

a radiating section coupled to the feedline, the radiating section including:

a dipole antenna including a proximal portion and a distal portion and a gap defining a feed point therebetween, wherein the feed point includes a dielectric spacer; and

a dielectric medium including a plurality of constituent dielectric materials of varied dielectric permittivity values disposed about at least a portion of the dipole antenna, the dielectric medium including the dielectric spacer of the feed point; and

a choke disposed around at least a portion of the feedline, the choke including an inner dielectric layer and an outer conductive layer, wherein a distal end of the inner dielectric layer is disposed between a distal end of the outer conductive layer and the gap.

8. The microwave antenna assembly according to claim 7 , further comprising:

a housing that defines a chamber therein, the chamber being dimensioned to house the feedline and the radiating section and configured to circulate a dielectric coolant fluid therethrough.

9. The microwave antenna assembly according to claim 8 , wherein the dielectric medium further includes:

an outer insulator disposed about a portion of the outer conductor;

a tubular dielectric loading disposed about at least a portion of the dipole antenna, the tubular dielectric loading extending from the outer insulator and enclosing the dielectric spacer; and

a dielectric coolant fluid circulatable through the chamber.

10. The microwave antenna assembly according to claim 9 , wherein the tubular dielectric loading is formed from a material selected from the group consisting of titanium oxide and alumina.

11. The microwave antenna assembly according to claim 10 , wherein the material of the tubular dielectric loading is deposited onto the radiating section via a method selected from the group consisting of spray coating, atomic layer deposition and vapor layer deposition.

12. The microwave antenna assembly according to claim 9 , wherein a dielectric permittivity of each of the tubular dielectric loading and of the dielectric coolant fluid is higher than a dielectric permittivity of the dielectric spacer.

13. The microwave antenna assembly according to claim 12 , wherein the dielectric permittivity of the dielectric spacer is higher than a dielectric permittivity of the outer insulator.

14. The microwave antenna assembly according to claim 1 , wherein the dipole antenna has a generally cylindrical shape.

15. The microwave antenna assembly according to claim 1 , wherein the proximal portion of the dipole antenna includes a distal portion of the outer conductor, and wherein the distal portion of the dipole antenna includes a conductive member, the outer conductor and the conductive member spaced apart by the gap defining the feed point.

16. The microwave antenna assembly according to claim 15 , wherein the proximal portion of the dipole antenna further includes a distal portion of the inner insulator, the inner insulator and the conductive member spaced apart by the gap defining the feed point.

17. The microwave antenna assembly according to claim 1 , wherein the dipole antenna is an unbalanced dipole antenna having proximal and distal portions of different lengths.

18. The microwave antenna assembly according to claim 7 , wherein the dielectric permittivity values of the constituent dielectric materials of the dielectric medium are selected to provide for a gradual increase in dielectric permittivity as the radial distance from the feed point increases.