Choked dielectric loaded tip dipole microwave antenna
A microwave antenna assembly is disclosed. The antenna assembly includes a feedline having an inner conductor, an outer conductor and an inner insulator disposed therebetween and a radiating section coupled to the feedline, the radiating section including a dipole antenna and a tubular dielectric loading disposed about the dipole 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 having a proximal portion and a distal portion and a feed point having a dielectric material therebetween; and
a tubular dielectric loading disposed about the dipole antenna, 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 a tubular structure having an inner cylindrical casing and an outer cylindrical casing defining a cavity therebetween configured to supply a dielectric coolant to the radiating section, the inner dielectric layer extending distally past a distal end of the tubular structure.
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 , further comprising:
an outer insulator disposed over the outer conductor, the outer insulator extending past a distal end of the choke.
5. The microwave antenna assembly according to claim 4 , wherein the dielectric permittivity of the dielectric material of the feed point is higher than a dielectric permittivity of the outer insulator.
6. The microwave antenna assembly according to claim 5 , 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 the dielectric coolant therethrough.
7. The microwave antenna assembly according to claim 6 , wherein a dielectric permittivity of the dielectric coolant is higher than the dielectric permittivity of the dielectric material of the feed point.
8. 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 and a dielectric medium, the dielectric medium including a plurality of constituent dielectric materials of varying dielectric permittivity values; and
a choke disposed around at least a portion of the feedline, the choke including an inner dielectric layer and an outer conductive layer, the inner dielectric layer extending distally past a distal end of the outer conductive layer.
9. The microwave antenna assembly according to claim 8 , 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 therethrough.
10. The microwave antenna assembly according to claim 9 , wherein the radiating section further includes a proximal portion and a distal portion and a feed point therebetween.
11. The microwave antenna assembly according to claim 10 , wherein the dielectric medium includes:
an outer insulator disposed about the outer conductor;
a dielectric spacer disposed at the feed point;
a tubular dielectric loading disposed about the dipole antenna, the tubular dielectric loading extending from the outer insulator and enclosing the dielectric spacer; and
the dielectric coolant circulated through the chamber.
12. The microwave antenna assembly according to claim 11 wherein the tubular dielectric loading is formed from a dielectric material selected from the group consisting of titanium oxide and alumina.
13. The microwave antenna assembly according to claim 12 , wherein the dielectric 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.
14. The microwave antenna assembly according to claim 11 , wherein a dielectric permittivity of each of the tubular dielectric loading and of the dielectric coolant is higher than a dielectric permittivity of the dielectric spacer of the feed point.
15. The microwave antenna assembly according to claim 14 , wherein the dielectric permittivity of the dielectric spacer is higher than a dielectric permittivity of the outer insulator.