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. A radiating portion is also included having an unbalanced dipole antenna including a proximal portion and a distal portion that are of different lengths. The proximal portion includes at least a portion of the inner conductor and the inner insulator and the distal portion includes a conductive member.
1. A microwave antenna assembly comprising:
a feedline including an inner conductor, an outer conductor and an inner insulator disposed therebetween;
a radiating portion including a dipole antenna having a proximal portion and a distal portion, wherein the proximal portion includes at least a portion of the inner conductor and the inner insulator and the distal portion includes a conductive member;
a connection hub including a cable connector coupled to the feedline;
an inlet fluid port;
an outlet fluid port;
a choke including an inner dielectric layer and an outer conductive layer, the choke disposed around at least a portion of the feedline;
a tip having an insertion base and coupled to the distal portion of the dipole antenna;
a solid dielectric loading disposed over the radiating portion and extending from the choke to the tip; and
a coolant jacket disposed between the connection hub and the choke, thereby defining a chamber around the feedline, the chamber being adapted to circulate dielectric coolant fluid therethrough.
2. A microwave antenna assembly according to claim 1 , further comprising:
a seal disposed around a distal end of the outer conductive layer of the choke.
3. A microwave antenna assembly according to claim 2 , wherein the solid dielectric loading includes a central cavity defined therein adapted to fit about the radiating portion, the solid dielectric loading being coupled to the seal.
4. A microwave antenna assembly according to claim 2 , further comprising:
at least one inflow tube coupled to the inlet fluid port and disposed within the chamber for supplying a dielectric coolant fluid thereto; and
at least one outflow tube coupled to the outlet fluid port and in fluid communication with the chamber for withdrawing the dielectric coolant fluid therefrom.
5. A microwave antenna assembly according to claim 1 , wherein the outer conductive layer is shorted to the outer conductor of the feedline.
6. A microwave antenna assembly according to claim 1 , wherein the inner dielectric layer extends distally past the outer conductive layer.
7. A microwave antenna assembly according to claim 1 , wherein the inner dielectric layer is selected from the group consisting of a tetrafluorethylene and a perfluorpropylene.
8. A microwave antenna assembly according to claim 1 , furthering comprising:
at least one inflow tube coupled to the inlet fluid port and disposed within the chamber for supplying a dielectric coolant fluid thereto; and
at least one outflow tube coupled to the outlet fluid port and in fluid communication with the chamber for withdrawing the dielectric coolant fluid therefrom.
9. A microwave antenna assembly according to claim 1 , wherein the solid dielectric loading is formed from a dielectric material having a dielectric constant from about 2.5 to about 150.
10. A microwave antenna assembly according to claim 1 , wherein the coolant jacket is a polyimide catheter.
11. A microwave antenna assembly according to claim 1 , wherein the tip has a tapered end and a pointed end.
12. A microwave antenna assembly according to claim 1 , wherein the dipole antenna is a balanced dipole antenna.
13. A microwave antenna assembly according to claim 1 , wherein the coolant jacket is formed from a medical grade metal.