Ablation devices with dual operating frequencies, systems including same, and methods of adjusting ablation volume using same

1. A method of adjusting an ablation volume, the method comprising:

positioning an ablation device within tissue, the ablation device including an inner conductor surrounded by an outer conductor and a dielectric material disposed between the inner conductor and the outer conductor;

delivering energy to the tissue via the inner and outer conductors;

controlling the energy to a first operating frequency configured to pass through a first balun structure disposed on the outer conductor; and

controlling the energy to a second operating frequency different than the first operating frequency, the second operating frequency configured to pass through a second balun structure disposed on the outer conductor axially spaced relative to the first balun structure.

2. The method according to claim 1 , further comprising directing the energy to at least one of the first balun structure or the second balun structure via a dielectric layer coaxially disposed around the outer conductor.

3. The method according to claim 2 , wherein the dielectric layer extends distally beyond a distal-most end of the inner conductor.

4. The method according to claim 1 , wherein delivering energy to tissue further comprises delivering energy to an electrically conductive element extending distally from a distal end of the inner conductor and having a diameter different than a diameter of the inner conductor.

5. The method according to claim 4 , wherein the electrically-conductive element is disposed distal to the first balun structure and the second balun structure.

6. The method according to claim 1 , wherein the first operating frequency is about 915 MHz.

7. The method according to claim 1 , wherein the second operating frequency is about 2.45 GHz.

8. The method according to claim 1 , further comprising controlling the energy to a third operating frequency different than the first operating frequency and the second operating frequency, the third operating frequency configured to pass through a third balun structure disposed on the outer conductor axially spaced relative to the first balun structure and the second balun structure.

9. The method according to claim 8 , wherein the third operating frequency is about 5.8 GHz.

10. The method according to claim 1 , further comprising delivering a cooling fluid to a lumen defined by the ablation device to control a temperature of the ablation device.

11. A method of adjusting an ablation volume, the method comprising:

positioning a microwave antenna within tissue, the microwave antenna including an inner conductor, an outer conductor surrounding the inner conductor, a dielectric material disposed between the inner conductor and the outer conductor, and an electrically conductive element extending distally from a distal end of the inner conductor;

delivering microwave energy to the tissue via the electrically conductive element and the inner conductor and the outer conductor;

controlling the microwave energy to a first operating frequency configured to pass through a first balun structure disposed on the outer conductor;

controlling the microwave energy to a second operating frequency different than the first operating frequency, the second operating frequency configured to pass through a second balun structure disposed on the outer conductor axially spaced relative to the first balun structure; and

directing the microwave energy to at least one of the first balun structure or the second balun structure via a dielectric layer coaxially disposed around the outer conductor.

12. The method according to claim 11 , wherein the dielectric layer extends distally beyond a distal-most end of the inner conductor.

13. The method according to claim 11 , wherein the first operating frequency is about 915 MHz.

14. The method according to claim 11 , wherein the second operating frequency is about 2.45 GHz.

15. The method according to claim 11 , further comprising controlling the energy to a third operating frequency different than the first operating frequency and the second operating frequency, the third operating frequency configured to pass through a third balun structure disposed on the outer conductor axially spaced relative to the first balun structure and the second balun structure.

16. The method according to claim 15 , wherein the third operating frequency is about 5.8 GHz.

17. The method according to claim 11 , further comprising delivering a cooling fluid to a lumen defined by the microwave antenna to control a temperature of the microwave antenna.

18. The method according to claim 11 , wherein the electrically-conductive element is disposed distal to the first balun structure and the second balun structure.

19. The method according to claim 11 , wherein a diameter of the electrically conductive element is different than a diameter of the inner conductor.

20. A method of delivering energy to an ablation target within a patient, the method comprising:

delivering energy to an ablation target within a patient via an ablation device having an inner conductor surrounded by an outer conductor and a dielectric material disposed between the inner conductor and the outer conductor;

delivering the energy at a first operating frequency through a first balun structure disposed on the outer conductor; and

delivering the energy at a second operating frequency through a second balun structure disposed on the outer conductor axially spaced relative to the first balun structure, the second operating frequency different than the first operating frequency.