Thermally tuned coaxial cable for microwave antennas
A coaxial cable, including an inner conductor and an outer conductor surrounding the inner conductor and a thermally responsive material positioned between the outer conductor and the inner conductor. The outer conductor is in a generally concentric relationship to the inner conductor and the inner and outer conductors are adapted to connect to an energy source. A thermal change in the thermally responsive material alters the generally concentric relationship between the outer conductor and the inner conductor.
1. A method for controlling alignment of an inner conductor and an outer conductor of a coaxial cable of a microwave antenna, the method comprising:
changing a temperature of at least one thermally responsive material disposed between an inner conductor and an outer conductor of a coaxial cable of a microwave antenna, the inner conductor being disposed within the outer conductor,
wherein a change in temperature of the at least one thermally responsive material alters alignment of the inner conductor within the outer conductor.
2. The method according to claim 1 , wherein the at least one thermally responsive material is a dielectric.
3. The method according to claim 1 , wherein changing the temperature of the at least one thermally responsive material includes heating the thermally responsive material via a plurality of resistive heating elements disposed within the thermally responsive material.
4. The method according to claim 1 , wherein the at least one thermally responsive material includes a shape memory alloy.
5. The method according to claim 1 , wherein the at least one thermally responsive material includes a plurality of spacers disposed in a longitudinally spaced apart relationship with respect to each other.
6. The method according to claim 1 , further comprising:
tuning the microwave antenna by altering the alignment of the inner conductor within the outer conductor.
7. The method according to claim 1 , wherein tuning further includes repositioning the inner conductor within the outer conductor from a first position wherein the inner conductor is concentrically aligned with the outer conductor to a second position wherein the inner conductor is not concentrically aligned with the outer conductor.
8. The method according to claim 1 , further comprising:
monitoring the position of the inner conductor relative to the outer conductor.
9. A method for controlling impedance of a coaxial cable of a microwave probe, the method comprising:
measuring impedance of a coaxial cable, the coaxial cable coupling a microwave probe to a microwave generator;
determining whether the impedance of the coaxial cable substantially matches impedance of at least one of the microwave generator or the microwave probe; and
changing a temperature of at least one thermally responsive material disposed between an inner conductor and an outer conductor of a coaxial cable of a microwave antenna based on the determination, the inner conductor being disposed within the outer conductor,
wherein a change in temperature of the at least one thermally responsive material alters alignment of the inner conductor within the outer conductor to substantially match the impedance of the at least one of the microwave generator or the microwave probe to the coaxial cable.
10. The method according to claim 9 , wherein the at least one thermally responsive material is a dielectric.
11. The method according to claim 9 , wherein changing the temperature of the at least one thermally responsive material includes heating the thermally responsive material via a plurality of resistive heating elements disposed within the thermally responsive material.
12. The method according to claim 9 , wherein the at least one thermally responsive material includes a shape memory alloy.
13. The method according to claim 9 , wherein the thermally responsive material includes a plurality of spacers disposed in a longitudinally spaced apart relationship with respect to each other.
14. The method according to claim 9 , further comprising:
tuning the microwave antenna by altering the alignment of the inner conductor within the outer conductor.
15. The method according to claim 14 , wherein tuning further includes positioning the inner conductor relative to the outer conductor from a first position wherein the inner conductor is concentrically aligned with the outer conductor to a second position wherein the inner conductor is not concentrically aligned within the outer conductor.
16. The method according to claim 9 , further comprising:
monitoring the position of the inner conductor within the outer conductor.