#$%^&*AU2011200698B220130711.pdf#####SELF-TUNING MICROWAVE ABLATION PROBE Abstract An electromagnetic surgical ablation probe (110) having a tunable helical antenna element (120) is disclosed. The probe includes a coaxial feedline having an inner conductor (103) coaxially disposed within a dielectric (104), and an outer conductor (105) coaxially disposed around the dielectric. The inner conductor and dielectric extend distally beyond a distal end of the outer conductor. A helical antenna element (120) is operably coupled to a distal end of the inner conductor. During use, the antenna may be tuned by changing at least one dimension of the helical antenna element. Embodiments are presented wherein a dimensions of the helical antenna element is changed by state change of a shape memory alloy, by a change in temperature, by activation of a piston by fluidic pressure, by linear motion of a conical tip, and by a manual screw-type adjustment. 3354684-1217 110~ L 1102N 101 108 s I+FIG. 2A 101 10504 11 108 103 FIG. 2B
