An electromagnetic surgical ablation probe having a coaxial feedline and cooling chamber is disclosed. The disclosed probe includes a dipole antenna arrangement having a radiating section, a distal tip coupled to a distal end of the radiating section, and a ring-like balun short, or choke, which may control a radiation pattern of the probe. A conductive tube disposed coaxially around the balun short includes at least one fluid conduit which provides coolant, such as dionized water, to a cooling chamber defined within the probe. A radiofrequency transparent catheter forms an outer surface of the probe and may include a lubricious coating.
