1. An ablation system comprising: an image database including a plurality of computed tomography (CT) images of a luminal network; a navigation system enabling, in combination with an endoscope and the CT images, navigation of a locatable guide and an extended working channel to a point of interest; one or more fiducial markers, placed in proximity to the point of interest; and a percutaneous microwave ablation device for applying energy to the point of interest, the percutaneous microwave ablation device including: a feedline; a balun disposed on an outer conductor of the feedline; and a balun short electrically connecting the balun to the outer conductor.