  Microwave ablation is a therapeutic procedure to eliminate abnormal tissue
within a body selectively. There are two types of ablations; the thermal one
aims to raise the temperature at the target, while the non-thermal one induces
a temporarily high electric field at the target to disrupt cellular membrane
integrity. This work identifies the fundamental bounds of the efficiency for
each type of ablation and the sources to achieve them. For both types, the
bounds exceed the performance of existing solutions by tenfold, showing a large
room for improvement. Finally, the optimal source for thermal ablation is
physically realized with an 11 x 11 dipole array, the performance of which
closely approaches the bound.
