This work focuses on interstitial microwave hyperthermia (microwave ablation), which is a popular medical method for the treatment of pathological human tissues containing cancerous tumors. The 2D finite element analysis is utilized to compare the models of a coaxial antenna with one, two, three, and four air slots. The presented models are based on the wave equation in the TM electromagnetic mode, coupled with the Pennes equation under a transient state condition. Moreover, the model takes into account the thermo-electrical properties of human tissue for the antenna operating frequency of 2.45 GHz. Simulation results for various multislot antenna configurations are presented. The comparative finite element analysis of the interstitial microwave ablation in liver tissue by single, double, third, and quadrupole slot antennas is carried out. According to the results presented, the fraction of damage of the tissue exposed to 2.45 GHz microwave energy decreases with adding the number of slots. Quadrupole case shows spherical melting zones with less normal tissue damage, especially along the axial direction.
