Multi-Objective Optimization Design and Numerical Study of Water-Cooled Microwave Ablation Antennas

Microwave ablation, as a minimally invasive technique used for the treatment of tumors, is highly dependent on the performance of ablation antennas for its therapeutic effect. Clinically, antennas are required to form roughly spherical ablation zones with sufficient volume within a limited time. To meet this requirement, this paper establishes finite element models and conducts multi-objective optimization on fully water-cooled dipole antenna and partially water-cooled choke dipole antenna based on different water-cooled structures. On the premise of minimizing reflection coefficient and maximizing ablation volume, a three-dimensional objective space is constructed by introducing the minimization of roundness error, and the set of Pareto solutions is solved. The CRITIC-TOPSIS method is used to balance multi-objective conflicts and select the unique optimal solution from the Pareto set. By analyzing the optimal solution, simulation results show that the optimized antennas can effectively form near-spherical ablation shapes while minimizing the reflection coefficient and maximizing the ablation volume. Among these, the partially water-cooled antenna exhibits superior electromagnetic characteristics and ablation profile, whereas the fully water-cooled antenna demonstrates better temperature field behavior.