Antenna design for catheter-based tissue heating

The work presents an improved coaxial line fed ring-slot antenna system for microwave coagulation therapy. The performance of a hyperthermia applicator is characterized by both impedance matching and specific absorption rate (SAR) distribution in the tissue of interest. First, we analyze the antenna of a conventional applicator and modify the configuration of the antenna to improve its heating characteristics, using finite difference time domain (FDTD) analysis and the finite integral method (FIM). We then calculate the return loss and SAR with the liver-equivalent phantom model at 2450 MHz. The computation results are compared with available measured values. Optimal dimensions of the applicator are also presented.