[Design and implementation of an improved invasive antenna for microwave hyperthermia].

A new 2450MHz invasive antenna for microwave hyperthermia is designed in this paper. The finite element method is employed to simulate the choke antenna and improved choke antenna, i.e., choke-umbrella antenna. The specific absorption rates (SAR) in tumors are calculated with the two kinds of antennas. S11 of choke-umbrella antenna is also compared with that of choke antenna. Multi-layered block of tissue-equivalent phantom is heated with the fabricated invasive antenna. The distribution of the temperature field in the invasive layer as well as the three-dimensional distribution of the temperature field in phantom is obtained with an infrared thermo graphic technique. Research results show that the improved choke-umbrella antenna can generate more uniform temperature distribution and meets the requirements of the actual clinical microwave hyperthermia better.