The Design And Research Of Antenna For Microwave Hyperthermia

The technology of microwave hyperthermia has been applied in many fields, such as the tumour therapy, stanching by heat coagulating, ablation of the abnormal hyperplasia tissue, etc. The microwave hyperthermia has more advantages than other methods in many cases, such as the simple equipment, low expense, easy to operate, few complications and little side effect and so on. So designing high effective and secure microwave hyperthermia antennas is very important to the effect of microwave hyperthermia.Three kinds of microwave hyperthermia antennas that used to cure the tumor of different body sites are designed in this paper. They are choke-vault antenna, planar spiral antenna and microstrip spiral antenna. The influence of structure parameters on the antenna performance is analyzed using HFSS software, and then the antenna parameters are optimized. Through muscle phantom experiments, the calculated results are verified. This research provided a theoretical foundation for the choice of antenna in microwave hyperthermia field.The main content of this paper includes:1. The choke-vault antenna is designed and optimized. Compared with monopole antenna and choke antenna, its reflection coefficient is smaller, energy leak is less, and they don't depend on the depth of the antenna inserting into the tissue. The vault not only increases the energy distribution of the antenna top but also matches with the impedance character better.2. The planar spiral antenna, which is made of shape memory alloy, used to cure tumor inside body cavity, and the micro strip spiral antenna used to cure tumor at body surface are designed. Their energy distributions are reasonable. By adjusting the antenna parameters, the size and the shape of the treatment volume can be adjusted. Their reflection coefficients are small, and they are not sensitive to their parameters and working frequency. The antenna made of shape memory alloy can enter body cavity through nature vessel and cure tumor without damage, which can reduce patients' suffering.3. Three antennas that optimized by numerical simulation are made, and the muscle phantom is confected. Using the three antennas, the reflection coefficient and energy distribution are both obtained at the hyperthermia condition. The experimental results of the antennas' reflection coefficient and energy distribution are consistent with the numerical calculation results well. Therefore, the validity of the numerical simulation method is verified.