Design of a wideband high gain applicator for microwave hyperthermia
SUN Bing 1,2 JIANG Guo-tai1 LU Xiao-feng3 CAO Yi4 (1.School of Life Sciences and Technology,Tongji University,Shanghai 200092,China; 2.School of Electronics and Information,Soochow University,Suzhou Jiangsu 215021,China;3. School of Computer Science & Technology,Soochow University,Suzhou Jiangsu 215021,China; 4. Institute of Radiation Medicine and Public Health,Soochow University,Suzhou Jiangsu 215021,China)
A printed dipole antenna with feeding Balun is proposed in this paper to overcome the narrow frequency and low gain problem of microstrip applicator with rectangle sheet structure commonly used in tumor microwave hyperthermia. The impedance characteristic of the antenna equivalent circuit is analyzed,and the bandwidth is increased by adding tuning branches in the feeder to optimize the impedance matching. Both simulation and test results indicate that the bandwidth and gain of the proposed antenna are better than the rectangle sheet antenna. Based on measurement of the far-infrared imaging instrument,the temperature changes caused by the two antennas radiating on sandwich simulative tissue model are compared. The experiment proves that the proposed antenna has higher heating efficiency which satisfies the requirement of tumor microwave hyperthermia.