The Research Of Coaxial Radiator For Medical Microwave Heating

Microwave heating technology is a research direction which combines two hot research fields of electromagnetic field and thermal science.It has always been one of the most important research contents of domestic and foreign scholars.The application in medical is a hot issue in recent years.At present,the microwave heating technology applied to medical field is largely based on the coaxial slot antenna,which converts microwave into heat energy in diseased tissue.The circular coaxial slot antenna using this form has the most stable and extensive research.Related research at home and abroad also focuses on the improvement of the circular coaxial slot antenna,and there is little research on the antenna form and principle.The domestic and international literature of microwave heating technology in the medical field has been investigated,and a planar coaxial slot antenna is proposed innovatively,and the related microwave heating research is further carried out in this paper.The main study and novel contents are as follows:1.The circuit research method of coaxial transmission line in loss medium is proposed.Firstly,the structure of the coaxial transmission line and the gap in the high loss medium respectively are analyzed to obtain the complex propagation constants.The equivalent circuit model is simulated in the circuit simulation software,and verified in the full-wave simulation software,which provides a convenient and systematic design method for the follow-up simulation design of coaxial transmission line.2.For testing the reliability of the circuit research method of coaxial transmission line in loss medium,the structure of coaxial transmission line with single and double slots based on multilayer board technology was optimized and tested.The consistence between the relevant data and the expected effect of antenna model is high.3.To adapt to the specific needs in the medical field,three types of microwave heating antennas are designed,which are rectangular coaxial monopole antenna,rectangular coaxial slot monopole antenna and rectangular coaxial unilateral slot monopole antenna.On the premise that the input reflection coefficient of the antenna is low and the energy fed to the medium to be heated is sufficient,the heating effect chart of each structure in the time domain to achieve the existing specific needs of microwave heating to achieve spherical,cylindrical and single-sided heating area.The design model and hardware were given.4.Three types of microwave heating antennas,rectangular coaxial monopole antenna,rectangular coaxial slot monopole antenna and rectangular coaxial unilateral slot monopole antenna,are tested for electromagnetic performance and heating.The experimental results are analyzed,and the relevant test data is consistent with the expected effect of the designed model.