辐射加热同轴天线的研制

Development of Radiation Heating Coaxial Antennas

为获得非单一辐射方向图,设计辐射电长度为3倍波长的同轴辐射天线。应用电磁场有限元分析方法分析天线与物料耦合时端口驻波比,确定同轴辐射天线内导体尺寸为479 mm,辐射天线端口驻波比不高于1.6;2.45 GHz时辐射天线效率高达95%。应用多物理场分析方法研究了热变形的天线端口驻波比变化情况,结果表明聚四氟乙烯护套最高温度为126℃时轴向最大变形量为0.1 mm,径向最大变形量为0.05 mm,辐射天线端口驻波比变换量不超过0.65%,该变化量在可接受范围内。对加工完成的天线应用物料水进行实测,三根天线的端口驻波比不高于1.54,大功率测试结果显示,三根天线满足基本使用要求。

In order to obtain the non-single radiation pattern,coaxial antennas with the radiation electric length of 3 times wavelength are designed.FEM method is used to analyze the voltage standing wave ratio(VSWR)at port when the antenna is coupled with the material.The size of inner conductor in the coaxial radiation antenna is determined to be 479 mm,the VSWR of the antenna is not higher than 1.6,and the efficiency of the antenna is 95% at 2.45 GHz.The change of VSWR at the antenna port with thermal deformation is studied by using multi-physics field analysis.The results show that when the maximum temperature of PTFE sheath is 126℃,the maximum axial deformation is 0.1 mm,the maximum radial deformation is 0.05 mm,and the change of VSWR at the radiation antenna port is not higher than 0.65%,which is acceptable.Three antennas are tested by using material water,the VSWRs are not higher than 1.54.High power test results show that the antennas meet the requirements of engineering application.