中文摘要：

建立非均匀传输线简化后的阶跃型均匀传输线的散射参数模型,提出计算阶跃型非均匀传输线的散射参数和电压分布的方法.根据天线电流的假设理论,计算阶跃型非均匀传输线的远场辐射电场强度以及辐射方向分布情况,对天线电流的假设理论进行辐射方向修正.将计算结果与ANSYS公司高频电磁场数值计算软件HFSS仿真结果进行对比分析,讨论不同相对介电常数的板材和铜箔厚度变化时的远场辐射变化情况.当相对介电常数较小和铜箔厚度较厚时可以有效地降低阶梯型非均匀传输线远场辐射强度.

英文摘要：

The scattering parameter model of step uniform transmission line was constructed after non-uni- form transmission line was simplified. The methods about calculating the scattering parameter and voltage distribution were proposed. According to the antenna current hypothesis, the far field -radiation intensity and distribution of radiation direction of the step non-uniform transmission were calculated aiming at the correction of radiation direction for the antenna current hypothesis. The calculation results were compared with the simulation results of HFSS, which was developed by ANSYS company. The situation about the far field-radiation variation was discussed among different relative dielectric constant and different copper thickness. Results show that when the relative dielectric constant is lower and the copper thickness is thic- ker, the far field-radiation intensity of step non-uniform transmission can be effectively reduced.