同轴型变阻抗线传输特性的电磁场与电路仿真比较

利用CST微波工作室软件对新一代Z箍缩驱动装置中变阻抗传输线部分进行了三维电磁场仿真,建立了同轴型指数线模型,在外导体内半径保持100mm不变、输入端特性阻抗0.203Ω、输出端特性阻抗2.16Ω、输入角频率14×106 rad/s的半正弦脉冲TEM波的情况下,发现传输过程中会产生少量非TEM模,线的尺寸变化越剧烈,产生的非TEM模能量越多。在传输线足够长的情况下,电磁场仿真得到的电压传输效率与电路仿真结果相差不到1%,因此可以用电路仿真结果代替电磁场仿真。

Comparison of transmission of coaxial nonuniform transmission lines between electromagnetic fields simulation and circuit simulation

The three-dimensional electromagnetic fields simulation of nonuniform transmission lines that were under consideration for the next generation of Z-pinch drivers was performed by a code called CST microwave studio. A coaxial exponential line model was established in which the inside radius of the outer conductor is 100 mm, the characteristic impedance is 0.203 at the input port and 2.16 at the output port and the input voltage is half-sine pulse wave as TEM mode with an angular frequency of 14106 rad/s. A little energy of non-TEM mode is found during the transmission process. The more severely the radius of the line changes, the more energy of non-TEM mode is found. If the length of the transmission line is long enough, the difference of voltage transmission efficiency between electromagnetic fields and circuit simulation will be less than 1%. In this situation, results of electromagnetic fields simulation can be replaced by circuit situation.