Improved measurements of ICRF antenna coupling at ASDEX Upgrade and comparison with the ICRF coupling code TOPICA
Improved measurements of ICRF antenna coupling at ASDEX Upgrade and comparison with the ICRF coupling code TOPICA
复制标题
DOI：
10.1016/j.fusengdes.2013.02.011
复制
发表时间：
2013-10
期刊：
影响因子：
--
通讯作者：
I. Stepanov;J. Noterdaeme;H. Faugel;H. Fünfgelder;F. Braun;V. Bobkov;D. Milanesio
中科院分区：
文献类型：
--
作者：
I. Stepanov;J. Noterdaeme;H. Faugel;H. Fünfgelder;F. Braun;V. Bobkov;D. Milanesio
在50 Ω测试线上比较了测量ASDEX Upgrade ICRF系统传输线上天线阻抗的三种方法-使用定向耦合器、电压探针阵列和电压/电流探针对。在最佳可用条件下（50 Ω直线），电压/电流探头对始终显示最高精度，高达1.2%，与VSWR无关。通过测量50 Ω线路上的耦合值校准电流和电压探头;通过使用简单电路模型计算两个探头的两条线路的耦合差，从50 Ω测量值获得25 Ω线路的值。新的测量系统在ASDEX升级天线上实施，并将补充定向耦合器的现有测量。除了提高精度外，它还具有每个天线产生两个复反射系数（每个带一个）而不是一个的优点。测量位置明显更靠近天线输入端（距离带状输入端1.3 m），从而减少了由于传输线几何复杂性而导致的误差。
Three methods of measuring antenna impedance on the transmission lines of the ASDEX Upgrade ICRF system have been compared on a 50 Ω test line – by using directional couplers, voltage probe arrays and voltage/current probe pairs. Under the best available conditions (straight 50 Ω line), the voltage/current probe pair consistently shows the highest accuracy, up to 1.2%, independent of VSWR. The current and voltage probes have been calibrated by measuring their coupling values on the 50 Ω line; the values for a 25 Ω line were obtained from the 50 Ω measured values by computing the difference in coupling in the two lines for both probes using simple circuit models. The new measurement system is implemented on ASDEX Upgrade antennas and will complement the already available measurements from directional couplers. In addition to improving the accuracy, it will also have the advantage of yielding two complex reflection coefficients per antenna (one for each strap) instead of one. The measurement is located significantly closer to the antenna input (∼3 m from the strap input), thereby reducing errors due to the geometrical complexity of the transmission lines.