负载牵引系统校准结果性能评价方法研究

Research on Performance Evaluation Method of Calibration Results of Load-Pull System

针对采用标准失配衰减网络实现负载牵引测量系统校准时,转换增益测量误差ΔG_(T)作为校准结果无法直观反映系统测量输出功率(P_(out))以及功率附加效率(PAE)的测量性能问题。通过在后端模块的负载端插入经校准的精密极化步进衰减器对ΔG_(T)进行衰减替代测量,给出了校准结果ΔG_(T)与P_(out)及PAE变化量的曲线族,方便设计师快速获取系统测量性能。其中,P_(out)误差随ΔG_(T)呈等量线性变化(斜率45°);PAE误差随ΔG_(T)线性增加,当PAE为70%、ΔG_(T)为0.5 dB时,对应的功率附加效率PAE的不确定度约为8.5%。经实验验证,P_(T)及PAE的曲线查询误差与实际测量误差的偏差小于1%,应用设计的查询曲线,可有效提高负载牵引应用工程师的设计效率。

A method for evaluating the Performance of the on-wafer load-pull measurement system by measuring the measurement errorΔG_(T) of the transducer gain of the passive mismatch attenuation network is introduced.The load-pull measurement system mainly measures the Performance of the power device under test from three aspects:output power(P_(out)),conversion gain(G_(T)) and power added efficiency(PAE).By inserting a calibrated precision polarization step attenuator into the load end of the back-end module,the attenuation substitution measurement ofΔG T is carried out,and gives the calibration resultΔG_(T)and the curve family of pout and PAE variation,which is convenient for designers to quickly obtain the system measurement Performance.Among them,the P_(out) error varies linearly withΔG_(T)(slope 45°);PAE error increases linearly withΔG_(T).When PAE is 70%andΔG_(T) is 0.5 dB,the corresponding power added efficiency PAE uncertainty is about 8.5%.After experimental verification,the deviation between the curve of P_(out) and PAE of measurement result is less than 1%.