基于混频器的非线性网络分析仪(NVNA)是一种新型的非线性网络测量平台。介绍了该平台的结构、原理、误差模型和经典校准流程。结合NVNA的时不变测量特性,提出了2种新的双端口校准方案——Absent Thru和Blind Thru,并给出了具体的校准流程。在新研制的NVNA原型样机上的实验表明,新方案与经典Unknown Thru方法的校准结果相一致。新方案丰富了双端口NVNA校准手段,为NVNA的误差模型合理性以及校准结果准确性提供了有效的检验手段。
Mixer-based nonlinear vector network analyzer (NVNA) is a new type of platform for nonlinear network measurements. This paper introduces its architecture, principle, error model and classical calibration procedure. Based on the time-invariant measuring feature of mixer-based NVNAs, two alternative two-port calibration schemes, Absent-Thru-based and blind-Thru-based schemes, are proposed with detailed illustrations. Experiments on a newly developed NVNA prototype verify the equivalence between the outcome of classical unknown-Thru-based calibration scheme and those of the new schemes. The new calibration procedures diversify the choices of two-port NVNA calibration, and offer a tool to examine the validity of the error model and the accuracy of calibration results of mixer-based NVNAs.