一种新型的变频器件群时延特性测量方法

Novel method for measuring group delay of frequency converting devices

群时延作为衡量变频器件相位线性的主要指标,对于变频系统来说更是重中之重,对射频器件测量中具有重要地位的群时延测量问题进行了研究。首先介绍了群时延的定义及概念,然后从群时延的测量原理入手,逐步讲明了利用PNA型矢量网络分析仪的标量混频器+相位(SMC)模式测量变频器件群时延的方法及适用性,最后利用实验对该新型群时延测量方法与传统测量方法结果进行对比。结果表明,利用标量混频器+相位模式测量变频器件的变频损耗与群时延与利用矢量混频器模式测量得到的结果较为一致,变频损耗测量误差在0.5dB以内,群时延测量误差在皮秒量级,证明了该方法的正确性及准确度。且无论从测试复杂性、稳定性与溯源性上均优于传统的矢量混频器法,因此该测试方案可广泛应用于变频器件的变频损耗与群时延测量。

Group delay is the most important characteristics for the frequency conversion system,as the phase linearity parameter.The group delay measurement problem that is important in the measurement of RF devices is studied.Firstly,author introduces the definition and concept of group delay and explains the measurement principle of group delay.Then,the method of measuring the delay of frequency converting devices using SMC mode which based on PNA vector network analyzer is explained step by step.Finally,the results of the new measurement method and the traditional measurement method are compared by experiments.The measurement error of conversion loss is less than 0.5 dB,and the measurement error of group delay is a few picoseconds,and the correctness and accuracy of the method are proved.It is superior to the traditional vector mixer method in terms of test complexity,stability and traceability.Therefore,this method can be widely used in the conversion loss and the group delay measurement of inverter devices.