适配器对电磁兼容射频传导耦合去耦网络阻抗测量的影响

The Impact of the Adapters on Impedance Measurement of EMC RF Conducted Coupling-Decoupling Network

耦合去耦网络被广泛用于电磁兼容射频传导抗扰度试验,阻抗是其校准的关键参数。为了测量耦合去耦网络的阻抗,适配器被用于连接矢量网络分析仪和耦合去耦网络的受试设备端。目前国内校准实验室普遍没有考虑到适配器对矢量网络分析仪自校准质量的影响,导致高频段阻抗模值测量结果偏差较大。因此,分别基于实验和理论计算原理,设计了同轴转换自校准法和电长度补偿计算修正法用于改善阻抗测量结果。数据表明,上述方法较好地减小了适配器的负面影响,对测量结果起到了改善作用。

The coupling-decoupling network (CDN) is widely applied in electromagnetic compatibility (EMC) for conducted radio frequency susceptibility tests.The impedance of equipment under test (EUT) port is the most important parameters in CDN calibration.To measure the impedance,adapters are required to connect the vector network analyzer (VNA) to the EUT port of the CDN.Until now,the impact of the adapters used has not been clearly demonstrated by the domestic calibration laboratories,while the impedance errors at high frequencies are caused by the adapters.Therefore,basing on experimental and theoretically calculating principles,two methods,which are defined as self calibration of VNA after coaxially converting and calculation by electrical length compensation,have been presented.The data indicate that the two methods are valid for removing the adpaters' impact,and the impedance measurement results have be improved.