同轴空气线电长度计算在VNA传输相位校准中的应用

The application of calculation of air line’s electrical length in calibration of VNA transmission phase

为验证矢量网络分析仪(VNA)校准后传输相位测量系统误差是否得到修正,是否满足测量技术要求,通常用同轴空气线作标准器件,当同轴空气线应用于验证频率范围较窄,比如大量使用的8GHz以下的VNA时,空气线校准证书提供频率点和相位点太少,还不足以证实校准中的VNA传输相位计量特性。为解决低频段VNA传输相位测量准确性验证问题,经理论分析,利用传输线理论,使用空气线技术资料和校准证书信息计算出其电长度,可获得任意频率点的相位参考值,同轴空气线资料缺失时也可很容易测量出其大致物理长度用于计算电长度,经实际计算、比较和校准验证,计算出参考值和参考值的不确定度完全满足理论推算和验证要求,对VNA传输相位校准,尤其是对测量频率较低的VNA传输相位校准,有较好实用意义。

To verify that the vector network analyzer(VNA)whether the transmitted phase measurement system error is corrected,whether it meets the measurement technical requirements after calibration,usually use the coaxial air line as a standard device,when the coaxial airline is applied to the low frequency,such as the VNA frequency range below 8GHz,the air line calibration certificate has few frequency points and phase points,not enough to confirm the VNA transmission phase.In order to solve the problem of verification of low-frequency VNA transmission phase measurement accuracy,after professional analysis,the transmission line theory is used to calculate the electrical length using the air line technical data and the calibration certificate information,and the phase reference value of any frequency point can be obtained,the coaxial air line It can also be easily measured even though the data is lacking,and the uncertainty for calculating the electrical length,though actual calculation,comparison,and calibration verification,the reference value and its uncertainty are completely satisfied for theoretical estimate and verification requirements.For the VNA transmission phase calibration,especially the VNA has low frequency,there is a good practical meaning.