四端对标准电容器频率特性的校验理论及测定方法

Calibration Theory and Measurement Method of the Frequency Characteristics of the Four-Pair-Terminal Standard Capacitor

对四端对阻抗测量仪在其使用频段内进行校准,须确定四端对标准电容器的频率特性。空气介质四端对标准电容器频率特性的校验理论,是从四端对标准器阻抗矩阵出发,按四端对导纳定义进行简化后,再用网络分析仪在较高频率对有关参数进行测定,分析计算后将确定的频率特性曲线回归到100kHz～13MHz范围内。给出标准电容器1000pF、100pF、10pF、1pF的频率特性曲线及不确定度分析,它将作为阻抗高频段计量的溯源依据。

The calibration of four-terminal-pair（4TP） impedance meters at their working frequencies requires the knowledge of 4TP standard capacitor frequency characteristic. The calibration theory of 4TP air-dielectric standard capacitor frequency characteristic is studied by the predigest of 4TP impedance matrix according to the definition of 4TP admittance. Then the driving point impedance values at very high frequencies are measured by network analyzer and a regression analysisis performed to predict the capacitor frequency characteristic at frequencies from 100 kHz to 13 MHz. Finally the frequency characteristics of 1 000 pF, 100 pF, 10 pF, 1 pF standard capacitor and their measurement uncertainties are given. The study may be the base of highfrequency impedance traceability.