The use of current probes in S-parameter determination

This paper presents a technique to determine S-parameters with two current probes. One probe is used to inject current, the other measure current. The method uses the probes as a device described by scattering parameters. The tradional method to measure scattering parameters needs disconnect the device from system and connects it to VNA. In topological analysis, the method we propose only requires that the ports of the device under test present a wire extension. Based on topological definition, the technique are described assuming that the probes behave like ideal transformers. The paper has a experiment to compare two methods. The methods has an ideal result correspond to traditional method below 10MHz, from 10MHz to 100MHz the error is smaller than 10dB. It is discovered that the main reason of the error is the limit of the performance of probes. So the method can be used in electromagnetic effect analysis of pulse that raise time smaller than 1ns, for its main frequency is smaller than 100MHz.