Design validation of low-cost RF current probe to estimate the Surface Transfer Impedance (STI) of co-axial cable under test using LabVIEW software

摘要

In recent years, Electromagnetic Compatibility (EMC) problems associated with high frequency & high speed interconnects carrying power, signal & data are becoming of increasing concern. Co-axial cables are the most popular interconnect between intra & inter systems and sub-systems in Radio Frequency applications. Transfer Impedance is a measure of assessing the Shielding Effectiveness of outer shield of a co-axial cable. In this paper, a low cost RF current probe is designed for measuring the current through the centre conductor of the cable sample under test. A calibration/ validation test fixture is prepared for validating the designed Current probe and in turn Surface Transfer Impedance (STI) of cable sample is estimated. LabVIEW automation software application is developed for validation of probe using validation test fixture and in turn estimating the STI of co-axial cable under test.