The Transfer Impedance Test Clamp - Improvements in Electronic Cable Shield Effectiveness Measurement Techniques

Abstract

In the paper a brief review of electronic cable shield effectiveness test techniques is given and a new concept of test fixture is introduced. A practical realization of the fixture is described. The implemented electrical schematics provides for measurements of transfer impedance and capacitive coupling impedance in both the low and high frequency ranges. The device is designed in the form of a clamp, which significantly facilitates and accelerates the measurements. This permits the required adjustments and changes, as well as sample aging and stability studies to be made without affecting shield evaluation test conditions. Since there is no need to pull the cable through the test chamber tubes and ferrite toroid assemblies, the sample preparation can be made in advance, including the attachment of connectors. Also, connectorized cable assemblies can be tested without taking the connectors off. Still greater advantages and time savings can be gained both in industrial and research applications if the proposed fixture is incorporated in an automatic test system with computerized data processing.