Making Differential Measurements With Copper Mountain Technologies VNAs

Balanced electrical circuits are designed with at least three ports, or more commonly four ports, as is standard for a simple differential transmission line. Many engineers prefer to perform differential measurements with 4-port instruments when characterizing electrical properties such as insertion loss and return loss, and S-parameters such as transmission and the reflection of single-ended, common-mode, and differential-mode signals. Download this application note for a brief introduction on balanced and differential circuits, and a demonstration of such measurements on a common-mode filter through the use of split-ring resonators.