Comparison between the ripple technique and the direct calibration method for characterisation of directional devices

A comparison between two different methods for measurement of directivity and test port match of directional couplers and bridges is presented. One of them, the popular ripple technique, is scalar. The other method, the so-called direct calibration method as derived by Juroshek (1997), with slight differences for the simultaneous measurement of both parameters, is vectorial. The two methods make use of a vector network analyser (VNA) and the calibrations performed are verified against known standards. The uncertainty associated with both techniques is computed