HILBERT-TRANSFORM-DERIVED RELATIVE GROUP DELAY

Many common types of microwave circuits, particularly filters, are req uired to meet a group delay ripple specification, This is normally mea sured using a vector network analyzer (VNA) or some specialized test c onfiguration, A new method of assessing the group delay ripple of a br oad class of microwave circuits is presented, which uses a scalar netw ork analyzer and a form of the Hilbert transform, Experimental results illustrating the usefulness of the technique are shown for a series o f examples and the principal sources of error are analyzed.