If the settling time between adjacent frequency points is larger than the settling time between the partial measurements, then the Alternate measurementis faster than a normal sweep so that a smaller sweep times can be set. On the other hand, an Alternate measurement provides a result only during the last partial sweep. 

Use the Alternate mode to increase the accuracy of measurements on DUTs with long level settling times (e.g. quartzes, SAW filters). To measure DUTs with short settling times and obtain a trace from the beginning of the sweep, deactivate the Alternate mode.

As an alternative to activating the Alternate mode, it is possible to insert a Meas. Delaybefore each partial measurement and thus improve the accuracy. The delay slows down the measurement.

In triggered measurements, Alternate has no effect if the triggered measurement sequence is identical to a single sweep point. The following table shows how the analyzer performs a sweep comprising m sweep points, assuming that each of them requires n partial measurements.