VectorStar™ MS4640A Series Microwave Vector Network Analyzers : Calibration and Measurement Enhancements : Processing Order
 
Processing Order
With so many post-processing choices available, it is important to note that the order of operations can matter. A few things are fixed by the way computations are performed and others are changeable to suit user needs. The sequence of computations is as follows for S-parameter measurements:
Acquire raw data and average/filter
Apply calibration if enabled
Apply EDE if enabled (impedance transform and reference plane)
Apply parameter conversions if enabled
Apply time domain if enabled
Reference Plane Processing Sequence
The selectable item is the order in which impedance transformation and reference plane control are applied. This matters since the current impedance state determines the impedance of the line length that is adjusted using reference plane control (unlike in E/DE where the impedance can be specified). The menu to make this order selection is shown below (Figure: PROCESSING ORDER Menu).
Group Delay Processing Sequence
The second selectable item concerns the order of the group delay computation and trace memory. If trace memory precedes group delay (normal), then the complex operation can precede the numerical differentiation that is part of group delay. This could be useful to do a data normalization prior to connecting a DUT. If group delay precedes trace memory then the trace match will act on the final group delay result. An example might be a group delay comparison using data(-)memory.
PROCESSING ORDER Menu
1. Reference Plane Order controls (at top).
2. Group Delay Order controls (at bottom).