Typically, characterization is performed by Anritsu since the process can be very carefully controlled for maximum accuracy. In certain cases, the customer may wish to perform the characterization themselves but it is important to note that all specifications for the calibration are void and the customer takes responsibility for performing a characterization of adequate quality. With that caveat, the process for performing a characterization is as follows:
1. Setup the instrument for the frequency range, point count, power level, and IFBW desired. It is particularly important to use as many points as reasonable in order to reduce interpolation needs.
2. Perform as high a quality manual calibration as possible at the reference planes that will be connected to the AutoCal module. LRL/LRM is recommended if possible.
3. Connect the AutoCal module to the reference planes, apply power, and connect the control cable to both the AutoCal module and to the MS4640A Series VNA. Allow the AutoCal module to reach operating temperature so the blue Operate LED illuminates.
4. Select the AUTOCAL CHARAC. menu (shown below) to start characterization. The VNA will automatically switch the unit through its various states and characterize them. Alternatively, the connected test port order may be specified and may be necessary if there is substantial loss in the test setup (note that this may indicate an accuracy hazard).
• MAIN | System | SYSTEM | Utility | UTILITY | AutoCal Characterization | AUTOCAL CHARAC.
5. Save the characterization file as appropriate. Note that the characterization file will be tied by serial number to the particular AutoCal module that was characterized.
