An Automatic Calibration Module, or ACM, is used to perform user calibration on a Copper Mountain Technologies Vector Network Analyzer (VNA). This is the calibration that is performed prior to making a series of measurements, not the one performed on an annual or semi-annual basis at a calibration laboratory. The ACM presents a series of calibration standards to the VNA – that is, one or more Opens, Shorts, Loads, and a Thru – to complete a SOLT (Short/Open/Load/Thru) full 2-port calibration, or a SOL 1-port calibration.
A mechanical calibration kit contains individual Open, Short, Load, and Thru calibration pieces, which must be attached to the VNA one after another. A calibration kit definition file informs the VNA of what reflection coefficient each piece should exhibit at each frequency, and calibration is calculated by comparing measured values to actual values.In contrast, the Short, Open, Load, and Thru in the ACM have been precisely characterized at the CMT factory and the results are stored in its non-volatile memory. The ACM completes the calibration process with a single connection to the test cables, automatically cycling through the internal calibration standards.
