A method for automatic tuner verification

This paper describes an automated procedure for verifying the characterization of mechanical tuners used in automated load-pull systems. Precise tuner characterization is critical for making accurate load-pull measurements, as small inaccuracies in the tuner S-parameters can lead to significant errors in measured results. A software routine was written to automate the tuner verification process by controlling a vector network analyzer and a tuner controller. The program is easy to use, customizable, quick, and low-cost to implement. Results are automatically summarized, describing the tuner’s S-parameter accuracy in terms of error vector magnitude (EVM). Example results are shown for tuners with accurate and inaccurate characterizations.