A robust approach for comparison and validation of large signal measurement systems

As time-domain RF measurement tools gain recognition and acceptance, it becomes increasingly important to identify and compare the different systems being used, and to quantify any differences observed. In this paper, a robust validation approach is identified and used to compare a number of completely different large-signal measurement systems. Unlike a previous ‘round-robin’ exercise, the solution does not require an accurately modeled non-linear reference component to account for system impedance variations when comparing results, which clearly introduces additional complexity and the possibility of errors. Instead, active loadpull, coupled with a common passive source network is used to present a consistent impedance environment to a device under test. After employing this method, large signal data from two completely different measurement architectures employing different instruments and calibration procedures showed excellent agreement. This approach has proved useful in the validation and comparison of a number of large signal measurement and could be used to increase confidence in such systems.