Curiosities on accurate large-signal measurements in combination with passive tuners

Since many years calibration techniques and measurement accuracy have been studied in depth for S-parameter measurements using vector network analyzers (VNA). Today, large-signal network analyzers (LSNA) are used to characterize the nonlinear behavior of components. In contrast to VNAs the stimulus cannot be switched from input to output (known as "forward mode") and vice versa ("reverse mode"). Also, LSNAs need to characterize components with source and load impedances different from 50 Ohms. These requirements demand special calibration care, even for the relative portion of the calibration process. This paper highlights some of the calibration issues without presenting an elaborate error analysis and demonstrates that accurate large-signal measurements can be performed with impedances different from 50 Ohms.