Calibration issues for the large signal network analyzer (LSNA)

There is a growing need for measuring the large signal (nonlinear) behavior of devices in their nonlinear regions under excitation of complex modulated signal schemes, as commonly used in telecom applications. The large-signal network analyzer (LSNA) based on J. Verspecht et al. (2002) developed by Agilent Technologies-NMDG is able to measure incident and scattered traveling voltage waves (or voltages and currents) appearing at both signal ports (input and output) of a DUT under periodical excitations or periodically modulated excitations. Since phase relations between the fundamental and higher harmonics are included in the measured signals, the complete behavior of the DUT is measured and accurate models to predict the DUT-behavior can now be extracted out of the measured data based on J. Verspecht and D. Schreurs (1999). In this paper, some solutions to carry out the LSNA calibration for broadband modulated multitone signals and some observations aiming at high-power applications related to the controllable step-attenuators in the measurement channels are discussed.