Calibrated oscilloscope measurements for system-level characterization of weakly nonlinear sources

We present a technique to characterize and correct for linear and weakly nonlinear distortion introduced by the nonideal response of a wideband, high-frequency modulated-signal source. The magnitude and phase relationships between frequency components in a measured modulated signal are maintained by use of a calibrated equivalent-time sampling oscilloscope. The nonidealities of the oscilloscope and other components of the measurement system are corrected during post processing. Determination of the uncertainties in the measurement allows a user to identify magnitude and phase distortion in the generated waveform.