Amplitude and phase characterization of nonlinear mixing products

This paper discusses the problem of amplitude and phase characterization of nonlinear mixing products arising from a broad class of nonlinear microwave devices. Realizing that the most difficult problem stands on the phase measurement, it starts by reviewing the most common approaches used for the phase characterization of spectral regrowth components. It is demonstrated that these methods can be viewed as correlation processes, and are so framed in a common theory. This allows a unique and universal definition of the input-output amplitude and phase relations, even for mixing products that fall on frequency positions for which there are no components present at the input, and for those arising from incommensurate excitations. Finally, it shows how that theory can be implemented in a laboratory measurement scheme, thus giving the introduced theoretical variables a practical engineering value