A Treatment of Non‐Linear Devices Based upon the Theory of Related Linear Functions

摘要

Because of the mathematical difficulties involved in the treatment of large‐signal detectors, experimental methods for obtaining design data were early adopted. The procedure has been to replace the detector by a ``model'' described by a rectification or transrectification diagram. The ``model'' for a large‐signal detector is developed from practical measurement results. Formulae and results may be extracted from the ``model'' if the existing analogy with the plate‐current vs. plate‐voltage diagram for a vacuum tube is made use of. This fundamental procedure may be extended to other non‐linear devices, and in particular to frequency converters. It is shown in the following that a general theory can be developed, of which the vacuum‐tube amplifier, the large‐signal detector, the frequency converter and other devices are applications. A double‐inpout superheterodyne mixer with straight input characteristics is discussed, and it is shown how the applied general theory predicts the necessity for non‐linearity. The general theory is then used for the development of a substituting ``model,'' from which important information on the behavior of a superheterodyne converter can be secured.