Noise Properties of Four-Pole Networks with Application to Parametric Devices

The ability to employ a new concept profitably is a matter of representation. If it can be shown to be of a kind with older and more familiar building blocks, and if a common formalism may be demonstrated, then the process of understanding is a good deal simpler. The parametric amplifier is, for all practical purposes, a product of recent technology, although its history can be traced for at least 100 years. Its mechanisms seem different from conventional structures, although it bears a dubious resemblance to mixers. Further, the noise processes come from signal and image sources, and some sort of new bookkeeping seems necessary for accounting purposes. It is the purpose of this paper to integrate the parametric amplifier into more conventional network theory. It is a linear network amply covered by general theorems applicable to all linear networks. However, because the noise theory of the parametric device is so relevant, these theorems will be expanded to permit general noise analysis.