Parametric amplifiers: static and dynamic inductance and capacitance and their significance in the non-linear and time-varying approaches

The analysis of circuits such as parametric amplifiers can be approached in two main ways, by regarding the variable element as having either non-linear characteristics largely controlled by a dominant pumping current or voltage, or linear characteristics subject to a specified timevariation. In the former case, ¿dynamic¿ inductance or capacitance may be used with advantage in analysis and measurement in place of the ¿static¿ parameters. In the latter case the distinction is invalid. The relation between the two cases is discussed in this paper.