Some Properties of Time Varying Networks

In this paper, the general theory of reactance amplifiers is exemplified, with attention centered on three aspects. 1. Why may gain be obtained from a nonlinear reactance and not from a nonlinear resistance? 2. Where there is gain and feedback, the possibility of oscillation exists. But the situation is more complex than it is with vacuum tube amplifiers because the feedback path is through the modulator so that an external impedance at one frequency may be reflected as an impedance at another frequency. 3. The particular case of three frequencies, e.g., p, g, p-q, is calculated for large signals. The phenomena of regeneration and oscillation, with subharmonic oscillation as a special case, are studied and illuminated.