An Analysis of the Magnetic Second-Subharmonic Oscillator

An analysis is given for the second-subharmonic parametric oscillator with two ferromagnetic cores. "Square-loop" reasoning is employed with extreme idealization of the magnetic core properties; the effects of hysteresis losses and saturated inductance are subsequently considered. The steady-state operation, both with voltage and with current pump drives, is studied to determine the values of the circuit parameters for which the subharmonic oscillations occur. The transient build-up is evaluated by means of difference equations, and the influence of the magnitude of the excitation signal upon the transient is illustrated. The experimental waveforms agree with the analytical predictions for a wide range of drive frequencies, the upper limit investigated being 3 Mc.