Simultaneous asynchronous oscillations in marginal oscillators

It is shown that a nonlinear active device is able to sustain simultaneous asynchronous oscillations in a linear network of two degrees of freedom. Coexisting oscillations are studied for soft buildup of oscillation and small amplitudes ("marginal oscillator"). In the case considered the even terms of the I-V nonlinear characteristics are to be taken into account, in addition to the usual odd terms. Such an oscillator gives a simple model for the multimode operation of a maser oscillator.