On the relationship between negative differential resistance and stability for nonlinear one-ports

We give results for nonlinear one-ports regarding the relationship between negative differential resistance at a particular dc operating point and the stability of that operating point. In particular, we illustrate that the presence of negative differential resistance does not necessarily imply instability for any positive resistive port termination hut that it does imply instability for either an open-circuit or a short-circuit termination.