Analysis of Immittances and Equivalent Circuits of non-Foster Elements based on One-pole Amplifiers

There are two major challenges in using electronic circuits that mimic negative capacitors and negative inductors (non-Foster elements): ensuring stable operation and minimizing the dependence of the generated negative immittance on frequency. Recently, it has been shown that there is an inevitable trade-off between these two goals, caused by the background physics of used negative impedance converters (NICs). In order to provide guidelines for practical design, we analyze the dispersion curves for open-circuit stable and short-circuit stable non-Foster elements based on NICs with one-pole amplifiers and develop associated equivalent circuits.