Simulation and experiment of a full-range non-foster response

We investigate the wideband response of a non-Foster element based on a radio frequency operational amplifier. Our results indicate that the input impedance of a non-Foster element co-existing with a stabilization network exhibit an inverted Lorentzian resonance. This makes its full-range frequency response satisfy the Kramers-Kronig relations. In this case, while the conventional non-Foster response can be observed in the low-frequency region on the left side of the resonance, a high-frequency non-Foster response can also be observed on the right side of the resonance. This special response can be potentially used to overcome the technical challenge in achieving radio frequency non-Foster elements.