Abstract

Under specific conditions, the small-signal series/parallel double-RC equivalent-network is a novel full mutual alternative for the resonant tunnelling diode quantum-inductance circuit model. Network optimisations to accurately match measured intrinsic impedances of stable, non-oscillating GaAs/AlAs devices, pointed at these conditions. The capacitance Cw of the series-RC branch, peaks needle-sharp at the negative dynamic conductance "maximum, indicating carrier discharge from the quantum well. The Rb Cw -time constant equals Lq Gd of the quantum-inductance model, so it is also an indication of the quasibound-state lifetime in the well. For CAD purposes, a very good RTD intrinsic impedance description in the entire bias/frequency space (0-2 V; 0.05-40.05 GHz) is obtained with frequency-independent intrinsic elements, scalable with device area.