On the functionality of RTD MOBILE circuits - A geometric approach

In this paper an alternative approach to the commonly used loadline construction for the analysis of circuits utilizing the series connection of resonant tunneling diodes (RTDs) is presented. The discussed method is explained by the example of the mono- and bistable transition logic element (MOBILE), which today is one of the most promising logic circuits in nanoelectronics. First, it will be shown how the configuration space, which here corresponds to the set of all possible DC operating points, can be constructed without disregarding any of them. Furthermore, the dynamics of the information storage process of the MOBILE is interpreted in a geometric manner. Especially the influence of the input current on the geometrical shape of the configuration space in conjunction with the proceeding of the trajectories will become clear by this new approach. Finally, the presented concept is used to clarify output voltage spikes, which are unresolved up to now.