Monitoring of the characteristics of Josephson microcircuits used in standards of the volt

The results of investigations of microcircuits based on Nb-AlO^sub x^-Nb Josephson tunnel junctions, used in modern standards of the volt, are presented. The measured static characteristics of the microcircuits, their temperature dependences in the 4.2-1.7 K temperature range, the frequency response in the 54-80 GHz frequency band, and the attenuation in a microstrip line are used to optimize the construction of microcircuits and their manufacturing technology at PTB (Physikalisch-Technische Bundesanstalt, Germany). It is shown that microcircuits of a new construction, made using a modified PTB technology, have better characteristics and can be used as the unit of voltage at the level of both 1 V and 10 V.[PUBLICATION ABSTRACT]