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Masayuki YAMADA Ken UCHIDA Yasuyuki MIYAMOTO
The delay time component (τs) of an InGaAs MOSFET caused by dynamic source resistance is discussed. On the basis of the relationship between the current density (J) and the dynamic source resistance (rs), the value of rs is proportional to 1/J with some offset at low current densities, whereas the offset becomes smaller in a region of high current density. The value of τs depends on the current in a way similar to rs. Because the offset in the high-current-density region is proportional to the square root of the effective mass, an InGaAs MOSFET with a small mass has a shorter rs than a Si MOSFET.
Akinori KANASUGI Mititada MORISUE Hiroshi NOGUCHI Masayuki YAMADAYA Hajime FURUKAWA
In this paper, oscillation modes produced in a Josephson circuit and its application to digital systems are described. The analysis is performed using an analog simulator to model the Josephson junction, in addition to computer simulation. The experimental results concerning oscillation modes agree well with the simulation results. The main advantage of the mapping for the oscillation modes is that it allows understanding of the relationships among oscillation modes and circuit parameters at first sight. In addition, a novel application of nonlinear oscillation to digital systems is described.