Electronic digital logic circuitry – Superconductor – Tunneling device
Reexamination Certificate
1999-12-01
2001-10-30
Tokar, Michael (Department: 2819)
Electronic digital logic circuitry
Superconductor
Tunneling device
C326S003000, C327S367000
Reexamination Certificate
active
06310488
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to a configuration of a superconductive logic circuit using a single flux quantum as an information binary digit.
The configuration of a superconductive logic circuit using a single flux quantum as an information binary digit is described in IEEE Transactions on Applied Superconductivity vol. 1 (1991) pp. 77-89.
SUMMARY OF THE INVENTION
In a single flux quantum logic circuit, it is necessary to set the inductance of a superconductive closed loop to tens pH or smaller for circuit operation and it is also necessary to set the load inductance to tens pH or smaller in order to obtain a large output current. In order to supply an output signal of a single flux quantum logic circuit to a single flux quantum logic circuit at the next stage, a load inductance part has to be taken out of the superconductive closed loop. As shown in FIG. 1 in the above literature, the single flux quantum logic circuit generally includes only one means for applying flux to the superconductive closed loop and the load inductance part is positioned inside of the superconductive closed loop in order to reduce the inductance. When the load inductance part is taken to the outside of the superconductive closed loop, as shown in FIG. 4 of the literature, since superconductive wires cross each other, a problem such that the fabrication process becomes difficult occurs. Since the wire becomes longer, the inductance increases. Consequently, a problem such that the margin of the circuit operation decreases and the output current becomes smaller occurs.
Further, in order to construct a logic circuit, a sequential circuit is necessary. In the conventional technique, as shown in FIG. 16 of the literature, a shift register as one of sequential circuits is fabricated by using a multi-phase clock. In the multi-phase clock, however, signals are transmitted and received at overlapped parts of clocks. Consequently, a problem such that the timings of the clocks have to be accurately provided arises.
In order to solve the problems, it is an object of the invention to provide a structure which can realize a flip-flop circuit as a basic element of a sequential circuit without using a multi-phase clock and take a load inductance part out of a superconductive closed loop without increasing the inductance.
The invention is realized by a structure in which a load inductance part of the superconductive logic circuit having two superconductive closed loops each comprising a Josephson junction and one or more inductor(s) has at least an inductor and a Josephson junction.
REFERENCES:
patent: 4342924 (1982-08-01), Howard et al.
patent: 4785426 (1988-11-01), Harada et al.
patent: 5162298 (1992-11-01), Chaudhari et al.
patent: 5233244 (1993-08-01), Suzuki
patent: 5831278 (1998-11-01), Berkowitz
patent: 363280474A (1988-11-01), None
patent: 410269783A (1998-10-01), None
IEEE Transactions on Applied Superconductivity, vol. 1, No. 2, Jun., 1991, “Quantum Flux Parametron: A Single Quantum Flux Device for Josephson Supercomputer”, M. Hosoya et al, pp. 77-89.
Fukazawa Tokuumi
Hasegawa Haruhiro
Takagi Kazumasa
Tarutani Yoshinobu
Cho James
Hitachi , Ltd.
Mattingly Stanger & Malur, P.C.
Tokar Michael
LandOfFree
Superconductive single flux quantum logic circuit does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Superconductive single flux quantum logic circuit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Superconductive single flux quantum logic circuit will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2613362