JPS60199216A - Josephson unipolar pulse power supply circuit - Google Patents

Abstract

PURPOSE:To supply a unipolar pulse current to a load with a large level by applying an AC current from an AC power supply to a Josephson junction circuit of a Josephson circuit as an AC current having an amplitude multiplied by a winding ratio of a superconduction thin film transformer. CONSTITUTION:In case of the Josephson unipolar pulse power supply circuit, since the AC current 7 is coupled to the Josephson junction circuit 2 of the Josephson circuit 4 via the superconduction thin film transformer 21 and a coupling capacitor 23, the winding ratio of the secondary winding 22b to the primary winding 22a of the superconduction thin film transformer 21 is decreased and the capacitance C of the coupling capacitor 23 is selected to a value sufficiently smaller than the impedance viewing the Josephson circuit 2 of the Josephson circuit 4 from the secondary winding of the superconduction thin film transformer 21, then the AC current Ia from the AC power supply 7 is formed into the AC current Ia' having an amplitude being a multiple of the winding ratio of the superconduction thin film transformer 21 and the current is supplied to the Josephson junction circuit 2.

Description

Detailed Description of the Invention The present invention provides a Josephson circuit having a Josephson junction circuit including a Josephson junction, and a υ control line for the Josephson junction circuit. The present invention relates to an improvement of a Josephson unipolar pulse power supply circuit that uses a Josephson circuit to output unipolar pulse current from the Josephson circuit.

Background of the Invention As such a Josephson unipolar pulse power supply circuit,
Conventionally, devices having the following configuration have been proposed.

In addition, there is a Josephson junction circuit 2 having a configuration in which one or more (plurality in the figure) Josephson junctions 1 are connected in series, and a control line 3 for the Josephson junction circuit 2. and has.

It also includes a DC bias power supply 5 that supplies a DC bias current 1d to the Josephson junction circuit 2 of the Josephson circuit 4. In this case, the DC bias power supply 5 is connected to the Josephson junction circuit 2 via a resistor 6 as required.

Furthermore, Josephson junction circuit 2 of Josephson circuit 4
It has an AC power supply 7 that supplies an AC current 1a to the AC power source 7. In this case, the AC power supply 7 is connected to the Josephson junction circuit 2 via an inductor 8 as necessary. Note that this inductor 8 is an AC! ! The inductance of the connection line of the source 7 to the Josephson junction circuit 2 may be used.

Also, a DC control current J is connected to the control line 3 of the Josephson circuit 4.
It has a DC υ1ull current source 9 that supplies c. In this case, the DC controlled current source 9 is connected to the control line 3, for example directly.

Furthermore, Josephson junction circuit 2 of Josephson circuit 4
A load 10 is connected to.

The above is the configuration of the conventionally proposed Josephson unipolar pulse l1li circuit.

According to the Josephson unipolar pulse power supply circuit having such a configuration, as shown in FIG. A DC bias power supply 1d from a power supply 5 is supplied superimposed on the DC bias power supply 1d, while a DC tsm current source 9 supplies a DC rII to the control line 3 of the Josephson circuit 4.
Since the JIll current 1c is supplied, by appropriately selecting the levels of the DC bias power supply 1d and the DC control current rc, and the amplitude of the AC current 1a, the AC current 1a can be made negative as shown in Figure 2B. In the interval from the time when the AC current IC takes a maximum value to the time after it enters the section where it takes a positive value to the time when the AC current IC takes a maximum positive value and before it enters the section where it takes a negative value, A unipolar pulse ff1llo, which is unipolar and has a unity level, can be supplied to the load 10.

Therefore, in the case of the conventional Josephson unipolar pulse power supply circuit shown in FIG. 1, it is possible to supply the load 10 with a unipolar pulse current IO having a constant level, which is synchronized with the alternating current 1a. It has m capabilities as a unipolar pulse power supply circuit.

By the way, in the case of the conventional Josephson unipolar pulse power supply circuit shown in FIG. can be adjusted to the value of

However, in the case of the conventional Josephson unipolar pulse power supply circuit shown in FIG.
In order to supply O at a large level, it is necessary to increase the current capacity of the AC power source 7, which has the drawback of making the AC power source 7 large and expensive.

In addition, in order to supply the unipolar pulse N current IO to the load 10 at a large level, if the amplitude of the alternating current 1a is increased to a large value, the connection line of the Josephson circuit 4 of the alternating current 1a to the Josephson junction circuit 2 If the connection line is long, the AC current 1a leaks to the outside from the connection line, and the leakage current is coupled to the Josephson junction circuit 2 of the Josephson circuit 4, the ti control line 3, or the load 10. However, it has the disadvantage that it may cause malfunction.

Accordingly, the present invention seeks to propose a new Josephson unipolar pulse power supply circuit which does not have the above-mentioned drawbacks.

According to the Josephson unipolar pulse power supply circuit according to the present invention, as in the case of the Josephson unipolar pulse power supply circuit described above in FIG. A Josephson circuit having a Son junction circuit and a control line for the Josephson junction circuit, a DC bias power supply supplying a DC bias current to the Josephson junction circuit of the Josephson circuit, and a Josephson junction circuit of the Josephson circuit. It has an AC 'RN that supplies alternating current to the control line of the Josephson circuit, and a DC bias power supply that supplies DC bias power to the control line of the Josephson circuit, and outputs a unipolar pulse current that is synchronized with the alternating current from the Josephson circuit. The AC power source is connected to the Josephson junction circuit of the Josephson circuit via a superconducting thin film transformer and a coupling capacitor in that order.

Therefore, the winding ratio of the secondary winding to the primary winding of the superconducting thin film transformer is made small, and the capacitance of the coupling content is changed from the secondary winding of the superconducting IP thin film transformer to the Josephson circuit of the Josephson circuit. By selecting a value that provides an impedance sufficiently smaller than the impedance seen on the junction circuit side, the alternating current from the alternating current source is converted into an alternating current having an amplitude twice the winding ratio of the super low profile transformer. It can be supplied to the junction circuit.

Therefore, according to the Josephson unipolar pulse power supply circuit according to the present invention, a large level of unipolar pulse current can be supplied to the load without using an AC power supply having a large current capacity. Therefore, in order to supply a large level of unipolar pulse current to the load,
There is no need to increase the current capacity of the i-source, so the AC power source does not become large or expensive.

Further, even if the connection line from the AC power source to the super-low S*a+- lance is long, the AC current will not leak to the outside from the connection line, or even if it does leak, the amount will be small. Furthermore, even if alternating current leaks to the outside from the connection line connected from the secondary winding of the superconducting thin film transformer to the Josephson junction circuit of the Josephson circuit via the coupling capacitor, the connection line Since the length can be shortened, the possibility of malfunction caused by leakage can be effectively avoided.

Preferred Embodiment of FIG. 3 shows an example of a Josephson unipolar pulse power supply circuit according to the present invention.

In FIG. 3, parts corresponding to those in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

An example of the Josephson unipolar pulse power supply circuit according to the present invention shown in FIG. 3 is similar to the conventional Josephson unipolar pulse power supply circuit described above in FIG. A super-depressed SiI film transformer 21 having a primary winding 22a made of a film and a secondary winding 22b electromagnetically coupled thereto, and a coupling capacitor 23 made of a known thin film. It has the same configuration as the conventional Josephson unipolar pulse power supply circuit described above with reference to FIG. 1, except that it is connected to the Josephson junction circuit 2 of the Josephson circuit 4 through the following in that order.

The above is the configuration of an example of the Josephson unipolar pulse power supply circuit according to the present invention. According to the Josephson unipolar pulse power supply circuit according to the present invention having such a configuration,
Since it has a similar configuration to the conventional Josephson unipolar pulse power supply circuit described above in FIG. 1, except for the matters mentioned above, the case of the conventional Josephson unipolar pulse power supply circuit described above in FIG. It is clear that the load 10 can be supplied with a unipolar pulsed current IO synchronized with the alternating current 1a from the alternating current power source 7 in the same way.

However, in the case of the Josephson unipolar pulse power supply circuit according to the present invention shown in FIG. Therefore, the secondary winding of superconducting S membrane transformer 21 is 1 m!
22b to the primary winding 22a, and the capacitance C of the coupling capacitor 23 is changed from the secondary winding of the superconducting thin film transformer 21 to the Josephson junction circuit 2 of the Josephson circuit 4. By selecting a value that provides an impedance sufficiently smaller than the impedance seen from the side, the AC current 1a from the AC power source 7 can be made super low! lJRM transformer 2
The AC cylinder 11a having an amplitude twice the above-mentioned winding ratio of 1 can be supplied to the Josephson junction circuit 2 of the Josephson circuit 4.

Therefore, according to the Josephson unipolar pulse power supply circuit according to the present invention, the unipolar pulse current 10
can be provided at a high level. Therefore, it is not necessary to increase the current capacity of the AC power supply 7 in order to supply the unipolar pulse current 10 at a large level to the load 10, and therefore the AC power supply 7 does not become large or expensive.
It has the following characteristics.

In addition, even if AC 1i17 superconducting thin film transformer 21
Even if the connection line to is long, the AC'R current 1a will not leak to the outside from the connection line, or even if it does leak, the amount will be small. Also, even if the secondary winding of superconducting thin film transformer 21! Even if the AC iI current 1a= leaks to the outside from the connection line connected from 22a to the Josephson junction circuit 2 of the Josephson circuit 4 via the coupling capacitor 23, the connection line can be shortened. Therefore, it has the feature that it is possible to effectively avoid the possibility of malfunction occurring due to the leakage.

Note that in the above description, the Josephson circuit 4 includes one or more Josephson junctions 1, and the Josephson junction circuit 2 has a configuration in which these junctions are connected in series, and the control for the Josephson junction circuit 2. The case where the configuration has line 3 has been described.

However, detailed illustrations and explanations are omitted, but for example, 2
Two Josephson junctions are loop-connected via an inductor, and a DC bias current 1d from a DC bias power supply 5 is supplied to the two Josephson junctions through the midpoint of the pair of connections. Even in the case of a configuration having a Josephson junction circuit configured with a
It is also possible to supply the alternating current from the alternating current power supply 7 to the two Josephson junctions via the connection midpoint between them as described above, to obtain the same excellent effect as described above. , should be obvious.

Various other modifications and changes may be made without departing from the spirit of the invention.

[Brief explanation of drawings]

FIG. 1 is a connection diagram showing a conventional Josephson unipolar pulse power supply circuit. FIGS. 2A and 2B show the DC bias current and the AC current supplied to the Josephson junction circuit of the Josephson circuit, for explaining the conventional Josephson unipolar pulse power supply circuit and the Josephson unipolar pulse power supply circuit according to the present invention. FIG. 3 is a diagram showing the waveform of the unipolar pulse current supplied to the load, and the waveform of the unipolar pulse current supplied to the load. FIG. 3 is a connection diagram showing an example of a Josephson unipolar pulse power supply circuit according to the present invention. 1・・・・・・・・・・・・・・・Josephson junction 2
・・・・・・・・・・・・・・・Josephson junction circuit 3・・・・・・・・・・・・・・・Control line 4・・・・
・・・・・・・・・Josephson circuit 5・・・・・・
......DC bias power supply 7...
・・・・・・・・・AC power supply 9・・・・・・・・・・・・
...DC um'rt, source 10...
...Load 21...Superconducting iI membrane transformer 23...
・Coupling capacitor Applicant Nippon Telegraph and Telephone Public Corporation Continued from page 1 0 Inventor Fuji 1) Osamu - Nippon Telegraph and Telephone Public Corporation Atsugi Telecommunications Research in the property of 183 Hata, Ono, Atsugi City

Claims (1)

[Claims] A Josephson circuit comprising a Josephson junction circuit including a Josephson junction, and a control line for the Josephson junction circuit; a DC bias power supply that supplies current; an AC power supply that supplies AC current to the Josephson junction circuit of the Josephson circuit; and a DC control 1wi current source that supplies DC control a current to the control line of the Josephson circuit. A Josephson unipolar pulse power supply circuit comprising: a Josephson unipolar pulse power supply circuit that outputs a unipolar pulse current synchronized with the alternating current from the Josephson circuit;
A Josephson unipolar pulse power supply circuit, characterized in that the AC power supply is connected to a Josephson junction circuit of the Josephson circuit via a superconducting thin film transformer and a coupling capacitor in that order.