JP2902017B2 - Superconducting electromagnetic wave mixer and superconducting electromagnetic wave mixing device using the same - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a heterodyne mixer using a superconductor and a superconducting electromagnetic wave mixing device using such a mixer, which is used for detecting electromagnetic waves such as millimeter waves. It is about.

[Related Art] Conventionally, a heterodyne detection device used for detecting an electromagnetic wave such as a millimeter wave has a configuration including an antenna, a local oscillator such as a gun oscillator or a klystron, and a heterodyne mixer element.

As such a heterodyne mixer element, a Josephson heterodyne mixer element using a metal superconductor such as Nb was used, and the mixer element was configured to have a capacitance at the junction by forming a SIS type laminated structure. .

By the way, such a conventional heterodyne detection device is configured as a local oscillator and a Josephson mixer element separately from each other, and is a very large device that connects these with each other via a waveguide. Further, the output of the local oscillator needs to be about 10 nW to 100 nW, and the power consumption is large.

On the other hand, an integrated heterodyne mixer (Josephson triode) using a niobium planar weakly coupled Josephson junction for a local oscillator and a mixer has been devised (Transactions of the Institute of Electronics, Communication and Communication Engineers, '86 /5Vol.J69). −C No.5, p
636-643 and IEICE Technical Report '87 / 5, SC
E87-9, p.49-54).

Since the Josephson triode is integrated, a device using such an element can be significantly reduced in size.

FIG. 11A shows a schematic configuration of the Josephson triode, where 1 is a converter terminal, 2 is an oscillator terminal, and 3 is a ground terminal. FIG. 11B shows an equivalent circuit thereof. Three weakly coupled Shosefson junctions JJ1, JJ2, JJ3
Among them, JJ1 is used as a converter for heterodyne detection, JJ2 is used as an oscillator for local oscillation, and JJ3 is used as an isolator for separating JJ1 and JJ2. The operation is
By applying a bias current to JJ2, local oscillation is caused by the AC Josephson effect, and a signal due to this local oscillation and an external electromagnetic wave are mixed by JJ1 as a converter to obtain an intermediate frequency signal.

However, in the above sucrose ceph Son triode, it is necessary to set the normal resistance R _n13, characteristics such as R _n12, R _n23 of each Josephson junction to each proper value,
In a conventional Josephson junction using a weak bond such as Nb, it was difficult to control characteristics at the time of fabrication. Therefore, the above-mentioned Shosefson triode was very difficult to produce.

Further, in the above-mentioned conventional apparatus or element, a material having a low critical temperature Tc (near liquid helium temperature) such as Nb is used as a superconducting material. -A very large cooling device using the Thomson effect was required.

Furthermore, in the above-mentioned conventional apparatus or element, the upper limit frequency that can be used is as low as about 1 THz, and it has become impossible to meet the recent demand for providing a mixer for a high frequency band.

[Problems to be Solved by the Invention] An object of the present invention is to provide an integrated type using an oxide high-temperature superconductor, which is small in size, easy to manufacture, and has a very simple structure in view of the above-mentioned problems in the conventional example. An electromagnetic wave mixer is provided.

[Means for Solving the Problems] A superconducting electromagnetic wave mixer according to the present invention is a local oscillator, and is electrically coupled to the local oscillator, and mixes an electromagnetic wave from the local oscillator with an external electromagnetic wave. A superconducting electromagnetic wave mixer having a receiver, wherein the local oscillator and the receiver are both formed by a Josephson junction using an oxide superconductor, and the local oscillator and the receiver are insulators. Alternatively, they are characterized in that they are connected via a conductive material different from the material forming the Josephson junction. In the superconducting electromagnetic mixer of the present invention, for example, a local oscillator and a receiver are formed by a plurality of Josephson junctions sharing at least one oxide superconductor layer,
By implanting ions into a region of the shared oxide superconductor layer between a Josephson junction serving as a local oscillation unit and a Josephson junction serving as a reception unit, the conduction characteristics of the region are changed, and the local oscillation unit is changed. And a receiver.

[Operation] In the configuration described above, a Josephson junction serving as a local oscillation unit generates a local oscillation signal when a bias current is applied. Since the local oscillator and the receiver are electrically coupled, the local oscillation signal is supplied to a Josephson junction serving as a receiver. At the Josephson junction serving as a receiving unit, an external electromagnetic wave and the local oscillation signal are mixed. As a result, the external electromagnetic wave is detected by the receiving unit, and an intermediate frequency signal having the frequency of the difference between the external electromagnetic wave and the local oscillation signal is extracted.

In a first aspect of the invention, a Josephson junction comprises:
This is based on a crystal grain boundary of an oxide superconducting volume film. In these Josephson junctions, at least one junction serving as a local oscillation unit and one junction serving as a reception unit are provided, and the junction serving as a local oscillation unit and the junction serving as a reception unit are made of an insulator or a conductor. Electrically coupled. The insulator couples the local oscillating unit and the receiving unit mainly capacitively or inductively, and the conductor couples them mainly resistively.

Specifically, referring to the drawings, the first aspect of the present invention will be described.
The superconducting electromagnetic wave mixer in the embodiment shown in FIGS. 1C and 1D and FIG.
And are generally classified into laminated types.

FIGS. 1C and 1D show a planar superconducting electromagnetic mixer in which a local oscillator and a receiver are coupled via an insulator. FIG. 1C is a plan view, and FIG.
It is sectional drawing a '. This planar superconducting electromagnetic mixer uses two Josephson junctions 6 and 7 using a crystal grain boundary of an oxide superconductor thin film 5 formed on a substrate 4 as a local oscillator and a receiver, respectively. The local oscillator and the receiver are arranged side by side on a substrate 4 with an insulator 8 interposed therebetween.

This planar type superconducting electromagnetic wave mixer deposits a polycrystalline oxide superconducting thin film 5 on a substrate 4 and then patterns it using a technique such as photolithography or ion implantation to form two Josephson junctions. 6 and 7 can be manufactured by forming them very close to each other in a plane with an insulator 8 interposed therebetween.

2D and 2E are a plan view and a bb 'sectional view of a laminated superconducting electromagnetic wave mixer. This laminated superconducting electromagnetic mixer comprises two Josephson junctions 6 and 7 using crystal grain boundaries of lower and upper oxide superconductor thin films 5a and 5b on a substrate 4, respectively, a local oscillator and a receiver. The local oscillating unit and the receiving unit are laminated with an insulator 8 interposed therebetween.

The laminated superconducting electromagnetic wave mixer deposits a polycrystalline lower oxide superconducting thin film 5a, an insulator 8 and an upper oxide superconducting thin film 5b on a substrate 4 in this order, and then uses a technique such as photolithography. To form two Josephson junctions 6 and 7 very close to each other with an insulator 8 interposed therebetween.

FIG. 4C is a plan view showing a planar superconducting electromagnetic wave mixer in which a local oscillation unit and a reception unit are connected via a conductor. The flat superconducting electromagnetic wave mixer shown in FIG.
And two planar or quasi-planar Josephson junctions 6, 7 using crystal grain boundaries of the oxide superconductor thin film 5,
One of them is a local oscillator, and the other is a receiver,
It has a structure in which the two Josephson junctions 6 and 7 are connected using a conductor 17.

The superconducting electromagnetic wave mixer shown in FIG. 4C can be manufactured by the following method. 4A to 4C, first, a superconducting thin film 5 is formed on a substrate 4 of, for example, MgO (FIG. 4A). Next, patterning is performed by photolithography or the like to form two Josephson junctions 6 and 7 (FIG. 4B). Next, a conductor 17 connecting the two Josephson junctions is formed (FIG. 4C).

By the way, when only one Josephson junction is included in the local oscillation (oscillator) unit, the voltage applied to the oscillator is low, and there is a problem that the local oscillation frequency fluctuates due to the instability of the bias power supply.

The multi-type superconducting electromagnetic wave mixer represented by FIGS. 3A and 3B and FIG. 5A addresses such a problem and has a plurality of local oscillating units and receiving units.

FIGS. 3A and 3B are a plan view and a cross-sectional view taken along the line cc 'of an electromagnetic wave mixer in which the multilayer superconducting electromagnetic wave mixer of FIGS. The multi-layer laminated superconducting electromagnetic mixer comprises lower and upper oxide superconductor thin films 5a and 5b laminated on a substrate 4 via an insulator 8, and Josephson junctions 6a and 6b serving as local oscillators. 6c and Josephson junctions 7a, 7b, 7c serving as receiving portions are formed via an insulator 8, and further, electrodes 13, 14, and 15, 16 are formed.

3A and 3B are exactly the same as the multi-layered superconducting electromagnetic wave mixer shown in FIGS. 2D and 2E except that more Josephson junctions are formed by patterning. The method can be used.

FIG. 5A is a plan view showing an electromagnetic mixer obtained by multiplying the planar superconducting electromagnetic mixer of FIG. 4C.
This multi-planar superconducting electromagnetic mixer mixes an oxide superconductor thin film 5 on a substrate 4 to form Josephson junctions 6a, 6b, 6c serving as local oscillators and a Josephson junction 7a serving as a receiver. , 7b, 7c are formed, the local oscillation unit and the reception unit are coupled via a conductor 17, and furthermore, the electrodes 13, 14
And 15,16.

This multi-type planar superconducting electromagnetic wave mixer is the same as the planar superconducting electromagnetic wave mixer shown in FIG.
Except for forming more Josephson junctions by patterning, the same method can be used.

Although not shown, in the planar superconducting electromagnetic mixer of FIGS. 1C and 1D in which the local oscillation section and the reception section are connected via an insulator, the local oscillation section and the Needless to say, it is possible to multiply the receiving unit.

The first aspect of the present invention is to use a Josephson junction comprising a crystal grain boundary of an oxide superconductor thin film, and a method using a polycrystalline thin film of an oxide superconductor, Materials and forms are not limited.

The insulator connecting the two Josephson junctions is MgO, Y
Insulating thin film such as SZ (yttrium stabilized zirconia) or polymer of organic substance, oxide superconductor made into insulator by means such as ion implantation, or gap produced by means such as etching
Almost the same effects can be obtained irrespective of the material, the manufacturing method, and the form such as the height and the level difference.

The conductor joining the two Josephson junctions is a metal,
Semiconductors, superconductors, etc., if it is conductive, its manufacturing method,
Regardless of the material.

A superconducting electromagnetic wave mixer according to a second aspect of the present invention has a local oscillator and a receiver configured by a tunnel-type Josephson junction using an oxide superconductor thin film, and includes the local oscillator and the receiver. Are coupled by any of a Josephson junction formed by a conductor or an insulator, capacitance, resistance, or inductance.

FIGS. 6A and 6B show an example of a schematic structure and a manufacturing method of the superconducting electromagnetic wave mixer according to the present embodiment.

First, a lower superconducting thin film 5 is formed on a substrate 4 such as MgO.
a, an insulating layer (tunnel barrier layer) 8 'and an upper superconducting thin film 5b are formed thereon (FIG. 6A). Next, patterning is performed by photolithography or the like to form a groove 18 (FIG. 6B). At this time, the bottom (joining portion) 19 of the groove 18
For example, the superconducting characteristics are changed by processing such as ion milling, and desired characteristics of the insulator and the conductor are obtained. The conductor here includes a semiconductor and a superconductor. This utilizes the property that the properties of the oxide superconductor are very sensitive to the composition ratio. By changing the left and right areas of the groove 18, a tunnel type Josephson junction pair having a Josephson current value suitable for the local oscillator and the receiver of the mixer is formed. Where groove 18
If it is possible to change the degree of coupling between the right and left Josephson junctions, it is not necessary that the grooves be physically cut.
It is also possible to form by a method such as ion implantation as shown in FIG. 6A to 6C, a local oscillation signal is generated by applying a bias current to the left Josephson junction 20 and introduced into the right Josephson junction 21 via the coupling portion 19. At the junction 21, mixing is performed with an electromagnetic wave radiated from outside, and heterodyne detection is performed. FIGS. 6A to 6C show an example in which processing is performed after lamination, but the manufacturing method is not limited to this.

In order for the superconducting electromagnetic wave mixer of the present invention to actually operate as an electromagnetic wave mixer, a Josephson current value I ₁ flowing through a Josephson junction forming a local oscillation portion and a Josephson current flowing through a Josephson junction forming a receiving portion are required. It is necessary that the relationship of I ₁ > I ₂ > I ₃ be established between the current value I ₂ and the isolator current I ₃ that can flow between the local oscillator and the receiver.

In order to achieve the nonuniformity of each current value, in the case of a planar superconducting electromagnetic mixer, the width of the Josephson junctions 6 and 7 in FIG. 1C is changed (the width of the local oscillator)>
(The width of the receiving section), or a thin film may be deposited under the receiving section or the local oscillation section to change the superconducting characteristics of the upper portion. The latter method is a preferable method because each Josephson current value can be easily controlled only by changing the material of the film or changing the film forming conditions.

FIG. 1E shows an example in which the width of the local oscillator 6 is wider than the width of the receiver 7. FIGS. 1F and 5B show that a film 9 such as a MgO thin film or a ZrO ₂ thin film is deposited only under the receiving portion 7 (or 7a, 7b, 7c) to reduce the Josephson current value of the receiving portion. Here is an example of a reduced size.

As the material of the film in the latter method, it is possible to use Ag, Au, Nb, NbN, Pb, Pb-Bi, and MgO, ZrO _2, SiOx, an a-Si and other oxides. With the above method for controlling Josephson current, if the Josephson current increases, the Josephson junction functions as a local oscillator, while if the Josephson current decreases, the Josephson junction functions as a receiver. I do.

In the case of a superconducting electromagnetic mixer using a tunnel-type Josephson junction, for example, the junction area between the Josephson junctions 20 and 21 in FIGS. 6B and 6C may be made non-uniform.

In the present invention, when the superconductor constituting the oxide superconductor thin film is represented by ABCD, A is La, Ce,
Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc, Y, Bi, at least one element selected from the group consisting of B, Ca, Sr, Ba , Pb
At least one element selected from the group consisting of V, Ti, Cr,
It is desirable that one or more elements selected from the group consisting of Mn, Fe, Ni, Co, Ag, Cd, Cu, Zn, Hg, and Ru, D, be O.

More specifically, (1) 214 type _{(La 1-x M x)} 2 CuO 4- ((M = Na, Ca, Sr, Ba) (Ln, Sr, Ce) 2 CuO 4- ((Ln = Lanthanoid elements such as Nd) (Ln, Ce) ₂ CuO _4- ((Ln = lanthanoid elements such as Pr, Nd) (2) 123 type LnBa ₂ Cu ₃ O _7- ((Ln = various lanthanoid elements) and L
n substituted with various elements (3) Bi-based Bi ₂ Sr ₂ CuOy Bi ₂ Sr _2-x Ln _x CuOy Bi ₂ Sr ₂ CaCu ₂ Oy Bi ₂ Sr _3-x Ln _x Cu ₂ Oy Bi _2-x Pb _{x Sr 2 Ca 2 Cu 3 Oy} Bi 2 Sr 2 (LnCe) 2 Cu 2 Oy ( or more, Ln: various lanthanoid element) (4) Tl-based _{Tl 2 Ba 2 Ca n Cu 1} + n Oy (n = 0,1 _{, 2,3 ......) TlBa 2 Ca n} Cu 1 + n Oy (n = 0,1,2,3 ......) (5) Pb -based _{Pb 2 Sr 2 Ca 1-x} Ln x Cu 3 Oy (x = (About 0.5) (6) 223 type (LnBa) ₂ (LnCe) ₂ Cu ₃ Oy (Ln: lanthanoid element) and the like.

Further, for example, Y-Ba-Cu-O system, Bi-Sr-Ca-Cu-O
Critical temperature like Tl-Ba-Ca-Cu-O superconductor
If a material of 77K or more is used, inexpensive liquid nitrogen can be used as a refrigerant. For continuous operation of the mixer,
A small and inexpensive cryostat without a Joule-Thomson valve can be used, and the Josephson triode as an integrated mixer is effective. In the case of the above material system, the energy gap 2Δ is several tens of mV,
One order of magnitude larger than that of niobium. This means that the upper limit frequency that can be used as a mixer extends to about 10 THz, which is an order of magnitude higher than that of niobium (about 1 THz).

In addition, the superconducting material forming the local oscillation unit and the receiving unit may be formed of a plurality of materials.

Next, a mixing device using the above-described superconducting electromagnetic wave mixer of the present invention will be described.

That is, the superconducting electromagnetic wave mixing device of the present invention has a local oscillator, and a receiver for mixing the electromagnetic wave from the local oscillator and an external electromagnetic wave, and the local oscillator and the receiver are both oxidized. A superconducting electromagnetic wave mixer formed by a Josephson junction using a material superconductor, an introduction unit for introducing an external electromagnetic wave into a receiving unit of the electromagnetic wave mixer, and an intermediate frequency band electromagnetic wave obtained by mixing the electromagnetic wave mixer. A superconducting electromagnetic wave mixing device comprising an amplifier for amplification and a cooler such as a cryostat for cooling at least the electromagnetic wave mixer.

Hereinafter, if described in detail with reference to the accompanying drawings, first, as shown in FIG.
The external electromagnetic wave 32 is introduced into the receiving part of the superconducting electromagnetic wave mixer 30 by an introduction part 33 of the external electromagnetic wave 32 such as a waveguide or a horn type antenna. In addition, a bias current is supplied from an external DC power supply 34 to the local oscillator of the superconducting electromagnetic wave mixer 30 to oscillate at a desired frequency. The external electromagnetic wave 32 and the local oscillation wave are mixed to obtain an electromagnetic wave 35 in an intermediate frequency band (IF). The IF
The wave 35 is amplified by the amplifier 36, and an output 37 after heterodyne mixing can be obtained.

However, in FIG. 10A, the introduction part 33 and the amplifier 36
Although it is installed in the cooling unit 31, it is not limited to this, and it is sufficient that at least the superconducting electromagnetic wave mixer 30 is cooled in the cooler 31.

Further, in the superconducting electromagnetic wave mixing apparatus of the present invention, as shown in FIG. 10B, a preferred embodiment uses a waveguide 38 as a part for introducing an external electromagnetic wave, and the superconducting electromagnetic wave mixer 30 is provided inside the waveguide 38. It is the aspect which installed. In this embodiment, since the superconducting electromagnetic wave mixer including the local oscillation section is provided inside the waveguide, the local oscillation wave can be generated in the same closed space as the introduction section of the external electromagnetic wave, and the mixing efficiency is improved. That is, the efficiency of propagation of the electromagnetic wave to the receiving unit increases. Furthermore, the power of the local oscillation output can be reduced, and accordingly, the heat inflow due to Joule heat also decreases,
This is more preferable because not only can the advantages of the miniaturization of the element itself be fully exhibited, but also the entire device including the cooler can be reduced in power consumption and miniaturized.

Example 1 FIGS. 1A to 1D show a schematic structure and a manufacturing process of a superconducting electromagnetic wave mixer according to an example of the present invention. This superconducting electromagnetic wave mixer is of a planar type, in which a local oscillator and a receiver are connected via an insulator. Here, as the insulator, a superconducting thin film 5 which has been ion-implanted by FIB into an insulator is used.

In the process shown in FIGS.
A superconductor thin film 5 was formed thereon (FIG. 1A). As the substrate 4, an MgO single crystal substrate was used. As the superconductor thin film 5, a Bi ₂ Sr ₂ Ca ₂ Cu ₃ O ₁₀ target was used, and an Ar pressure of 1 × 10 ⁻² Torr, RF power of 200 W,
A film is formed at a substrate temperature of 100 ° C.
What was heat-processed at ° C was used. The superconductor thin film 5 was a polycrystalline film having a thickness of 0.2 μm and having crystal grains having a size of 2 to 3 μm, and became a superconductive state at a temperature of 95 K or less.

Next, patterning was performed by photolithography to form a constriction 5 'in the superconductor thin film 5 (FIG. 1B). The size of the constriction 5 ′ is 5 μm in length and 8 μ in width.
m.

Further, along the center line of the constriction 5 ', the A
r ions are implanted to a width of 0.5 μm, and a part of the superconductor thin film 5 is made into an insulator to form an insulating portion 8, thereby dividing the constriction 5 ′ into two, and joining the Josephson junctions 6 and 7.
Was formed very close, and at the same time, the superconductor thin film 5 was divided into two (FIGS. 1C and 1D). Here, the dimensions of the Josephson junctions 6 and 7 are both 5 μm in length and 3.7 to 5 in width.
3.8 μm.

The superconducting electromagnetic wave mixer manufactured in this manner is cooled down to 40K using a simple cooling device, and a bias current is applied to the Josephson junction 6 by a constant current power supply to form a local oscillation section. When the device was irradiated with electromagnetic waves as a receiver, the device operated well as a mixer for electromagnetic waves in the range of 100 GHz to 1 THz.

Further, instead of the superconductor thin film material of the present embodiment, Bi which is a superconductor thin film material in which a part of Bi of the material is replaced with lead.
A superconducting electromagnetic wave mixer produced using _2-X Pb _X Sr ₂ Ca ₂ Cu ₃ O ₁₀ and in the same manner as in the present example other than the above also operated in the same manner as in this example.

Embodiment 2 FIG. 1E shows a schematic configuration of a superconducting electromagnetic wave mixer according to a second embodiment of the present invention. The superconducting electromagnetic wave mixer shown in FIG.
The two Josephson junctions 6 and 7 are formed to have different dimensions. Here, the Josephson junction 6 has a length and width of 5 μm, and the Josephson junction 7 has a width of 2 μm.
μm and the length was 5 μm. The Josephson currents of these Josephson junctions 6 and 7 were 23 mA and 11 mA, respectively.

When the Josephson junction 6 was operated as a local oscillator and the Josephson junction 7 was operated as a receiver, an electromagnetic wave of an intermediate frequency could be taken out with a larger power than that of the first embodiment. Works as well as the ones.

Third Embodiment FIG. 1F shows a configuration of a superconducting electromagnetic wave mixer according to a third embodiment of the present invention. This mixer deposits a thin film 9 such as MgO or ZrO ₂ on the half surface on the side of the substrate 4 on which the Josephson junction 7 serving as a receiving section is formed, and then processes the Josephson junctions 6 and 7 in the same manner as in the first embodiment. Is formed.

This superconducting electromagnetic wave mixer worked well as in Example 2.

Example 4 FIGS. 2A to 2E show a schematic structure and a manufacturing process of a laminated superconducting electromagnetic wave mixer according to a fourth example of the present invention.

In the steps shown in FIGS. 2A to 2E, Y ₁ Ba ₂ Cu ₃ O _7-x (x = 0) is formed on the substrate 4 by using a cluster ion beam method.
.About.0.5) was formed (FIG. 2A). As the substrate 4, an SrTiO ₃ single crystal substrate was used. In this case, Y, BaO, and Cu were used as evaporation sources, the acceleration voltage and ionization current were 1 KV and 300 mA for each element, the substrate temperature was 500 ° C., and 1 × 10 ⁻³ Torr of oxygen was used during evaporation. Gas was introduced. The lower superconductor thin film 5a has a thickness of 0.1 μm,
It is a polycrystalline film having crystal grains of about 1 μm.
The resistance became 0 at a temperature of K or less.

Next, an MgO thin film was deposited by RF sputtering to form an insulator 8 (FIG. 2B). The film formation conditions at this time were Mg
Using an O target, in a sputtering gas of Ar: O ₂ = 1: 1, 1 × 10 ^-2 Torr, a substrate temperature of 200 ° C. and a sputtering power of 200 W
And The thickness was 0.08 μm.

Subsequently, an upper superconductor thin film 5b was formed in the same manner as the lower superconductor thin film 5a (FIG. 2C). The upper superconductor thin film 5b became zero resistance at a temperature of 81K or less.

Further, patterning was performed by photolithography to form two Josephson junctions 6 and 7 in a stacked form (FIGS. 2D and 2E). Each of the two Josephson junctions 6 and 7 has a width of 2 μm and a length of 3 μm.
m.

The superconducting electromagnetic wave mixer produced in this manner operated in the same manner as that of Example 1.

Further, instead of the superconductor thin film material of this embodiment, Y of the material Y ₁ Ba ₂ Cu ₃ O _7-x (x = 0 to 0.5) is replaced with Ho, Er, Yb, Eu, La
A superconducting electromagnetic wave mixer produced in the same manner as in this example except that a material substituted with a lanthanoid-based element such as described above also operated in the same manner as in this example.

Further, the same operation was performed when the upper superconductor thin film and the lower superconductor thin film of this example were formed using different oxide superconducting materials.

Embodiment 5 FIGS. 3A and 3B show a schematic configuration of a superconducting electromagnetic wave mixer according to a fifth embodiment of the present invention. The superconducting electromagnetic wave mixer shown in the figure is provided with six Josephson junctions constituting a local oscillation unit and a reception unit, respectively, and capacitively coupling the local oscillation unit and the reception unit via an insulator. Fig. A
Is a plan view, and FIG. 3B is a cross-sectional view taken along the line cc 'of FIG. 3A. In the manufacturing process of this superconducting electromagnetic wave mixer, first, an SrTiO ₃ single crystal substrate was used as the substrate 4, and a lower oxide superconductor thin film 5a was formed thereon. The lower oxide superconductor thin film 5a uses a cluster ion beam method, and Y: Ba: Cu = 1: 2:
It vapor-deposited so that it might be set to 1.5. The accelerating voltage and the ionization current were 1 KV and 300 mA for each element, and an oxygen gas of 1 × 10 ⁻³ Torr was introduced during vapor deposition, and the substrate temperature was 500 ° C. The lower oxide superconductor thin film 5a was a polycrystalline film having a thickness of 0.1 μm and having crystal grains of about 1 μm, and became a superconductive state at a temperature of 83K or less.

Next, an MgO thin film was deposited using an RF sputtering method to form an insulator 8. The film formation conditions at this time were as follows: a MgO target was used, the substrate temperature was 200 ° C., and the sputtering power was 200 W in a sputtering gas of Ar: O ₂ = 1: 1, 1 × 10 ⁻² Torr. The thickness was 0.08 μm.

Subsequently, an upper oxide superconductor thin film 5b was formed in the same manner as the lower oxide superconductor thin film 5a. This upper oxide superconductor thin film 5b became superconductive at a temperature of 81K or lower.

Furthermore, these oxide superconductor thin films 5a and 5b are subjected to patterning by photolithography, and the Josephson junctions 6a, 6b, 6c serving as local oscillators and the Josephson junctions 7a, 7b, 7c serving as receivers are formed. Were laminated and deposited by resistance heating to deposit Cr with a thickness of 0.01 μm and Au with a thickness of 0.05 μm to form electrodes 13, 14 and 15, 16.

When the superconducting electromagnetic wave mixer produced in this way was cooled to 40K using a simple cooling device,
It worked well as a mixer for electromagnetic waves in the region of ~ 1 THz.

At this time, the voltage required to apply the bias current to the local oscillation unit is 3 to 4 times higher than the voltage of the fourth embodiment,
More stable operation was possible.

Further, for this embodiment, the superconductor thin film material was changed to Nd.
A superconducting electromagnetic wave mixer was produced in exactly the same manner except that _1.85 Ce _0.15 CuO _y was used. This superconducting electromagnetic wave mixer
Since the critical temperature Tc of the used superconductor thin film material was 25 K, it was operated in the same manner as that of the present example when cooled to 20 K.

Embodiment 6 FIGS. 4A to 4C show a schematic configuration of a superconducting electromagnetic wave mixer according to a sixth embodiment of the present invention. The superconducting electromagnetic wave mixer shown in FIG. 1 has a Josephson junction serving as a local oscillator and a Josephson junction serving as a receiver connected by a conductor.

In the steps shown in FIGS.
Using an O single crystal substrate, a Bi ₂ Sr ₂ Ca ₂ Cu ₃ O _x superconductor thin film 5 was formed on the substrate 4 by RF magnetron sputtering. The film formation conditions at this time are: Ar: O ₂ = 1: 1, pressure 0.5 Pa, an atmosphere of Bi ₂ Sr ₂ Ca ₂ Cu ₃ O _x sintered body, a sputtering power of 100 W, a substrate temperature of 200 After the film formation, heat treatment was performed at 850 ° C. for 1 hour in an oxidizing atmosphere. 0.8μ thickness
m. This thin film was a polycrystalline thin film having crystal grains having a size of 2 to 3 μm (FIG. 4A). Next, patterning was performed by photolithography to form two Josephson junctions 6 and 7 close to each other. The size of each joint was 8 μm in length and 4 μm in width, and the distance between the two joints was 1 μm (FIG. 4B). Next, a 0.5 μm thick Ag film was formed thereon by vacuum evaporation using resistance heating, and patterning was performed by photolithography.
The conductor 17 was formed (FIG. 4C). Here, the Josephson junction utilizes a crystal grain boundary (FIG. 4D).

The electromagnetic wave mixer manufactured in this way is 100 GHz to 1 T
It works well as a heterodyne mixer in the Hz range.

At this time, the power introduced into the local oscillation unit was about one digit smaller than the power of the first embodiment.

Further, for this embodiment, the superconductor thin film material was Pb ₂ Sr ₂ Ca
A superconducting electromagnetic wave mixer produced in the same manner as in this example except that _0.5 Cu ₃ O _y was used also operated in the same manner as in this example.

Example 7 FIGS. 4A to 4C show a case where SrTiO ₃ is used as a substrate, a YBaCuO-based material is used as a superconducting material, and a cluster ion beam evaporation method is used as a method for forming a superconductor thin film 5. First, a Y ₁ Ba ₂ Cu ₃ O _7-x (x = 0.1 to 0.4) superconductor thin film 5 is formed on a substrate 4 by using a cluster ion beam evaporation method.
Was formed. The deposition conditions at this time were as follows:
Using BaO, Cu, the acceleration voltage and ionization current are 2K in Y
V, 100mA, 4KV, 200mA for BaO, 4KV, 200mA for Cu,
The substrate temperature was 600 ° C., and 1 × 10 ⁻² Torr O ₂ gas was introduced during the vapor deposition. Further, the film thickness was 0.5 μm. This thin film was a polycrystalline thin film having crystal grains of about 2 μm, and became superconductive without heat treatment (FIG. 4A). This was patterned in the same manner as in Example 6 to form two Josephson junctions 6, 7 (FIG. 4B). Further, an electrode 5 was similarly formed (FIG. 4C).

The electromagnetic mixer manufactured in this manner performed the same good operation as that of the sixth embodiment.

Embodiment 8 FIG. 5A shows a schematic structure of a superconducting electromagnetic wave mixer according to an eighth embodiment of the present invention. The superconducting electromagnetic wave mixer shown in FIG. First, the substrate 4
An MgO single crystal substrate was used as a substrate, and an oxide superconductor thin film 5 was formed thereon. The oxide superconductor thin film 5 is made of Bi ₂ S
r ₂ Ca ₂ Cu ₃ O ₁₀ target is deposited to a thickness of 0.25 μm by RF magnetron sputtering under the conditions of sputtering power 150 W, sputtering gas Ar, gas pressure 2 × 10 ⁻³ Torr, and substrate temperature 150 ° C. After that, a heat treatment at 860 ° C. was performed in an atmosphere of O ₂ 30% + N ₂ 70% to form a film. This thin film became a polycrystalline film having a particle size of about 2 μm, and became a superconductive state at a temperature of 95 K or less.

The oxide superconductor thin film 5 is patterned by photolithography, and the Josephson junctions 6a, 6b, 6c serving as local oscillators and the Josephson junctions 7a, 7 serving as receivers are formed.
Both b and 7c were formed to have a width and length of 4 μm.

Next, by resistance heating, Cr 0.01 μm, Au 0.05 μm
Laminated and deposited, the conductor 17 and the electrodes 13, 14 and 15,
16 formed.

When the superconducting electromagnetic wave mixer produced in this way was cooled to 40K using a simple cooling device,
It worked well as a mixer for electromagnetic waves in the region of ~ 1 THz.

In addition, the superconductor thin film material was
_{Tl 2 Ba 2 Ca n Cu 1} + n O y (n = 1,2,3) or _{TlBa 2 Ca n Cu 1 + n} O y
A superconducting electromagnetic wave mixer manufactured in the same manner as in the present embodiment except that (n = 1, 2, 3) was operated in the same manner as that of the present embodiment.

Ninth Embodiment FIG. 5B shows a schematic configuration of a superconducting electromagnetic wave mixer according to a ninth embodiment of the present invention. The superconducting electromagnetic wave mixer shown in the figure was manufactured by the following steps.

First, an MgO single crystal substrate was used as the substrate 4, and a ZrO ₂ thin film 9 was formed by half on the MgO single crystal substrate. Next, using RF magnetron sputtering, the target was YSZ (yttrium stabilized zirconia), and Ar: O ₂ = 1: 1,
The film was formed in a sputtering gas of 1 × 10 ⁻² Torr at a substrate temperature of 200 ° C. and a sputtering power of 150 W. Thereafter, by the same manufacturing method as in the eighth embodiment, the Josephson junctions 6a, 6b, and 6c serving as local oscillation units and the Josephson junction 7 serving as a reception unit are used.
Each of a, 7b, and 7c was formed to have a width and length of 4 μm. Here, the Josephson current value of the local oscillators 6a, 6b, 6c was 3.5 mA, and the Josephson current value of the receivers 7a, 7b, 7c was 0.7 mA. The superconducting electromagnetic wave mixer manufactured in this manner can extract an intermediate frequency electromagnetic wave having a larger power than that of the eighth embodiment,
In other respects, the operation was as good as that of the eighth embodiment.

Example 10 FIGS. 6A and 6B show an example of a manufacturing process and a structure of a superconducting electromagnetic wave mixer using a tunnel-type Josephson junction.

In the steps shown in FIGS. 6A and 6B, MgO
Using a single crystal substrate and ion beam sputtering on the substrate 4
A lower superconductor thin film 5a of Bi ₂ Sr ₂ Ca ₂ Cu ₃ O _x was formed. The film forming conditions at this time were as follows: target Bi ₂ Sr ₂ Ca ₂ Cu ₃ O sintered body, background pressure 2 × 10 ⁻⁶ Torr, Ar pressure 3 × 10 ⁻³ Torr, ion current 100 μA, acceleration voltage 7 KV, substrate At a temperature of 600 ° C., the film thickness was 0.05 μm. Next, MgO was deposited by RF sputtering.
Under conditions of a target, an Ar pressure of 0.5 Pa, a sputter power of 100 W and a substrate temperature of 150 ° C., the MgO thin film (tunnel barrier layer) 8 ′ is placed on a surface of the substrate at a pressure of 0.5 μm.
001 μm, and Bi ₂ Sr ₂ Ca ₂
An upper superconductor thin film 5b of Cu ₂ O was formed to a thickness of 0.05 μm (FIG. 6A). Next, patterning was performed by photolithography to form Josephson junctions 20 and 21 in FIG. 6B. The junction area is 10 μm × 8 for Josephson junction 20
μm, the Josephson junction 21 is 5 μm × 8 μm, and the groove is
The width of 18 was 1 μm, and the thickness of the joint 19 was 0.015 μm.

At this time, when the current-voltage characteristics between the lower thin film 5a of the Josephson junction 20 and the lower thin film of the Josephson junction 21 were measured at the liquid nitrogen temperature, the characteristics of the microbridge type Josephson junction were shown. That is, the joint 19 was a weakly-coupled Josephson junction. Josephson current is 80μ
A.

The electromagnetic wave mixer created in this way was set in a waveguide cooled with liquid nitrogen and evaluated.
It worked well as a heterodyne mixer in the region of ~ 800GHz.

Example 11 In the steps shown in FIGS. 6A and 6C, SrTiO
_{3 Using a} single crystal substrate, using a YBaCuO-based superconductor,
A case where a Christer ion beam evaporation method is used as a method for forming the superconductor thin film 5 will be described. First, YBa ₂ Cu ₃ O _7-x was formed on the substrate 4 by using a Christer ion beam evaporation method.
(X = 0.1-0.4) The lower superconductor thin film 5a was formed. The film forming conditions at this time were as follows: Y, BaO and Cu as evaporation sources.
The acceleration voltage and ionization current are 3KV in Y, 100m
A and BaO were 5 KV and 200 mA, Cu was 5 KV and 200 mA, the substrate temperature was 700 ° C., and 5 × 10 ⁻³ torr O ₂ gas was introduced during vapor deposition. The thickness of the thin film was 0.06 μm. Next, by the resistance heating method
Ag is evaporated 0.002 μm, and Z is deposited on it by RF sputtering.
rO ₂ was formed at 0.001 μm. At this time, the target is YSZ, A
The r pressure was 7 × 10 ⁻³ torr, the sputter power was 100 W, and the substrate temperature was 100 ° C. Further, the upper thin film 5 of YBaCuO is further formed thereon at a substrate temperature of 550 ° C. by the above-mentioned Christer ion beam method.
b was formed at 0.08 μm (FIG. 6A). Next, Josephson junctions 20 and 21 were formed by photolithography and focused ion implantation (FIG. 6C). The ion implantation was performed with 5 KeV Ar ions. The junction area is 12 μm × 10 μm for the Josephson junction 20 and 6 for the Josephson junction 21.
μm × 10 μm, and the width of the ion-implanted portion 22 is 0.8 μm.
m.

When the electrical characteristics of the joint 19 were measured in the same manner as in Example 10, the result was semiconductor-like. The resistivity at the temperature of liquid nitrogen was about 10 ³ Ω · cm.

The electromagnetic wave mixer thus produced performed the same good operation as in Example 10 at the liquid nitrogen temperature.

Embodiment 12 FIGS. 7A to 7E show a twelfth embodiment. First, Example 10
Y-based thin film 0.06 processes and in the same manner on the SrTiO ₃ substrate 4
[mu] m, the lower film 5a and the ZrO ₂ film made of a Ag film 0.002 .mu.m (tunnel barrier layer) 8 ', and laminated and 0.001μm in this order, and patterning was performed by photolithography (FIG. 7 A). Next, a Y-based upper thin film 5b is formed thereon.
Was formed at 0.06 μm and patterned by photolithography to form a series array of tunnel-type Josephson junctions (FIG. 7B). Then, the junction at the left end was etched using an excimer laser to form a groove 18 (FIG. 7C). FIG. 7D and FIG.
2 shows cross-sectional views at aa ′ and bb ′. 7C groove
18 had a width of 0.5 μm. When the electrical characteristics of the joint 19 were measured in the same manner as in Example 10, the resistivity was 10 ⁶ Ωcm
As described above, the electric capacitance was about 1 nF.

 FIG. 8 shows an equivalent circuit of this element.

That is, the local oscillation unit 23 and the reception unit 24 are both in a serial array of ten. By doing so, the operating voltage when a bias current flows through the local oscillator is 10
The operating voltage at the receiving unit can be increased by a factor of ten. This has advantages in stability and noise resistance when actually moving the element.

The electromagnetic wave mixer prepared in this way operated well as a heterodyne mixer in the range of 100 GHz to 800 GHz at the temperature of liquid nitrogen.

Embodiment 13 FIGS. 9A to 9D show a configuration and schematic steps of a superconducting electromagnetic mixer according to a thirteenth embodiment of the present invention. This mixer is manufactured by utilizing a step formed on a substrate to form a Josephson junction.

First, a step of 0.5 μm was formed on the MgO single crystal substrate 4 by photolithography (FIG. 9A). next,
An Er ₁ Ba ₂ Cu ₃ O _7-x (x = 0.1 to 0.4) superconductor thin film 5 was formed on the stepped substrate 4 using RF magnetron sputtering. Film forming conditions, Er ₁ as a target in an Ar gas pressure of 7 × 10 ^-3 in torr of the atmosphere _{Ba 2 Cu 3 O 7-x} (x = 0.1~0.
4) Using sintered body, sputter power 150W, substrate temperature 100 ℃
After the film formation, heat treatment was performed at 900 ° C. for 1 hour in an oxidizing atmosphere. The thickness was 0.5 μm. This thin film is 4-6
It was a polycrystalline thin film having crystal grains having a size of μm (No. 9
Figure B). Next, patterning was performed in the same manner as in Example 6, and two Josephson junctions 6 and 7 were formed. However, the size of the joint was 16 μm in length and 8 μm in width (FIG. 9C). Further, an electrode 17 was formed in the same manner as in Example 6 (FIG. 9D).

The electromagnetic wave mixer manufactured in this way is described in Example 6.
The same good operation as described above was performed.

Embodiment 14 FIG. 10A is a plan view showing a schematic configuration of a superconducting electromagnetic wave mixing apparatus according to a fourteenth embodiment of the present invention.

In the figure, reference numeral 30 denotes a superconducting electromagnetic wave mixer manufactured according to any one of Examples 1 to 13, 31 denotes a cryostat for cooling the superconducting electromagnetic wave mixer 30, and 33 denotes an external electromagnetic wave 32 of the superconducting electromagnetic wave mixer 30. An introduction unit 33 for introducing the signal to the reception unit. The introduction unit 33 is configured by a waveguide, a horn-type antenna, or the like. Reference numeral 34 denotes a DC power supply for supplying a bias current to the local oscillator of the superconducting electromagnetic mixer 30, and 36 denotes a superconducting electromagnetic mixer 30.
This is an amplifier for amplifying the signal 35 output from the controller and sending it out as a heterodyne output 37.

Here, the superconducting electromagnetic wave mixer 30 and the introduction section 33
And the amplifier 36 is installed in the cryostat 31, and only the DC power supply 34 is installed outside the cryostat 31, but this is not limiting, and at least the superconducting electromagnetic wave mixer 30 may be cooled in the cryostat 31. .

When a bias current is supplied from the DC power supply 34 to the local oscillator, the superconducting electromagnetic wave mixer 30 in FIG. 10A oscillates at a frequency corresponding to the bias current. This local oscillation output is supplied to the receiving section of the superconducting electromagnetic wave mixer 30. Thereby, in the receiving unit, the external electromagnetic wave 32 introduced from the introducing unit 33 and the local oscillation output are mixed, and an intermediate frequency (Frequency of a difference between the frequency of the external electromagnetic wave 32 and the frequency of the local oscillation output) IF) electromagnetic wave output 35 is obtained. The amplifier 36 amplifies the IF wave output 35 to generate a heterodyne mixed output 37.

Embodiment 15 FIG. 10B is a side sectional view showing a schematic configuration of a superconducting electromagnetic wave mixing apparatus according to a fifteenth embodiment of the present invention.

As shown in the figure, the superconducting electromagnetic wave mixer 30 manufactured by the method of the first embodiment is installed at one end of a rectangular waveguide 38 having a cross section of 1 mm × 0.5 mm in inner diameter, and this end is filled with He gas. Cold head of circulating chiller (cryostat) 31
Fixed to 31 'and cooled to 15K. The junction between the other end of the waveguide 38 and the waveguide 38 'outside the cryostat 31 is separated by a Teflon plate 39 having a thickness of 0.2 mm.
The inside of 1 was kept vacuum. Further, a DC power supply 34 for supplying a bias current to the local oscillator of the superconducting electromagnetic wave mixer 30 is provided outside the cryostat 31.

In this configuration, an electromagnetic wave of 200 GHz is introduced into the waveguide 38 using a gun oscillator and a doubler (not shown), and a bias current of 15 to 30 mA flows. As a result, mixing at a frequency of 1 to 0.7 GHz (intermediate frequency) is performed. Output 35 was obtained.
This mixing output 35 was amplified by an amplifier 36 composed of a GaAs FET amplifier, and could be taken out of the cryostat 31 as an intermediate frequency output 37.

[Effects of the Invention] As described above, the electromagnetic wave mixer of the present invention is different from the conventional heterodyne detection device in that both the local oscillation unit and the heterodyne mixer unit are provided in one device, so that the This eliminates the need for a local oscillator and a waveguide for connecting the local oscillator and the receiving unit, and the mixing apparatus using such an electromagnetic wave mixer can be made very small. In addition, when an external local oscillator was used, a local oscillation output of 10 nW to 100 nW was required, but in the device according to the present invention, the output was about 0.1 nW to 1 nW, and power consumption was significantly reduced.

Furthermore, according to the present invention, it is possible to manufacture an electromagnetic wave mixer that operates even at a relatively high temperature (around the temperature of liquid nitrogen) by using an oxide superconductor having a relatively high critical temperature Tc, and a small-sized compact cooling device is simplified. And a low-cost system could be constructed.

Furthermore, the mixer of the present invention could be used for a higher frequency band than a conventional mixer using Nb or the like. That is, the upper limit of the usable frequency was about 700 GHz in the mixer using Nb, whereas it was about 10 THz in the Y-based mixer of the present invention. This means that when the mixer according to the present invention is used, the information transmission speed is 10 times or more and the bandwidth is about 10 times that of the conventional mixer, and the information that can be transmitted in the same time increases to nearly two digits. Thus, the reason why the mixer of the present invention can be used in a higher frequency band is as follows.
It is considered that the present invention uses an oxide superconductor having a larger band gap than Nb or the like. For example, while the energy gap of Nb is about 3 meV, the Y-based oxide superconductor is one order of magnitude larger.

Further, according to the present invention, the local oscillation section and the reception section could be successfully coupled due to the property of the oxide superconductor in which the electrical characteristics greatly changed due to the composition change. Furthermore, by making it a tunnel type Josephson junction,
It became easy to obtain a desired Josephson current value.
As described above, it has become possible to produce an integrated superconducting electromagnetic wave mixer with good yield.

Further, it is preferable that the local oscillation unit and the reception unit of the mixer be connected by an insulator or a conductor, rather than by a gap or space. For example, when the local oscillating unit and the receiving unit are coupled by an insulator, the mixing efficiency (the propagation efficiency of the electromagnetic wave from the local oscillating unit) is higher than when the coupling is performed by vacuum. Further, when the connection is made by a conductor instead of an insulator, the mixing efficiency is further improved.

This is because, even when coupled by an insulator, the dielectric constant of the insulator is approximately one order of magnitude higher than the vacuum permittivity ε ₀ , and the electric capacity interposed between the local oscillator and the receiver is larger than that in the gap. It is believed that the bond between the two parts is stronger. Further, it is considered that when the bonding is performed by a conductor instead of the insulator, the bonding is further strengthened, so that the mixing efficiency is further improved.

At a frequency of several hundred GHz or more, the grain boundary type Josephson coupling, which is a weak coupling, was preferable to the tunnel type Josephson junction in terms of the operating frequency and the mixing efficiency. This is desirable from the viewpoint of fully utilizing the advantages of using the high-temperature oxide superconductor applicable to the high frequency band described above.

In addition, by using a plurality of Josephson junctions constituting the local oscillation section, the voltage applied to the local oscillation section could be made larger, and the local oscillation frequency could be made more stable. .

Further, by using a plurality of Josephson junctions constituting the receiving unit, the detection efficiency could be improved.

[Brief description of the drawings]

1A, 1B, and 1C are plan views schematically showing a structure and a manufacturing process of a superconducting electromagnetic wave mixer according to one embodiment of the present invention, and FIG. 1D is a view taken along aa 'of FIG. 1C. FIG. 1E is a plan view showing a schematic structure of a superconducting electromagnetic wave mixer according to a second embodiment of the present invention. FIG. 1F is a superconducting electromagnetic wave mixer according to a third embodiment of the present invention. 2A, 2B, 2C, and 2D are plan views showing a schematic structure and a manufacturing process of a superconducting electromagnetic wave mixer according to a fourth embodiment of the present invention. 2E is a cross-sectional view taken along the line bb 'of FIG. 2D, and FIGS. 3A and 3B are views showing a schematic configuration of a superconducting electromagnetic wave mixer according to a fifth embodiment of the present invention. 4A is a plan view, FIG. 4B is a sectional view taken along the line cc 'of FIG. 4A, and FIGS. 4A, 4B, and 4C are superconducting materials according to the sixth and seventh embodiments of the present invention. Electromagnetic waves FIG. 4D is an enlarged sectional view showing the structure of the Josephson junction of the superconducting electromagnetic wave mixer, and FIG. 5A is an eighth embodiment of the present invention. FIG. 5B is a cross-sectional view showing a schematic structure of the superconducting electromagnetic wave mixer according to the ninth embodiment of the present invention. FIG. C is a cross-sectional view showing a schematic manufacturing process of the superconducting electromagnetic wave mixer according to the tenth and eleventh embodiments of the present invention, and FIGS. 7A, B, and C relate to the twelfth embodiment of the present invention. FIG. 7D is a cross-sectional view of aa ′ in FIG. 7C, FIG. 7E is a cross-sectional view of bb ′ in FIG. 7C, FIG. E is an equivalent circuit diagram of the superconducting electromagnetic wave mixer, and FIGS. 9A, 9B, 9C, and 9D are perspective views showing a schematic manufacturing process of the superconducting electromagnetic wave mixer according to the thirteenth embodiment of the present invention. FIG. 10A is a plan view showing a schematic configuration of a superconducting electromagnetic wave mixing device according to a fourteenth embodiment of the present invention. FIG. 10B is a superconducting electromagnetic wave mixing device according to a fifteenth embodiment of the present invention. FIG. 11A is a perspective view showing a schematic structure of a conventional Josephson triode, and FIG. 11B is an electrical diagram of the Josephson triode shown in FIG. 11A. It is an equivalent circuit diagram. 4: substrate 5, 5a, 5b: oxide superconductor thin film 5 ': constriction 8: insulator, 8': insulating layer (tunnel barrier layer) 6, 6a, 6b, 6c: grain boundary type Josephson junction ( Local oscillation part) 7,7a, 7b, 7c: Josephson junction (reception part) of crystal grain boundary type 9: Josephson current control film 13,14,15,16: Electrode 17: Conductor 18: Groove 19: Coupling (bottom of groove) 20,21: Tunnel type Josephson junction 23: Local oscillator 24: Receiver 30: Superconducting electromagnetic wave mixer 31: Cooler 32: External electromagnetic wave 33: Introducing part 36: Amplifier 37: Heterodyne mixing output

──────────────────────────────────────────────────続 き Continuing on the front page (31) Priority claim number Japanese Patent Application No. Hei 1-274925 (32) Priority date Hei 1 (1989) October 24 (33) Priority claim country Japan (JP) (72) Inventor Norio Kaneko 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (56) References JP-A-59-210678 (JP, A) JP-A-63-250878 (JP, A) JP-A-1- 129481 (JP, A) JP-A-63-275190 (JP, A) IEICE Technical Report, SC E87-9, (1987-5-20), Vol. 29pp49-54 Transactions of the Institute of Electronics, Information and Communication Engineers, '89 / 5, (1986-5-25), Vol. J69-C, No. 5, pp. 636-643 JAPANESE JOURNAL OF APPLIED PHYSICS, Vol. 27, No. 6, June, 1988 pp. L1110-1112 (58) Field surveyed (Int.Cl. ⁶ , DB name) H01L 39/00 H01L 39/22 H01L 39/24 H04B 1/26

Claims (8)

(57) [Claims] 1. A superconducting electromagnetic mixer comprising: a local oscillator; and a receiver electrically coupled to the local oscillator and mixing an electromagnetic wave from the local oscillator with an external electromagnetic wave. The local oscillator and the receiver are both formed by a Josephson junction using an oxide superconductor, and the local oscillator and the receiver are capacitively or inductively coupled via an insulator. A superconducting electromagnetic mixer. 2. The superconducting electromagnetic mixer according to claim 1, wherein said Josephson junction is a Josephson junction using a crystal grain boundary of an oxide superconducting thin film. 3. The superconducting electromagnetic mixer according to claim 1, wherein said Josephson junction is a tunnel-type Josephson junction. 4. The superconducting electromagnetic mixer according to claim 2, wherein a thin film for controlling a Josephson current value is formed under the local oscillation section or the reception section. 5. The superconducting electromagnetic wave mixer according to claim 1, wherein a width of a Josephson junction of said local oscillator is wider than a width of a Josephson junction of said receiver. 6. A superconducting electromagnetic wave mixer having a local oscillator, and a receiver electrically coupled to the local oscillator and mixing an electromagnetic wave from the local oscillator with an external electromagnetic wave. The local oscillation section and the reception section are both formed by a Josephson junction using an oxide superconductor, and the local oscillation section and the reception section form a Josephson junction serving as the local oscillation section and the reception section. A superconducting electromagnetic mixer characterized in that the superconducting electromagnetic wave mixer is combined with a conductive material different from the material for the superconducting material. 7. A local oscillation section and a receiving section electrically coupled to the local oscillation section for mixing an electromagnetic wave from the local oscillation section with an external electromagnetic wave, wherein the local oscillation section and the receiving section are connected to each other. A superconducting electromagnetic wave mixer, both formed by a Josephson junction using an oxide superconductor, wherein the local oscillator and the receiver are capacitively or inductively coupled via an insulator; and An introduction unit that introduces an external electromagnetic wave into the receiving unit, an amplifier that amplifies an electromagnetic wave in an intermediate frequency band obtained by a mixing action in the electromagnetic wave mixer, and a cooler that cools at least the electromagnetic wave mixer. Superconducting electromagnetic wave mixing device. 8. A method of manufacturing a superconducting electromagnetic wave mixer having a local oscillator, and a receiver electrically coupled to the local oscillator and mixing an electromagnetic wave from the local oscillator and an external electromagnetic wave. Wherein the local oscillator and the receiver are formed by a Josephson junction sharing at least one oxide superconductor layer;
By implanting ions into a region of the shared oxide superconductor layer between a Josephson junction serving as a local oscillator and a Josephson junction serving as a receiver, the conduction characteristics of the region are changed, and A method for manufacturing a superconducting electromagnetic wave mixer, comprising separating an oscillating unit and a receiving unit.