JP2014212427A - Oscillator, transmitting device, rectifier, rectifying device, receiver, receiving device and transceiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oscillator, a transmitting device, a rectifier, a rectifying device, a receiver, a receiving device and a transceiver capable of being miniaturized.SOLUTION: An oscillator comprises: an oscillation part whose threshold magnetic field for starting the oscillation, is more than zero; a conductor connected to the oscillation part in series; and a magnetic field application means for applying a first magnetic field to the oscillation part. The oscillation part and the conductor are arranged so that a second magnetic field generated by the current flowing into the conductor, is applied to the oscillation part, and the first magnetic field is smaller than the threshold magnetic field and a composite magnetic field of the first magnetic field and the second magnetic field is larger than the threshold magnetic field.

Description

  The present invention relates to an oscillator, a transmission device, a rectifier, a rectification device, a receiver, a reception device, and a transmission / reception device.

  In recent years, microwave oscillation and reception using magnetoresistive elements have been studied. For example, Patent Document 1 discloses that the oscillation frequency can be changed by applying an external magnetic field to a CCP-CPP (Current Confined Path-Current Perpendicular to Plane) oscillation element.

JP 2007-124340 A

  However, in the prior art, the magnetic field necessary for oscillation and microwave reception has been generated by external wiring or an external coil or magnet not connected to the magnetoresistive effect element. For example, in Patent Document 1, a magnetic field is applied to a magnetoresistive effect element, which is an oscillation element, by an external magnet and an external wiring. Therefore, in the prior art, since the number of parts increases and the dimensions of the oscillator and detector increase, it is difficult to reduce the size.

  In order to reduce the size, it is conceivable to use an external magnet that generates a stronger magnetic field and to use the magnet with a smaller size. However, drastically improving the strength of the magnetic field generated by a magnet requires research and development from the basis of material design, and it is difficult to realize it immediately. Therefore, in order to reduce the size of the oscillator, it is necessary to reduce the size of the existing magnet and to compensate for the decrease in the magnetic field strength. Further, in the prior art, electric power for flowing current to the external wiring is necessary, and energy saving has been demanded.

  Therefore, the present invention has been made in view of the above, and an object thereof is to provide an oscillator, a transmission device, a rectifier, a rectification device, a receiver, and a reception device that can be reduced in size and power consumption. It is another object of the present invention to provide a transmission / reception apparatus that can be reduced in size and power consumption by providing such an oscillator and a receiver.

  To achieve the above object, in the oscillator according to the first aspect of the present invention, an oscillation unit having a threshold magnetic field for starting oscillation larger than zero, a conductor connected in series to the oscillation unit, and the oscillation An oscillator having a magnetic field applying means for applying a first magnetic field to the part, wherein the oscillating part and the conductor have a second magnetic field generated by a current flowing through the conductor applied to the oscillating part, The first magnetic field is smaller than the threshold magnetic field, and the combined magnetic field of the first magnetic field and the second magnetic field is larger than the threshold magnetic field. This makes it possible to reduce the size of the oscillator.

  Furthermore, in the oscillator according to the second aspect of the present invention, the threshold magnetic field is larger than the geomagnetism.

  Furthermore, in the oscillator according to the third aspect of the present invention, in the first aspect or the second aspect, it is preferable that the oscillation unit is a magnetoresistive effect element.

  A transmission device according to a fourth aspect of the present invention includes the oscillator according to any one of the first aspect to the third aspect, and an electric circuit that is galvanically insulated from the oscillator, Electromagnetic coupling means for electromagnetically coupling the conductor and the electric circuit is provided.

  Moreover, in the rectifier according to the fifth aspect of the present invention, a rectifying unit having a threshold magnetic field larger than zero for generating a rectifying action, a conductor connected in series to the rectifying unit, and a first rectifier unit A rectifier having a magnetic field applying means for applying a magnetic field, wherein the rectifying unit and the conductor are applied with a second magnetic field generated by a current flowing through the conductor, and the first magnetic field is applied to the rectifying unit. It is smaller than a threshold magnetic field, and it is arrange | positioned so that the synthetic | combination magnetic field of a said 1st magnetic field and a said 2nd magnetic field may become larger than the said threshold magnetic field.

  Furthermore, in the rectifier according to the sixth aspect of the present invention, the threshold magnetic field is larger than the geomagnetism.

  Furthermore, in the rectifier according to the seventh aspect of the present invention, in the fifth aspect or the sixth aspect, it is preferable that the rectifier is a magnetoresistive element.

  A rectifier according to an eighth aspect of the present invention includes the rectifier according to any one of the fifth to seventh aspects, and an electric circuit that is galvanically insulated from the rectifier, and the conductor Electromagnetic coupling means for electromagnetically coupling the electric circuit is provided.

  A receiver according to a ninth aspect of the present invention is characterized in that the rectifier according to any one of the fifth aspect to the seventh aspect is provided for signal reception.

  A receiving device according to a tenth aspect of the present invention includes the receiver according to the ninth aspect and an electric circuit that is galvanically insulated from the receiver, and the conductor and the electric circuit are electromagnetically coupled. An electromagnetic coupling means is provided.

  The transceiver apparatus according to the eleventh aspect of the present invention includes the oscillator according to any one of the first aspect to the third aspect, and the receiver according to the ninth aspect, and the conductor of the oscillator The conductor of the receiver is electromagnetically coupled to perform wireless communication or wireless power transmission.

  The present invention has been made in view of the above problems, and can provide an oscillator, a transmission device, a rectifier, a rectification device, a receiver, a reception device, and a transmission / reception device that can be miniaturized.

1 is a schematic diagram of an oscillator according to Embodiment 1 of the present invention. It is a figure which shows the structural example of the magnetoresistive effect element which concerns on embodiment of this invention. It is a figure which shows the peripheral circuit of the oscillator which concerns on Embodiment 1 of this invention. It is a schematic diagram of the oscillator according to Embodiment 2 of the present invention. It is a schematic diagram of the oscillator concerning Embodiment 3 of the present invention. It is a schematic diagram of the oscillator which concerns on Embodiment 4 of this invention. FIG. 10 is a schematic diagram of an oscillator related to embodiment 5 of this invention. It is a figure which shows the peripheral circuit of the rectifier which concerns on Embodiment 5 of this invention. It is a circuit diagram of the transmitter which concerns on Embodiment 8 of this invention. It is a figure which shows the transmission / reception apparatus in Embodiment 11 of this invention.

  Hereinafter, an example of an embodiment for carrying out the present invention will be described with reference to the drawings. The following description exemplifies a part of the embodiments of the present invention, and the present invention is not limited to these embodiments, so long as the form has the technical idea of the present invention. It is included in the scope of the present invention. Each configuration in each embodiment, a combination thereof, and the like are examples, and the addition, omission, replacement, and other changes of the configuration can be made without departing from the spirit of the present invention.

(Embodiment 1)
FIG. 1 is a diagram illustrating an oscillator 100 according to the first embodiment. The oscillator 100 according to the first embodiment includes an oscillating unit 101, a conductor 103 connected in series to the oscillating unit 101, and two magnets 102. The conductor 103 includes a conductor 103a that causes the direct current I to flow into the oscillation unit 101 and a conductor 103b that causes the direct current I to flow out. Incidentally, although two magnets 102 are illustrated here, it is sufficient that even one magnetic field can be applied to the oscillation unit 101.

  However, it is preferable to arrange two magnets 102 rather than one because the bias of the magnetic field applied to the oscillation unit 101 is reduced. The magnet may be a hard bias film formed of a magnetic metal such as cobalt, iron, nickel, or chromium and an alloy thereof, or an alloy in which boron is mixed into the magnetic alloy.

Magnets 102 as a first magnetic field, are arranged to apply a magnetic field H _m to the oscillation portion 101. Field H _m is a threshold magnetic field less than the required for the oscillation unit 101 oscillates. Here, the threshold magnetic field is the minimum magnetic field required for the oscillation unit 101 to oscillate when the direct current I is supplied to the oscillation unit 101.

  In order to cause the oscillation unit 101 to oscillate using the oscillation unit having a threshold magnetic field greater than zero, it is necessary to apply a magnetic field greater than zero together with the direct current I to the oscillation unit 101. When the oscillating unit 101 that does not oscillate only by the direct current I is used, a magnetic field greater than the geomagnetism is applied. Incidentally, the geomagnetism here indicates the earth magnetism acting on the oscillator, and for example, the earth magnetism on the earth's surface is 37 A / m as a guide.

When the direct current I is supplied to the oscillator 100, the second magnetic field H is generated by the direct current I flowing through the conductor 103. The conductor 103 is disposed so that the combined magnetic field of the first magnetic field _Hm and the second magnetic field H is larger than the threshold magnetic field. The oscillation unit 101 oscillates when a direct current I and a synthetic magnetic field are applied.

  If the applied magnetic field intensity is adjusted by changing the position of the magnet 102, the oscillation frequency of the oscillation unit 101 can be changed.

  The magnetic field applying means for applying the first magnetic field is not limited to a magnet, and for example, an external wiring, an external coil, or an electromagnet can be used.

  Since the conductor 103 can be disposed in the very vicinity of the oscillation unit 101, a strong magnetic field can be applied to the oscillation unit 101. Therefore, since the magnetic field applied to the oscillation unit 101 from an external magnetic field application mechanism such as a magnet can be reduced, the external magnetic field application mechanism can be reduced in size. In addition, since the external current for applying the magnetic field used in the prior art can be eliminated or reduced, energy saving can be achieved.

  For the oscillation unit 101, for example, a magnetoresistive effect element can be used.

  FIG. 2 shows a configuration example of the magnetoresistive effect element. The magnetoresistive effect element 205 includes a pinned layer 206a that is a magnetic layer, a free layer 206b that is a magnetic layer, and a spacer layer 207 disposed therebetween. Here, the magnetization direction of the pinned layer 206a is fixed, and the arrow 209a indicates the pinned direction of the magnetization of the pinned layer 206a. The magnetization direction of the free layer 206b is in the direction of the effective magnetic field before the current is applied, and the arrow 209b indicates the direction of the effective magnetic field. The effective magnetic field is the sum of an anisotropic magnetic field, an exchange magnetic field, an external magnetic field, and a demagnetizing field generated in the free layer 206b. In FIG. 2, the magnetization direction of the pinned layer 206a and the effective magnetic field direction of the free layer 206b are opposite to each other, but the directions are not limited to this.

  The magnetoresistive effect element 205 is not particularly limited. For example, a GMR element, a TMR element, or a magnetoresistive effect element in which a current confinement path exists in the insulating layer of the spacer layer 207 can be used.

  When a GMR element is used for the magnetoresistive effect element 205, the spacer layer 207 can be made of a nonmagnetic metal such as copper, for example. As a material of the free layer 206b and the pinned layer 206a of the GMR element, for example, a magnetic metal such as cobalt, iron, nickel, and chromium and an alloy thereof, or an alloy in which boron is mixed into the magnetic alloy can be used. In order to fix the magnetization of the pinned layer 206a, exchange coupling with an antiferromagnetic layer made of an alloy such as iridium, iron, platinum, manganese, or a magnetic metal multilayer film (for example, a multilayer film of cobalt iron-ruthenium-cobalt iron) is used. Antiferromagnetic coupling can be used. The thickness of each layer is preferably about 0.1 to 50 nm. Since the spacer layer 207 is made of metal, the GMR element has a resistance value lower than that of other magnetoresistive elements. For this reason, when connecting the magnetoresistive effect element 205 to a low impedance circuit, it is preferable from the viewpoint of impedance matching.

  When a TMR element is used as the magnetoresistive effect element 205, the spacer layer 207 can be an insulating layer of alumina or magnesium oxide (MgO), for example. As a material of the free layer 206b and the pinned layer 206a of the TMR element, for example, a magnetic metal such as cobalt, iron, nickel, and chromium and an alloy thereof, or an alloy mixed with boron as a magnetic alloy can be used. In order to fix the magnetization of the pinned layer 206a, exchange coupling with an antiferromagnetic layer made of an alloy such as iridium, iron, platinum, manganese, or a magnetic metal multilayer film (for example, a multilayer film of cobalt iron-ruthenium-cobalt iron) is used. Antiferromagnetic coupling can be used. The thickness of each layer is preferably about 0.1 to 50 nm. Since the spacer layer 207 is made of an insulating layer, the TMR element has a higher resistance value than other magnetoresistive elements. For this reason, it is preferable from the viewpoint of impedance matching when the magnetoresistive effect element 205 is connected to a high impedance circuit.

Further, when a magnetoresistive effect element having a current confinement path in the insulating layer of the spacer layer 207 is used as the magnetoresistive effect element 205, the insulating layer of the spacer layer 207 is made of Al ₂ O ₃ or the like. For the current confinement path of the spacer layer 207, for example, a nonmagnetic metal such as copper, a magnetic metal such as cobalt, iron, nickel, or chromium and an alloy thereof, or a magnetic metal obtained by mixing boron into the magnetic alloy can be used. For the magnetization free layer and the magnetization fixed layer of the magnetoresistive effect element 205, for example, a magnetic metal such as cobalt, iron, nickel, and chromium and an alloy thereof, or an alloy in which boron is mixed into the magnetic alloy can be used. In order to fix the magnetization of the pinned layer 206a, exchange coupling with an antiferromagnetic layer made of an alloy such as iridium, iron, platinum, manganese, or a magnetic metal multilayer film (for example, a multilayer film of cobalt iron-ruthenium-cobalt iron) is used. Antiferromagnetic coupling can be used. The thickness of each layer is preferably about 0.1 to 50 nm. The magnetoresistive effect element 205 has a current confinement path, and the current density can be increased by the current confinement path. For this reason, the input current to the element can be reduced as compared with other magnetoresistive elements. By using the magnetoresistive effect element 205 for the oscillation unit 101, a circuit with reduced power consumption can be obtained.

  The self-excited oscillation of the magnetoresistive effect element 205 according to this embodiment will be described. Here, self-excited oscillation is a phenomenon in which electrical vibration is induced by a non-vibrating direct current. When a direct current I is passed through the magnetoresistive effect element 205, conduction electrons 208 flow in the opposite direction of the direct current I, that is, from the pinned layer 206a to the free layer 206b via the spacer layer 207. In the pinned layer 206a magnetized in the direction of the arrow 209a, the spin of the conduction electron 208 is polarized in the direction of the arrow 209a. An arrow 209 c represents the spin direction of the conduction electron 208. The spin-polarized electrons 208 flow into the free layer 206b through the spacer layer 207, thereby transferring magnetization and angular momentum of the free layer 206b. As a result, the action of tilting the magnetization direction of the free layer 206b from the direction of the arrow 209b indicating the direction of the effective magnetic field works. On the other hand, a damping action is performed to stabilize the magnetization direction of the free layer 206b in the direction of the arrow 209b indicating the direction of the effective magnetic field. Therefore, these two effects are balanced, and the magnetization direction of the free layer precesses around the direction of the effective magnetic field. This precession is expressed as a movement of an arrow 209d indicating the magnetization direction of the free layer around an arrow 209b indicating the direction of the effective magnetic field, and a locus of the precession indicated by the arrow 209d is indicated by a one-dot chain line 209e. Since the magnetization direction of the free layer changes at a high frequency with respect to the magnetization direction of the pinned layer, the resistance value also varies due to the magnetoresistive effect in which the resistance changes depending on the relative angle between the magnetization direction of the free layer and the magnetization direction of the pinned layer Changes at high frequencies. Since the resistance value changes at a high frequency with respect to the direct current I, a voltage that oscillates at a high frequency of about 100 MHz to 1 THz is generated. The direction of the effective magnetic field not only has an angle of 180 degrees opposite to the magnetization direction of the pinned layer 206a, but also an angle such as 0 degrees, 45 degrees, 90 degrees, or 135 degrees that is the same direction. Can have.

  The applied magnetic field and the oscillation frequency are approximately proportional. Therefore, it is desirable that the external magnetic field is large in order to generate high-frequency oscillation.

  FIG. 3 is a diagram illustrating an example of a peripheral circuit for using the oscillator 100 according to the first embodiment. The peripheral circuit 300 includes a direct current source 302, a load 304, an inductor La, and a capacitor Ca. The inductor La can prevent the high frequency output generated by the oscillator 100 from flowing into the direct current source 302, and the capacitor Ca can prevent the direct current from flowing into the load 304.

  When a direct current is supplied from the direct current source 302 to the oscillator 100, the oscillator 100 outputs a high frequency. The high-frequency signal mainly passes through the capacitor Ca having a smaller impedance than the inductor La, and is detected by the load 304.

In the following description of the embodiments, the peripheral circuit 300 is omitted.

(Embodiment 2)
In the above, the form which applies the magnetic field which the electric current supplied to an oscillation part generate | occur | produces to the oscillation part was demonstrated. In the second embodiment, a means for increasing the current is used as another means for increasing the magnetic field. However, since the current here cannot exceed the withstand current of the oscillation unit, in Embodiment 2, the magnetic field applied to the oscillation unit is increased without increasing the current supplied to the oscillation unit.

  FIG. 4 is a schematic diagram according to the second embodiment. An oscillator 400 according to the second embodiment includes an oscillating unit 101, conductors 103a and 103b connected in series to the oscillating unit 101, two magnets 102, and a current amplifying unit 401 that is a current amplifying unit. The current amplifying unit 401 has an input end and an output end, amplifies the current input from the input end, and outputs the amplified current to the output end. The oscillation unit 101 is connected in series to the input end of the current amplification unit 401, and the conductor 103 b is connected in series to the output end of the current amplification unit 401.

  Although two magnets 102 are illustrated here, the number of the magnets 102 may be one. However, it is preferable to arrange two magnets because the bias of the magnetic field applied to the oscillation unit 101 is reduced. The magnet may be a hard bias film made of a magnetic metal such as cobalt, iron, nickel, or chromium and an alloy thereof, or an alloy in which boron is mixed into the magnetic alloy.

Magnets 102 as a first magnetic field, are arranged to apply a magnetic field H _m to the oscillation portion 101. Field H _m is a threshold magnetic field less than the required for the oscillation unit 101 oscillates.

When a DC current I to the oscillation unit 101, current amplifier 401 generates an amplified current _{I A.} Conductor 103b generates a second magnetic field H in the position of the oscillator 101 by amplifying the current _{I A} flows. The conductor 103b is arranged so that the combined magnetic field of the first magnetic field _Hm and the second magnetic field H is larger than the threshold magnetic field.

  By changing the position of the magnet 102, the applied magnetic field intensity can be adjusted, and the oscillation frequency of the oscillation unit 101 can be changed.

  The magnetic field applying means for applying the first magnetic field is not limited to a magnet, and for example, an external wiring, an external coil, or an electromagnet can be used.

  A transistor, a commercially available chip-shaped amplifier, an amplifier circuit, or the like can be used for the current amplifier 401, but is not limited thereto.

  Since the conductor 103 can be disposed in the very vicinity of the oscillation unit 101, a strong magnetic field can be applied to the oscillation unit 101. Accordingly, it is not necessary to increase the magnetic field from an external magnetic field application mechanism such as a magnet, and the magnetic field application mechanism can be downsized. In other words, this configuration enables the size of the entire oscillator to be reduced.

  In the second embodiment, since a stronger magnetic field can be applied to the oscillation unit 101, oscillation at a higher frequency can be obtained. The oscillator 400 is configured such that the current flowing through the conductor 103b is larger than the current flowing through the oscillation unit 101. Therefore, since a large current does not flow through the oscillation unit 101, the oscillation unit 101 can be protected from an overcurrent.

  The arrangement of the current amplification means is not limited to the arrangement in which the oscillation unit 101 and the current amplification means are in series as shown in the second embodiment. Any structure may be used as long as the current flowing through the conductor 103b is larger than the current flowing through the oscillation unit 101. For example, an arrangement in which the oscillation unit 101 and the current amplifying means are in parallel can be used.

(Embodiment 3)
A third embodiment in which a magnetic field can be applied more efficiently by using a loop for a conductor that applies a magnetic field to the oscillation unit 101 will be described.

  FIG. 5 is a schematic diagram according to the third embodiment. An oscillator 500 according to the third embodiment includes an oscillating unit 101, conductors 103 a and 103 b connected in series to the oscillating unit 101, and a magnet 102. The conductor 103a has a loop portion 501 that is a magnetic field application portion.

  It is preferable to arrange two magnets 102 rather than one because the bias of the magnetic field applied to the oscillation unit 101 is reduced. The magnet may be a hard bias film formed of a magnetic metal such as cobalt, iron, nickel, or chromium and an alloy thereof, or an alloy in which boron is mixed into the magnetic alloy.

Magnets 102 as a first magnetic field, are arranged to apply a magnetic field H _m to the oscillation portion 101. This magnetic field H _m is smaller than a threshold magnetic field required for the oscillation unit 101 to oscillate.

When the direct current I is passed through the oscillation unit 101, the loop unit 501 generates the second magnetic field H at the position of the oscillation unit 101. The loop unit 501 is arranged so that the combined magnetic field of the first magnetic field _Hm and the second magnetic field H is larger than the threshold magnetic field.

For example, the oscillation unit 101 is arranged at the center of the loop unit 501, and the loop unit 501 has a shape with an n-turn radius r. The direction of the first magnetic field H is approximately the direction of the current flowing through the oscillation unit 101. The magnitude of the first magnetic field H [A / m] can be obtained by the following equation (1) according to Bio-Savart's law.
H = nI / 2r (1)
Here, I [A] is a direct current flowing through the loop portion 501, r [m] is the radius of the loop portion 501, and n is the number of turns (number of turns) of the loop portion 501. Although the loop portion 501 in FIG. 5 has four turns, the number of turns of the loop portion 501 is not limited to four turns. The first magnetic field H can be adjusted by the number of turns n of the loop portion 501, the direct current I, or the radius r of the loop portion 501. Further, the application direction of the first magnetic field H penetrating the oscillation unit 101 can be adjusted in the reverse direction by reversely winding the loop unit 501.

  Since the loop unit 501 can be disposed in the very vicinity of the oscillation unit 101, a stronger magnetic field can be applied to the oscillation unit 101 by reducing the radius r as shown in the equation (1). Therefore, it is not necessary to increase the magnetic field from an external magnetic field application mechanism such as a magnet, and the magnetic field application mechanism can be downsized. In addition, since the external current for applying the magnetic field used in the prior art can be eliminated or reduced, energy saving can be achieved.

  Furthermore, the loop unit 501 in the third embodiment can also be used as an antenna that emits the electric power oscillated by the oscillation unit 101 as an electromagnetic field. Therefore, when the electromagnetic field is emitted from the oscillator to the outside, it is not necessary to newly provide an antenna, and the entire oscillator can be reduced in size. Here, the antenna means not only an antenna for transmitting an electromagnetic wave to a distance sufficiently larger than a wavelength, but also an antenna, a resonator, or the like that transmits an electromagnetic field to a distance that is the same as or shorter than the wavelength.

  In the third embodiment, in order to effectively apply the magnetic field generated by the loop unit to the oscillation unit 101, the loop unit 501 is disposed on the upper side of the oscillation unit 101 (on the side of the conductor 103a of the DC current I input). Other arrangements may be used as long as the magnetic field necessary for the oscillation is applied to the oscillation unit 101. For example, the structure which arrange | positions a loop part to the conductor 103b can be used. Moreover, the loop part can also use the spiral form formed on the same plane, and the solenoid form formed in three dimensions.

  The oscillation frequency of the oscillator 500 can be changed by adjusting the magnetic field strength applied to the oscillation unit 101 by changing the position of the magnet 102.

  The magnetic field applying means for applying the first magnetic field is not limited to a magnet, and for example, an external wiring, an external coil, or an electromagnet can be used.

  In FIG. 5, the direction of the second magnetic field H when the oscillating unit 101 is the magnetoresistive effect element 205 shown in FIG. 2 is substantially perpendicular to the film surface constituting the magnetoresistive effect element 205. On the other hand, the magnetoresistive element 205 may oscillate when a magnetic field is applied in a substantially in-plane direction with respect to the film surface. In that case, for example, the axis of the loop portion 501 is made parallel to the film surface of the magnetoresistive effect element 205 so that the second magnetic field H is applied in the in-plane direction of the magnetoresistive effect element 205. To place. The direction of the second magnetic field H applied to the magnetoresistive effect element 205 is not limited to the perpendicular direction or the in-plane direction with respect to the film surface, and by adjusting the angle formed by the loop portion and the magnetoresistive effect element 205, The angle of the magnetic field applied to the magnetoresistive effect element 205 can be arbitrarily set.

(Embodiment 4)
In the fourth embodiment, a stronger magnetic field is applied to the oscillation unit 101 than the configuration described in the second and third embodiments is used.

  FIG. 6 is a schematic diagram according to the fourth embodiment. An oscillator 600 according to the fourth embodiment includes an oscillating unit 101, conductors 103 a and 103 b connected in series to the oscillating unit 101, two magnets 102, and a current amplifying unit 401. The conductor 103b has a loop portion, and the loop portion is expressed by an inductor 601. The oscillation unit 101 is connected in series to the input end of the current amplification unit 401, and the loop unit is connected in series to the output end of the current amplification unit 401.

  Here, an example in which two magnets 102 are used is shown, but the number of magnets 102 is not particularly limited as long as a magnetic field can be applied to the oscillation unit 101. However, for example, it is preferable to arrange two magnets because the bias of the magnetic field applied to the oscillation unit 101 is reduced. The magnet may be a hard bias film formed of a magnetic metal such as cobalt, iron, nickel, or chromium and an alloy thereof, or an alloy in which boron is mixed into the magnetic alloy.

The magnet 102 is disposed so as to apply a first magnetic field H _m smaller than a threshold magnetic field required for the oscillation unit 101 to oscillate to the oscillation unit 101.

When a DC current I to the oscillation unit 101, current amplifier 401 generates an amplified current _{I A.} The loop unit generates a second magnetic field H at the position of the oscillation unit 101 when the amplified current I _A flows. The loop unit is arranged so that a combined magnetic field of the first magnetic field _Hm and the second magnetic field H is larger than a threshold magnetic field of the oscillation unit 101.

  The oscillation frequency of the oscillator 600 can be changed by adjusting the strength of the magnetic field applied to the oscillation unit 101 by changing the position of the magnet 102.

  The magnetic field applying means for applying the first magnetic field is not limited to a magnet, and for example, an external wiring, an external coil, or an electromagnet can be used.

  The current amplifying unit 401 can use a transistor, a commercially available chip-shaped amplifier, an amplifier circuit, or the like, but is not limited thereto.

  Since the loop portion can be disposed in the very vicinity of the oscillation unit 101, a strong magnetic field can be applied to the oscillation unit 101. Accordingly, it is not necessary to increase the magnetic field from an external magnetic field application mechanism such as a magnet, and the magnetic field application mechanism can be downsized. In other words, this configuration enables the size of the entire oscillator to be reduced.

  Since a relatively strong magnetic field is applied to the oscillation unit 101, this is a preferred embodiment for oscillation at a high frequency. The oscillator 600 is configured such that the current flowing through the conductor 103b is larger than the current flowing through the oscillation unit 101. Therefore, since a large current does not flow through the oscillation unit 101, the oscillation unit 101 can be protected from an overcurrent.

  The arrangement of the current amplifying means is not limited to the arrangement in which the oscillation unit 101 and the current amplifying means are in series as shown in the fourth embodiment. Any configuration may be used as long as the current flowing through the loop section is larger than the current flowing through the oscillation section 101. For example, an arrangement in which the oscillation unit 101 and the current amplifying means are in parallel can be used.

  A typical configuration has been described above, but the embodiment of the present invention is not limited to this. For example, a configuration in which the oscillating unit 101 is arranged in the middle of the loop unit, the oscillating unit 101 is arranged in the middle of a separate loop unit, or the oscillating unit 101 is arranged at an arbitrary position near the loop unit can be used. . Furthermore, although the description has been given using the loop unit as the magnetic field application unit, the magnetic field application unit is not limited to the loop unit. For example, the magnetic field application unit may be formed in a semicircular winding shape that does not lead to complete formation of the loop, or in other shapes such as a linear shape.

(Embodiment 5)
In Embodiment 5, replacing the oscillation portion 101 of the embodiment 1 to the rectifier unit, by further into AC current I _AC and DC current I, shows a rectifier for converting alternating current into direct current. Further, the magnetoresistive effect element 205 is used in the rectifier of the fifth embodiment.

FIG. 7 is a schematic diagram of the rectifier of the fifth embodiment. In the fifth embodiment, the direct current I in FIG. 1 of the first embodiment is replaced with an alternating current _IAC , and the oscillation unit 101 is replaced with a rectification unit using the magnetoresistive effect element 205. Magnets 102 as a first magnetic field, it is arranged to the magnetoresistive element 205 so as to apply a magnetic field H _m. Field _{H m} is a threshold magnetic field less than the required to spin torque FMR (Ferromagnetic Resonance) effect which will be described later magnetoresistive element 205 occurs. Here, the threshold magnetic field is the magnitude of the minimum magnetic field required for the magnetoresistive element 205 to exhibit the spin torque FMR effect when an alternating current is supplied to the magnetoresistive element 205.

Upon application of an alternating current _{I AC} through the conductors 103 to the magnetoresistive element 205, the conductor 103 generates a second magnetic field _{H AC} by an alternating current _{I AC.} Conductor 103 is synthetic magnetic field of the first magnetic field H _m and the second magnetic field H _AC is arranged to be larger than the threshold magnetic field.

  When the combined magnetic field exceeds the threshold magnetic field, the magnetoresistive effect element 205 converts alternating current into direct current. That is, the rectifier 700 according to the fifth embodiment is a rectifier that exhibits a rectifying action for converting alternating current into direct current.

  Here, the spin torque FMR effect will be described. Consider the case where an alternating current is applied to the magnetoresistive effect element 205 in FIG. 2 in the direction perpendicular to the plane of each layer. When electrons 208 are injected from the pinned layer 206a into the free layer 206b in a half cycle of alternating current, the magnetization direction of the free layer 206b rotates so that the magnetizations of the free layer 206b and the pinned layer 206a are parallel to each other. The resistance value of the element 205 decreases. Conversely, in the half cycle in which electrons 208 are injected from the free layer 206b to the pinned layer 206a, the magnetization direction of the free layer rotates so that the magnetization directions of the free layer 206b and the pinned layer 206a are antiparallel to each other, and the resistance value is Go up. This resistance change phenomenon occurs alternately by the alternating current, and a direct current voltage component is generated along with the oscillating voltage. That is, it shows a rectifying action for converting alternating current into direct current. This is called the spin torque FMR effect. Since the frequency at which the spin torque FMR effect occurs, that is, the rectification frequency depends on the applied magnetic field, it is necessary to apply a sufficient magnetic field to generate the spin torque FMR effect at a desired frequency.

  The rectification frequency of the rectifier 700 can be changed by adjusting the magnetic field strength applied to the magnetoresistive effect element 205 by changing the position of the magnet 102.

  The magnetic field applying means for applying the first magnetic field is not limited to a magnet, and for example, an external wiring, an external coil, or an electromagnet can be used.

  Since the conductor 103 can be disposed in the very vicinity of the magnetoresistive effect element 205 which is a rectifying unit, a strong magnetic field can be applied to the rectifying unit. Accordingly, it is not necessary to increase the magnetic field from an external magnetic field application mechanism such as a magnet, and the magnetic field application mechanism can be downsized. In other words, this configuration enables the size of the entire rectifier to be reduced.

  FIG. 8 is a diagram illustrating an example of a peripheral circuit for using the rectifier 700 according to the fifth embodiment. The peripheral circuit 800 includes an alternating current source 802, a load 804, an inductor La, and a capacitor Ca. The inductor La can prevent the alternating current from flowing into the load 804, and the capacitor Ca can prevent the direct current flowing into the alternating current source 802 generated by the spin torque FMR effect.

The alternating current I _AC from the alternating current source 802 passes through the capacitor Ca having a small impedance, but hardly passes through the inductor La having a large impedance. Therefore, the alternating current I _AC is efficiently supplied to the rectifier 700. The rectifier 700 converts alternating current into direct current, and the direct current output is detected by the load 804.

  In the following description of the embodiment, the peripheral circuit 800 is omitted.

(Embodiment 6)
In Embodiment 6, in 4 from embodiment 2, replacing the rectifying section of the oscillation portion 101 using a magneto-resistance effect element 205, by further into AC current I _AC and DC current I, generated by an alternating current I _AC efficiently applying a magnetic field _{H AC} to the magnetoresistive effect element 205. Embodiment 6, an AC current I _AC to the magnetoresistive element 205, that the first magnetic field H _m and synthetic magnetic field of the second magnetic field H _AC is applied, the magneto-resistance effect element by the spin torque FMR effect Since 205 rectifies alternating current into direct current, it becomes a rectifier.

Further, in the third and fourth embodiments, the oscillation unit 101 is replaced with a rectifying unit using the magnetoresistive effect element 205, and the loop part in the sixth embodiment in which the direct current I is changed to the alternating current _IAC is changed to an external electromagnetic field. It can also be used as an antenna that receives and supplies power to the magnetoresistive effect element 205. Therefore, when an electromagnetic field is supplied to the rectifier from the outside, it is not necessary to newly provide an antenna, and the rectifier can be miniaturized. Here, the term “antenna” includes not only an antenna for receiving an electromagnetic wave coming from a distance sufficiently larger than a wavelength, but also an antenna and a resonator for receiving an electromagnetic field from a distance similar to or smaller than the wavelength.

  In the rectifier according to the sixth embodiment, a loop portion is used as the magnetic field application unit. However, the magnetic field application unit has another shape such as a semicircular winding shape or a straight shape that does not lead to the complete formation of the loop instead of the loop portion. You may comprise.

(Embodiment 7)
In the seventh embodiment, the magnetic field generated by the signal current is efficiently applied to the magnetoresistive effect element 205 by changing the alternating current _IAC to the signal current in the fifth or sixth embodiment. In the seventh embodiment, a signal current and a combined magnetic field of the first magnetic field H _m and a magnetic field generated by the signal current are applied to the magnetoresistive effect element 205, so that the spin torque FMR effect is generated. It becomes the receiver which rectifies and receives.

(Embodiment 8)
In the eighth embodiment, in order to wirelessly transmit the output of the oscillating unit, means for transmitting the output of the oscillating unit by electromagnetic coupling is provided in an electric circuit that is galvanically insulated from the oscillator. Electromagnetic coupling includes inductive coupling by electromagnetic induction, coupling by capacitance, coupling by electromagnetic resonance, coupling by electromagnetic waves, and the like. In the eighth embodiment, an embodiment using inductive coupling will be described.

  FIG. 9 is a circuit diagram of a transmission device 900 according to the eighth embodiment. The transmission device 900 includes a first electric circuit 901 and a second electric circuit 902. The first electric circuit 901 includes the oscillator 500 and the electric circuit 905 according to the third embodiment. The loop unit 501 of the oscillator 500 is expressed by a first inductor 903. Here, for simplification of the figure, the magnet is not shown. The second electric circuit 902 includes a conductor 904 and an electric circuit 906. Although not shown, the electric circuit 906 includes an antenna that transmits a signal to the outside of the transmission device 900. The conductor 904 has a loop portion and is represented by a second inductor 907. The oscillator 500 and the second electric circuit 902 are galvanically isolated. The first inductor 903 and the second inductor 907 are galvanically isolated but are inductively coupled.

  When the oscillator 500 oscillates, a time-varying current flows through the first inductor 903, and a signal from the electric circuit 901 is transmitted to the electric circuit 902 through the second inductor 907 by inductive coupling.

If impedance matching is considered in the inductive coupling portion, reflection is reduced in the inductive coupling portion, so that signal transmission is performed more efficiently. The impedance of the first electric circuit 901 is Z1, and the impedance of the second electric circuit 902 is Z2. In order to match the impedances of the two electric circuits, the number of turns of the first inductor 903 and the second inductor 907 is adjusted. This technique is known as an impedance matching technique using a transformer. If the number of turns N1 of the first inductor 903 and the number of turns N2 of the second inductor 907 are determined so as to satisfy the following formula (2), the first electric circuit 901 and the second electric circuit 902 Impedance matches.
(N1 / N2) ² = Z1 / Z2 (2)

  The magnitude of the magnetic field applied to the oscillating unit 101 can be adjusted by the number of windings of the inductor, as shown in Equation (1). When the number of turns N1 of the first inductor 903 is adjusted for impedance matching, the magnetic field applied to the oscillation unit 101 is changed. Therefore, it is desirable to adjust the number of turns N2 of the second inductor 907.

  The first inductor 903 and the second inductor 907 are, for example, a configuration in which an iron core or other magnet is disposed in the shaft portion of the loop portion, or a configuration in which the first inductor 903 and the second inductor 907 are provided in the toroidal core. It may be. The configuration is a preferable form when it is desired to strengthen inductive coupling.

  Although the oscillator 500 of the third embodiment has been described as an example of the oscillator, the oscillator is not particularly limited, and for example, an oscillator in another embodiment can be used.

(Embodiment 9)
In the ninth embodiment, in the oscillator 500 of the eighth embodiment, the oscillating unit 101 is replaced with a rectifying unit using the magnetoresistive effect element 205. In this configuration, when an alternating current _{IAC is} passed through the conductor 904, the magnetic field and current generated by the inductively coupled first inductor 903 are applied to the magnetoresistive effect element 205, so that the ninth embodiment is a magnetoresistive effect element. The rectifier generates a DC voltage from an AC current by the spin torque FMR effect of 205.

The configuration of the rectifying device is not limited to the configuration in which the oscillating unit 101 in the oscillator 500 of the eighth embodiment is replaced with a rectifying unit using the magnetoresistive effect element 205. For example, in the eighth embodiment, the rectifier can be configured by replacing the oscillator 500 with the oscillator in the other embodiments and further replacing the oscillating unit 101 with the magnetoresistive effect element 205 which is a rectifying unit. In this configuration, when an alternating current _{IAC is} passed through the conductor 904, a magnetic field and current generated by electromagnetic coupling are applied to the magnetoresistive effect element 205, so that the magnetoresistive effect element 205 is alternating current due to the spin torque FMR effect. A DC voltage is generated from the current. Here, the electromagnetic coupling means inductive coupling by electromagnetic induction, coupling by capacitance, coupling by electromagnetic resonance, coupling by electromagnetic waves, etc., but is not limited thereto.

(Embodiment 10)
In the tenth embodiment, in the rectifier described in the ninth embodiment, a signal current is passed through the conductor 904 and a magnetic field and current generated by electromagnetic coupling are applied to the magnetoresistive effect element 205. In this case, since the magnetoresistive effect element 205 rectifies and receives the signal current to direct current by the spin torque FMR effect, the tenth embodiment becomes a receiving device. Here, the electromagnetic coupling means inductive coupling by electromagnetic induction, coupling by capacitance, coupling by electromagnetic resonance, coupling by electromagnetic waves, etc., but is not limited thereto.

(Embodiment 11)
An embodiment 11 in which a conductor that applies a magnetic field to the oscillation unit 101 is used as a communication antenna will be described.

  FIG. 10 is a diagram illustrating a transmission / reception apparatus according to the eleventh embodiment. The transmission / reception device 1000 includes an oscillator 1001a and a receiver 1001b. The oscillator 1001a is described as Embodiment 3 as an example. The oscillator 1001a includes an oscillating unit 101 and a conductor 103a and a conductor 103b that are connected in series to the oscillating unit 101 and input a transmission signal. The conductor 103a has a loop portion 501. Here, the magnet is not shown for simplification of the figure. The receiver 1001b includes a conductor 1002 having means for receiving an electromagnetic field generated by the loop unit 501 and a conversion unit 1003 for converting the electromagnetic field received by the conductor 1002 into a received signal.

  The operation of the transmission / reception device 1000 will be described. In the description here, NRZ (Non-Return-to-Zero) is used as the communication encoding method. NRZ is an encoding method in which the voltage is not zero when the signal is “1” and the voltage is zero when the signal is “0”. However, the encoding method that can be used in the present invention is not limited to this.

  When the signal value is “1”, a current flows through the loop unit 501 and the oscillation unit 101 for a time interval of “1”, and the loop unit 501 generates a magnetic field H. The oscillation unit 101 oscillates at a desired frequency when a current necessary for oscillation and a magnetic field H are applied. When the oscillated voltage is applied, the loop unit 501 generates an electromagnetic field EM superimposed on the magnetic field H. The electromagnetic field EM is received by the conductor 1002 of the receiver 1001b. The received electromagnetic field is converted into a received signal by the converter 1003, and the signal value “1” is transmitted.

  When the signal value is “0”, no current flows through the oscillating unit 101 and no magnetic field is generated, so that the electromagnetic field is not transmitted to the receiver 1001b. That is, the signal value “0” is transmitted.

  In this embodiment, the loop unit 501 provided for applying a magnetic field to the oscillation unit 101 is also used as an antenna for wireless transmission. Therefore, it is not necessary to newly provide an antenna for wireless transmission, and the transmission / reception apparatus can be downsized.

  In addition, when the signal value is “0”, no current flows through the loop unit 501, and therefore an electromagnetic field unnecessary for communication is not generated. That is, this embodiment can also be expected to save power and reduce noise.

  Transmission between the loop portion 501 and the conductor 1002 is determined by, for example, an electromagnetic induction method in which two loop portions face each other, an electromagnetic resonance method by LC resonance in which the resonance frequency is determined by inductance and capacitance, and the resonance frequency by the line length of the pattern conductor. Electromagnetic resonance, coupling by capacitance between conductors, etc. can be used.

  The conversion unit 1003 may be a magnetoresistive element 205. When the high-frequency output generated by the oscillation unit 101 at the time interval of the signal value “1” is input to the magnetoresistive effect element 205 via the loop unit 501 and the conductor 1002, the magnetoresistive effect element 205 is caused by the spin torque FMR effect. Convert high frequency output to DC output. That is, the signal value “1” transmitted as a high frequency output is demodulated.

  By disposing the magnetoresistive effect element 205 so that a magnetic field generated by the loop portion 501 and the conductor 1002 can be applied, the mechanism for applying the magnetic field to the magnetoresistive effect element 205 can be reduced in size, and the size of the transmission / reception device can be reduced. Can be realized.

  In the eleventh embodiment, the case where the oscillator according to the third embodiment is used as the oscillator 1001a is described. However, the present invention is not limited to the third embodiment, and an oscillator according to another embodiment may be used. As the receiver 1001b, the receiver described in Embodiment 7 can be used. That is, it is possible to configure the transmission / reception device with the same configuration of the oscillator and the receiver, or it is also possible to configure the transmission / reception device with the configuration of the oscillator and the receiver different from each other. In these transmission / reception apparatuses, a conductor portion to which a magnetic field is applied is also used as an antenna used for wireless transmission. Therefore, it is not necessary to newly provide an antenna for wireless transmission, and the transmission / reception apparatus can be downsized. Here, the term “antenna” includes not only an antenna used for communication over a distance sufficiently larger than a wavelength but also an antenna and a resonator used for communication over a distance equivalent to or smaller than the wavelength.

  Further, the present embodiment can be applied to wireless power feeding. If the signal value is always “1”, the oscillation signal, that is, energy is always supplied to the receiver 1001b, so that wireless power can be supplied.

  The oscillator, the transmission device, the rectifier, the receiver, the reception device, and the transmission / reception device according to the present invention can be used for wireless communication, wireless power feeding, and the like.

DESCRIPTION OF SYMBOLS 101 ... Oscillating part, I ... Current, 103 ... Conductor, 103a ... Conductor that flows current into the oscillating part, 103b ... Conductor that allows current to flow out from the oscillating part, 102 ... Magnet , H, H _m ... Magnetic field, 205... Magnetoresistive effect element, 401... Current amplification unit, 501... Loop unit, H _AC .. magnetic field, 901, 902. 903, 907 ... inductor, 1001a ... oscillator, 1001b ... receiver, 1002 ... conductor, 1003 ... converter

Claims (11)

An oscillation unit having a threshold magnetic field for starting oscillation larger than zero;
A conductor connected in series to the oscillation unit;
An oscillator having magnetic field applying means for applying a first magnetic field to the oscillating unit,
The oscillating unit and the conductor have a second magnetic field generated by a current flowing through the conductor applied to the oscillating unit, the first magnetic field is smaller than the threshold magnetic field, and the first magnetic field and the conductor An oscillator characterized by being arranged such that a combined magnetic field with two magnetic fields is larger than the threshold magnetic field.   The oscillator according to claim 1, wherein the threshold magnetic field is larger than geomagnetism.   The oscillator according to claim 1, wherein the oscillation unit is a magnetoresistive effect element. The oscillator according to any one of claims 1 to 3,
An electrical circuit that is galvanically isolated from the oscillator,
A transmission apparatus comprising electromagnetic coupling means for electromagnetically coupling the conductor and the electric circuit. A rectifying unit having a threshold magnetic field larger than zero for developing a rectifying action;
A conductor connected in series to the rectifying unit;
A rectifier having magnetic field applying means for applying a first magnetic field to the rectifying unit,
The rectifying unit and the conductor have a second magnetic field generated by a current flowing through the conductor applied to the rectifying unit, the first magnetic field is smaller than the threshold magnetic field, and the first magnetic field and the conductor The rectifier is arranged such that a combined magnetic field with the two magnetic fields is larger than the threshold magnetic field.   The rectifier according to claim 5, wherein the threshold magnetic field is larger than geomagnetism.   The rectifier according to claim 5, wherein the rectifying unit is a magnetoresistive element. A rectifier according to any one of claims 5 to 7,
An electrical circuit that is galvanically isolated from the rectifier,
A rectifier comprising electromagnetic coupling means for electromagnetically coupling the conductor and the electric circuit.   A receiver comprising the rectifier according to any one of claims 5 to 7 for receiving a signal. A receiver according to claim 9;
An electrical circuit that is galvanically isolated from the receiver;
A receiver comprising electromagnetic coupling means for electromagnetically coupling the conductor and the electric circuit. The oscillator according to any one of claims 1 to 3,
A receiver according to claim 9,
A transmitter / receiver characterized in that wireless communication or wireless power transmission is performed by electromagnetically coupling the conductor of the oscillator and the conductor of the receiver.

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