JP6486256B2 - Wireless power transmission apparatus and wireless power transmission system - Google Patents

Description

  The present invention relates to a wireless power transmission / reception technique for performing power transmission using electromagnetic waves such as microwaves.

  Development of a wireless power transmission / reception technology that uses an electromagnetic wave such as a microwave or a laser beam and enables power transmission between two points separated by a distance sufficiently longer than the wavelength of the electromagnetic wave is underway. For example, in a space solar power system (SSPS), a power generation satellite arranged in outer space converts sunlight into electrical energy, which is converted into microwaves or laser light to the earth. Power is transmitted to the upper power receiving device. The power receiving device on the earth can receive microwaves or laser light from the power generation satellite, and can convert the received microwaves or laser light into DC electric energy. Not only a space solar power generation system but also a wireless power transmission / reception technology can be used for power transmission between two points on the ground.

  Such a wireless power transmission / reception technique is disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-95190. Patent Document 1 discloses a power generation satellite group including a plurality of power generation satellites that transmit microwaves to a ground power base. In this power generation satellite group, the phase of the microwave is adjusted for each power generation satellite so that the antenna element groups of a plurality of power generation satellites form a phased array antenna as a whole. Each power generation satellite transmits the phase-adjusted microwave by incoherently modulating it with a spread spectrum modulation method. Thereby, the beam width of the microwave can be adjusted according to the receiving antenna size of the power base.

JP 2002-95190 A (for example, FIG. 1 and FIG. 2 and paragraphs 0011 and 0016)

  In the wireless power transmission technology of Patent Document 1, a control satellite that individually and precisely controls the microwave phase amount of a plurality of power generation satellites must be separately prepared, and each power generation satellite receives control from the control satellite. A complicated circuit configuration for processing signals is required.

  In the wireless power transmission / reception technique disclosed in Patent Document 1, each power generation satellite performs incoherent modulation of the microwave after phase adjustment using a spread spectrum modulation method. However, this incoherent modulation may destabilize the transmission direction to the power base and reduce the transmission efficiency.

  In view of the above, an object of the present invention is to provide a wireless power transmitting apparatus capable of realizing stable power transmission using an array antenna and a wireless power transmitting system using the wireless power transmitting apparatus.

  A wireless power transmission device according to an aspect of the present invention generates an array antenna including N regularly arranged power transmission antenna elements (N is an integer of 2 or more) and a radio wave having a phase that changes randomly or pseudo-randomly. An oscillating circuit, a distributor that distributes the radio waves to N transmission radio waves, and a phase shift of the N radio transmission waves individually to supply the N power transmission antenna elements to the N power transmission antenna elements, respectively. And a phase controller that radiates a power transmission beam from the power transmission antenna element.

  A wireless power transmission system according to another aspect of the present invention includes a plurality of the wireless power transmission devices.

  According to the present invention, since the phase modulation that changes the phase of the radio wave randomly or pseudo-randomly is performed, the radio wave interference in the power receiving antenna element can be reduced. In addition, since the N system transmission radio waves are generated using one system radio wave as a distribution source, the temporal fluctuation of the relative phase difference between the output waves of the N power transmission antenna elements is avoided even if the phase modulation is performed. Therefore, it is possible to prevent the transmission direction from becoming unstable due to the phase modulation. Therefore, stable power transmission can be realized using the array antenna, and power transmission efficiency can be improved.

It is a functional block diagram which shows schematic structure of the wireless power transmission apparatus of Embodiment 1 which concerns on this invention. (A) is a figure which shows the structural example of the phase control part of Embodiment 1, (B) is a figure which shows the other structural example of the phase control part of Embodiment 1. FIG. (A) is a figure which shows the modification of the phase control part of Embodiment 1, (B) is a figure which shows the other modification of the phase control part of Embodiment 1. (A), (B) is a figure which shows the structural example of the oscillation circuit of Embodiment 1. FIG. 1 is a block diagram showing a schematic configuration of a wireless power transmission system according to Embodiment 1. FIG. FIG. 5 is a block diagram illustrating a schematic configuration of an oscillation circuit according to a second embodiment. FIG. 6 is a block diagram illustrating a schematic configuration of an oscillation circuit according to a third embodiment. FIG. 6 is a block diagram illustrating a schematic configuration of an oscillation circuit according to a fourth embodiment.

  Hereinafter, various embodiments according to the present invention will be described in detail with reference to the drawings. In addition, the component which attached | subjected the same code | symbol in drawing shall have the same structure and the same function.

Embodiment 1 FIG.
FIG. 1 is a functional block diagram showing a schematic configuration of the wireless power transmitting apparatus Tx according to the first embodiment of the present invention. This wireless power transmission device Tx is used for power transmission between two points separated by a distance sufficiently longer than the wavelength of the electromagnetic wave used for wireless power transmission. This power transmission may be performed either outdoors or indoors. The wireless power transmission device Tx of the present embodiment can be applied to, for example, a space solar power generation system that converts solar energy into electromagnetic waves and transmits it, or a power feeding system that transmits power to a moving body such as a vehicle or an aircraft. However, it is not limited to these.

As shown in FIG. 1, the wireless power transmitting apparatus Tx includes an array antenna 10 composed of _N (N is an integer of 2 or more) power transmitting antenna elements AN ₁ ,. And. The power transmission antenna elements AN ₁ ,..., AN _N are arranged in a line or a plane. The apparatus main body 11 includes an oscillation circuit 12 that outputs a radio wave Pw having a phase that changes randomly or pseudo-randomly, a distributor 14 that distributes the radio wave Pw to N transmission radio waves Pw ₁ ,..., Pw _N , and these Telecommunications Pw 1 _feed, ..., a phase control unit 13 which Pw _N were individually phase-shifted to produce a transfer phase feeding electric wave N systems, the radiation directivity of the array antenna 10 by controlling the operation of the phase control unit 13 And a beam direction control unit 15 for controlling the characteristics.

As shown in FIG. 1, the phase controller 13 has N phase controllers 13 ₁ ,..., 13 _N. These phase controllers 13 ₁ ,..., 13 _N individually shift the phase of the transmitted radio waves Pw ₁ ,..., Pw _N by the amount of phase change specified by the control signal Bc supplied from the beam direction controller 15. Generates phase-shifting radio waves for the system. These N phase-shifting radio waves are controlled so as to have a certain phase difference. Then, the phase controller ₁₃ 1, ..., 13 _N are each transmission antenna element _AN 1 radio transfer phase feeding of these N lines, ..., the power transmission antenna element _AN 1 by supplying the AN _N, ..., from the AN _N The power transmission beam Tw is radiated. That is, the array antenna 10 and the phase controllers 13 ₁ ,..., 13 _N constitute a phased array antenna.

  The beam direction control unit 15 can variably control the direction of the power transmission beam Tw through the control signal Bc. When the wireless power transmission device Tx is mounted on a mobile body such as a power generation satellite, the beam direction control unit 15 is a known device that automatically directs the direction of the power transmission beam Tw to the arrival direction of the pilot signal received from the power reception device. It may have a retro-directive function.

  As the transmitted radio wave, for example, it is preferable to use a microwave having a frequency band of 10 GHz or less that passes through rain, fog, or clouds. When the wireless power transmission device Tx is mounted on a power generation satellite, a 2.45 GHz band or a 5.8 GHz band microwave can be used as a transmission wave. However, since an appropriate frequency band varies depending on the power transmission environment, the present invention does not limit the frequency band.

Specifically, the phase controllers 13 ₁ ,..., 13 _N can be configured using a variable phase shifter. 2 (A) is variable phase shifter _PS 1, ..., a diagram schematically showing a configuration example of the phase control unit 13 consisting of PS _N. In the example of FIG. 2A, the variable phase shifters PS ₁ ,..., PS _N shift the transmitted radio waves Pw ₁ ,..., Pw _N by the amount of phase shift specified by the control signal Bc (ie, _N phase-shifted radio waves are generated (by shifting the phase of the radio waves Pw ₁ ,..., Pw _N ).

Further, the phase controllers 13 ₁ ,..., 13 _N may be configured using an injection locked oscillator. FIG. 2B is a diagram illustrating another configuration example of the phase control unit 13 including the injection locking oscillators IL ₁ ,..., IL _N. In the example of FIG. 2 (B), the injection-locked oscillator _IL 1, ..., IL _N, respectively power transmission wave _Pw 1, ..., a Pw _N and injected wave, the injected wave by oscillating in synchronization with these infusion wave Output an oscillation wave of the same frequency as. In addition, since the injection locking oscillators IL ₁ ,..., IL _N have a function of shifting the phase of the oscillation wave in accordance with the control signal Bc, the phase-shifted oscillation wave is output as a phase-shifting radio wave. Can do. Such injection locked oscillators IL ₁ ,..., IL _N can be configured to function also as amplifiers.

Further, the phase control unit 13 may be modified to have an amplifier circuit that amplifies the amplitude of the N systems of transmission radio waves Pw ₁ ,..., Pw _N or the amplitude of the N systems of phase transmission radio waves. Thereby, big electric power can be transmitted. 3A and 3B are diagrams showing a modification of the phase control unit 13. Phase control unit 13A of the modified example shown in FIG. 3 (A), phase controller ₁₃ 1, ..., amplifier ₂₀ 1 which is disposed downstream than 13 _N, ..., having a 20 _N. These amplifiers ₂₀ 1, ..., 20 _N, the phase controller ₁₃ 1, ..., it is possible to amplify the amplitude of the phase shift transmission wave which is the output of 13 _N. On the other hand, the phase control unit 13B of the modified example shown in FIG. 3 (B), phase controller ₁₃ 1, ..., an amplifier ₂₁ 1 disposed upstream than 13 _N, ..., having a 21 _N. These amplifiers ₂₁ 1, ..., 21 _N are radio _Pw 1 feed, ..., phase controller ₁₃ 1 corresponding respectively to amplify the amplitude of Pw _N, ..., it can be output to the 13 _N.

  Next, the configuration of the oscillation circuit 12 will be described. FIG. 4A is a diagram illustrating a configuration example of the oscillation circuit 12. In the configuration example of FIG. 4A, the oscillation circuit 12 includes a high-frequency oscillator 22, a variable phase shifter 23 that generates a radio wave Pw by shifting the output wave of the high-frequency oscillator 22 randomly or pseudo-randomly, And a random phase control unit 24 that controls the operation of the variable phase shifter 23. The random phase control unit 24 randomly changes the phase shift amount, that is, the phase change amount of the output wave of the high frequency oscillator 22 using a physical random number sequence (true random number sequence), or uses the pseudo random number sequence to generate a high frequency oscillator 22. The amount of phase shift of the output wave is changed pseudo-randomly. When using a physical random number sequence, the random phase control unit 24 has a nonvolatile memory in which data of the physical random number sequence is stored, and the data may be read and used. When using a pseudo-random number sequence, the random phase control unit 24 only needs to have an arithmetic circuit for calculating the pseudo-random number sequence by a known pseudo-random number generation algorithm. This type of arithmetic circuit can be constituted by a random number generation circuit using a known linear feedback shift register, for example. Further, it is possible to generate a physical random number or a pseudo-random number by using a circuit in which a nonlinear map (for example, logistic map) that generates a chaos phenomenon (non-periodic operation) appears in a voltage waveform or signal processing.

  For the phase shift amount control of the variable phase shifter 23, for example, a configuration in which a control voltage is supplied from the random phase control unit 24 to the variable phase shifter 23 can be employed. The amount of phase shift can be changed randomly or pseudo-randomly by switching the value of the control voltage supplied to the variable phase shifter 23 to a random or pseudo-random value.

As described above, when the phase of the radio wave Pw changes randomly or pseudo-randomly, an effect of reducing radio wave interference in the power receiving antenna element can be obtained. FIG. 5 schematically illustrates an example of a combination of the wireless power transmission system 1 including M (M is an integer of 3 or more) wireless power transmission devices Tx ₁ , Tx ₂ ,..., Tx _M and the wireless power reception device Rx. FIG. There are three or more wireless power transmission devices Tx _{1 to} Tx _M constituting the wireless power transmission system 1, but the present invention is not limited to this, and the wireless power transmission system may be configured by two wireless power transmission devices. The wireless power transmission devices Tx _{1 to} Tx _M shown in FIG. 5 have the same configuration as the wireless power transmission device Tx described above. On the other hand, the wireless power receiving device Rx includes an array antenna 30 composed of a plurality of power receiving antenna elements, and a device main body 31 that converts radio waves received by the array antenna 30 into DC electrical energy Eng. As illustrated in FIG. 5, the wireless power transmission devices Tx _{1 to} Tx _M each transmit M power transmission beams toward the array antenna 30 of the wireless power receiving device Rx. For this reason, radio wave interference occurs in the array antenna 30 that receives these power transmission beams. However, since the phase of the radio wave of each power transmission beam changes randomly or pseudo-randomly, the radio wave interference in the array antenna 30 is reduced, and a null point (radio wave) Occurrence can be avoided. Thereby, power transmission efficiency improves.

The random or pseudo-random control of the output phase of the high-frequency oscillator 22 as described above is performed by increasing the time Δt required for the phase change Δθ of the radio wave Pw (in other words, by reducing the slope Δθ / Δt). ), Which can accommodate an acceptable modulation band. For example, if the maximum modulation amount of the phase of the radio wave Pw is π and the allowable modulation frequency is FM _max , the time Δt required for the phase state change Δθ is 1 / (2 × FM _max ) or more. What should I do.

  In order to drive the high-frequency oscillator 22, DC (direct current) power may be supplied from an oscillation circuit 12 connected to the power generator 2 as shown in FIG. 4B. The power generation device 2 is a device that converts light energy such as sunlight, mechanical energy by a motor, chemical energy, or thermal energy into DC power. The power generation device 2 may be a DC power supply source that drives not only the high-frequency oscillator 22 but also the entire wireless power transmission device.

As described above, in the wireless power transmitting apparatus Tx according to the present embodiment, phase control for determining the direction of the transmitted power beam Tw is performed on the transmitted radio waves Pw ₁ ,..., Pw _N. In addition, the random phase modulation that changes the phase of the radio wave Pw randomly or pseudo-randomly is performed independently of the phase control, so that radio wave interference in the power receiving antenna element can be reduced. Further, before the phase control for determining the direction of the transmission beam Tw is performed, the random phase modulation performed in radio Pw, Telecommunications Pw 1 _feed, ..., Pw _N is generated radio Pw of one system as a distribution source Therefore, the phases of the transmitted radio waves Pw ₁ ,..., Pw _N change randomly or pseudo-randomly in synchronization with each other. Thus, the random phase modulation due transmitting antenna element AN _1, ..., since the temporal variation of the relative phase difference between the output waves of AN _N is avoided, unstable transmission direction due to its random phase modulation Can be prevented. Therefore, stable power transmission can be realized using the array antenna 10, and power transmission efficiency can be improved.

Further, a plurality of wireless power transmission device _{Tx 1,} Tx 2 as shown in FIG. 5, ..., if the wireless transmission system 1 consisting of Tx _M, the wireless power transmission device _{Tx 1,} Tx 2, ..., the oscillation circuit of Tx _M 12, 12,... 12 need only generate uncorrelated radio waves, and there is an advantage that the operations of these oscillation circuits 12, 12,.

The wireless power transmission device Tx in the present embodiment, three or more transmission antenna elements AN _1, ..., is provided with the AN _N, is not limited to this, the number of transmission antenna elements 2 It may be.

In addition, the wireless power receiving device Rx illustrated in FIG. 5 converts the received power from the wireless power transmitting devices Tx _{1 to} Tx _M into electrical energy Eng and outputs the electrical energy Eng, but is not limited thereto, and the received power is converted into electrical energy. You may convert into energy sources other than. For example, the received power can be converted into mechanical energy by driving the motor using the received power, or the received power can be converted into thermal energy by consuming the received power with a resistor. .

Embodiment 2. FIG.
Next, a second embodiment according to the present invention will be described. FIG. 6 is a block diagram showing a schematic configuration of the oscillation circuit 12A according to the second embodiment. The wireless power transmitting apparatus according to the present embodiment has the same configuration as the wireless power transmitting apparatus Tx according to the first embodiment, except that the oscillator circuit 12A of FIG. 6 is provided instead of the oscillator circuit 12 of the first embodiment.

  The oscillation circuit 12A according to the present embodiment includes a random voltage control unit 41 that outputs a control voltage that changes randomly or pseudo-randomly, and a high-frequency oscillator that includes a controlled terminal 40t to which the control voltage is applied. 40. The high frequency oscillator 40 outputs an oscillating wave having a frequency corresponding to the control voltage applied to the controlled terminal 40t as the radio wave Pw.

  Since the control voltage supplied to the high-frequency oscillator 40 changes randomly or pseudo-randomly, the time average of the control voltage over a certain period is substantially equal to the control voltage when the random or pseudo-random phase control is not executed. equal. Therefore, the time average of the output frequency of the high-frequency oscillator 40 during the certain period does not change. On the other hand, the output frequency of the high-frequency oscillator 40 changes randomly or pseudo-randomly within a period that is extremely shorter than the predetermined period, whereby the phase of the output wave of the oscillation circuit 12 also changes randomly or pseudo-randomly.

  The random voltage control unit 41 changes the phase of the output wave of the high-frequency oscillator 40 at random using a physical random number sequence, or changes the phase of the output wave of the high-frequency oscillator 40 at random using a pseudo-random number sequence. The control voltage to be output is output. In the case of using a physical random number sequence, the random voltage control unit 41 has a nonvolatile memory in which data of the physical random number sequence is stored, and the data may be read and used. When the pseudo random number sequence is used, the random voltage control unit 41 only needs to have an arithmetic circuit for calculating the pseudo random number sequence using a known pseudo random number generation algorithm. This type of arithmetic circuit can be constituted by a random number generation circuit using a known linear feedback shift register, for example. Further, it is possible to generate a physical random number or a pseudo-random number by using a circuit in which a nonlinear map (for example, logistic map) that generates a chaos phenomenon (non-periodic operation) appears in a voltage waveform or signal processing.

  As described above, also in the oscillation circuit 12A according to the present embodiment, the random phase modulation that changes the phase of the radio wave Pw randomly or pseudo-randomly is executed, similarly to the oscillation circuit 12 of the first embodiment. Thus, radio wave interference in the power receiving antenna element can be reduced. Further, as in the case of the first embodiment, it is possible to prevent the power transmission direction from becoming unstable due to the random phase modulation. Therefore, stable power transmission can be realized using the array antenna 10, and power transmission efficiency can be improved.

  Furthermore, in the oscillation circuit 12 according to the first embodiment, the variable phase shifter 23 disposed at a stage after the high frequency oscillator 22 shifts the output wave of the high frequency oscillator 22, so that the power loss is caused by the variable phase shifter 23. Occur. In contrast, in the oscillation circuit 12A of the present embodiment, since the oscillation frequency of the high-frequency oscillator 40 is variably controlled, there is no variable phase shifter 23 compared to the oscillation circuit 12, and power loss can be suppressed. There is an advantage.

  Note that the high-frequency oscillator 40 of the present embodiment is also from a power generation device (not shown) that generates DC power from another energy source, similarly to the high-frequency oscillator 22 (FIG. 4B) of the first embodiment. You may drive by receiving supply of DC electric power.

Embodiment 3 FIG.
Next, a third embodiment according to the present invention will be described. FIG. 7 is a block diagram showing a schematic configuration of the oscillation circuit 12B according to the third embodiment. The wireless power transmitting apparatus according to the present embodiment has the same configuration as the wireless power transmitting apparatus Tx according to the first embodiment, except that the oscillation circuit 12B of FIG. 7 is provided instead of the oscillator circuit 12 of the first embodiment.

  The oscillation circuit 12B according to the present embodiment includes a high-frequency oscillator 50 including a voltage-controlled oscillator, and a PLL (Phase-Locked Loop) circuit 51B that supplies a control voltage to the high-frequency oscillator 50 and outputs a radio wave Pw. And a random frequency division number controller 58B that changes the control voltage randomly or pseudo-randomly.

  As shown in FIG. 7, the PLL circuit 51B has a directional coupler 52 that branches a part of the output wave of the high-frequency oscillator 50, and the frequency of the branch output of the directional coupler 52 is 1 / K (K is A frequency divider 53 that outputs a frequency division frequency), a reference oscillator 54 that outputs a reference oscillation wave having a reference frequency, and a current corresponding to the phase difference between the reference oscillation wave and the frequency division or It has a phase comparator 55 that outputs a voltage, and a loop filter 56 that filters the output of the phase comparator 55 and outputs a control voltage. The high frequency oscillator 50 can output a radio wave Pw having an oscillation frequency corresponding to the control voltage input from the loop filter 56.

  The random frequency division number control unit 58B can switch the frequency division number K in the frequency divider 53 to a random or pseudo random value using a physical random number sequence or a pseudo random number sequence. Since the frequency division number K is controlled to change randomly or pseudo-randomly, the time average of the frequency division number K over a certain period is the frequency division when the random or pseudo-random frequency division control is not executed. Is substantially equal to the number. Therefore, the time average of the output frequency of the high-frequency oscillator 50 during the certain period does not change. On the other hand, the output frequency of the frequency divider 53 is changed randomly or pseudo-randomly, and the phase of the output wave of the high-frequency oscillator 50 is changed randomly or pseudo-randomly within a period shorter than the predetermined period. . As a result, the output frequency of the high-frequency oscillator 50 is constant as a time average and instantaneously changes randomly, so that the phase of the output wave changes randomly or pseudo-randomly. Therefore, the random frequency division number control unit 58B has a phase control function for changing the output phase of the high-frequency oscillator 50 randomly or pseudo-randomly.

  When the frequency division number control unit 58B uses the physical random number sequence to control the frequency division number K, the random frequency division number control unit 58B has a nonvolatile memory in which data of the physical random number sequence is stored, and reads and uses the data. do it. When the frequency division number K is controlled using a pseudo random number sequence, the random frequency division number control unit 58B has an arithmetic circuit for calculating a pseudo random number sequence by a known pseudo random number generation algorithm. Good. This type of arithmetic circuit can be constituted by a random number generation circuit using a known linear feedback shift register, for example. Further, it is possible to generate a physical random number or a pseudo-random number by using a circuit in which a nonlinear map (for example, logistic map) that generates a chaos phenomenon (non-periodic operation) appears in a voltage waveform or signal processing.

  As described above, also in the oscillation circuit 12B according to the present embodiment, the random phase modulation that changes the phase of the radio wave Pw randomly or pseudo-randomly is executed, similarly to the oscillation circuit 12 of the first embodiment. Thus, radio wave interference in the power receiving antenna element can be reduced. Further, as in the case of the first embodiment, it is possible to prevent the power transmission direction from becoming unstable due to the random phase modulation. Therefore, stable power transmission can be realized using the array antenna 10, and power transmission efficiency can be improved.

  Furthermore, since the oscillation circuit 12B according to the present embodiment employs the PLL circuit 51B that generates the control voltage while comparing the divided frequency with a highly stable reference oscillation wave, the frequency stability is obtained when viewed as a time average. There is an effect that the radio wave Pw having a high degree can be created.

  Note that the high-frequency oscillator 50 of the present embodiment is also from a power generation device (not shown) that generates DC power from another energy source, similarly to the high-frequency oscillator 22 (FIG. 4B) of the first embodiment. You may drive by receiving supply of DC electric power.

Embodiment 4 FIG.
Next, a fourth embodiment according to the present invention will be described. FIG. 8 is a block diagram showing a schematic configuration of an oscillation circuit 12C according to the fourth embodiment. The wireless power transmitting apparatus according to the present embodiment has the same configuration as the wireless power transmitting apparatus Tx according to the first embodiment, except that the oscillation circuit 12C of FIG. 8 is provided instead of the oscillator circuit 12 of the first embodiment.

  The oscillation circuit 12C according to the present embodiment includes a high-frequency oscillator 50 formed of a voltage-controlled oscillator, a PLL circuit 51C that supplies a control voltage to the high-frequency oscillator 50 and outputs a radio wave Pw, and the control voltage is random or pseudo-random. And a random phase control unit 58C for changing to

  As shown in FIG. 8, the PLL circuit 51C divides a directional coupler 52 that branches a part of the output wave of the high-frequency oscillator 50, and a frequency of the branched output of the directional coupler 52 by setting the frequency to 1 / K. A frequency divider 53 that outputs a frequency, a reference oscillator 54 that outputs a reference oscillation wave having a reference frequency, a variable phase shifter 57 that shifts the phase of the reference oscillation wave, and an output wave of the variable phase shifter 57 A phase comparator 55 that outputs a current or a voltage corresponding to a phase difference between the divided frequency and a loop filter 56 that outputs a control voltage by filtering the output of the phase comparator 55 are provided. The high frequency oscillator 50 can output the radio wave Pw having an oscillation frequency corresponding to the control voltage input from the loop filter 56, as in the case of the third embodiment.

  The random phase control unit 58C can switch the phase shift amount in the variable phase shifter 57 to a random or pseudo random value using a physical random number sequence or a pseudo random number sequence. Since the phase shift amount is controlled to change randomly or pseudo-randomly, the time average of the phase shift amount over a certain period is the phase shift amount when the random or pseudo-random phase shift amount control is not executed. Substantially equal. Therefore, the time average of the output frequency of the high-frequency oscillator 50 during the certain period does not change. On the other hand, the phase of the output wave of the variable phase shifter 57 changes randomly or pseudo-randomly, and the phase of the output wave of the high-frequency oscillator 50 changes randomly or pseudo-randomly within a period that is extremely shorter than the fixed period. Be controlled. Therefore, the random phase shift control unit 58C has a phase control function for changing the output phase of the high-frequency oscillator 50 randomly or pseudo-randomly.

  For the phase shift amount control of the variable phase shifter 57, for example, a configuration in which a control voltage is supplied from the random phase shift control unit 58C to the variable phase shifter 57 can be employed. The amount of phase shift can be changed randomly or pseudo-randomly by switching the value of the control voltage supplied to the variable phase shifter 57 to a random or pseudo-random value.

  When controlling the amount of phase shift using a physical random number sequence, the random phase shift control unit 58C has a nonvolatile memory in which data of the physical random number sequence is stored, and reads and uses the data. Good. When controlling the amount of phase shift using a pseudo random number sequence, the random phase shift control unit 58C only needs to have an arithmetic circuit for calculating a pseudo random number sequence by a known pseudo random number generation algorithm. This type of arithmetic circuit can be constituted by a random number generation circuit using a known linear feedback shift register, for example. Further, it is possible to generate a physical random number or a pseudo-random number by using a circuit in which a nonlinear map (for example, logistic map) that generates a chaos phenomenon (non-periodic operation) appears in a voltage waveform or signal processing.

  As described above, also in the oscillation circuit 12C according to the present embodiment, the random phase modulation for changing the phase of the radio wave Pw randomly or pseudo-randomly is executed as in the oscillation circuit 12 of the first embodiment. Thus, radio wave interference in the power receiving antenna element can be reduced. Further, as in the case of the first embodiment, it is possible to prevent the power transmission direction from becoming unstable due to the random phase modulation. Therefore, stable power transmission can be realized using the array antenna 10, and power transmission efficiency can be improved.

  Furthermore, the oscillation circuit 12C according to the present embodiment employs a PLL circuit 51C that generates a control voltage while comparing the divided frequency with a highly stable reference oscillation wave. There is an effect that the radio wave Pw having a high degree can be created. In addition, the phase change of the reference oscillation wave in the variable phase shifter 57 affects the oscillation frequency in the output wave of the high-frequency oscillator 50 by a frequency division number (K times). There is an advantage that a large change in the phase state can be obtained.

Although various embodiments according to the present invention have been described above with reference to the drawings, these embodiments are examples of the present invention, and various forms other than these embodiments can be adopted. For example, in the first to fourth embodiments, electrical energy can be used as a power source of the wireless power transmission devices Tx, Tx _{1 to} Tx _M , but the present invention is not limited to this, and energy other than electrical energy is used as the power source. May be used.

  Within the scope of the present invention, it is possible to freely combine Embodiments 1 to 4, to modify any component in each embodiment, or to omit any component in each embodiment.

Tx, Tx _{1 to} Tx _M wireless power transmission device, Rx wireless power reception device, 1 wireless power transmission system, 2 power generation device, 10 array antenna, 11 device body, 12, 12A, 12C oscillation circuit, 13, 13A, 13B phase control unit, 13 _{1 to} 13 _N phase controller, 14 distributor, 15 beam direction control unit, 20 _{1 to} 20 _N , 21 _{1 to} 21 _N amplifier, 22 high frequency oscillator, 23 variable phase shifter, 24 random phase control unit, 40 high frequency Oscillator, 40t controlled terminal, 41 random voltage control unit, 50 high frequency oscillator, 51B, 51C PLL circuit, 52 directional coupler, 53 divider, 54 reference oscillator, 55 phase comparator, 56 loop filter, 57 variable shift phase vessel, 58B random divisor control unit, 58C random phase shift control _unit, AN 1 _{~AN N} transmission antenna _elements, IL 1 _~IL Injection locked _oscillator, PS 1 _{~PS N} variable phase shifter.

Claims (11)

An array antenna composed of N (N is an integer of 2 or more) power transmission antenna elements regularly arranged;
An oscillation circuit that generates a radio wave having a phase that changes randomly or pseudo-randomly;
A distributor that distributes the radio waves to N transmission radio waves;
A phase control unit that radiates a power transmission beam from the N power transmission antenna elements by individually shifting the phases of the N transmission radio waves and supplying the N power transmission radio waves to the N power transmission antenna elements, respectively. Wireless power transmission device.   2. The wireless power transmission device according to claim 1, wherein the phase control unit includes N variable phase shifters that respectively phase-shift the N-system transmission radio waves.   2. The wireless power transmission device according to claim 1, wherein the phase control unit includes N injection-locked oscillators that respectively change phases of the N-system transmission radio waves.   4. The wireless power transmission apparatus according to claim 1, further comprising an amplifier circuit that individually controls amplitudes of the N-system transmission radio waves. 5.   5. The wireless power transmission device according to claim 1, wherein the oscillation circuit shifts a phase of an output wave of the high-frequency oscillator and the high-frequency oscillator randomly or pseudo-randomly. And a variable phase shifter for generating the wireless power transmission device.   5. The wireless power transmission device according to claim 1, wherein the oscillation circuit includes a random voltage control unit that outputs a control voltage that changes randomly or pseudo-randomly, and the control voltage. And a voltage-controlled oscillator that outputs an oscillation wave having a corresponding frequency as the radio wave.   5. The wireless power transmission device according to claim 1, wherein the oscillation circuit supplies a control voltage to a voltage-controlled oscillator and the voltage-controlled oscillator, and the voltage-controlled oscillator supplies the control voltage to the voltage-controlled oscillator. A wireless power transmission apparatus comprising: a PLL circuit that outputs radio waves; and a random phase control unit that controls an operation of the PLL circuit to change an output phase of the voltage controlled oscillator randomly or pseudo-randomly.   The wireless power transmission apparatus according to any one of claims 1 to 7, wherein the power transmission beam is made of a microwave.   The wireless power transmission device according to claim 1, wherein the wireless power transmission device uses energy other than electric energy as a power source.   A wireless power transmission system comprising a plurality of wireless power transmission devices according to any one of claims 1 to 9. A wireless power transmission system, comprising: the wireless power transmission device according to any one of claims 1 to 9 ; and a wireless power reception device that is an energy source conversion device for other than electrical energy.

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