JP2004007932A - Microwave transmitting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize an accurate phase synchronization control in a plurality of transmitting units separately constituted, while eliminating necessity of a phase synchronization control means common to a system, and further to prevent a system down by a fault of the partial transmitting unit. <P>SOLUTION: Each power transmitting unit distributes a pilot signal received by a receiving antenna 11 to each transmitting unit by distributor 13, a phase difference between the pilot signal of the won unit and that of the other unit is detected by a phase difference detecting circuit 14, a conjugate phase generating circuit 15 calculates a transmitting angle of the pilot signal from the phase difference, and obtains phase control values δ1 to δn for directing a microwave transmitting beam to the direction, and the microwave transmitted from the microwave power transmitter 18 is phase controlled by a phase shifter 17. A phase synchronizing circuit 20 makes phase synchronization controls to correct the phase error included in the pilot signal received by each transmitting unit. <P>COPYRIGHT: (C)2004,JPO

Description

【００４８】
とすると、ユニット１での位相遅延φ_１（１）〜φ_１（ｎ）は、それぞれ以下の演算になる。
【００４９】
【数７】

【００５０】
但し、等比級数を用いて、
【００５１】
【数８】

【００５２】
とした。
【００５３】
このように、ユニット１での位相遅延φ_１（ｎ）は、（φ_１＋φ_２＋φ_３）／３に収束し、位相同期状態を維持することができる。同様に、ユニット２、３の位相遅延φ_２（ｎ）、φ_３（ｎ）についても、（φ_１＋φ_２＋φ_３）／３に収束し、位相同期状態を維持することができる。
【００５４】
（実施形態２）
図４は、本発明の他の実施形態を示すシステム構成図である。同図は図１と原理的には同等になり、異なる部分を以下に説明する。
【００５５】
パイロット信号を受信アンテナ１０１で受信し、位相共役生成回路１０２にて、受信パイロット信号の共役位相信号を生成する。この信号に、隣接ユニットとの位相差を検出するための基準信号同期回路１０３によって、算出された位相補正値を重畳する。基準信号同期回路１０３は、パイロット信号を隣接する送電ユニットへ伝送、返送して、ユニット間の位相差を検出する回路であり、隣接ユニットととは、送受信アンテナ１０４，１０５でインタフェースを得る。
【００５６】
位相共役回路１０２からの信号は、分配器１０６によって、同一送信ユニット内のマイクロ波電力送信部１０７に伝送される。マイクロ波電力送信部１０７では、同一送信ユニット内に設置されたパイロット受信アンテナで受信した信号の位相差δ１〜δｎを位相差検出回路１０８にて算出し、ここで得られた結果を、各マイクロ波電力送信部１０７の構成品である移相器に移相量を与える。
【００５７】
図５は基準信号同期回路１０３の構成を示す。パイロット信号受信アンテナ１１１で受信したパイロット信号は、分配器１２１によって分配され、送信アンテナ１１２によって隣接ユニットへ伝送する。隣接ユニットからは、送信アンテナ１１２によって伝送された信号を受信アンテナ１１３で受信したものと、隣接ユニットで受信したパイロット信号を受信アンテナ１１４で受信したものの２種の信号が伝送される。受信アンテナ１１３で受信した信号は、ミキサ１１５、フィルター１１６、分割器１１７を用いてユニット間の位相差成分のみを算出するとともに、受信アンテナ１１４で受信した信号も同様にミキサ１１８、フィルター１１９を通してパイロット信号と隣接ユニットのパイロット信号の位相差信号を算出する。両者の信号をミキサ１２０で合成した信号を分配器１２１で分配された信号とミキサ１２４で合成することによって隣接ユニットにおける位相差を得ることができる。この値をＶＣＯ（電圧制御発振器）１２５でコントロールすることによって、ＰＬＬを構成する。ここで得られた信号は、分配器１２６によって、共役位相生成回路１０２へ伝送すると共に、送信アンテナ１２７を用いて次の隣接ユニットへ、ユニット間基準信号情報を伝送する。
【００５８】
（実施形態３）
図６〜図８は本発明の他の実施形態を示し、送信ユニット間のつながりを示したものである。図６は、ユニット間基準信号情報のネットワーク構成を示したものである。ユニット間位相差の基準として複数の送信ユニットから構成されるマスターネットワーク１３１を設定する。このマスターネットワーク１３１で、ユニット間の位相補正を行い、その値が図５で示したユニット間位相同期回路を介して隣接するスレーブネットワーク１３２〜１３７へ伝送する。
【００５９】
図７の（ａ）は、マスターネットワークの内部構成を示したものである。マスターネットワーク内では、ユニット間位相差の基準となる送信ユニット１４１があり、このユニットと隣接するユニット１４２間で位相補正を行う。この位相補正を１４３，１４４，１４５…と順次行い、ユニット１４７まで行う。各ユニットで補正された値は、各ユニットから隣接するスレーブネットワーク内のユニットに伝送される。万が一、マスターネットワーク内の接続の一部が切断された場合には、図７の（ｂ）に示す手順で、♯１〜♯６（マスターネットワーク１４１−１４７）間の接続を立ち上げ、正常動作を維持する。
【００６０】
図８は、スレーブネットワークの内部構成を示したものである。スレーブネットワーク内では、マスターネットワークからの位相補正情報を隣接するスレーブネットワーク内のユニット１５１で受信する。ユニット１５１で受信した位相補正情報は、順次図５に示す各ユニットの基準信号同期回路を介してスレーブネットワーク１５２−１６２間の位相補正を行っていく。
【００６１】
本スレーブネットワークを構成するユニットの一部１５２，１５８では、さらに隣接するスレーブネットワークへ位相情報を伝送する。基本的に位相情報の伝送は、図中実線の系で行われるが、いずれかのユニットが故障した場合も、点線で示す系を立ち上げ、正常動作を維持するものとする。
【００６２】
以上のように、本実施形態では、複数の導電ユニットで構成されるマスターネットワーク間で基準信号の同期を行い、その同期された信号を別の複数ユニットで構成されるスレーブネットワークに接続し、複数ユニット間の位相同期を行う。マスターネットワーク間の位相同期は、ある基準となるユニット（図示では♯０）において、パイロット信号を受信すると、ユニット♯１に位相情報を伝送する。そして、ユニット♯１では、ユニット♯０からの信号を組み合わせてユニット♯０と♯１間の位相同期を行う。これをユニット♯２→♯３→…と行っていくことにより、最終的にユニット♯Ｎまですべてユニット♯０と位相同期を得ることができる。つまり、基準となるユニット♯０が全体のユニットに対する位相基準となる。ただし、ユニット♯０は位相基準発振器を設けるものでなく、位相基準となるものは、地上からのパイロット信号である。
【００６３】
なお、以上までの実施形態では、マイクロ波送電システムの場合を示すが、本発明は複数の送信ユニットに分離構成した移動体用通信システム等に適用して同等の作用効果を得ることができる。
【００６４】
【発明の効果】
以上のとおり、本発明によれば、複数の送信ユニットが受信するパイロット信号を無線通信で送信ユニット間で互いに伝送し、パイロット信号間の位相差分を基に位相同期制御を送信ユニット毎に行うようにしたため、以下の効果がある。
【００６５】
（１）複数の送信ユニットからある目標装置に信号または電力を送信するのに、システムに共通の位相同期制御手段を不要にしながら分離構成した複数の送信ユニットの位相同期制御ができる。
【００６６】
（２）一部の送信ユニットや送信衛星の故障にも残りの健全な送信ユニットや送信衛星によるマイクロ波送信を継続でき、システムダウンを回避できる。
【００６７】
（３）各送電ユニットを分離構成した場合、それらの間のひずみ、ねじれ等による高低差がパイロット信号の位相誤差となる場合にも、これら誤差を位相同期回路によって自動的に補正することができ、高精度位相同期制御ができる。
【図面の簡単な説明】
【図１】本発明の実施形態１を示すマイクロ波送電システムの構成図。
【図２】実施形態１における位相同期回路の回路構成例。
【図３】実施形態１における位相同期回路の計算アルゴリズムを説明するための図。
【図４】本発明の実施形態２を示すマイクロ波送電システムの構成図。
【図５】実施形態２における位相同期回路の回路構成例。
【図６】本発明の実施形態３を示すユニット間の基準信号情報のネットワーク構成図。
【図７】実施形態３におけるマスターネットワークの内部構成図。
【図８】実施形態３におけるスレーブネットワークの内部構成図。
【図９】送電システムの概略構成図。
【図１０】レトロディレクティブ方式の原理的な説明図。
【図１１】分散送電方式の概略構成図。
【符号の説明】
１１、２１…パイロット信号受信アンテナ
１２、２２…逓倍器
１３、１６、２５、２９、３２…分配器
１４…位相差検出回路
１５…共役位相生成回路
１７、２３、２６…移相器
１８…マイクロ波電力送信部
１９…送信アンテナ
２０…位相同期回路
２４、２７…位相比較器
２８…分割器
４１…加算器
４２…割算器
１０１…パイロット信号受信アンテナ
１０２…共役位相生成回路
１０３…基準信号同期回路
１０６…分配器
１０７…マイクロ波電力送信部
１０８…位相差検出回路
１３１、１４１〜１４７…マスターネットワーク
１３２〜１３７、１５１〜１６２…スレーブネットワーク[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a microwave transmission system for transmitting power or transmitting a signal from a plurality of transmission units to the same target device by microwaves, and particularly to a microwave transmission system using a phase difference between pilot signals transmitted from a target device side. The present invention relates to a method for obtaining phase synchronization with a transmitted microwave.
[0002]
[Prior art]
As this type of system, for example, there is a microwave power transmission system for transmitting electric power generated by a solar power generation satellite to a power receiving device by microwave, or a mobile communication system.
[0003]
The microwave power transmission system uses a solar power satellite launched from the earth into a geosynchronous orbit as a power generation device to generate power using solar energy, and this power is transmitted from the microwave antenna element to a power receiving device at a power generation base on the ground side, for example. The power is transmitted to the power generation base and used as power. Note that the power receiving device may be provided at a power generating base on the ground side, or may be provided at a flying object, a space station, a space factory, or the like as a power transmission target.
[0004]
In such a power transmission system, as shown in a schematic configuration in FIG. 9, since the construction of a power generation satellite has a limitation on the mass and volume in one equipment launch transport, the power generation satellite is divided into a plurality of power transmission units 1a to 1n. It is preferable to unitize the power transmission from the antenna elements of the power transmission units 1a to 1n to the power generation base 2.
[0005]
In this case, in order to make the microwaves transmitted by the power transmission units 1a to 1n converge in the same direction as the arrival direction of the pilot signal and have the same phase, the microwaves transmitted from the power transmission units are phase-adjusted and transmitted to the power generation base 2. There is a need to. For this reason, there is provided a control device 3 for performing phase synchronization control between power transmission units in a retrodirective system, which is one type of phased array antenna, based on the phase difference between pilot signals received by each of the power transmission units 1a to 1n. Various phase synchronization control methods and circuit configurations have been proposed, and are also used in mobile communication systems.
[0006]
For example, JP-A-6-327172 and JP-A-8-37743, 1983 IEICE General Conference, "One Method of Improving Beam Direction Error of 782 Retro Directive Array Antenna", IEEE TRANSACTION ON ANTENNAS AND PROPAGATION. VOL AP-27 No. 4JULY 1979, "Large Active Retroactive Array for Space Applications".
[0007]
The above-described retrodirective method will be described in principle in the case of a microwave power transmission system with reference to FIG. In FIG. 10, the position of the power receiving device is A, a pilot signal having a frequency ω _i is radiated from the position A toward the power transmission unit, and the pilot signal is received by each antenna element on the power transmission unit side, and the frequency ω _t Is radiated toward the position A. At this time, assuming that the pilot signal emitted from position A arrives at the center (reference point) P ₀ on the power transmission unit side at a distance x ₀ after time t, the phase of the pilot signal at reference point P ₀ is ,
[0008]
(Equation 1)
φ ₀ = ω _i (t ₀ −x ₀ / C) (1)
It becomes. Here, C is the speed of light. Similarly, the phase at a point P ₁ on the power transmission unit side that is a distance x ₁ away from the position A is
[0009]
(Equation 2)
φ ₁ = ω _i (t ₀ −x ₁ / C) (2)
It is expressed as The phase difference Φ _i between the two points at this time is
[Equation 3]
_{Φ i = φ 1 -φ 0 =} -ω i r / C ... (3)
It becomes. However, it is _{r =} x 1 -x _0.
[0011]
At the point P _0, P _1, if tentatively radiate microwaves in phase, the phase difference at position A, since the frequency of the microwave is omega _t, from equation (3),
[0012]
(Equation 4)
_{Φ t = -ω t r / C} ... (4)
It becomes. Therefore, in order for the phases of the microwaves from the two points P ₀ and P ₁ to be equal at the position A,
[0013]
(Equation 5)
_{Φ c = ω t r / C} ... (5)
The better to phase adjustment in P ₁ point. By performing this phase adjustment in each power transmission unit, the phases of all the microwaves emitted from each power transmission unit become equal at the position A. This is the retro-directive phase synchronization method.
[0014]
In order to apply the above-described retrodirective method to all antenna elements of each power transmission unit, each power transmission unit is provided with a pilot signal receiving system and a phase conjugate circuit. For this reason, a large number of power transmitting antenna elements are divided into several sub-array blocks, one pilot signal receiving system and one phase conjugate circuit are provided for each sub-array, and all antenna elements in each sub-array receive the same phase. The method of transmitting power is adopted.
[0015]
Furthermore, in order to transmit a large amount of power to the power receiving device, a plurality of power generation satellites of the retrodirective system and the sub-array antenna system are each transmitted to one power receiving device as a power transmitting unit, and the distributed power transmission is integrated on the power receiving device side. A scheme has also been proposed.
[0016]
For example, the system proposed in JP-A-2001-309581 has the configuration shown in FIG. The three power generation satellites 4 to 6 transmit microwave power to the micro receiving antenna 2A of the power generation base 2. In this distributed power transmission system, a control satellite 7 is provided in the direction of the antenna 2A viewed from each of the power generation satellites 4 to 6 and the phase synchronization of microwaves reaching the antenna 2A from each of the power generation satellites 4 to 6, and controls the reception of pilot signals. The satellite 7 performs phase synchronization control between the power generation satellites by a retrodirective method. It should be noted that a method in which one power generation satellite 6 has the control function of the control satellite 7 is also disclosed.
[0017]
[Problems to be solved by the invention]
The microwave power transmission system shown in FIG. 9 is divided into a plurality of power transmission units, and since these power transmission units are integrated into a single structure that is mechanically coupled to each other, high-precision phase synchronization control using a retrodirective method is possible. become. However, when each power transmission unit is a system mechanically separated from each other, there are the following problems.
[0018]
In the microwave power transmission system illustrated in FIG. 9, control device 3 detects a phase change between power transmission units 1 a to 1 n that respectively receive pilot signals by a phase difference detection circuit, and detects the information and the pilot detected by the angle detection circuit. Based on the information on the direction of arrival of the signal, the phase difference at which the microwave transmitted from the antenna element of each of the power transmission units 1a to 1n converges to the power receiving device of the power generation base 2 is calculated, and the phase difference of the microwave transmitted by each power transmission unit is calculated. Control the phase.
[0019]
Here, if the power transmission unit is configured separately, the height difference due to distortion between units, torsion, etc. becomes a phase error of the pilot signal, and the radiation direction is calculated by the phase difference detection circuit while having an offset, There is a risk that microwave power will be transmitted in a direction different from the original.
[0020]
Further, since the conventional system has a configuration in which the control device 3 and each power transmission unit are connected by wire, it can be applied only to a power generation satellite having a configuration in which each power transmission unit is integrally connected.
[0021]
Further, when a failure occurs in the control device 3, even if each power transmission unit is sound, phase synchronization cannot be achieved, and there is a possibility that the system will be down.
[0022]
Similarly, in the system shown in FIG. 10, each power generation satellite is separately configured as a plurality of power transmission units, and a height difference between power transmission units (between power generation satellites) is generated as a shift in the direction of microwaves. Further, if the control satellite 7 breaks down, even if each power generation satellite is healthy, phase synchronization between the satellites cannot be obtained, and the system may be down. Even when one power generation satellite is equipped with the function of a control satellite, if the power generation satellite equipped with this function fails, the system goes down.
[0023]
In addition, there is a similar problem when the present invention is applied to a mobile communication system or the like configured to be separated into a plurality of transmission units.
[0024]
An object of the present invention is to enable high-precision phase synchronization control of a plurality of separated transmission units while eliminating the need for a common phase synchronization control means in the system. Another object of the present invention is to provide a microwave transmission system capable of continuing microwave transmission by a simple transmission unit.
[0025]
[Means for Solving the Problems]
The present invention solves the above problems by transmitting pilot signals received by a plurality of transmission units among the transmission units by wireless communication, and for each transmission unit, performing phase synchronization based on a phase difference between the pilot signals. Performing control, or a certain reference transmission unit generates a phase reference signal from a pilot signal, and the other transmission units perform phase synchronization control using this as a phase reference, characterized by the following configuration I do.
[0026]
(1) When transmitting power or transmitting a signal to the same target device by microwaves from a plurality of separated transmission units, a phase difference between pilot signals sent from the target device to each of the transmission units is detected, and the phase difference is detected. A microwave transmission system that performs phase synchronization of microwaves transmitted from each transmission unit based on the
Each of the transmission units includes a phase synchronization circuit that performs phase synchronization control based on a phase difference between pilot signals transmitted between the transmission units.
[0027]
(2) The phase locked loop controls phase synchronization by comparing the phase of a pilot signal received by its own unit with a pilot signal received by another unit, and generates a reference signal between each unit for each unit. It is characterized by having.
[0028]
(3) A configuration in which the phase synchronization circuit performs phase synchronization control with a plurality of other units by averaging the phase difference between a pilot signal received by the own unit and a pilot signal received from a plurality of other units. It is characterized in that.
[0029]
(4) The phase synchronization circuit generates a phase reference signal from a pilot signal received by a reference transmission unit, and the other transmission units perform phase synchronization control based on a phase difference between a received pilot signal and the phase reference signal. Is performed.
[0030]
(5) The phase synchronization circuit transmits a pilot signal received by its own unit as a pilot signal in phase synchronization control of another unit, and also receives a pilot signal reciprocating in another unit, and transmits the pilot signal by reciprocal transmission. The transmission delay of a pilot signal received from another unit is corrected based on the transmission delay.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
(Embodiment 1)
FIG. 1 is a configuration diagram of a case where the present invention is applied to a microwave power transmission system according to an embodiment of the present invention. The power generation satellite is divided into n power transmission units, and microwaves transmitted from each power transmission unit are retro-directed. This is a case where phase synchronization control is performed by
[0032]
Each of the N power transmission units multiplies N pilot signals received by the n reception antennas 11 of the N power transmission units by a multiplier 12, and one of the pilot signals is distributed to each signal processing circuit in the power transmission unit by a distributor 13. The signals are distributed, and the remaining pilot signals are directly connected to the phase difference detection circuit 14.
[0033]
In each power transmission unit, the phase difference detection circuit 14 detects the phase difference between the pilot signal received by itself and other pilot reception signals in the same unit, and determines the arrival direction (transmission angle) of the pilot signal from this phase difference. And the phase control values δ1 to δn for directing the microwave power transmission beam in that direction. The conjugate phase generation circuit 15 is a circuit that superimposes a conjugate phase of a signal from the distributor 13 and a phase synchronization signal from an adjacent unit and transmits the signal to a subsequent stage.
[0034]
The distributor 16 distributes the conjugate phase wave of the pilot signal generated by the conjugate phase generation circuit 15 to the microwave generator (PCM) 17 in the power transmission unit. The microwave power transmission unit 17 in the same power transmission unit has a phase shifter for controlling the phase control values δ1 to δn, a magnetron as a microwave generation source, and a waveguide for transmitting and emitting microwaves. Then, a microwave controlled to the phase corrected by the phase shifter is generated. The power transmitting antenna 19 of each power transmitting unit radiates the microwave from the transmitting unit 18 toward the ground power receiving antenna.
[0035]
In the configuration described above, the direction of arrival of the transmitted microwave is calculated by the phase difference detection circuit 14 after receiving the pilot signal. At this time, if the power transmission units are separated into n units, the height difference due to distortion or twist between the units becomes a phase error of the pilot signal, and the radiation direction is calculated by the phase difference detection circuit 14 with the offset. As a result, the microwave receiving efficiency is reduced due to interference in a direction different from the original direction or on the power receiving surface.
[0036]
Therefore, the received pilot signal is also introduced into the phase synchronization circuit 19 through the distributor 13, and in the phase synchronization circuit 19, based on the phase difference between the pilot signals received by each power transmission unit in wireless communication through a propagation path between the units. The phase synchronization control is performed, and this phase correction amount is used for the phase control calculation in the conjugate phase generation circuit 15, thereby enabling the original beam control.
[0037]
FIG. 2 shows a circuit configuration of the phase synchronization circuit 19, in which phase synchronization between two power transmission units is obtained. Both units are provided with the same configuration of the phase synchronization circuit, and the following description will be made mainly with respect to the unit 1.
[0038]
In the unit 1, the pilot signal is received by the antenna 21 and is multiplied by the multiplier 22 to be converted into a pilot high-frequency signal. Then, the distributor 23 introduces a part of the high-frequency signal into the phase locked loop.
[0039]
The phase shifter 24 and the phase comparator 25 are configured in a phase locked loop (PLL) through a four divider 26, and the pilot high frequency signal received from the unit 2 obtained by the pilot 23 from the distributor 23 and the phase shifter 27 is combined with the pilot high frequency signal. Are repeated, and the operation of controlling the amount of phase shift of the phase shifter 24 in accordance with the phase difference is repeated, so that the phase synchronization of the pilot signals received by the units 1 and 2 is obtained. The high-frequency signal is extracted as a reference phase signal of the unit 1 through the four divider 26.
[0040]
The phase comparator 28, the divider 29, and the two divider 30 correct a transmission delay when the pilot high-frequency signal of the unit 2 is wirelessly transmitted to the unit 1. To this end, the pilot high-frequency signal obtained by the four-divider 26 of the unit 1 is transmitted to the unit 2 through the antenna 31, the signal is received by the antenna 32 of the unit 2, and the signal is distributed by the two-divider 33 to obtain the unit. The signal is taken in as a pilot high-frequency signal from 1 and transmitted to the antenna 35 of the unit 1 through the antenna 34, and this signal is used as a phase comparison input of the phase comparator 28 of the unit 1.
[0041]
The phase comparator 28 detects the phase difference between the signal transmitted to the unit 2 and the signal received back and forth in the unit 2 to obtain a phase difference corresponding to the transmission delay of the signal back and forth in the unit 2. By dividing the signal into two by the divider 29, a phase difference corresponding to a one-way transmission delay from the unit 2 to the unit 1 is obtained. By adjusting the phase shift amount of the phase shifter 27 with this phase difference, a signal in which the transmission delay of the pilot high-frequency signal received from the unit 2 is corrected is obtained at the output.
[0042]
According to the phase synchronization circuit configured as described above, by transmitting and receiving a pilot high-frequency signal between a plurality of power transmission units, it is possible to generate a reference signal for the power transmission system, and generate a reference signal for phase synchronization control. There is no need to provide a separate vessel. As a result, even in a system configuration in which a plurality of power transmission units are separately configured, phase synchronization control can be performed without using a control device or control satellite common to the conventional system. Moreover, since the phase synchronization control is performed by the cooperation of the plurality of power transmission units, when some of the units fail, the phase synchronization control by the remaining healthy units can be continued, and a system down can be avoided.
[0043]
In addition, when each power transmission unit is separately configured, even when a height difference due to distortion, twist, etc. between them becomes a phase error of a pilot signal, these errors can be automatically corrected by a phase synchronization circuit, High-precision phase synchronization control is possible.
[0044]
FIG. 3 is a schematic diagram (a) and a circuit block diagram (b) for explaining a calculation algorithm by the phase synchronization circuit 19, and circuits equivalent to those in FIG. 2 are denoted by the same reference numerals.
[0045]
As shown in FIG. 2A, when the power transmission units 1 to 3 receive pilot signals and the units 2 and 3 transmit the received pilot signals to the power transmission unit 1, the phase synchronization control in the unit 1 is performed. This is a circuit block shown in FIG. In this block diagram, an adder 41 adds a phase difference ε2 between units 1 and 3 to a phase difference ε1 between units 1 and 2, and a divider 42 divides by the number of units added by the adder 41. To obtain the average value of the phase difference.
[0046]
Now, let the phase delays φ of the pilot signals received by the units 1 to 3 be φ ₁ = φ ₁ (0) = r / C, φ ₂ (0) = φ ₂ , φ ₃ (0) = φ _3, and The phase delay when n repetitive operations are performed by the phase locked loop of the phase shifter 24, the phase comparator 25, the distributor 26, the adder 41, and the divider 42,
[0047]
(Equation 6)

[0048]
Then, the phase delays φ ₁ (1) to φ ₁ (n) in the unit 1 are calculated as follows.
[0049]
(Equation 7)

[0050]
However, using geometric series,
[0051]
(Equation 8)

[0052]
And
[0053]
As described above, the phase delay φ ₁ (n) in the unit 1 converges to (φ ₁ + φ ₂ + φ ₃ ) / 3, and the phase synchronization state can be maintained. Similarly, the phase delays φ ₂ (n) and φ ₃ (n) of the units 2 and 3 converge to (φ ₁ + φ ₂ + φ ₃ ) / 3, and can maintain the phase synchronization state.
[0054]
(Embodiment 2)
FIG. 4 is a system configuration diagram showing another embodiment of the present invention. This figure is equivalent in principle to FIG. 1, and different parts will be described below.
[0055]
The pilot signal is received by the receiving antenna 101, and a phase conjugate generation circuit 102 generates a conjugate phase signal of the received pilot signal. A phase correction value calculated by the reference signal synchronization circuit 103 for detecting a phase difference with an adjacent unit is superimposed on this signal. The reference signal synchronization circuit 103 is a circuit that transmits and returns a pilot signal to an adjacent power transmission unit and detects a phase difference between the units, and obtains an interface with the adjacent unit by transmitting and receiving antennas 104 and 105.
[0056]
The signal from the phase conjugation circuit 102 is transmitted by the distributor 106 to the microwave power transmission unit 107 in the same transmission unit. In the microwave power transmission unit 107, the phase differences δ1 to δn of the signals received by the pilot receiving antennas installed in the same transmission unit are calculated by the phase difference detection circuit 108, and the result obtained is A phase shift amount is given to a phase shifter which is a component of the wave power transmission unit 107.
[0057]
FIG. 5 shows the configuration of the reference signal synchronization circuit 103. The pilot signal received by the pilot signal reception antenna 111 is distributed by the distributor 121 and transmitted to the adjacent unit by the transmission antenna 112. Two types of signals are transmitted from the adjacent unit, one in which the signal transmitted by the transmission antenna 112 is received by the reception antenna 113 and the other in which the pilot signal received by the adjacent unit is received by the reception antenna 114. For the signal received by the receiving antenna 113, only the phase difference component between the units is calculated using a mixer 115, a filter 116, and a divider 117, and the signal received by the receiving antenna 114 is similarly pilot-passed through a mixer 118 and a filter 119. The phase difference signal between the signal and the pilot signal of the adjacent unit is calculated. A phase difference between adjacent units can be obtained by combining a signal obtained by combining the two signals with the mixer 120 and a signal distributed by the distributor 121 with the mixer 124. By controlling this value by a VCO (voltage controlled oscillator) 125, a PLL is formed. The obtained signal is transmitted to the conjugate phase generation circuit 102 by the distributor 126, and the inter-unit reference signal information is transmitted to the next adjacent unit using the transmission antenna 127.
[0058]
(Embodiment 3)
6 to 8 show another embodiment of the present invention and show connections between transmission units. FIG. 6 shows a network configuration of the inter-unit reference signal information. A master network 131 composed of a plurality of transmission units is set as a reference for the phase difference between units. The master network 131 corrects the phase between the units and transmits the value to the adjacent slave networks 132 to 137 via the inter-unit phase synchronization circuit shown in FIG.
[0059]
FIG. 7A shows the internal configuration of the master network. In the master network, there is a transmission unit 141 serving as a reference for the phase difference between units, and phase correction is performed between this unit and an adjacent unit 142. This phase correction is sequentially performed for 143, 144, 145,. The value corrected by each unit is transmitted from each unit to an adjacent unit in the slave network. In the unlikely event that a part of the connection in the master network is disconnected, the connection between # 1 to # 6 (master networks 141-147) is started up according to the procedure shown in FIG. To maintain.
[0060]
FIG. 8 shows the internal configuration of the slave network. In the slave network, the phase correction information from the master network is received by the unit 151 in the adjacent slave network. The phase correction information received by the unit 151 sequentially corrects the phase between the slave networks 152 and 162 via the reference signal synchronization circuit of each unit shown in FIG.
[0061]
Some of the units 152 and 158 constituting the slave network transmit phase information to further adjacent slave networks. Basically, the transmission of the phase information is performed by the system indicated by the solid line in the figure. However, even if one of the units fails, the system indicated by the dotted line is started up to maintain the normal operation.
[0062]
As described above, in the present embodiment, the reference signal is synchronized between the master networks composed of a plurality of conductive units, and the synchronized signal is connected to the slave network composed of another plurality of units. Performs phase synchronization between units. The phase synchronization between the master networks is such that when a pilot signal is received in a unit serving as a reference (# 0 in the figure), the phase information is transmitted to the unit # 1. Unit # 1 performs phase synchronization between units # 0 and # 1 by combining signals from unit # 0. By performing this operation from the unit # 2 to the unit # 3,..., Phase synchronization with the unit # 0 can finally be obtained for all the units #N. That is, the reference unit # 0 is a phase reference for all units. However, unit # 0 is not provided with a phase reference oscillator, and the one serving as a phase reference is a pilot signal from the ground.
[0063]
In the embodiments described above, the case of the microwave power transmission system is described. However, the present invention can be applied to a mobile communication system or the like in which a plurality of transmission units are separately provided to obtain the same operation and effect.
[0064]
【The invention's effect】
As described above, according to the present invention, pilot signals received by a plurality of transmission units are mutually transmitted between the transmission units by wireless communication, and phase synchronization control is performed for each transmission unit based on a phase difference between the pilot signals. Therefore, the following effects are obtained.
[0065]
(1) In transmitting signals or power from a plurality of transmission units to a target device, phase synchronization control of a plurality of transmission units separately configured can be performed without using a phase synchronization control unit common to the system.
[0066]
(2) Even if some of the transmitting units and transmitting satellites fail, microwave transmission by the remaining healthy transmitting units and transmitting satellites can be continued, and system down can be avoided.
[0067]
(3) When each power transmission unit is separately configured, even when a difference in height due to distortion, twist, or the like between them results in a phase error of the pilot signal, these errors can be automatically corrected by the phase synchronization circuit. And high-precision phase synchronization control.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a microwave power transmission system according to a first embodiment of the present invention.
FIG. 2 is a circuit configuration example of a phase locked loop circuit according to the first embodiment.
FIG. 3 is a diagram for explaining a calculation algorithm of a phase locked loop according to the first embodiment.
FIG. 4 is a configuration diagram of a microwave power transmission system according to a second embodiment of the present invention.
FIG. 5 is a circuit configuration example of a phase locked loop circuit according to a second embodiment.
FIG. 6 is a network configuration diagram of reference signal information between units according to the third embodiment of the present invention.
FIG. 7 is an internal configuration diagram of a master network according to a third embodiment.
FIG. 8 is an internal configuration diagram of a slave network according to a third embodiment.
FIG. 9 is a schematic configuration diagram of a power transmission system.
FIG. 10 is a diagram illustrating the principle of the retrodirective method.
FIG. 11 is a schematic configuration diagram of a distributed power transmission system.
[Explanation of symbols]
11, 21 pilot signal receiving antennas 12, 22 multipliers 13, 16, 25, 29, 32 distributor 14 phase difference detection circuit 15 conjugate phase generation circuits 17, 23, 26 phase shifter 18 micro Wave power transmitting unit 19 ... Transmission antenna 20 ... Phase synchronization circuits 24 and 27 ... Phase comparator 28 ... Divider 41 ... Adder 42 ... Divider 101 ... Pilot signal reception antenna 102 ... Conjugate phase generation circuit 103 ... Reference signal synchronization Circuit 106 Distributor 107 Microwave power transmission unit 108 Phase difference detection circuits 131, 141 to 147 Master networks 132 to 137, 151 to 162 Slave network

Claims (5)

When transmitting power or transmitting a signal to the same target device by microwaves from a plurality of separated transmission units, a phase difference of a pilot signal sent from the target device to each of the transmission units is detected, and based on the phase difference. A microwave transmission system that performs phase synchronization of microwaves transmitted from each transmission unit by a retrodirective method,
The microwave transmission system, wherein each of the transmission units includes a phase synchronization circuit that performs phase synchronization control based on a phase difference between pilot signals transmitted between the transmission units. The phase synchronization circuit includes a phase locked loop that performs phase synchronization control by comparing the phase of a pilot signal received by its own unit with a pilot signal received by another unit, and generates a reference signal between each unit for each unit. The microwave transmission system according to claim 1, wherein: The phase synchronization circuit is configured to perform phase synchronization control between a plurality of other units by averaging and averaging the phase differences between a pilot signal received by the own unit and a pilot signal received from a plurality of other units. The microwave transmission system according to claim 1 or 2, wherein: The phase synchronization circuit is configured to generate a phase reference signal from a pilot signal received by a reference transmission unit, and perform another phase synchronization control based on a phase difference between a pilot signal to be received and the phase reference signal. The microwave transmission system according to claim 1 or 2, wherein: The phase synchronization circuit transmits a pilot signal received by its own unit as a pilot signal for phase synchronization control of another unit, and also receives as a pilot signal reciprocated to and from another unit. The microwave transmission system according to any one of claims 1 to 4, wherein the transmission delay amount of a pilot signal received from another unit is corrected based on the following.

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