JP4486539B2 - Phased array antenna and phase control method thereof - Google Patents

Description

  The present invention relates to a phased array antenna applied to, for example, SSPS (Space Solar Power System), and more particularly to a phased array antenna capable of controlling the direction of a power transmission beam to a power receiving facility with high accuracy and a phase control method thereof. Is.

In recent years, environmental problems such as global warming and energy problems such as depletion of fossil fuels have been highlighted as the amount of carbon dioxide emissions increased due to the use of fossil fuels. For this reason, the demand for clean energy is increasing year by year, and the SSPS plan is cited as one of the solutions to these problems.
In the SSPS plan, as shown in FIG. 6, an artificial satellite equipped with a huge solar cell panel is launched above the equator, and electric power generated by sunlight is converted into microwaves by a transmission module in the solar cell panel. Then, the microwave 100 is transmitted from the microwave power transmission unit 101 to the power receiving facility 102 provided on the ground, and converted into electric power again on the ground and used.
As a result, clean energy can be stably supplied without being influenced by the weather and time zone, which are disadvantages of solar power generation. In order to realize this plan, high power transmission, microwave beam control, reduction of operation cost, and the like are listed as technical issues. As one of the methods for satisfying them, stacked active integration in the microwave transmission unit 101 is performed. A method using an antenna (Active Integrated Antenna: AIA) is mentioned. In order to further increase the efficiency of power transmission, it is considered to install a retrodirective function on the above-mentioned laminated active integrated antenna.

  The retrodirective function refers to receiving a pilot signal (induction signal) transmitted from the power receiving facility 102 provided on the ground by the power transmission antenna included in the microwave power transmission unit 101, and transmitting phase information of the received pilot signal to the power transmission antenna. This is a function of directing the transmission wave in the direction of arrival of the pilot signal by reflecting it in the transmission wave radiated from.

This retrodirective function is a method that is often used in the past, and an example thereof is disclosed in, for example, Japanese Patent Application Laid-Open No. 8-37743 (Patent Document 1). In addition, in the technique disclosed in Japanese Patent Application Laid-Open No. 2004-32879 (Patent Document 2), the detection accuracy of the pilot signal arrival direction angle is improved in the retrodirective function, and the accuracy of phase control of the transmission wave is improved. ing.
JP-A-8-37743 JP 2004-32879 A

By the way, in the power transmission antenna in SSPS as described above, a large-area antenna panel is constructed by coupling two-dimensionally arranged approximately 1 m square antenna panels 200 at coupling points. For this reason, as shown in FIG. 7, each antenna panel 200 may be bent around the junction point P. Moreover, since each panel 200 is not a rigid body, each panel 200 may vibrate continuously.
Even in such a case, by using the above-described retrodirective function, it is possible to align the transmission direction of the transmission wave for each antenna panel 200 as shown in FIG.

  However, since the phase planes of the microwaves radiated from the respective antenna panels 200 cannot be aligned as a whole panel, there is a problem that high power transmission efficiency cannot be obtained. In addition, since the phase planes of the microwaves are different between the antenna panels 200, unnecessary waves with high power levels may be radiated in directions other than the target point, which may adversely affect other systems. There was also a problem that there was.

  The present invention has been made to solve the above problems, and by adjusting the phase shift amount of the signal output from each antenna element, the phase plane of the signal radiated from each panel is made uniform for the entire antenna panel. Accordingly, it is an object of the present invention to provide a phased array antenna capable of performing highly efficient power transmission and a phase control method thereof.

In order to solve the above problems, the present invention employs the following means.
The present invention has a configuration in which a plurality of antenna panels each having a plurality of antenna elements arranged and arranged are connected linearly or two-dimensionally , and receiving signals by controlling the phase of signals input to and output from each of the antenna elements. A phased array antenna that radiates a signal with respect to the arrival direction of a pilot signal transmitted from a facility, wherein the antenna reference surface is orthogonal to the arrival direction of the pilot signal and sets a common antenna reference surface for all the antenna panels Setting means, panel reference plane setting means for setting a panel reference plane orthogonal to the direction of arrival of the pilot signal for each antenna panel, and for each antenna element arranged in each antenna panel, An antenna that passes through any reference position set for the antenna element and is parallel to the antenna reference plane. Tener element surface setting means, first distance calculating means for calculating a distance between the panel reference surface and each antenna element surface in units of the antenna panel, and the panel reference surface of the adjacent antenna panel A second distance calculating means for calculating the distance between the antenna reference plane and each panel reference plane by calculating the distance between the panel reference planes and integrating the calculated distances between the panel reference planes; A third distance for calculating a distance between the antenna reference plane and each antenna element plane by using the calculation result by the first distance calculation means and the calculation result by the second distance calculation means. a calculation unit, depending on the distance between the calculated the antenna reference plane and each of said antenna element plane, respectively determined phase shift amount of the signal to be radiated from each of said antenna elements We are providing a phased array antenna comprising a that phase shift amount determining means.

According to the above arrangement, the distance between the antenna reference line and the antenna elements perpendicular to the arrival direction of the pilot signal is calculated.
Specifically, for each antenna panel, the distance between the panel reference line set in the antenna panel and each antenna element arranged in the antenna panel is calculated by the first calculation means. . In addition, the distance between the panel reference lines of adjacent antenna panels is calculated by the second calculation means. Further, the distance between the panel reference line and the antenna element calculated by the first distance calculating means is added to the distance between the antenna reference line and the panel reference line obtained by the second calculating means. Thus, the distance between the antenna reference line and each antenna element is calculated.
Then , the phase shift amount determining means determines the phase shift amount according to the distance calculated for each antenna element . The use of these phase shift, it is possible to align the phase front of the signal radiated from the antenna elements arranged disposed on each antenna panel antenna as a whole panel.

In phased array antenna above SL, the panel reference plane, may be set so as to pass through the end portion of the antenna panel.

According to the above configuration, since the panel reference plane is set so as to pass through the end of the antenna panel, the distance between the panel reference planes set on adjacent antenna panels can be easily calculated.

In the phased array antenna, the plurality of antenna panels are two-dimensionally arranged, and the calculation of the amount of phase shift of the signal radiated from each antenna element is performed individually for each row and each column, An abnormality may be detected when the difference between the phase shift amounts calculated for each element exceeds a preset allowable error amount.
The present invention provides a space solar power generation system including the phased array antenna described above.
The present invention is used for a phased array antenna having a configuration in which a plurality of antenna panels in which a plurality of antenna elements are arranged and arranged are connected linearly or two-dimensionally , and controls the phase of signals input to and output from each antenna element. A phased array antenna phase control method for radiating a signal with respect to an arrival direction of a pilot signal transmitted from a reception facility, wherein the phase control method is orthogonal to the arrival direction of the pilot signal and is common to all the antenna panels. An antenna reference plane setting process for setting an antenna reference plane, a panel reference plane setting process for setting a panel reference plane orthogonal to the arrival direction of the pilot signal for each antenna panel, and an array arrangement for each antenna panel For each of the antenna elements, it passes through any reference position set for each of the antenna elements, and An antenna element plane setting process for setting an antenna element plane parallel to the antenna reference plane, and a first distance calculation process for calculating a distance between the panel reference plane and each antenna element plane for each antenna panel And calculating the distance between the panel reference planes of the adjacent antenna panels, and integrating the calculated distance between the panel reference planes, thereby calculating the distance between the antenna reference plane and each panel reference plane. By using the second distance calculation process to be calculated, the calculation result by the first distance calculation means, and the calculation result by the second distance calculation means, the antenna reference plane, each antenna element plane, depending the distance between the distance between the third distance calculating step of calculating respectively, and the calculated the antenna reference plane and each of the antenna element plane, each said a To provide a phase control method for a phased array antenna comprising a phase shift amount determining process of determining the amount of phase shift of the signal to be emitted from each antenna element.

  According to the phased array antenna of the present invention and the phase control method thereof, the phase shift amount of the signal output from each antenna element is adjusted, and the phase plane of the signal radiated from each antenna panel is aligned as the entire antenna panel. There is an effect that highly efficient power transmission can be performed.

Hereinafter, an embodiment in which a phased array antenna according to the present invention is applied to SSPS will be described with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of a phased array antenna according to an embodiment of the present invention.
As shown in FIG. 1, the phased array antenna according to this embodiment includes a plurality of antenna panels C that are two-dimensionally arranged in N rows and N columns on an XY plane in an O-XYZ orthogonal coordinate system. Yes. Adjacent antenna panels C are coupled at each coupling point (not shown). Each antenna panel C is, for example, a square whose side is A (for example, about 1 m), and such antenna panels C are coupled to each other, so that a large phased array antenna of 1 km square is constructed as a whole panel. ing.

  In each antenna panel C, a plurality of antenna elements 20 are two-dimensionally arranged at predetermined distance intervals in the X-axis direction and the Y-axis direction. For example, in each antenna panel C, the antenna elements 20 are two-dimensionally arranged in the X-axis direction and the Y-axis direction so that both distance intervals are a. The distance between the end face of the antenna panel C and the antenna element 20 closest to the end face is a / 2.

Next, the electrical configuration of the phased array antenna according to the present embodiment will be described with reference to FIG.
FIG. 2 is a block diagram showing an electrical configuration of the phased array antenna according to the present embodiment. In this figure, the same components as those in FIG. 1 are denoted by the same reference numerals.

In FIG. 2, the receiving circuit 30 amplifies or attenuates the pilot signal received by the receiving antenna element 120 to a predetermined level, and outputs the amplified signal to the angle detection circuit 40. The angle detection circuit 40 includes an RF interferometer, and the power receiving equipment 102 that has transmitted the pilot signal by measuring the phase difference of the pilot signals received by the plurality of receiving antenna elements 120 included in each antenna panel C. A direction (for example, see FIG. 6) is obtained, and an angle signal indicating the direction is output to the arithmetic processing unit 50.
The arithmetic processing unit 50 includes a microcomputer, and calculates a phase shift amount of the microwave output from each antenna element 20 by executing a phase control process described later based on the input angle signal. And output to each variable phase shifter 60.

On the other hand, the microwave generation unit 60 generates a reference microwave signal and outputs it to the branching circuit 70. The demultiplexing circuit 70 demultiplexes the input reference microwave signal and outputs it to the variable phase shifter 80 provided corresponding to each antenna element 20.
Each variable phase shifter 80 generates a phase shift amount in the reference phase microwave input from the demultiplexing circuit 70 based on the initial phase signal input from the arithmetic processing circuit 50, and outputs it to the power amplifier 90. To do.
The power amplifier 90 is provided corresponding to each of the antenna elements 20 and amplifies the power supplied from the external power source (space solar power generation unit) to the microwave of the phase and frequency of the signal output from the variable phase shifter 80. To the antenna element 20.
The antenna element 20 radiates microwaves having respective phase differences that have been subjected to power amplification toward the power receiving facility 102 (see FIG. 6).

  Next, the phase control process performed by the arithmetic processing unit 50 described above will be described. The phase control processing according to the present embodiment is performed for each column in the phased array antenna arranged in the O-XYZ coordinate system. Here, for convenience of explanation, in the phased array antenna arranged in the O-XYZ coordinate system shown in FIG. 1, the antenna elements 20 arranged in the column of Y = a / 2 are taken as an example, and these antenna elements 20 are taken as an example. The phase control process for the microwaves output from will be described.

  FIG. 3 is a diagram showing a part of the ZX cross-sectional view extracted from Y = a / 2 in the phased array antenna shown in FIG. In the following description, in FIG. 1, the leftmost antenna panel is defined as an antenna panel C1, and the rightmost antenna panel is defined as an antenna panel Cn. In FIG. 3, antenna panels Cm−1, Cm, and Cm + 1 arranged in the M−1 row, the M row, and the M + 1 row among these antenna panels C1 to Cn are extracted and shown as an example. ing.

First, in the phase control processing by the arithmetic processing unit 50 according to the present embodiment, panel reference lines L1 to Ln (not shown, the same applies hereinafter) are set for each antenna panel in the XZ plane as shown in FIG. Furthermore, an antenna reference line S that is used as a reference in all the antenna panels C1 to Cn (not shown) is set.
In the present embodiment, the panel reference lines L1 to Ln pass through predetermined panel reference points P1 to Pn (not shown, the same applies hereinafter) set on the antenna panels C1 to Cn, respectively, and the pilot signals It is set to be orthogonal to the direction of arrival. Here, as an example, the panel reference points P1 to Pn are set at the left end portions of the antenna panels C1 to Cn (for example, the connection points of the panels at the left end portions). Furthermore, the panel reference line L1 of the antenna panel C1 is used as the antenna reference line S.

  In the phase control process executed by the arithmetic processing unit 50 according to the present embodiment, the distances between the antenna reference line S and the antenna elements 20 arranged in the antenna panels C1 to Cn are respectively obtained ( FIG. 5 shows the distance calculation processing), and determines the phase shift amount corresponding to the distance for each antenna element 20 (phase shift amount determination processing), and gives the determined phase shift amount to each antenna element 20. As described above, the phase planes of the microwaves output from all the antenna elements 20 arranged in all the antenna panels C1 to Cn are aligned.

First, among the antenna elements arranged in the antenna panel Cm shown in FIG. 3, the antenna elements 20m, n arranged nth from the panel reference point Pm of the antenna panel Cm and the antenna reference line S The distance D _{M, n} between can be calculated by the following equation (1).

In the above (1), D _M, as shown in FIG. 3, the distance between the antenna reference line S and the panel reference line Lm, d _{m, n,} the panel reference line Lm and the antenna element 20 m, It is the distance between n.
Here, the distance dm _{, n} is the distance K measured along the panel surface from the panel reference point Pm of the antenna panel Cm to the antenna element 20m, n, the normal direction of the panel surface of the antenna panel Cm, and the pilot. Using the arrival direction angle θm formed by the signal, it can be obtained by the following equation (2) (first distance calculation processing; step SA1 in FIG. 4).

Next, the distance D _M in the above equation (1) is calculated as the distance between panel reference lines (hereinafter referred to as “inter-panel distance”) D1 to Dn−1 between adjacent antenna panels, and then the antenna panel Cm. 4 can be obtained by integrating the inter-panel distances D1 to Dm-1 related to the antenna panels C1 to Cm-1 interposed between the antenna reference line S and the antenna reference line S (second distance calculation process; step SA2 in FIG. 4). ).

  First, the inter-panel distance Dm between adjacent antenna panels Cm and Cm + 1 shown in FIG. 3 is given by the following (3) using the length A of the panel antenna Cm and the arrival direction angle θm.

Then, the inter-panel distances D1 to Dm-1 in the antenna panels C1 to Cm-1 interposed between the antenna panels C1 and Cm are obtained by the same method, and these inter-panel distances D1 to Dm-1 are integrated. it makes it possible to calculate the distance D _M between the antenna reference line S and the panel reference line Lm. This is expressed by the following equation (4).

  Then, by substituting the above expression (3) into the above expression (4), the above expression (4) is expressed by the following expression (5).

By using the above equations (1), (2), and (5), the distance D _{M, n} between the antenna reference line S and the antenna element 20 _{m, n} can be _expressed by the following equation (6). It is expressed as follows.

  In this way, the arithmetic processing unit 50 calculates the distance between the antenna reference line S and each antenna element for each antenna element 20 disposed in each antenna panel C1 to Cn (third). Distance calculation processing: Step SA3 in FIG.

  When the distance between each antenna element and the antenna reference line S is obtained, the arithmetic processing unit 50 calculates a phase shift amount corresponding to the obtained distance (step SA4 in FIG. 4). This phase shift amount may be obtained by multiplying the distance by 2π / λ and is given by the following equation (7).

When the amount of phase shift is determined for each of the antenna elements in one row in this way, the same phase control processing is executed for the antenna elements in the other rows, thereby performing the above operation on the phased array antenna shown in FIG. Corresponding phase shift amounts are determined for all antenna elements.
When the phase shift amounts are determined for all the antenna elements, the arithmetic processing unit 50 outputs the determined phase shift amounts to the variable phase shifter 80 shown in FIG. 2 (step SA5 in FIG. 4). Thereby, as shown in FIG. 5, it becomes possible to make the phase plane of the microwave output from the antenna element arrange | positioned at all the antenna panels uniform among all the antenna panels, and can improve power transmission efficiency.

  In the above-described embodiment, as shown in FIG. 1, the phase control processing is executed for each column for the phased array antenna arranged in the O-XYZ coordinate system. However, the present invention is not limited to this example. You may make it perform a phase control process.

  Further, when the above equation (7) is expanded two-dimensionally, it can be expressed as the following equation (8), and the phase control processing may be executed using the following equation.

  Alternatively, two phase shift amounts may be calculated for each antenna element by individually executing the above-described phase control processing for each column and each row. In this case, by comparing the two calculated phase shift amounts, it is possible to improve the reliability of the phase shift amount obtained by the above-described method. In other words, when the phased array antenna is functioning normally, the phase shift amount, which is the calculation result for each column and row for the same antenna element, is almost the same value, but part of the phased array antenna. If there is an abnormality in the calculation result, the calculation result obtained for each column and each row has a large error. Thus, it is good also as a structure which collates the calculation results of both and detects abnormality when the calculation error exceeds the preset allowable error amount.

  As described above, according to the phased array antenna according to the present embodiment, the distance between the antenna reference line and each antenna element is calculated, and the phase shift amount for each antenna element is determined according to this distance. Since microwaves having a phase difference corresponding to the amount of phase shift are output from each antenna element, the phase planes of the microwaves radiated from each antenna element are aligned as a whole antenna panel as shown in FIG. It becomes possible. Thereby, the efficiency of power transmission can be improved.

As mentioned above, although embodiment of this invention was explained in full detail with reference to drawings, the specific structure is not restricted to this embodiment, The design change etc. of the range which does not deviate from the summary of this invention are included.
1stly, in embodiment mentioned above, although the left end part was set as a panel reference point set to each panel antenna, it is not restricted to this example, The panel reference point is set in any one on a panel antenna surface. The position is not particularly limited. Further, the setting position of the panel reference point may be different between the antenna panels.
Second, in the above-described embodiment, any one of the panel reference lines set for each panel antenna is adopted as the antenna reference line S. However, the antenna reference line S is not limited to this example. It is not always necessary to use the panel reference line.

It is the figure which showed the arrangement | sequence of the antenna panel and antenna element in the phased array antenna which concerns on one Embodiment of this invention. It is a block diagram which shows the electrical constitution of the phased array antenna which concerns on one Embodiment of this invention. FIG. 2 is a diagram illustrating a part of a ZX cross-sectional view at Y = a / 2 in the phased array antenna illustrated in FIG. 1. It is a flowchart which shows the process sequence of the phase control process performed by the arithmetic processing part shown in FIG. It is a figure which shows the effect of the phased array antenna which concerns on one Embodiment of this invention. It is explanatory drawing shown about the space solar power generation system. It is explanatory drawing shown about the problem of the conventional phased array antenna. It is explanatory drawing shown about the problem of the conventional phased array antenna.

Explanation of symbols

20 antenna element 40 angle detection circuit 50 arithmetic processing unit 60 microwave generation unit 70 branching circuit 80 variable phase shifter 90 power amplifier C antenna panel

Claims (5)

It has a configuration in which a plurality of antenna panels in which a plurality of antenna elements are arranged and arranged are connected linearly or two-dimensionally , and is transmitted from a receiving facility by controlling the phase of signals input to and output from each antenna element. A phased array antenna that radiates a signal in the direction of arrival of the pilot signal,
An antenna reference plane setting means for setting a common antenna reference plane for all the antenna panels orthogonal to the arrival direction of the pilot signal;
Panel reference plane setting means for setting a panel reference plane orthogonal to the arrival direction of the pilot signal for each antenna panel;
For each antenna element arranged and arranged in each antenna panel, an antenna element surface setting that passes through an arbitrary reference position set for each antenna element and is parallel to the antenna reference plane Means,
First distance calculation means for calculating a distance between the panel reference plane and each antenna element plane in units of the antenna panel;
Calculate the distance between the panel reference planes of the adjacent antenna panels, and calculate the distance between the antenna reference plane and each panel reference plane by integrating the calculated distances between the panel reference planes. Second distance calculating means for
A distance between the antenna reference plane and each antenna element plane is calculated by using a calculation result by the first distance calculation means and a calculation result by the second distance calculation means, respectively. A distance calculating means;
A phased array antenna comprising phase shift amount determining means for determining the amount of phase shift of a signal radiated from each antenna element according to the calculated distance between the antenna reference plane and each antenna element plane . The phased array antenna according to claim 1 , wherein the panel reference plane is set so as to pass through an end portion of the antenna panel.   The plurality of antenna panels are two-dimensionally arranged,
  Calculation of the amount of phase shift of the signal radiated from each antenna element is executed individually for each row and each column,
  3. The phased array according to claim 1, wherein an abnormality is detected when a difference between the phase shift amounts calculated by two for each of the antenna elements exceeds a preset allowable error amount. 4. antenna.   A space solar power generation system comprising the phased array antenna according to any one of claims 1 to 3. Used for a phased array antenna having a configuration in which a plurality of antenna panels in which a plurality of antenna elements are arranged and arranged are connected linearly or two-dimensionally , by controlling the phase of signals input to and output from each of the antenna elements, A phased array antenna phase control method for radiating a signal in the direction of arrival of a pilot signal transmitted from a receiving facility,
An antenna reference plane setting process orthogonal to the direction of arrival of the pilot signal and setting a common antenna reference plane for all the antenna panels;
A panel reference plane setting process for setting a panel reference plane orthogonal to the direction of arrival of the pilot signal for each antenna panel;
For each antenna element arranged and arranged in each antenna panel, an antenna element surface setting that passes through an arbitrary reference position set for each antenna element and is parallel to the antenna reference plane Process,
A first distance calculating step of calculating a distance between the panel reference plane and each antenna element plane in units of the antenna panel;
Calculate the distance between the panel reference planes of the adjacent antenna panels, and calculate the distance between the antenna reference plane and each panel reference plane by integrating the calculated distances between the panel reference planes. A second distance calculating process,
A distance between the antenna reference plane and each antenna element plane is calculated by using a calculation result by the first distance calculation means and a calculation result by the second distance calculation means, respectively. The distance calculation process,
A phased array antenna comprising: a phase shift amount determining step for determining a phase shift amount of a signal radiated from each antenna element according to the calculated distance between the antenna reference plane and each antenna element plane; Phase control method.

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