Circularly Polarized Antenna Device and Correction Control Quantity Determination Method

Abstract

A circular polarization antenna device (1) comprises: a correction control amount calculation unit (11) for calculating a correction control amount for axial ratio correction, on the basis of a function representing the shape of the radiation pattern of a high-frequency signal radiated from an antenna element (2) and the amount of coupling between a first power feed terminal (2-1) and a second power feed terminal (2-2); an amplitude adjustment control unit (7) for controlling amplitude adjustment performed by a first amplitude adjustment circuit (3-1) and a second amplitude adjustment circuit (3-2), on the basis of the correction control amount; and a phase shifter control unit (8) for controlling phase adjustment performed by a first phase shifter (4-1) and a second phase shifter (4-2), on the basis of the correction control amount.

Description

Technical Field

[0001] The present disclosure relates to a circularly polarized antenna device and a correction control amount determination method.

Background Art

[0002] A circularly polarized antenna device is an antenna device designed such that the polarization direction of radio waves transmitted and received is circular. Since the transmitting and receiving antenna of the circularly polarized antenna device has more directivity than the vertical polarized antenna and the horizontal polarized antenna and does not require adjustment of the polarization direction, it is used in various fields such as satellite communication and microwave power transmission. One of the circularly polarized antenna devices is an electronically scanned circularly polarized phased array antenna. The circularly polarized phased array antenna is a phased array antenna capable of controlling the polarization direction, and can transmit and receive or transmit radio waves to / from a moving object whose position changes due to movement or various positions.

[0003] Generally, a circularly polarized antenna device has a good radiation pattern of circular polarization component, that is, a characteristic of low axial ratio, in the front direction of the antenna or in the vicinity thereof, and in the wide-angle direction, the cross-polarization component increases and the axial ratio tends to deteriorate. For example, when scanning a beam in the wide-angle direction in a circularly polarized phased array antenna, the cross-polarization component may increase and the communication quality or power transmission efficiency may deteriorate. As a conventional technique for solving this problem, for example, there is an antenna described in Patent Document 1.

[0004] The antenna described in Patent Document 1 includes a set of feeding antenna elements, a finite-length reflector on which the feeding antenna elements are mounted, a phase shifter for giving a phase difference between the feeding antenna elements, a phase shifter for giving an excitation amplitude to each feeding antenna element, and a feeding circuit composed of a set of hybrids. By adjusting the two phase shifters, a desired excitation current amplitude ratio and phase difference for the feeding antenna elements can be obtained, and a desired circularly polarized incoming wave can be effectively received. On the other hand, an arbitrary polarization wave having a desired axial ratio in a specified direction can be synthesized so as not to receive an unnecessary elliptically polarized wave.

Prior Art Documents

Patent Document

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In a conventional circularly polarized antenna device, there has been a problem that since the radiation pattern changes due to re-radiation from adjacent antenna elements, it is impossible to determine a correction control amount for improving the axial ratio. For example, the circularly polarized antenna device described in Patent Document 1 assumes a pair of dipole antennas arranged orthogonally as a set of feeding antenna elements. If, for example, a patch antenna with two-point feeding is used instead of a pair of dipole antennas, the mutual coupling between the feeding points becomes too large to be ignored. As a result, in a conventional circularly polarized antenna device, since the radiation pattern changes due to re-radiation from adjacent antenna elements, it is impossible to determine a correction control amount for improving the axial ratio.

[0007] Also, similar to Patent Document 1, in a circularly polarized phased array antenna in which a plurality of antenna elements that are a pair of dipole antennas are arranged, the dipole antennas are not arranged orthogonally between adjacent antenna elements. For this reason, the mutual coupling between the antenna elements becomes too large to be ignored, the radiation pattern changes due to re-radiation from adjacent antenna elements, and it is impossible to determine a correction control amount for improving the axial ratio.

[0008] The present disclosure solves the above problems, and an object thereof is to obtain a circularly polarized antenna device capable of determining a correction control amount for improving the axial ratio.

Means for Solving the Problems

[0009] The circularly polarized antenna device according to the present disclosure is A radiating element capable of radiating or receiving radio waves having two orthogonal polarization characteristics respectively, a first feeding terminal son yo and the Second power supply terminal first and second feeding terminals are arranged such that the main polarization components of the radio waves transmitted and received via the first feeding terminal and the main polarization components of the radio waves transmitted and received via the second feeding terminal are orthogonal to each other. An antenna element, a first amplitude adjustment circuit that adjusts the amplitude of a high-frequency signal transmitted and received via a first power supply terminal, a second amplitude adjustment circuit that adjusts the amplitude of a high-frequency signal transmitted and received via a second power supply terminal, a first phase shifter that adjusts the phase of the high-frequency signal input to and output from the first amplitude adjustment circuit, a second phase shifter that adjusts the phase of the high-frequency signal input to and output from the second amplitude adjustment circuit, and a distribution synthesis circuit that distributes the high-frequency signal to the first phase shifter and the second phase shifter and synthesizes the high-frequency signals from the first phase shifter and the second phase shifter. A circularly polarized antenna device comprising: a correction control amount calculation unit that calculates a correction control amount for axial ratio correction based on a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element via the first power supply element and the second power supply element, and the coupling amount between the first power supply element and the second power supply element; an amplitude adjustment control unit that controls the amplitude adjustment by the first amplitude adjustment circuit and the second amplitude adjustment circuit based on the correction control amount; and a phase shifter control unit that controls the phase adjustment by the first phase shifter and the second phase shifter based on the correction control amount.

Effects of the Invention

[0010] According to the present disclosure, a correction control amount for axial ratio correction is calculated based on a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element via the first power supply element and the second power supply element, and the coupling amount between the first power supply element and the second power supply element. Based on the correction control amount, the amplitude adjustment by the first amplitude adjustment circuit and the second amplitude adjustment circuit is controlled, and based on the correction control amount, the phase adjustment by the first phase shifter and the second phase shifter is controlled. Thereby, the circularly polarized antenna device according to the present disclosure can determine a correction control amount that improves the axial ratio.

Brief Description of the Drawings

[0011]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0012] Embodiment 1. FIG. 1 is a block diagram showing the configuration of a circular polarization antenna device 1 according to Embodiment 1. In FIG. 1, the circular polarization antenna device 1 is an antenna device that transmits and receives high-frequency signals of circular polarization. The circular polarization antenna device 1 includes an antenna element 2, a first amplitude adjustment circuit 3-1, a second amplitude adjustment circuit 3-2, a first phase shifter 4-1, a second phase shifter 4-2, a distribution and synthesis circuit 5, an input / output terminal 6, an amplitude adjustment control unit 7, a phase shifter control unit 8, a radiation pattern function storage unit 9, a coupling coefficient storage unit 10, and a correction control amount calculation unit 11. Further, the antenna element 2 includes a first power supply terminal 2-1 and a second power supply terminal 2-2.

[0013]

[0014] The antenna element 2 is a radiation element capable of radiating or receiving radio waves each having two orthogonal polarization characteristics. For example, the antenna element 2 is a pair of radiation elements including a first radiation element and a second radiation element, and the first radiation element and the second radiation element are circular or rectangular patch antennas, or a pair of dipole antennas arranged orthogonally, etc.The first power supply terminal 2-1 is the power supply terminal of the antenna element 2, and the second power supply terminal 2-2 is the power supply terminal provided at a position different from that of the first power supply terminal 2-1 in the antenna element 2. The first power supply terminal 2-1 and the second power supply terminal 2-2 are arranged such that the main polarization component of the radio wave radiated or received by the first radiating element via the first power supply terminal 2-1 is orthogonal to the main polarization component of the radio wave radiated or received by the second radiating element via the second power supply terminal 2-2.

[0015] The first amplitude adjustment circuit 3-1 is a circuit that adjusts the amplitude of the high-frequency signal transmitted and received via the first power supply terminal 2-1, and the second amplitude adjustment circuit 3-2 is a circuit that adjusts the amplitude of the high-frequency signal transmitted and received via the second power supply terminal 2-2. The first amplitude adjustment circuit 3-1 and the second amplitude adjustment circuit 3-2 are constituted by, for example, a variable amplifier, or an amplifier and a variable attenuator, etc.

[0016] The first phase shifter 4-1 is a circuit that adjusts the phase of the high-frequency signal input and output to and from the first amplitude adjustment circuit 3-1, and the second phase shifter 4-2 is a circuit that adjusts the phase of the high-frequency signal input and output to and from the second amplitude adjustment circuit 3-2. The first phase shifter 4-1 and the second phase shifter 4-2 are constituted by, for example, a phase shift circuit that changes the phase of a signal using elements such as a capacitor or an inductor, or a PLL (phase comparator loop) that compares the phases of signals and changes the phase of a signal using the difference therebetween.

[0017] The distribution synthesis circuit 5 is a circuit that distributes a high-frequency signal to the first phase shifter 4-1 and the second phase shifter 4-2 and synthesizes the high-frequency signals from the first phase shifter 4-1 and the second phase shifter 4-2. As shown in FIG. 1, the distribution synthesis circuit 5 is connected to an input / output terminal 6 to which a high-frequency signal is input and output, separately from the first phase shifter 4-1 and the second phase shifter 4-2.

[0018] The amplitude adjustment control unit 7 controls the amplitude adjustment performed by the first amplitude adjustment circuit 3-1 and the second amplitude adjustment circuit 3-2 based on the correction control amount related to the amplitude of the high-frequency signal calculated by the correction control amount calculation unit 11. For example, the amplitude adjustment control unit 7 generates a control signal for controlling so that the adjustment amount of the amplitude by the first amplitude adjustment circuit 3-1 and the second amplitude adjustment circuit 3-2 becomes a predetermined value, and outputs the generated control signal to the first amplitude adjustment circuit 3-1 and the second amplitude adjustment circuit 3-2 respectively.

[0019] The phase shifter control unit 8 controls the phase adjustment by the first phase shifter 4-1 and the second phase shifter 4-2 based on the correction control amount related to the phase of the high-frequency signal calculated by the correction control amount calculation unit 11. For example, the phase shifter control unit 8 generates a control signal for controlling so that the adjustment amount of the phase by the first phase shifter 4-1 and the second phase shifter 4-2 becomes a predetermined value, and outputs the generated control signal to the first phase shifter 4-1 and the second phase shifter 4-2 respectively.

[0020] The radiation pattern function storage unit 9 is a storage unit that stores a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 2 via the first power supply terminal 2-1 and the second power supply terminal 2-2. For example, the function representing the shape of the radiation pattern of the high-frequency signal is a function representing the shape of the electric field radiation pattern radiated from the antenna element 2 when a power supply of a predetermined reference amplitude and a predetermined reference phase is performed independently on each of the first power supply terminal 2-1 and the second power supply terminal 2-2.

[0021] The coupling coefficient storage unit 10 is a storage unit that stores the coupling amount between the first power supply terminal 2-1 and the second power supply terminal 2-2. This coupling amount represents the amplitude and phase of the high-frequency signal corresponding to the coupling amount between the first power supply terminal 2-1 and the second power supply terminal 2-2.

[0022] The radiation pattern function storage unit 9 and the coupling coefficient storage unit 10 are, for example, the memory 103 described later with reference to FIG. 3. Note that the radiation pattern function storage unit 9 and the coupling coefficient storage unit 10 may be any as long as they are accessible by the correction control amount calculation unit 11 provided in the circularly polarized wave antenna device 1, and may be provided outside the circularly polarized wave antenna device 1.

[0023] The correction control amount calculation unit 11 calculates a correction control amount for axial ratio correction based on a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 2 via the first power supply terminal 2-1 and the second power supply terminal 2-2, and the coupling amount between the first power supply terminal 2-1 and the second power supply terminal 2-2.

[0024] For example, the correction control amount calculation unit 11 reads from the radiation pattern function storage unit 9 a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 2 via the first power supply terminal 2-1 and a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 2 via the second power supply terminal 2-2, and reads the coupling amount from the coupling coefficient storage unit 10. In addition to these pieces of information, the correction control amount calculation unit 11 uses preset information regarding the frequency of the high-frequency signal, the axial ratio correction direction, and the excitation polarization condition, and calculates, according to the correction control amount calculation formula, a correction control amount regarding the amplitude of the high-frequency signal necessary for axial ratio correction and a correction control amount regarding the phase.

[0025] Then, the correction control amount calculation unit 11 outputs a correction control amount regarding the amplitude of the high-frequency signal radiated from the antenna element 2 via the first power supply terminal 2-1 to the first amplitude adjustment circuit 3-1, and outputs a correction control amount regarding the amplitude of the high-frequency signal radiated from the antenna element 2 via the second power supply terminal 2-2 to the second amplitude adjustment circuit 3-2. Further, the correction control amount calculation unit 11 outputs a correction control amount regarding the phase of the high-frequency signal input to and output from the first amplitude adjustment circuit 3-1 to the first phase shifter 4-1, and outputs a correction control amount regarding the phase of the high-frequency signal input to and output from the second amplitude adjustment circuit 3-2 to the second phase shifter 4-2.

[0026] Next, the operation of the circular polarization antenna device 1 functioning as a transmission antenna will be described. First, the distribution synthesis circuit 5 distributes the high-frequency signal input to the input / output terminal 6 into high-frequency signals with approximately equal amplitudes and equal phases, and outputs them to the first phase shifter 4-1 and the second phase shifter 4-2. The first phase shifter 4-1 adjusts the phase of the high-frequency signal input from the distribution synthesis circuit 5 according to the control signal input from the phase shifter control unit 8, and outputs the high-frequency signal with the adjusted phase to the first amplitude adjustment circuit 3-1. Similarly, the second phase shifter 4-2 adjusts the phase of the high-frequency signal input from the distribution synthesis circuit 5 according to the control signal input from the phase shifter control unit 8, and outputs the high-frequency signal with the adjusted phase to the second amplitude adjustment circuit 3-2.

[0027] The first amplitude adjustment circuit 3-1 adjusts the amplitude of the high-frequency signal input from the first phase shifter 4-1 according to the control signal input from the amplitude adjustment control unit 7, and outputs the high-frequency signal with the adjusted amplitude to the antenna element 2 via the first power supply terminal 2-1. Similarly, the second amplitude adjustment circuit 3-2 adjusts the amplitude of the high-frequency signal input from the second phase shifter 4-2 according to the control signal input from the amplitude adjustment control unit 7, and outputs the high-frequency signal with the adjusted amplitude to the antenna element 2 via the second power supply terminal 2-2.

[0028] The high-frequency signals input to the antenna element 2 via the first power supply terminal 2-1 and the second power supply terminal 2-2 are radiated into the external space as radio waves. The main polarization components of the radio waves radiated from the antenna element 2 via the first power supply terminal 2-1 and the main polarization components of the radio waves radiated from the antenna element 2 via the second power supply terminal 2-2 are orthogonal to each other. By adjusting the amplitude and phase of the high-frequency signal passing through the first amplitude adjustment circuit 3-1 and the first phase shifter 4-1, and adjusting the amplitude and phase of the high-frequency signal passing through the second amplitude adjustment circuit 3-2 and the second phase shifter 4-2, the high-frequency signals of these two orthogonal polarization components can be controlled to have equal amplitudes and a 90-degree phase difference from each other, and good circular polarization characteristics can be realized.

[0029] For example, in a spherical coordinate system with the center of the antenna element 2 as the origin, when the first power supply terminal 2-1 is powered with a predetermined reference amplitude and reference phase, the signals of each polarization component of the electric field in the (θ, φ) direction radiated from the antenna element 2 are represented by E θ1 (θ, φ) and E φ1 (θ, φ). Here, the subscript θ represents the signal of the linearly polarized wave component in the θ direction, and the subscript φ represents the signal of the linearly polarized wave component in the φ direction. These signals are signals of linearly polarized wave components orthogonal to each other. Furthermore, these signals do not include re-radiation components due to mutual coupling with the second power supply terminal 2-2. Similarly, when the second power supply terminal 2-2 is powered with a predetermined reference amplitude and reference phase, each polarization component of the electric field in the (θ, φ) direction radiated from the antenna element 2 is represented by E θ2 (θ, φ) and E φ2 (θ, φ). Hereinafter, for simplicity of notation, the arguments (θ, φ) of each polarization component of the electric field are omitted. Also, these components do not include re-radiation components due to mutual coupling with the first power supply terminal 2-1.

[0030] E θ1 、E φ1 、E θ2 and E φ2 are functions of (θ, φ) representing the shape of the electric field radiation pattern expressed by trigonometric functions, Bessel functions, or Hankel functions, and are obtained in advance by performing radiation pattern measurement, electromagnetic field analysis, or theoretical analysis, etc. E θ1 、E φ1 、E θ2 and E φ2 are stored in the radiation pattern function storage unit 9.

[0031] The first amplitude adjustment circuit 3-1 multiplies the amplitude of the high-frequency signal by A1 times the reference amplitude, and the second amplitude adjustment circuit 3-2 multiplies the amplitude of the high-frequency signal by A2 times the reference amplitude. The first phase shifter 4-1 phase-shifts the phase of the high-frequency signal by ψ1 from the reference phase, and the second phase shifter 4-2 phase-shifts the phase of the high-frequency signal by ψ2 from the reference phase. Consider the electric field radiated from the antenna element 2 in these cases.

[0032] The radiated electric field when the first power supply terminal 2-1 and the second power supply terminal 2-2 are excited independently can be obtained by considering the reradiation component caused by the mutual coupling between the first power supply terminal 2-1 and the second power supply terminal 2-2. The coupling amount c of this mutual coupling can be expressed by the following formula (1). In the following formula (1), I1 = A1e jψ1 and I2 = A2e jψ2 is. TIFF0007714144000001.tif12166

[0033] The coupling amount c shall be obtained in advance based on pattern measurement, electromagnetic field analysis, or theoretical analysis, and stored in the coupling coefficient storage unit 10. When expressing the above formula (1) in terms of circular polarization components, the left-handed circular polarization component E L (θ, φ) and the right-handed circular polarization component E R (θ, φ) are respectively expressed by the following formula (2). TIFF0007714144000002.tif42166

[0034] To correct the axial ratio, the circular polarization component corresponding to the cross-polarization component may be set to 0. For example, when radiating right-handed circular polarization, I1 and I2 may be controlled so as to satisfy the equation of E L (θ, φ) = 0. Conversely, when radiating left-handed circular polarization, I1 and I2 may be controlled so as to satisfy the equation of E R (θ, φ) = 0. These equations have an infinite number of solutions, but generally, it is desirable to control so that the radiated electric field strength becomes as large as possible.

[0035] For example, when the reference amplitude is the maximum amplitude in the first amplitude adjustment circuit 3-1 and the second amplitude adjustment circuit 3-2, and the amplitude adjustment amounts are controlled so that A1 ≤ 1 and A2 ≤ 1, the solution that satisfies the above two equations while maximizing the radiated electric field strength of the antenna element 2 is expressed by the following formula (3). In the following formula (3), I1 and I2 are expressed as complex numbers, + corresponds to the case of exciting with left-handed circular polarization as the main polarization, and - corresponds to the case of exciting with right-handed circular polarization as the main polarization. TIFF0007714144000003.tif52166

[0036] Next, the correction control amount determination method according to Embodiment 1 will be described. FIG. 2 is a flowchart showing the correction control amount determination method according to Embodiment 1, and shows a series of processes in the correction control amount determination method executed by the circularly polarized antenna device 1. The correction control amount calculation unit 11 reads the radiation pattern function E of the high-frequency signal radiated through the first power supply terminal 2-1, which is stored in the radiation pattern function storage unit 9. θ1 and E φ1 and reads the radiation pattern function E of the high-frequency signal radiated through the second power supply terminal 2-2. θ2 and E φ2 (Step ST1). Subsequently, the correction control amount calculation unit 11 reads the coupling amount c between the first power supply terminal 2-1 and the second power supply terminal 2-2, which is stored in the coupling coefficient storage unit 10 (Step ST2).

[0037] The correction control amount calculation unit 11 acquires the axial ratio correction direction (θ0, φ0) and the excitation polarization condition (Step ST3). For example, the axial ratio correction direction (θ0, φ0) and the excitation polarization condition are set by the user to the correction control amount calculation unit 11 using an operating device (not shown) in FIG. 1, or are stored in the radiation pattern function storage unit 9 or the coupling coefficient storage unit 10.

[0038] The correction control amount calculation unit 11 calculates the control amounts I1 and I2 required for axial ratio correction according to the above formula (3) using this information, calculates the correction control amounts A1 and A2 regarding the amplitude in the calculated control amounts I1 and I2, and calculates the correction control amounts ψ1 and ψ2 regarding the phase (Step ST4).

[0039] The correction control amount calculation unit 11 outputs the correction control amounts A1 and A2 to the amplitude adjustment control unit 7, and outputs the correction control amounts ψ1 and ψ2 to the phase shifter control unit 8 (Step ST5). Based on the correction control amount, the amplitude adjustment control unit 7 generates a control signal for setting the first amplitude adjustment circuit 3-1 and outputs the generated control signal to the first amplitude adjustment circuit 3-1. Furthermore, based on the correction control amount, the amplitude adjustment control unit 7 generates a control signal for setting the second amplitude adjustment circuit 3-2 and outputs the generated control signal to the second amplitude adjustment circuit 3-2. The phase shifter control unit 8 generates a control signal for setting the first phase shifter 4-1 based on the correction control amount and outputs the generated control signal to the first phase shifter 4-1. The phase shifter control unit 8 generates a control signal for setting the second phase shifter 4-2 based on the correction control amount and outputs the generated control signal to the second phase shifter 4-2. As a result, the radio wave radiated from the circularly polarized antenna device 1 to the external space is controlled so that the cross-polarization component becomes 0. Therefore, it is possible to improve the axial ratio.

[0040] The control amount determined in the antenna described in Patent Document 1 is equal to that assuming that the coupling amount c is 0 in the above formula (3). Since the coupling amount c is usually of a finite magnitude, the axial ratio improvement effect by the control amount in Patent Document 1 becomes small. On the other hand, as shown in the above formula (3), since the circularly polarized antenna device 1 determines the control amount in consideration of the finite coupling amount c, even when the re-radiation component due to the mutual coupling between the first feeding terminal 2-1 and the second feeding terminal 2-2 is large, a high axial ratio improvement effect can be obtained in a predetermined direction as compared with Patent Document 1. Although the case where the circularly polarized antenna device 1 functions as a transmitting antenna has been described, the same effect can be obtained even when the circularly polarized antenna device 1 functions as a receiving antenna.

[0041] FIG. 3 is a block diagram showing a hardware configuration for realizing the functions of the circular polarization antenna device 1. For example, the circular polarization antenna device 1 has, as a hardware configuration, an input interface 100, an output interface 101, a processor 102, and a memory 103. The functions of the amplitude adjustment control unit 7, the phase shifter control unit 8, and the correction control amount calculation unit 11 provided in the circular polarization antenna device 1 are realized by executing an information processing application in these hardware configurations.

[0042] The input interface 100 relays the data read from the radiation pattern function storage unit 9 and the coupling coefficient storage unit 10 and outputs it to the processor 102. The output interface 101 relays the control signals output from the amplitude adjustment control unit 7 to the first amplitude adjustment circuit 3-1 and the second amplitude adjustment circuit 3-2, and relays the control signals output from the phase shifter control unit 8 to the first phase shifter 4-1 and the second phase shifter 4-2.

[0043] Programs of the information processing applications for realizing the functions of the amplitude adjustment control unit 7, the phase shifter control unit 8, and the correction control amount calculation unit 11 are stored in the memory 103. The processor 102 executes the above program read from the memory 103, whereby the functions of the amplitude adjustment control unit 7, the phase shifter control unit 8, and the correction control amount calculation unit 11 are realized. Note that the memory 103 is, for example, a hard disk device or a RAM (Random Access Memory).

[0044] As described above, the circularly polarized antenna device 1 according to Embodiment 1 includes a correction control amount calculation unit 11 that calculates a correction control amount for axial ratio correction based on a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 2 and the coupling amount between the first power supply terminal 2-1 and the second power supply terminal 2-2, an amplitude adjustment control unit 7 that controls the amplitude adjustment by the first amplitude adjustment circuit 3-1 and the second amplitude adjustment circuit 3-2 based on the correction control amount, and a phase shifter control unit 8 that controls the phase adjustment by the first phase shifter 4-1 and the second phase shifter 4-2 based on the correction control amount. Thereby, even when the re-radiation component due to the mutual coupling between the first power supply terminal 2-1 and the second power supply terminal 2-2 is large, a high axial ratio improvement effect can be obtained in a predetermined direction. Therefore, the circularly polarized antenna device 1 can determine a correction control amount that improves the axial ratio.

[0045] In the circularly polarized antenna device 1 according to Embodiment 1, the antenna element 2 includes a first radiation element that is arranged orthogonally to each other and radiates a high-frequency signal whose linearly polarized wave is the main polarized wave component, and a second radiation element that radiates a high-frequency signal whose linearly polarized wave is orthogonal to the linearly polarized wave of the high-frequency signal radiated by the first radiation element and whose linearly polarized wave is the main polarized wave component. The first power supply terminal 2-1 is connected to either the first radiation element or the second radiation element, and the second power supply terminal 2-2 is connected to the remaining one of the first radiation element and the second radiation element. Thereby, the circularly polarized antenna device 1 can determine a correction control amount that improves the axial ratio.

[0046] In the circularly polarized antenna device 1 according to Embodiment 1, the first radiation element and the second radiation element are a dipole antenna or a patch antenna. Thereby, various types of antenna devices can be realized as the circularly polarized antenna device 1.

[0047] In the circularly polarized antenna device 1 according to Embodiment 1, the antenna element 2 is a single radiation element that can radiate two orthogonal linearly polarized waves. Thereby, various types of antenna devices can be realized as the circularly polarized antenna device 1.

[0048] In the circularly polarized antenna device 1 according to Embodiment 1, the radiating element is a circular or rectangular patch antenna. Two line segments connecting the connection point with the first feeding terminal 2-1 or the second feeding terminal 2-2 and the center point of the radiating element are perpendicular to each other. Thereby, the circularly polarized antenna device 1 can realize good circular polarization characteristics.

[0049] In the circularly polarized antenna device 1 according to Embodiment 1, the correction control amount calculation unit 11 calculates the correction control amount according to the above formula (3). Thereby, the circularly polarized antenna device 1 can determine a correction control amount that optimally improves the axial ratio.

[0050] The correction control amount determination method according to Embodiment 1 includes a step in which the correction control amount calculation unit 11 calculates a correction control amount for axial ratio correction based on a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 2 via the first feeding terminal 2-1 and the second feeding terminal 2-2 and the coupling amount between the first feeding terminal 2-1 and the second feeding terminal 2-2, a step in which the amplitude adjustment control unit 7 controls the amplitude adjustment by the first amplitude adjustment circuit 3-1 and the second amplitude adjustment circuit 3-2 based on the correction control amount, and a step in which the phase shifter control unit 8 controls the phase adjustment by the first phase shifter 4-1 and the second phase shifter 4-2 based on the correction control amount. By executing this method, the circularly polarized antenna device 1 can determine a correction control amount that improves the axial ratio.

[0051] Embodiment 2. FIG. 4 is a block diagram showing the configuration of the circularly polarized antenna device 1A according to Embodiment 2. In FIG. 4, the circularly polarized antenna device 1A is a circularly polarized phased array antenna composed of a plurality of antenna elements that transmit and receive circularly polarized high-frequency signals. When n is an integer from 1 to N and N is the number of antenna elements, the circularly polarized antenna device 1A includes N antenna units having antenna elements 20-n, first amplitude adjustment circuits 22-1-n, second amplitude adjustment circuits 22-2-n, first phase shifters 23-1-n, second phase shifters 23-2-n, and distribution synthesis circuits 24-n, a distribution synthesis circuit 25, input / output terminals 26, an amplitude adjustment control unit 27, a phase shifter control unit 28, a radiation pattern function storage unit 29, a coupling coefficient storage unit 30, an antenna element coordinate storage unit 31, a beam forming control amount calculation unit 32, and a correction control amount calculation unit 33. Further, the antenna element 20-n includes a first power supply terminal 21-1-n and a second power supply terminal 21-2-n.

[0052] The antenna element 20-n is a radiating element capable of radiating or receiving radio waves having two orthogonal polarization characteristics respectively. For example, the antenna element 20-n is a pair of radiating elements each composed of a first radiating element and a second radiating element, and the first radiating element and the second radiating element are circular or rectangular patch antennas, or a pair of dipole antennas arranged orthogonally, etc.

[0053] The first power supply terminal 21-1-n is a power supply terminal of the antenna element 20-n, and the second power supply terminal 21-2-n is a power supply terminal provided at a position different from the first power supply terminal 2-1 in the antenna element 2. The first power supply terminal 21-1-n and the second power supply terminal 21-2-n are arranged such that the main polarization component of the radio wave radiated or received by the first radiating element via the first power supply terminal 21-1-n is orthogonal to the main polarization component of the radio wave radiated or received by the second radiating element via the second power supply terminal 2-2.

[0054] The first amplitude adjustment circuit 22-1-n is a circuit that adjusts the amplitude of a high-frequency signal transmitted and received via the first power supply terminal 21-1-n, and the second amplitude adjustment circuit 22-2-n is a circuit that adjusts the amplitude of a high-frequency signal transmitted and received via the second power supply terminal 21-2-n. The first amplitude adjustment circuit 22-1-n and the second amplitude adjustment circuit 22-2-n are constituted by, for example, a variable amplifier, or an amplifier and a variable attenuator, etc.

[0055] The first phase shifter 23-1-n is a circuit that adjusts the phase of a high-frequency signal input to and output from the first amplitude adjustment circuit 22-1-n, and the second phase shifter 23-2-n is a circuit that adjusts the phase of a high-frequency signal input to and output from the second amplitude adjustment circuit 22-2-n. The first phase shifter 23-1-n and the second phase shifter 23-2-n are constituted by, for example, a phase shift circuit that changes the phase of a signal using an element such as a capacitor or an inductor, or by a PLL (phase comparator loop) that compares the phases of signals and changes the phase of a signal using the difference therebetween.

[0056] The distribution synthesis circuit 24-n is a first distribution synthesis circuit that distributes a high-frequency signal to the first phase shifter 23-1-n and the second phase shifter 23-2-n, and synthesizes the high-frequency signals from the first phase shifter 23-1-n and the second phase shifter 23-2-n. The distribution synthesis circuit 25 is a second distribution synthesis circuit that distributes a high-frequency signal to the distribution synthesis circuit 24-n, and synthesizes the high-frequency signal from the distribution synthesis circuit 24-n. As shown in FIG. 4, the distribution synthesis circuit 25 is connected to an input / output terminal 26 to which a high-frequency signal is input and output separately from the distribution synthesis circuit 24-n.

[0057] The amplitude adjustment control unit 27 controls the amplitude adjustment performed by the first amplitude adjustment circuits 22-1-n and the second amplitude adjustment circuits 22-2-n based on the correction control amount regarding the amplitude of the high-frequency signal calculated by the correction control amount calculation unit 33. For example, the amplitude adjustment control unit 27 generates a control signal for controlling such that the adjustment amount of the amplitude by the first amplitude adjustment circuits 22-1-n and the second amplitude adjustment circuits 22-2-n becomes a predetermined value, and outputs the generated control signal to the first amplitude adjustment circuits 22-1-n and the second amplitude adjustment circuits 22-2-n, respectively.

[0058] The phase shifter control unit 28 controls the phase adjustment by the first phase shifters 23-1-n and the second phase shifters 23-2-n based on the correction control amount regarding the phase of the high-frequency signal calculated by the correction control amount calculation unit 33. For example, the phase shifter control unit 28 generates a control signal for controlling such that the adjustment amount of the phase by the first phase shifters 23-1-n and the second phase shifters 23-2-n becomes a predetermined value, and outputs the generated control signal to the first phase shifters 23-1-n and the second phase shifters 23-2-n, respectively.

[0059] The radiation pattern function storage unit 29 is a storage unit that stores a function representing the shape of the radiation pattern of the high-frequency signal. When n0 is an integer from 1 to N, the above function stored in the radiation pattern function storage unit 29 is a function representing the shape of the electric field radiation pattern radiated from the antenna element 20-n0 when power is supplied to the first power supply terminal 21-1-n0 and the second power supply terminal 21-2-n0 provided in the reference antenna element 20-n0 among the antenna elements 20-n, respectively, alone with a predetermined reference amplitude and reference phase.

[0060] The coupling coefficient storage unit 30 is a storage unit that stores the coupling amount between the first power supply terminal 21-1-n0 and the second power supply terminal 21-2-n0 provided in the reference antenna element 20-n0. This coupling amount represents the amplitude and phase of the high-frequency signal corresponding to the coupling amount between the first power supply terminal 21-1-n0 and the second power supply terminal 21-2-n0. Furthermore, the coupling coefficient storage unit 30 stores the coupling amounts between the first power supply terminal 21-1-n0 provided in the reference antenna element 20-n0, the second power supply terminal 21-2-n0, the first power supply terminals 21-1-m provided in the M antenna elements 20-m arranged around the reference antenna element 20-n0, and the second power supply terminals 21-2-m. This coupling amount also represents the amplitude and phase of the corresponding high-frequency signal. Note that m is an integer other than n0.

[0061] The antenna element coordinate storage unit 31 is a storage unit that stores the coordinate information of each of the antenna elements 20-n that the N antenna units respectively have. The coordinate information is the coordinate information indicating the element position of the antenna element 20-n.

[0062] The radiation pattern function storage unit 29, the coupling coefficient storage unit 30, and the antenna element coordinate storage unit 31 are, for example, the memory 103 shown in FIG. 3. Note that the radiation pattern function storage unit 29, the coupling coefficient storage unit 30, and the antenna element coordinate storage unit 31 only need to be accessible by the beamforming control amount calculation unit 32 and the correction control amount calculation unit 33 provided in the circular polarization antenna device 1A, and may be provided outside the circular polarization antenna device 1A.

[0063] The beamforming control amount calculation unit 32 calculates the amplitude control amount and the phase control amount necessary for beamforming by using the coordinate information of the antenna elements 20-n that the N antenna units respectively have. For example, the beamforming control amount calculation unit 32 reads out the coordinate information of the antenna elements 20-n that the N antenna units respectively have from the antenna element coordinate storage unit 31, and further obtains the frequency of the high-frequency signal, the information regarding the beam scanning direction, the correction control amount regarding the phase of the high-frequency signal for calibration, and the correction control amount regarding the amplitude for applying an amplitude distribution to the high-frequency signal radiated from the antenna element 20-n for low sidelobe reduction.

[0064] Subsequently, the beam forming control quantity calculation unit 32 uses the acquired coordinate information of the antenna element 20-n, the frequency of the high-frequency signal, the information regarding the beam scanning direction, the correction control quantity regarding the phase of the high-frequency signal, and the correction control quantity regarding the amplitude, and calculates, according to the control quantity calculation formula, the correction control quantity regarding the amplitude of the high-frequency signal necessary for beam forming and the correction control quantity regarding the phase of the high-frequency signal. The correction control quantity regarding the amplitude is output from the beam forming control quantity calculation unit 32 to the amplitude adjustment control unit 27, and the correction control quantity regarding the phase is output from the beam forming control quantity calculation unit 32 to the phase shifter control unit 28.

[0065] Also, the correction control quantity regarding the amplitude is a correction control quantity for the amplitude adjustment control unit 27 to generate a control signal output to the first amplitude adjustment circuits 22-1-n and the second amplitude adjustment circuits 22-2-n. The correction control quantity regarding the phase is a correction control quantity for the phase shifter control unit 28 to generate a control signal output to the first phase shifters 23-1-n and the second phase shifters 23-2-n.

[0066] The correction control quantity calculation unit 33 calculates a correction control quantity for axial ratio correction based on a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 20-n via the first power supply terminals 21-1-n and the second power supply terminals 21-2-n, and the coupling amount between the first power supply terminals 21-1-n and the second power supply terminals 21-2-n.

[0067] For example, the correction control amount calculation unit 33 reads, from the radiation pattern function storage unit 29, a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 20-n via the first power supply terminal 21-1-n, and a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 20-n via the second power supply terminal 21-2-n, reads the coupling amount from the coupling coefficient storage unit 30, and reads the coordinate information of the antenna element 20-n that each of the N antenna units has from the antenna element coordinate storage unit 31. In addition to these pieces of information, the correction control amount calculation unit 11 uses the preset information regarding the frequency of the high-frequency signal, the axial ratio correction direction, and the excitation polarization condition, and calculates, according to the correction control amount calculation formula, the correction control amount regarding the amplitude of the high-frequency signal necessary for axial ratio correction and the correction control amount regarding the phase. Note that the axial ratio correction direction is the same as the above-described beam scanning direction.

[0068] Then, the correction control amount calculation unit 33 outputs the correction control amount regarding the amplitude of the high-frequency signal radiated from the antenna element 20-n via the first power supply terminal 21-1-n to the first amplitude adjustment circuit 22-1-n, and outputs the correction control amount regarding the amplitude of the high-frequency signal radiated from the antenna element 20-n via the second power supply terminal 21-2-n to the second amplitude adjustment circuit 22-2-n. Further, the correction control amount calculation unit 33 outputs the correction control amount regarding the phase of the high-frequency signal input to and output from the first amplitude adjustment circuit 22-1-n to the first phase shifter 23-1-n, and outputs the correction control amount regarding the phase of the high-frequency signal input to and output from the second amplitude adjustment circuit 22-2-n to the second phase shifter 23-2-n.

[0069] Next, the operation of the circular polarization antenna device 1A that functions as a transmission antenna will be described. First, the distribution and synthesis circuit 25 distributes the high-frequency signal input to the input / output terminal 26 into N high-frequency signals with approximately equal amplitudes and equal phases, and outputs them to the distribution and synthesis circuits 24-n, respectively. The distribution and synthesis circuit 24-n distributes the input high-frequency signal into N high-frequency signals with approximately equal amplitudes and equal phases, and outputs them to the first phase shifter 23-1-n and the second phase shifter 23-2-n.

[0070] The first phase shifter 23-1-n adjusts the phase of the high-frequency signal input from the distribution synthesis circuit 24-n according to the control signal input from the phase shifter control unit 28, and outputs the high-frequency signal with the adjusted phase to the first amplitude adjustment circuit 22-1-n. Similarly, the second phase shifter 23-2-n adjusts the phase of the high-frequency signal input from the distribution synthesis circuit 24-n according to the control signal input from the phase shifter control unit 28, and outputs the high-frequency signal with the adjusted phase to the second amplitude adjustment circuit 22-2-n.

[0071] The first amplitude adjustment circuit 22-1-n adjusts the amplitude of the high-frequency signal input from the first phase shifter 23-1-n according to the control signal input from the amplitude adjustment control unit 27, and outputs the high-frequency signal with the adjusted amplitude to the antenna element 20-n via the first power supply terminal 21-1-n. Similarly, the second amplitude adjustment circuit 22-2-n adjusts the amplitude of the high-frequency signal input from the second phase shifter 23-2-n according to the control signal input from the amplitude adjustment control unit 27, and outputs the high-frequency signal with the adjusted amplitude to the antenna element 20-n via the second power supply terminal 21-2-n.

[0072] The high-frequency signals input to the antenna element 20-n via the first power supply terminal 21-1-n and the second power supply terminal 21-2-n are radiated into the external space as radio waves. The main polarization component of the radio waves radiated from the antenna element 20-n via the first power supply terminal 21-1-n and the main polarization component of the radio waves radiated from the antenna element 20-n via the second power supply terminal 21-2-n are orthogonal to each other.

[0073] By adjusting the amplitude and phase of the high-frequency signal passing through the first amplitude adjustment circuit 22-1-n and the first phase shifter 23-1-n, and adjusting the amplitude and phase of the high-frequency signal passing through the second amplitude adjustment circuit 22-2-n and the second phase shifter 23-2-n, it is possible to control the high-frequency signals of these two orthogonal polarization components to have equal amplitudes and a 90-degree phase difference from each other, and good circular polarization characteristics can be realized.

[0074] Furthermore, in the circularly polarized antenna device 1A, the phase of the radio wave radiated from the antenna element 20-n is controlled to be the same phase in a predetermined direction by adjusting the phase of the high-frequency signal by the first phase shifter 23-1-n and the second phase shifter 23-2-n. Thereby, the circularly polarized antenna device 1A can scan the main radiation direction of the radio wave in the predetermined direction.

[0075] For example, when the antenna element 20-1 is used as a reference antenna element, in the spherical coordinate system with the center of the antenna element 20-1 as the origin, when the first power supply terminal 21-1-1 is supplied with power at a predetermined reference amplitude and reference phase, the signals of the respective polarization components of the electric field in the (θ, φ) direction radiated from the antenna element 20-1 are represented by E θ1 (θ, φ) and E φ1 (θ, φ). The subscript θ represents the signal of the linearly polarized wave component in the θ direction, and the subscript φ represents the signal of the linearly polarized wave component in the φ direction. These signals are signals of linearly polarized wave components orthogonal to each other. Furthermore, these signals do not include re-radiation components caused by mutual coupling between the second power supply terminal 2-2 and the antenna elements around the antenna element 20-1. Similarly, when the second power supply terminal 21-2-1 is supplied with power at a predetermined reference amplitude and reference phase, the respective polarization components of the electric field in the (θ, φ) direction radiated from the antenna element 20-1 are represented by E θ2 (θ, φ) and E φ2 (θ, φ).

[0076] Hereinafter, for simplicity of notation, the argument (θ, φ) of each polarization component of the electric field is omitted. These components do not include re-radiation components caused by mutual coupling between the first power supply terminal 21-1-1 and the power supply terminals provided on the antenna elements around the antenna element 20-1.

[0077] E θ1 、E φ1 、E θ2 and E φ2is a function of (θ, φ) representing the shape of the electric field radiation pattern expressed by a trigonometric function, Bessel function, or Hankel function, and is obtained in advance through pattern measurement, electromagnetic field analysis, theoretical analysis, etc. E θ1 , E φ1 , E θ2 and E φ2 are stored in the radiation pattern function storage unit 29.

[0078] The first amplitude adjustment circuit 22-1-1 connected to the reference antenna element 20-1 multiplies the amplitude of the high-frequency signal by A1 times the reference amplitude, and the second amplitude adjustment circuit 22-2-1 multiplies the amplitude of the high-frequency signal by A2 times the reference amplitude. The first phase shifter 23-1-1 phase-shifts the phase of the high-frequency signal by ψ1 from the reference phase, and the second phase shifter 23-2-1 phase-shifts the phase of the high-frequency signal by ψ2 from the reference phase. Consider the electric field radiated from the antenna element 20-1 in these cases.

[0079] It can be obtained by considering the mutual coupling between the first power supply terminal 21-1-1 and the second power supply terminal 21-2-1 when they are excited independently, and the re-radiation components caused by the mutual coupling between the first power supply terminal 21-1-m and the second power supply terminal 21-2-m provided on the antenna elements around the antenna element 20-1.

[0080] Coupling amount c 12 (1) is the mutual coupling amount between the first power supply terminal 21-1-1 and the second power supply terminal 21-2-1 provided on the reference antenna element 20-1. Coupling amount c 11 (m) is the mutual coupling amount between the first power supply terminal 21-1-1 provided on the antenna element 20-1 and the first power supply terminal 21-1-m provided on the surrounding antenna element 20-m. Coupling amount c 21 (m) is the mutual coupling amount between the second power supply terminal 21-2-1 provided on the antenna element 20-1 and the second power supply terminal 21-2-m provided on the surrounding antenna element 20-m. Coupling amount c 12(m) is the amount of mutual coupling between the second power supply terminal 21-2-1 provided on the antenna element 20-1 and the first power supply terminal 21-1-m provided on the surrounding antenna element 20-m. The coupling amount c 22 (m) is the amount of mutual coupling between the second power supply terminal 21-2-1 provided on the antenna element 20-1 and the second power supply terminal 21-2-m provided on the surrounding antenna element 20-m.

[0081] In this case, the radiated electric field E θ (θ,φ) and E φ (θ,φ) are represented by the following formula (4). In the following formula (4), I1 = A1e jψ1 , I2 = A2e jψ2 where Ψ m = k0(x m cosφsinθ + y m sinφsinθ + z m cosθ), and k0 is the wave number at the operating frequency. (x m , y m , z m ) are the position coordinates of the antenna element 20-m around the antenna element 20-1 with the position coordinates of the reference antenna element 20-1 as the origin. Also, c 11 (1) = c 22 (1) = 1, and c 21 (1) = c 12 (1). These mutual coupling amounts are obtained in advance based on pattern measurement, electromagnetic field analysis, or theoretical analysis, etc., and stored in the coupling coefficient storage unit 30. TIFF0007714144000004.tif32166

[0082] The above formula (4) approximates that the antenna element 20-m has the same radiation pattern as the radio wave radiated from the reference antenna element 20-1, but in an array antenna with a large number of antenna elements, it is known that this approximation generally holds. When the above formula (4) is expressed in terms of the circular polarization component, the left-handed circular polarization component E L(θ, φ) and the right-handed circular polarization component E R (θ, φ) is represented by the following formula (5) respectively. TIFF0007714144000005.tif69166

[0083] To correct the axial ratio, the circular polarization component, which is the cross-polarization component, may be set to 0. For example, when the circular polarization antenna device 1A emits right-handed circular polarization, E L I1 and I2 may be controlled so as to satisfy the equation of E(θ, φ) = 0. Conversely, when emitting left-handed circular polarization, E R I1 and I2 may be controlled so as to satisfy the equation of E(θ, φ) = 0. These equations have an infinite number of solutions. Generally, it is desirable to control so that the radiated electric field strength becomes as large as possible.

[0084] For example, when the reference amplitude is set to the maximum amplitude in the first amplitude adjustment circuit 22-1-1 and the second amplitude adjustment circuit 22-2-1, and the amplitude adjustment amounts are controlled so that A1 ≤ 1 and A2 ≤ 1, the solution that satisfies the above two equations while maximizing the radiated electric field strength of the antenna element 20-1 is represented by the following formula (6). In the following formula (6), I1 and I2 are expressed as complex numbers. The + corresponds to the case of exciting with left-handed circular polarization as the main polarization, and the - corresponds to the case of exciting with right-handed circular polarization as the main polarization. c ij (m) is the coupling amount between the j-th feeding terminal of the reference antenna element and the i-th feeding terminal of the m-th antenna element among the M antenna elements around the j-th feeding terminal. i and j are integers of 1 or 2. TIFF0007714144000006.tif96166

[0085] Next, the embodiment 2 will be described for the correction control amount determination method according to it. FIG. 5 is a flowchart showing the correction control amount determination method according to the second embodiment, and shows a series of processes in the correction control amount determination method executed by the circular polarization antenna device 1A. The correction control amount calculation unit 33 reads the radiation pattern functions E of the high-frequency signals radiated through the first power supply terminals 21-1-n, which are stored in the radiation pattern function storage unit 29. θ1 and E φ1 and reads the radiation pattern functions E of the high-frequency signals radiated through the second power supply terminals 21-2-n. θ2 and E φ2 (Step ST21).

[0086] Next, the correction control amount calculation unit 33 reads the coupling amounts c 11 (m), c 21 (m), c 12 (m) and c 22 (m) between the first power supply terminals 21-1-n and the second power supply terminals 21-2-n, which are stored in the coupling coefficient storage unit 30 (Step ST22). The correction control amount calculation unit 33 reads the coordinate information of the antenna element 20-n stored in the antenna element coordinate storage unit 31 (Step ST23).

[0087] The correction control amount calculation unit 33 acquires the axial ratio correction direction (θ0, φ0) and the excitation polarization condition (Step ST24). For example, the axial ratio correction direction (θ0, φ0) and the excitation polarization condition are set by the user to the correction control amount calculation unit 33 using an operating device (not shown) in FIG. 1, or are those stored in the radiation pattern function storage unit 29, the coupling coefficient storage unit 30, or the antenna element coordinate storage unit 31.

[0088] The correction control amount calculation unit 33 calculates the control amounts I1 and I2 necessary for axial ratio correction according to the above formula (6) using this information, calculates the correction control amounts A1 and A2 regarding the amplitude in the calculated control amounts I1 and I2, and calculates the correction control amounts ψ1 and ψ2 regarding the phase (Step ST25).

[0089] The correction control amount calculation unit 33 outputs the correction control amounts A1 and A2 to the amplitude adjustment control unit 27, and outputs the correction control amounts ψ1 and ψ2 to the phase shifter control unit 28 (Step ST5). The amplitude adjustment control unit 27 generates a control signal for setting the first amplitude adjustment circuit 22-1-n based on the correction control amount, and outputs the generated control signal to the first amplitude adjustment circuit 22-1-n. Further, the amplitude adjustment control unit 27 generates a control signal for setting the second amplitude adjustment circuit 22-2-n based on the correction control amount, and outputs the generated control signal to the second amplitude adjustment circuit 22-2-n.

[0090] The phase shifter control unit 28 generates a control signal for setting the first phase shifter 23-1-n based on the correction control amount, and outputs the generated control signal to the first phase shifter 23-1-n. The phase shifter control unit 28 generates a control signal for setting the second phase shifter 23-2-n based on the correction control amount, and outputs the generated control signal to the second phase shifter 23-2-n. As a result, the radio wave radiated from the circularly polarized antenna device 1A to the external space is controlled so that the cross-polarization component becomes 0. Therefore, it is possible to improve the axial ratio.

[0091] Note that the above formula (6) is a relational expression representing the control amount considering only the radiation electric field of the reference antenna element 20-1. On the other hand, in an array antenna with a large number of elements, a similar discussion approximately holds for many antenna elements except for the antenna elements at the ends of the array antenna. Therefore, the circularly polarized antenna device 1A is configured to give the same correction control amount regarding amplitude and the correction control amount regarding phase based on the above formula (6) to all the antenna elements 20-n.

[0092] The beam forming control amount calculation unit 32 scans the main radiation direction of the radio wave in the beam scanning direction and forms a predetermined array pattern based on the element coordinates (x n , y n , z n ) of the antenna element 20-n, the frequency, and the beam scanning direction (θ0, φ0), and calculates the control amount w n according to the following formula (7). In the following formula (7), V n is the amplitude value set for the high-frequency signal radiated from the antenna element 20-n in order to give an amplitude distribution to the high-frequency signal, and Pn is the amount of phase set for the high-frequency signal radiated from the antenna element 20-n for calibration. TIFF0007714144000007.tif9166

[0093] The beam forming control quantity calculation unit 32 calculates the control quantity w n The control quantity V related to the amplitude of the high-frequency signal included in n and the control quantity Φ related to the phase of the high-frequency signal n and calculates the control quantity V n and the control quantity Φ n are output to the amplitude adjustment control unit 27 and the phase shifter control unit 28, respectively.

[0094] The amplitude adjustment control unit 27 generates control signals for setting the first amplitude adjustment circuit 22-1-n and the second amplitude adjustment circuit 22-2-n, respectively, based on the control quantities related to the amplitude input from the correction control quantity calculation unit 33 and the beam forming control quantity calculation unit 32, and transmits the control signals to the first amplitude adjustment circuit 22-1-n and the second amplitude adjustment circuit 22-2-n.

[0095] The phase shifter control unit 28 generates control signals for setting the first phase shifter 23-1-n and the second phase shifter 23-2-n, respectively, based on the control quantities related to the phase input from the correction control quantity calculation unit 33 and the beam forming control quantity calculation unit 32, and transmits the control signals to the first phase shifter 23-1-n and the second phase shifter 23-2-n. The control quantity set for the first amplitude adjustment circuit 22-1-n connected to the antenna element 20-n is A1 + V n is. Also, the control quantity set for the second amplitude adjustment circuit 22-2-n is A2 + V n is. Furthermore, the control quantity set for the first phase shifter 23-1-n is ψ1 + Φ n is. The phase control quantity set for the second phase shifter 23-2-n is ψ2 + Φ n is.

[0096] The main radiation direction of the radio wave radiated into space by the circular polarization antenna device 1A is a predetermined beam scanning direction (θ0, φ0). That is, the radio wave radiated into space is scanned in the beam scanning direction (θ0, φ0) and is controlled so that the cross-polarization component in that direction becomes 0. Therefore, the circular polarization antenna device 1A can improve the axial ratio.

[0097] The control amount determined in the antenna described in Patent Document 1 is determined by ignoring the re-radiation due to the mutual coupling between the feeding terminals of the antenna elements around the reference antenna element. Therefore, even if this control amount is applied to the phased array antenna, the axial ratio improvement effect is small. On the other hand, as shown in the above formula (6), the circular polarization antenna device 1A determines the control amount in consideration of the re-radiation component due to the coupling between the feeding terminals. Therefore, even when the re-radiation component is large, a higher axial ratio improvement effect can be obtained compared to Patent Document 1. Although the case where the circular polarization antenna device 1A functions as a transmitting antenna has been described, the same effect can be obtained even when the circular polarization antenna device 1A functions as a receiving antenna.

[0098] For example, the circular polarization antenna device 1A has an input interface 100, an output interface 101, a processor 102, and a memory 103 as the hardware configuration shown in FIGS. 3A and 3B. The functions of the amplitude adjustment control unit 27, the phase shifter control unit 28, and the correction control amount calculation unit 33 provided in the circular polarization antenna device 1A are realized by executing an information processing application in these hardware configurations.

[0099] The input interface 100 relays the data read from the radiation pattern function storage unit 29, the coupling coefficient storage unit 30, and the antenna element coordinate storage unit 31 and outputs it to the processor 102. The output interface 101 relays the control signal output from the amplitude adjustment control unit 27 to the first amplitude adjustment circuit 22-1-n and the second amplitude adjustment circuit 22-2-n, and relays the control signal output from the phase shifter control unit 28 to the first phase shifter 23-1-n and the second phase shifter 23-2-n.

[0100] Programs of information processing applications for realizing the functions of the amplitude adjustment control unit 27, the phase shifter control unit 28, and the correction control amount calculation unit 33 are stored in the memory 103. By executing the program read from the memory 103, the processor 102 realizes the functions of the amplitude adjustment control unit 27, the phase shifter control unit 28, and the correction control amount calculation unit 33. Note that the memory 103 is, for example, a hard disk device or a RAM.

[0101] As described above, the circular polarization antenna device 1A according to the second embodiment distributes a high-frequency signal to the distribution synthesis circuit 24-n included in the N antenna units, and synthesizes the high-frequency signals from the distribution synthesis circuit 24-n included in the N antenna units. A beam forming control amount calculation unit 32 that calculates the amplitude control amount and the phase control amount necessary for beam forming using the coordinate information of the antenna elements 20-n included in the N antenna units, the coordinate information of the antenna elements 20-n, the first power supply terminal 21-1-n, and the second A function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 20-n via the power supply terminal 21-2-n, the coupling amount between the first power supply terminal 21-1-n and the second power supply terminal 21-2-n, and the antenna element 20-n Based on the coordinate information, a correction control amount calculation unit 33 that calculates a correction control amount for axial ratio correction, and an amplitude adjustment control unit 27 that controls the amplitude adjustment by the first amplitude adjustment circuit 22-1-n and the second amplitude adjustment circuit 22-2-n based on the correction control amount , A phase shifter control unit 28 that controls the phase adjustment by the first phase shifter 23-1-n and the second phase shifter 23-2-n based on the correction control amount. Thereby, in addition to the effects shown in the first embodiment, even when the circular polarization antenna device 1A is a phased array antenna in which the re-radiation component due to the mutual coupling between adjacent antenna elements is large, a high axial ratio improvement effect can be obtained in a predetermined beam scanning direction.

[0102] In the circularly polarized antenna device 1A according to Embodiment 2, the antenna element 20-n includes a first radiating element that is arranged orthogonally to each other and radiates a high-frequency signal whose linearly polarized wave is the main polarization component, and a second radiating element that radiates a high-frequency signal whose linearly polarized wave is orthogonal to the linearly polarized wave of the high-frequency signal radiated by the first radiating element and whose linearly polarized wave is the main polarization component. The first power supply terminal 21-1-n is connected to either the first radiating element or the second radiating element. The second power supply terminal 21-2-n is connected to the remaining one of the first radiating element and the second radiating element. Thereby, the circularly polarized antenna device 1A can determine a correction control amount for improving the axial ratio.

[0103] In the circularly polarized antenna device 1A according to Embodiment 2, the first radiating element and the second radiating element are dipole antennas or patch antennas. Thereby, various types of antenna devices can be realized as the circularly polarized antenna device 1A.

[0104] In the circularly polarized antenna device 1A according to Embodiment 2, the antenna element 20-n is a single radiating element capable of radiating two orthogonal linearly polarized waves. Thereby, various types of antenna devices can be realized as the circularly polarized antenna device 1A.

[0105] In the circularly polarized antenna device 1A according to Embodiment 2, the radiating element is a circular or rectangular patch antenna. Two line segments connecting the connection point with the first power supply terminal 21-1-n or the second power supply terminal 21-2-n and the center point of the radiating element are orthogonal. Thereby, the circularly polarized antenna device 1A can realize good circularly polarized wave characteristics.

[0106] In the circularly polarized antenna device 1A according to Embodiment 2, the correction control amount calculation unit 33 calculates the correction control amount according to the above formula (6). Thereby, the circularly polarized antenna device 1A can determine a correction control amount for optimally improving the axial ratio.

[0107] The correction control amount determination method according to Embodiment 2 includes steps where the distribution synthesis circuit 25 distributes a high-frequency signal to the distribution synthesis circuits 24-n respectively possessed by N antenna units, and synthesizes the high-frequency signals from the distribution synthesis circuits 24-n respectively possessed by the N antenna units; the beam forming control amount calculation unit 32 calculates the amplitude control amount and phase control amount necessary for beam forming using the coordinate information of the antenna elements 20-n respectively possessed by the N antenna units; the correction control amount calculation unit 33 calculates a correction control amount for axial ratio correction based on the coordinate information of the antenna element 20-n, a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 20-n via the first power supply terminal 21-1-n and the second power supply terminal 21-2-n, the coupling amount between the first power supply terminal 21-1-n and the second power supply terminal 21-2-n, and the coordinate information of the antenna element 20-n; the amplitude adjustment control unit 27 controls the amplitude adjustment by the first amplitude adjustment circuits 22-1-n and the second amplitude adjustment circuits 22-2-n based on the correction control amount; and the phase shifter control unit 28 controls the phase adjustment by the first phase shifters 23-n and the second phase shifters 23-2-n based on the correction control amount. By executing this method, the circular polarization antenna device 1A, which is a phased array antenna, can obtain a high axial ratio improvement effect even in a predetermined beam scanning direction in addition to the effects shown in Embodiment 1.

[0108] Embodiment 3. FIG. 6 is a block diagram showing the configuration of a circular polarization antenna device 1B according to Embodiment 3. The circular polarization antenna device 1B is a so-called circular polarization phased array antenna that transmits and receives circular polarization high-frequency signals. In the circular polarization antenna device 1A shown in Embodiment 2, when it is difficult to directly obtain the mutual coupling amount between the power supply terminals stored in the coupling coefficient storage unit 30, these mutual coupling amounts are determined by calculation using the radiation pattern measurement results or electromagnetic field analysis results performed in advance. In FIG. 6, the same components as those in FIG. 4 are denoted by the same reference numerals and the description thereof is omitted. n is an integer from 1 to N, and N is the number of antenna elements.

[0109] The circularly polarized antenna device 1B includes N antenna units each having an antenna element 20-n, a first amplitude adjustment circuit 22-1-n, a second amplitude adjustment circuit 22-2-n, a first phase shifter 23-1-n, a second phase shifter 23-2-n, and a distribution synthesis circuit 24-n, a distribution synthesis circuit 25, an input / output terminal 26, an amplitude adjustment control unit 27, a phase shifter control unit 28, a radiation pattern function storage unit 29, a coupling coefficient storage unit 30, an antenna element coordinate storage unit 31, a beam forming control quantity calculation unit 32, a correction control quantity calculation unit 33, and a calculation unit 40. The calculation unit 40 includes a measurement analysis result storage unit 41 and a coupling coefficient calculation unit 42. The antenna element 20-n includes a first power supply terminal 21-1-n and a second power supply terminal 21-2-n.

[0110] The calculation unit 40 calculates so that the difference between the coupling amount between the first power supply terminal 21-1-n0 and the second power supply terminal 21-2-n0 of the reference antenna element 20-n0, the function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 20-n via the first power supply terminal 21-1-n and the second power supply terminal 21-2-n, the sum of the function representing the shape of the radiation pattern of the radio wave caused by the coupling between the first power supply terminal 21-1-n0 and the second power supply terminal 21-2-n0 of the reference antenna element 20-n0 and the coupling between the first power supply terminal 21-1-m and the second power supply terminal 21-2-m of the antenna element 20-m adjacent to the reference antenna element 20-n0, and the measurement analysis value of the radiation pattern of the radio wave radiated from the reference antenna element 20-n0 is minimized.

[0111] The measurement analysis result storage unit 41 is a storage unit that stores the measurement analysis result of the radiation pattern of the radio wave radiated from the reference antenna element 20-n0 among the antenna elements 20-n. The measurement analysis result of the radiation pattern of the radio wave is, for example, the result obtained by actually measuring the radiation pattern of the reference antenna element 20-n0 or by simulation using electromagnetic field analysis. The measurement analysis result storage unit 41 is a hard disk device or a RAM. Further, the measurement analysis result storage unit 41 only needs to be accessible by the coupling coefficient calculation unit 42, and may be provided outside the circularly polarized antenna device 1B.

[0112] The coupling coefficient calculation unit 42 calculates the coupling amount between the first power supply terminal 21-1-n0 and the second power supply terminal 21-2-n0 in the reference antenna element 20-n0. For example, the coupling coefficient calculation unit 42 reads out the radiation pattern function of each power supply terminal stored in the radiation pattern function storage unit 29, the coordinate information of each antenna element 20-n stored in the antenna element coordinate storage unit 31, and the radiation pattern measurement analysis result stored in the measurement analysis result storage unit 41. Then, the coupling coefficient calculation unit 42 uses these pieces of information to calculate the amplitude and phase of the high-frequency signal corresponding to the coupling amount between the first power supply terminal 21-1-n0 and the second power supply terminal 21-2-n0 in the reference antenna element 20-n0 according to the correction control amount calculation formula. Further, the coupling coefficient calculation unit 42 calculates the amplitude and phase of the high-frequency signal corresponding to the coupling amount between the first power supply terminal 21-1-m and the second power supply terminal 21-2-m in the M antenna elements 20-m around the first power supply terminal 21-1-n0 and the second power supply terminal 21-2-n0 of the reference antenna element 20-n0. The coupling coefficient information indicating the amplitude and phase of the high-frequency signal corresponding to the coupling amount between the power supply terminals calculated by the coupling coefficient calculation unit 42 is stored in the coupling coefficient storage unit 30.

[0113] For example, when the antenna element 20-1 is used as the reference antenna element, in the spherical coordinate system with the center of the antenna element 20-1 as the origin, when the first power supply terminal 21-1-1 is fed with a predetermined reference amplitude and reference phase, the signals of each polarization component of the electric field in the (θ, φ) direction radiated from the antenna element 20-1 are represented by E θ1 (θ, φ) and E φ1 (θ, φ). The subscript θ represents the signal of the linearly polarized wave component in the θ direction, the subscript φ represents the signal of the linearly polarized wave component in the φ direction, and these signals are signals of linearly polarized wave components orthogonal to each other. Furthermore, these signals do not include re-radiation components resulting from the mutual coupling between the second power supply terminal 2-2 and the antenna elements surrounding the antenna element 20-1. Similarly, when the second power supply terminal 21-2-1 is fed with a predetermined reference amplitude and reference phase, each polarization component of the electric field radiated from the antenna element 20-1 in the (θ, φ) direction is represented by E θ2 (θ, φ) and E φ2 (θ, φ).

[0114] Hereinafter, for simplicity of notation, the arguments (θ, φ) of each polarization component of the electric field are omitted. These components do not include re-radiation components resulting from the mutual coupling between the first power supply terminal 21-1-1 and the power supply terminal provided on the antenna element surrounding the antenna element 20-1.

[0115] E θ1 、E φ1 、E θ2 and E φ2 are functions of (θ, φ) representing the shape of the electric field radiation pattern expressed by trigonometric functions, Bessel functions, or Hankel functions, and are obtained in advance by performing pattern measurement, electromagnetic field analysis, or theoretical analysis, etc. E θ1 、E φ1 、E θ2 and E φ2 are stored in the radiation pattern function storage unit 29.

[0116] The coupling amount c 12 (1) is the mutual coupling amount between the first power supply terminal 21-1-1 and the second power supply terminal 21-2-1 provided on the reference antenna element 20-1. The coupling amount c 11 (m) is the mutual coupling amount between the first power supply terminal 21-1-1 provided on the antenna element 20-1 and the first power supply terminal 21-1-m provided on the surrounding antenna element 20-m. The coupling amount c 21 (m) is the mutual coupling amount between the second power supply terminal 21-2-1 provided on the antenna element 20-1 and the second power supply terminal 21-2-m provided on the surrounding antenna element 20-m. The coupling amount c 12(m) is the mutual coupling amount between the second power supply terminal 21-2-1 provided on the antenna element 20-1 and the first power supply terminal 21-1-m provided on the surrounding antenna element 20-m. Coupling amount c 22 (m) is the mutual coupling amount between the second power supply terminal 21-2-1 provided on the antenna element 20-1 and the second power supply terminal 21-2-m provided on the surrounding antenna element 20-m.

[0117] The radiated electric field E radiated from the antenna element 20-1 when the first power supply terminal 21-1-1 and the second power supply terminal 21-2-1 provided on the reference antenna element 20-1 are powered with a predetermined reference amplitude and reference phase θ (θ, φ) and E φ (θ, φ) is represented by the following formula (8). In the following formula (8), Ψ m = k0(x m cosφsinθ + y m sinφsinθ + z m cosθ), where k0 is the wave number at the operating frequency. (x m , y m , z m ) are the position coordinates of the antenna element 20-m around the antenna element 20-1 with the position coordinates of the reference antenna element 20-1 as the origin. Also, c 11 (1) = c 22 (1) = 1, and c 21 (1) = c 12 (1). TIFF0007714144000008.tif35166

[0118] The coupling coefficient calculation unit 42 minimizes the evaluation function f represented by the following formula (9) so that the theoretical value of the radiated electric field represented by the above formula (8) is approximately the same as the measurement and analysis results of the radiation pattern, F θ and F φ , to obtain c 11 (m), c 21 (m), c 12 (m) and c 22 (m). In the following formula (9), (θ p, φ q ) indicates the (p, q)-th evaluation direction, P is the evaluation score in the θ direction, and Q is the evaluation score in the φ direction. The minimization problem represented by the following formula (9) can be solved by an algorithm based on an iterative method such as the conjugate gradient method, a genetic algorithm, or a metaheuristic algorithm such as particle swarm optimization. Operations of the circular polarization antenna device 1B other than the above are the same as those of the circular polarization antenna device 1A, and as a result, the same effects as those shown in the second embodiment can be obtained. TIFF0007714144000009.tif20166

[0119] The coupling coefficient calculation unit 42 calculates the coupling amount between the feeding terminals that minimizes the difference between the measurement analysis result of the radiation pattern of the reference antenna element 21-n0 stored in the measurement analysis result storage unit 41 and the function representing the shape of the radiation pattern of each feeding terminal stored in the radiation pattern function storage unit 29. Here, the theoretical value of the function representing the shape of the radiation pattern is the sum of the function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 20-n through the first feeding terminal 21-1-n and the second feeding terminal 21-2-n, and the function representing the shape of the radiation pattern of the radio wave caused by the coupling between the first feeding terminal 21-1-n0 and the second feeding terminal 21-2-n0 in the reference antenna element 20-n0 and the coupling between the first feeding terminal 21-1-n and the second feeding terminal 21-2-n in the antenna element 20-m adjacent to the reference antenna element 20-n0.

[0120] The correction control amount calculation unit 33 calculates a correction control amount that satisfies the above formula (6) using the coupling amount calculated by the coupling coefficient calculation unit 42. Thereby, even when it is difficult to directly obtain the coupling amount between the feeding terminals by measurement analysis, the circular polarization antenna device 1B can obtain a high axial ratio improvement effect in a predetermined beam scanning direction.

[0121] Although the case where the circular polarization antenna device 1B includes the arithmetic unit 40 has been described, the arithmetic unit 40 may be provided in an external device provided separately from the circular polarization antenna device 1B. In this case, when the coupling coefficient arithmetic unit 42 provided in the external device calculates the coupling amount, it accesses the circular polarization antenna device 1B and stores the calculated coupling amount in the coupling coefficient storage unit 30 provided in the circular polarization antenna device 1B.

[0122] Also, the coupling coefficient storage unit 30 in the circular polarization antenna device 1B may be omitted, and the coupling coefficient arithmetic unit 42 may directly output the calculated coupling amount to the correction control amount arithmetic unit 33. Furthermore, although the case where the circular polarization antenna device 1B is a circular polarization phased array antenna has been described, the circular polarization antenna device 1B may be a single circular polarization antenna. In this case, M = 1 may be set in the above formula (9).

[0123] For example, as the hardware configuration shown in FIGS. 3A and 3B, the circular polarization antenna device 1B has an input interface 100, an output interface 101, a processor 102, and a memory 103. The functions of the amplitude adjustment control unit 27, the phase shifter control unit 28, the correction control amount arithmetic unit 33, and the arithmetic unit 40 provided in the circular polarization antenna device 1B are realized by executing an information processing application in these hardware configurations.

[0124] The input interface 100 relays the data read from the radiation pattern function storage unit 29, the coupling coefficient storage unit 30, the antenna element coordinate storage unit 31, and the measurement analysis result storage unit 41 and outputs it to the processor 102. The output interface 101 relays the control signal output from the amplitude adjustment control unit 27 to the first amplitude adjustment circuit 22-1-n and the second amplitude adjustment circuit 22-2-n, and relays the control signal output from the phase shifter control unit 28 to the first phase shifter 23-1-n and the second phase shifter 23-2-n.

[0125] Programs of information processing applications for realizing the functions of the amplitude adjustment control unit 27, the phase shifter control unit 28, the correction control amount calculation unit 33, and the calculation unit 40 are stored in the memory 103. The processor 102 executes the program read from the memory 103, thereby realizing the functions of the amplitude adjustment control unit 27, the phase shifter control unit 28, the correction control amount calculation unit 33, and the calculation unit 40. Note that the memory 103 is, for example, a hard disk device or a RAM.

[0126] As described above, the circular polarization antenna device 1B according to Embodiment 3 calculates, among the N antenna elements 20-n, the coupling amount between the first power supply terminal 21-1-n and the second power supply terminal 21-2-n in the reference antenna element 20-n0 so that the difference between the sum of a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element 20-n via the first power supply terminal 21-1-n and the second power supply terminal 21-2-n and a function representing the shape of the radiation pattern of the radio wave caused by the coupling between the first power supply terminal 21-1-n0 and the second power supply terminal 21-2-n0 in the reference antenna element 20-n0 and the coupling between the first power supply terminal 21-1-n and the second power supply terminal 21-2-n in the antenna element 20-m adjacent to the reference antenna element 20-n0 and the measured analysis value of the radiation pattern of the radio wave radiated from the reference antenna element 20-n0 is minimized. The circular polarization antenna device 1B is provided with a calculation unit 40. Thereby, in addition to the effects shown in Embodiments 1 and 2, the circular polarization antenna device 1B can obtain a high axial ratio improvement effect in a predetermined beam scanning direction even when it is difficult to directly obtain the coupling amount between the power supply terminals by measurement analysis.

[0127] Note that the arithmetic unit 40 described above may be applied to the circularly polarized antenna device 1 including a single antenna unit. In this case, the arithmetic unit 40 calculates a function representing the shape of the radiation pattern of the high-frequency signal radiated via the first power supply terminal 2-1 and the second power supply terminal 2-2, a function representing the shape of the radiation pattern of the radio wave caused by the coupling between the first power supply terminal 2-1 and the second power supply terminal 2-2, and calculates the coupling amount between the first power supply terminal 2-1 and the second power supply terminal 2-2 so that the difference from the measurement analysis value of the radiation pattern of the radio wave radiated from the antenna element 2 becomes minimum. By the circularly polarized antenna device 1 including the arithmetic unit 40, In addition to the effects shown in the first embodiment, the circularly polarized antenna device 1 can obtain a high axial ratio improvement effect in a predetermined beam scanning direction even when it is difficult to directly obtain the coupling amount between the power supply terminals by measurement analysis.

[0128] Note that combinations of each embodiment, or modifications of any component of each embodiment, or omissions of any component in each embodiment are possible.

Industrial Applicability

[0129] The circularly polarized antenna device according to the present disclosure can be used, for example, in satellite communication or microwave power transmission.

Explanation of Signs

[0130] 1, 1A, 1B Circular polarization antenna device, 2, 20-1, 20-n, 20-m Antenna elements, 2-1, 21-1, 21-1-n, 21-1-n0, 21-1-m First power supply terminals, 2-2, 21-2, 21-2-n, 21-2-n0, 21-2-m Second power supply terminals, 3-1, 22-1, 22-1-n First amplitude adjustment circuits, 3-2, 22-2, 22-2-n Second amplitude adjustment circuits, 4-1, 23-1, 23-1-n First phase shifters, 4-2, 23-2, 23-2-n Second phase shifters, 5, 24-n, 25 Distribution synthesis circuits, 6, 26 Input / output terminals, 7, 27 Amplitude adjustment control units, 8, 28 Phase shifter control units, 9, 29 Radiation pattern function storage units, 10, 30 Coupling coefficient storage units, 11, 33 Correction control amount calculation units, 31 Antenna element coordinate storage units, 32 Beam forming control amount calculation units, 40 Calculation units, 41 Measurement analysis result storage units, 42 Coupling coefficient calculation units, 100 Input interfaces, 101 Output interfaces, 102 Processors, 103 Memories.

Claims

Claim 1: A radiating element capable of radiating or receiving radio waves having two orthogonal polarization characteristics, wherein a first power supply terminal and a second power supply terminal are arranged such that the main polarization component of the radio wave transmitted and received via the first power supply terminal and the main polarization component of the radio wave transmitted and received via the second power supply terminal are orthogonal to each other; an antenna element, a first amplitude adjustment circuit for adjusting the amplitude of the high-frequency signal transmitted and received via the first power supply terminal; a second amplitude adjustment circuit for adjusting the amplitude of the high-frequency signal transmitted and received via the second power supply terminal; a first phase shifter for adjusting the phase of the high-frequency signal input to and output from the first amplitude adjustment circuit; a second phase shifter for adjusting the phase of the high-frequency signal input to and output from the second amplitude adjustment circuit; a distribution and synthesis circuit that distributes a high-frequency signal to the first phase shifter and the second phase shifter and synthesizes the high-frequency signals from the first phase shifter and the second phase shifter, a circularly polarized antenna device comprising: a correction control amount calculation unit that calculates a correction control amount for axial ratio correction based on a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element via the first power supply terminal and the second power supply terminal, and the coupling amount between the first power supply terminal and the second power supply terminal; an amplitude adjustment control unit that controls the amplitude adjustment by the first amplitude adjustment circuit and the second amplitude adjustment circuit based on the correction control amount; a phase shifter control unit that controls the phase adjustment by the first phase shifter and the second phase shifter based on the correction control amount, comprising: A circularly polarized antenna device characterized by the above.

2. The antenna element is composed of a first radiating element and a second radiating element arranged orthogonally to each other, when a linearly polarized wave component of a radio wave is radiated from the first radiating element, the second radiating element radiates a linearly polarized wave component of a radio wave orthogonal to the linearly polarized wave component of the radio wave radiated from the first radiating element, the first power supply terminal is connected to either the first radiating element or the second radiating element, the second power supply terminal is connected to the remaining one of the first radiating element and the second radiating element The circularly polarized antenna device according to claim 1, characterized by the above.

3. The first radiating element and the second radiating element are a dipole antenna or a patch antenna The circularly polarized antenna device according to claim 2, characterized by the above.

4. The antenna element is a single radiation element capable of radiating two orthogonal linear polarized waves. The circularly polarized antenna device according to claim 1, characterized in that.

5. The radiation element is a circular or rectangular patch antenna, Two line segments connecting the connection point between the first power supply terminal or the second power supply terminal and the center point of the radiation element are orthogonal. The circularly polarized antenna device according to claim 4, characterized in that.

6. The correction control amount calculation unit calculates the correction control amount according to the following formula, In the following formula, + is the case of exciting a left-handed circularly polarized wave as the main polarized wave, and - is the case of exciting a right-handed circularly polarized wave as the main polarized wave. I １ represents the correction control amount set for the first amplitude adjustment circuit and the first phase shifter as a complex number, I ２ represents the correction control amount set for the second amplitude adjustment circuit and the second phase shifter in complex number notation, E θ１ and E φ１ is a function representing the shape of the radiation patterns of two orthogonal linearly polarized waves of the high-frequency signal radiated through the first power supply terminal, E θ２ and E φ２ is a function representing the shape of the radiation patterns of two orthogonal linearly polarized high-frequency signals radiated through the second power supply terminal, c is the coupling amount between the first power supply terminal and the second power supply terminal. The circularly polarized antenna device according to any one of claims 1 to 5, characterized in that.

7. A function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element via the first power supply terminal and the second power supply terminal, and a function representing the shape of the radiation pattern of the radio wave caused by the coupling between the first power supply terminal and the second power supply terminal. An arithmetic unit that calculates the coupling amount between the first power supply terminal and the second power supply terminal so that the difference from the measured analysis value of the radiation pattern of the radio wave radiated from the antenna element is minimized. The circularly polarized antenna device according to any one of claims 1 to 5, characterized in that.

8. A radiation element capable of radiating or receiving radio waves having two orthogonal polarization characteristics respectively, and the first power supply terminal and the second power supply terminal are arranged such that the main polarization components of the radio waves transmitted and received via the first power supply terminal and the main polarization components of the radio waves transmitted and received via the second power supply terminal are orthogonal to each other. An antenna element, A first amplitude adjustment circuit that adjusts the amplitude of the high-frequency signal transmitted and received via the first power supply terminal, A second amplitude adjustment circuit that adjusts the amplitude of the high-frequency signal transmitted and received via the second power supply terminal, A first phase shifter that adjusts the phase of the high-frequency signal input and output to the first amplitude adjustment circuit, A second phase shifter that adjusts the phase of the high-frequency signal input and output to the second amplitude adjustment circuit, A first distribution and synthesis circuit that distributes high-frequency signals to the first phase shifter and the second phase shifter and synthesizes the high-frequency signals from the first phase shifter and the second phase shifter. A circularly polarized antenna array in which a plurality of antenna units having the above are arranged. A second power distribution / synthesis circuit that distributes a high-frequency signal to the first power distribution / synthesis circuits respectively included in the plurality of antenna units and synthesizes the high-frequency signals from the first power distribution / synthesis circuits respectively included in the plurality of antenna units; A beam forming control amount calculation unit that calculates an amplitude control amount and a phase control amount necessary for beam forming using the coordinate information of the antenna elements respectively included in the plurality of antenna units; A correction control amount calculation unit that calculates a correction control amount for axial ratio correction based on the coordinate information of the antenna element, a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element via the first power supply terminal and the second power supply terminal, the coupling amount between the first power supply terminal and the second power supply terminal, and the coordinate information of the antenna element; An amplitude adjustment control unit that controls the amplitude adjustment by the first amplitude adjustment circuit and the second amplitude adjustment circuit based on the correction control amount; A phase shifter control unit that controls the phase adjustment by the first phase shifter and the second phase shifter based on the correction control amount, and A circularly polarized antenna device characterized by the above.

9. The antenna element Comprises a first radiation element and a second radiation element arranged orthogonally to each other, When the first radiation element radiates a radio wave of a linearly polarized wave component, the second radiation element radiates a radio wave of a linearly polarized wave component orthogonal to the linearly polarized wave component of the radio wave radiated from the first radiation element, The first power supply terminal is connected to either one of the first radiation element and the second radiation element, The second power supply terminal is connected to the remaining one of the first radiation element and the second radiation element The circularly polarized antenna device according to claim 8, characterized by the above.

10. The first radiation element and the second radiation element are dipole antennas or patch antennas The circularly polarized antenna device according to claim 9, characterized by the above.

11. The antenna element is a single radiation element capable of radiating two orthogonal linearly polarized waves The circularly polarized antenna device according to claim 8, characterized by the above.

12. The radiation element is a circular or rectangular patch antenna, Two line segments connecting the connection point with the first power supply terminal or the second power supply terminal and the center point of the radiation element are orthogonal The circularly polarized antenna device according to claim 11, characterized by the above.

13. The correction control amount calculation unit calculates the correction control amount according to the following formula: In the following formula, + indicates the case where the left-handed circularly polarized wave is excited as the main polarized wave, and - indicates the case where the right-handed circularly polarized wave is excited as the main polarized wave. I １ represents the correction control amount set for the first amplitude adjustment circuit and the first phase shifter respectively included in the antenna unit in complex numbers, I ２ represents the correction control amount set for the second amplitude adjustment circuit and the second phase shifter respectively included in the antenna unit, expressed as a complex number, E θ１ and E φ１ is a function representing the shape of radiation patterns of two orthogonal linearly polarized waves of a high-frequency signal radiated through the first power supply terminal, E θ２ and E φ２ is a function representing the shape of radiation patterns of two orthogonal linearly polarized waves of a high-frequency signal radiated through the second power supply terminal, i and j are integers of 1 or 2. c ｉｊ (m) is the coupling amount between the j-th power supply terminal of the antenna element of the reference antenna unit and the i-th power supply terminal of the m-th antenna element among the M antenna elements around the j-th power supply terminal, and Ψ ｍ = k ０ (x ｍ cos φ sin θ + y ｍ sin φ sin θ + z ｍ cos θ), where k ０ is the wave number at the operating frequency, (x ｍ , y ｍ , z ｍ ) are the element coordinates of the m-th antenna element, and (θ, φ) is the axial ratio correction direction The circularly polarized antenna device according to any one of claims 8 to 12, characterized in that.

14. Among the plurality of antenna elements, the coupling amount between the first power supply terminal and the second power supply terminal in the reference antenna element is A function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element via the first power supply terminal and the second power supply terminal, and the coupling between the first power supply terminal and the second power supply terminal in the reference antenna element and the first power supply terminal and the second power supply terminal in the antenna element adjacent to the reference antenna element. An arithmetic unit that calculates so that the difference from the measured analysis value of the radiation pattern of the radio wave radiated from the reference antenna element is minimized, The circularly polarized antenna device according to any one of claims 8 to 12, characterized in that.

15. A radiation element capable of radiating or receiving radio waves having two orthogonal polarization characteristics, and a first power supply terminal and a second power supply terminal are arranged such that the main polarization components of the radio waves transmitted and received via the first power supply terminal are orthogonal to the main polarization components of the radio waves transmitted and received via the second power supply terminal. An antenna element, A first amplitude adjustment circuit that adjusts the amplitude of the high-frequency signal transmitted and received via the first power supply terminal; A second amplitude adjustment circuit that adjusts the amplitude of the high-frequency signal transmitted and received via the second power supply terminal; A first phase shifter that adjusts the phase of the high-frequency signal input and output to the first amplitude adjustment circuit; A second phase shifter that adjusts the phase of the high-frequency signal input and output to the second amplitude adjustment circuit; A distribution and synthesis circuit that distributes the high-frequency signal to the first phase shifter and the second phase shifter and synthesizes the high-frequency signals from the first phase shifter and the second phase shifter; A method for determining a correction control amount by a circularly polarized antenna device including: The correction control amount calculation unit calculates a correction control amount for axial ratio correction based on a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element via the first power supply terminal and the second power supply terminal, and the coupling amount between the first power supply terminal and the second power supply terminal. The amplitude adjustment control unit controls the amplitude adjustment by the first amplitude adjustment circuit and the second amplitude adjustment circuit based on the correction control amount. The phase shifter control unit controls the phase adjustment by the first phase shifter and the second phase shifter based on the correction control amount. A correction control amount determination method characterized by the above.

16. A radiation element capable of radiating or receiving radio waves having two orthogonal polarization characteristics, wherein the first power supply terminal and the second power supply terminal are arranged such that the main polarization component of the radio wave transmitted and received via the first power supply terminal and the main polarization component of the radio wave transmitted and received via the second power supply terminal are orthogonal to each other. An antenna element, A first amplitude adjustment circuit that adjusts the amplitude of the high-frequency signal transmitted and received via the first power supply terminal. A second amplitude adjustment circuit that adjusts the amplitude of the high-frequency signal transmitted and received via the second power supply terminal. A first phase shifter that adjusts the phase of the high-frequency signal input to and output from the first amplitude adjustment circuit. A second phase shifter that adjusts the phase of the high-frequency signal input to and output from the second amplitude adjustment circuit. A first distribution and synthesis circuit that distributes a high-frequency signal to the first phase shifter and the second phase shifter and synthesizes the high-frequency signals from the first phase shifter and the second phase shifter. A method for determining a correction control amount by a circularly polarized antenna device in which a plurality of antenna units having the above are arranged, A second distribution and synthesis circuit distributes a high-frequency signal to the first distribution and synthesis circuits respectively provided in the plurality of antenna units, and synthesizes the high-frequency signals from the first distribution and synthesis circuits respectively provided in the plurality of antenna units. The beam forming control amount calculation unit calculates an amplitude control amount and a phase control amount necessary for beam forming using the coordinate information of the antenna elements respectively provided in the plurality of antenna units. The correction control amount calculation unit calculates a correction control amount for axial ratio correction based on the coordinate information of the antenna element, a function representing the shape of the radiation pattern of the high-frequency signal radiated from the antenna element via the first power supply terminal and the second power supply terminal, the coupling amount between the first power supply terminal and the second power supply terminal, and the coordinate information of the antenna element; The amplitude adjustment control unit controls the amplitude adjustment by the first amplitude adjustment circuit and the second amplitude adjustment circuit based on the correction control amount; The phase shifter control unit controls the phase adjustment by the first phase shifter and the second phase shifter based on the correction control amount, and A correction control amount determination method characterized by the above.

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