Antenna, control device, control method and control program

Abstract

To improve isolation characteristics of an antenna.SOLUTION: An antenna 1 comprises: a transmission antenna 10 which transmits a radio wave in a predetermined frequency; a reception antenna 20 which receives a radio wave in the same frequency as the frequency of the radio wave the transmission antenna 10 transmits; and a control device 30 which is connected to the transmission antenna 10 and the reception antenna 20. The control device 30 detects an installation angle, at which reception power is minimized, in reception power in the reception antenna 20 in a case where the transmission antenna 10 is rotated in a circumferential direction, transmits an instruction of setting at a first installation angle to the transmission antenna 10, then detects a second installation angle, at which reception power is minimized, in reception power in the reception antenna in a case where the reception antenna 20 is rotated in the circumferential direction, and transmits an instruction of setting at the second installation angle to the reception antenna 20.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an antenna, a control device, a control method, and a control program. [Background technology]

[0002] In wireless communication systems, there is full-duplex wireless communication, which transmits and receives on the same frequency. Full-duplex wireless communication can double the frequency utilization efficiency compared to half-duplex communication.

[0003] However, full-duplex communication can cause self-interference, which occurs when the same frequency is used for transmission and reception, and the receiving antenna receives both the radio waves transmitted from the transmitting antenna of the terminal itself and the radio waves of the communication partner at that frequency.

[0004] To suppress this self-interference, it is necessary to increase the isolation characteristic, which represents the degree of separation between the transmitting antenna and the receiving antenna. One method of ensuring high isolation characteristics is to block, cancel, or attenuate the radio waves that sneak from the transmitting antenna to the receiving antenna. High isolation characteristics can also be ensured by aligning the direction of weak radiation of the transmitting antenna and the direction of weak radiation of the receiving antenna toward each other.

[0005] For example, there is an antenna that ensures isolation characteristics between a transmitting antenna and a receiving antenna (Patent Document 1). Patent Document 1 discloses that the isolation characteristics are ensured by installing the transmitting antenna and the receiving antenna so that their respective minimum near-field directions face each other. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 10-200326 Summary of the Invention [Problem to be solved by the invention]

[0007] However, Patent Document 1 assumes that the direction of minimum near field is known, and does not disclose any technology for ensuring isolation characteristics when the direction of minimum near field is unknown or when the antenna characteristics are affected by the antenna installation environment.

[0008] The present invention has been made in view of the problems inherent in the conventional techniques, and an object of the present invention is to provide a technique for improving the isolation characteristics of an antenna. [Means for solving the problem]

[0009] An antenna according to an embodiment of the present invention includes a transmitting antenna that transmits radio waves at a predetermined frequency, a receiving antenna that receives radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna, and a control device connected to the transmitting antenna and the receiving antenna and that determines the installation angles of the transmitting antenna and the receiving antenna. The control device detects a first installation angle at which the received power at the receiving antenna is minimized when a first antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction, and transmits an instruction to the first antenna to set it to the first installation angle. After that, the control device detects a second installation angle at which the received power at the receiving antenna is minimized when a second antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction, and transmits an instruction to the second antenna to set it to the second installation angle, thereby determining the installation angles of the transmitting antenna and the receiving antenna.

[0010] A control device according to another aspect of the present invention includes a connecting unit that connects a transmitting antenna that transmits radio waves at a predetermined frequency to a receiving antenna that receives radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna, and a control unit that detects a first installation angle at which the received power at the receiving antenna is minimized when a first antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction, transmits an instruction to the first antenna to set it to the first installation angle, and then detects a second installation angle at which the received power at the receiving antenna is minimized when a second antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction, transmits an instruction to the second antenna to set it to the second installation angle.

[0011] In another aspect of the present invention, a control method includes a computer connected to a transmitting antenna that transmits radio waves at a predetermined frequency and a receiving antenna that receives radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna, the computer detects a first installation angle at which the received power at the receiving antenna is minimized when a first antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction, and transmits an instruction to the first antenna to set it to the first installation angle.The computer then detects a second installation angle at which the received power at the receiving antenna is minimized when a second antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction, and transmits an instruction to the second antenna to set it to the second installation angle.

[0012] A control program according to another aspect of the present invention causes a computer connected to a transmitting antenna that transmits radio waves at a predetermined frequency and a receiving antenna that receives radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna to function as a control unit that detects a first installation angle at which the receiving antenna receives the smallest received power when a first antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction, transmits an instruction to the first antenna to set it to the first installation angle, and then detects a second installation angle at which the receiving antenna receives the smallest received power when a second antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction, and transmits an instruction to the second antenna to set it to the second installation angle. [Effects of the Invention]

[0013] According to the present invention, it is possible to provide a technique for improving the isolation characteristics of an antenna. [Brief explanation of the drawings]

[0014] [Figure 1] 1A and 1B are a conceptual diagram showing an example of an antenna according to an embodiment of the present invention, and side views of a transmitting antenna and a receiving antenna. [Figure 2] 3A and 3B are top views of a transmitting antenna and a receiving antenna according to the present embodiment. [Figure 3A] 10A and 10B are top views illustrating a rotation angle of the transmitting antenna according to the present embodiment. [Figure 3B] 4A and 4B are top views illustrating the rotation angle of the receiving antenna according to the present embodiment. [Figure 4] FIG. 2 is a diagram illustrating functional blocks of a control device in the antenna according to the present embodiment. [Figure 5] 3 is a flowchart illustrating a control method according to the present embodiment. [Figure 6] 10 is a flowchart illustrating a condition determination process of a control method according to the present embodiment. [Figure 7A]10A and 10B are diagrams illustrating the relationship between the rotation angle of the transmitting antenna and the isolation value according to the present embodiment. [Figure 7B] 10A and 10B are diagrams illustrating the relationship between the rotation angle of the receiving antenna and the isolation value according to the present embodiment. [Figure 8A] 10A and 10B are diagrams illustrating an electromagnetic field simulation before rotation of the transmitting antenna according to the present embodiment. [Figure 8B] 10A and 10B are diagrams illustrating an electromagnetic field simulation before rotation of the receiving antenna according to the present embodiment. [Figure 9A] 10A and 10B are diagrams illustrating an electromagnetic field simulation after the transmitting antenna is set to an installation angle in this embodiment. [Figure 9B] 10A and 10B are diagrams illustrating an electromagnetic field simulation after the receiving antenna is set to an installation angle in this embodiment. [Figure 10] FIG. 10 is a top view of the present embodiment in which a transmitting antenna and a receiving antenna are installed near a metal wall. [Figure 11] FIG. 10 is a side view of the present embodiment in which a transmitting antenna and a receiving antenna are installed near a metal wall. [Figure 12A] 10A and 10B are diagrams illustrating the relationship between the rotation angle of a transmitting antenna installed near a metal wall and the isolation value in this embodiment. [Figure 12B] 10A and 10B are diagrams illustrating the relationship between the rotation angle of a receiving antenna installed near a metal wall and the isolation value in this embodiment. [Figure 13A] 10A and 10B are diagrams illustrating an electromagnetic field simulation before rotation of a transmitting antenna installed near a metal wall in the present embodiment. [Figure 13B] 10A and 10B are diagrams illustrating an electromagnetic field simulation before rotation of a receiving antenna installed near a metal wall in the present embodiment. [Figure 14A] 10A and 10B are diagrams illustrating an electromagnetic field simulation after a transmitting antenna installed near a metal wall is set to an installation angle in this embodiment. [Figure 14B]10A and 10B are diagrams illustrating an electromagnetic field simulation after a receiving antenna installed near a metal wall is set to an installation angle in this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0015] The antenna according to this embodiment will be described in detail below with reference to the drawings. Note that the dimensional proportions in the drawings are exaggerated for the sake of explanation and may differ from the actual proportions.

[0016] 1 includes a transmitting antenna 10, a receiving antenna 20, and a control device 30. The antenna 1 is mounted on a communication terminal or connected to the communication terminal. The antenna 1 realizes full-duplex wireless communication in the communication terminal.

[0017] The transmitting antenna 10 transmits radio waves at a predetermined frequency. The receiving antenna 20 receives radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna 10. Two antennas having the same specifications may be used as the transmitting antenna 10 and the receiving antenna 20.

[0018] The transmitting antenna 10 emits circularly polarized radio waves at a frequency f0. The transmitting antenna 10 includes a dielectric substrate 11, an antenna element 12, a rotating portion 13, and a feeding point 14, as shown in FIGS.

[0019] The dielectric substrate 11 has an antenna element 12 and a feeding point 14 on its upper surface, and a rotating portion 13 on its lower surface. The feeding point 14 is a connection point with a feeder line that supplies power to the transmitting antenna 10.

[0020] The rotating unit 13 rotates the antenna element 12 in the circumferential direction of the rotation axis 15, which is perpendicular to the dielectric substrate 11. The rotating unit 13 may be, for example, an RF (Radio Frequency) connector with a rotation function. The rotation axis 15 may have any length, or may be an imaginary axis.

[0021] The receiving antenna 20 detects circularly polarized radio waves at frequency f0. As shown in Figures 1 and 2, the receiving antenna 20 includes a dielectric substrate 21, an antenna element 22, a rotating portion 23, and a feed point 24. Each portion of the receiving antenna 20 is formed in the same manner as each portion of the transmitting antenna 10.

[0022] The transmitting antenna 10 and the receiving antenna 20 are placed at a distance of 4.67λ0, where λ0 is the wavelength of the center frequency f0 of the signal band. Note that the distance between the transmitting antenna 10 and the receiving antenna 20 is an example and is not limited to this.

[0023] The antenna 1 according to this embodiment measures the isolation characteristics by rotating each of the transmitting antenna 10 and the receiving antenna 20 in the circumferential direction. The antenna 1 determines the installation angles of the transmitting antenna 10 and the receiving antenna 20 to positions that improve the isolation characteristics.

[0024] In this embodiment, the rotation angle θ of the transmitting antenna 10 t 3A, is the counterclockwise angle from a predetermined position when the transmitting antenna 10 is observed from the side where the antenna element 12 is provided. Similarly, the rotation angle θ of the receiving antenna 20 r As shown in Fig. 3B, the angle is the counterclockwise angle from a predetermined position when the receiving antenna 20 is observed from the side where the antenna element 22 is provided. In the examples shown in Figs. 3A and 3B, the predetermined position is the feed point 14 or 24.

[0025] In this embodiment, the transmitting antenna 10 and the receiving antenna 20 are described as rotating counterclockwise, but this is not limiting. The transmitting antenna 10 and the receiving antenna 20 may also be rotated clockwise. Furthermore, the transmitting antenna 10 and the receiving antenna 20 may use polarized waves with different rotation directions.

[0026] In this embodiment, the antenna 1 is described as a patch antenna with a single feed point, but is not limited to this. The antenna 1 may be any antenna as long as it can obtain circularly polarized waves. The shape, type, and presence or absence of a substrate of the antenna element disclosed in this embodiment are merely examples and are not limited to these. The transmitting antenna 10 and the receiving antenna 20 are described as being arranged on a single imaginary plane with the rotation axes 15 and 25 parallel to each other, but are not limited to this. The transmitting antenna 10 and the receiving antenna 20 may be formed on different planes. The rotating axes 15 and 25 are described as being parallel to each other, but they do not have to be parallel.

[0027] The control device 30 is connected to the transmitting antenna 10 and the receiving antenna 20. The control device 30 inputs, to each of the transmitting antenna 10 and the receiving antenna 20, instruction signals for driving, instruction signals for rotation by the rotating units 13, 23, etc. The control device 30 also acquires received signals including state values ​​and the like from the transmitting antenna 10 and the receiving antenna 20. The state values ​​include, for example, the received power of the receiving antenna 20 and the installation angles of the transmitting antenna 10 and the receiving antenna, which are used to identify the isolation characteristics.

[0028] The control device 30 can be realized using a microcomputer including a CPU (Central Processing Unit) and the like. The microcomputer installs, stores, and executes a computer program (control program) that causes the microcomputer to function as the control device 30. As a result, the microcomputer functions as multiple information processing units included in the control device 30. Note that while the present embodiment illustrates an example in which the control device 30 is realized primarily by software, it is of course possible to configure the control device 30 using dedicated hardware for executing each information processing. The dedicated hardware can include devices such as application-specific integrated circuits (ASICs), FPGAs, or conventional circuit components arranged to perform the functions described in this embodiment. An ASIC is an Application Specific Integrated Circuit. An FPGA is a Field Programmable Gate Array. Alternatively, the multiple information processing units included in the control device 30 may be configured as separate hardware. Furthermore, the control device 30 may also serve as an electronic control device used to control an electronic device not shown in FIG. 4.

[0029] The control device 30 includes a connection unit 31 and a control unit 32 .

[0030] The connection unit 31 is an interface that connects to the transmitting antenna 10 and the receiving antenna 20. The connection unit 31 receives an instruction signal from the control unit 32 and outputs the instruction signal to each of the transmitting antenna 10 and the receiving antenna 20. The control unit 32 receives a received signal from each of the transmitting antenna 10 and the receiving antenna 20 and inputs it to the control unit 32.

[0031] The control unit 32 transmits instruction signals and processes received signals to control the transmitting antenna 10 and the receiving antenna 20 .

[0032] In this embodiment, the control unit 32 rotates the transmitting antenna 10 and the receiving antenna 20 to determine the installation angle of the transmitting antenna 10 and the receiving antenna 20. The control unit 32 determines the installation angle so that the isolation characteristics between the transmitting antenna 10 and the receiving antenna 20 are improved at least compared to before the rotation. More preferably, the control unit 32 optimizes the installation angle so that the isolation characteristics between the transmitting antenna 10 and the receiving antenna 20 are best. The control unit 32 sends instructions to the transmitting antenna 10 and the receiving antenna 20 to install them at the determined installation angle.

[0033] Specifically, improving the isolation means that less power leaks from the transmitting antenna 10 to the receiving antenna 20. More specifically, the control unit 32 determines, as the installation angles, the rotation angles of the transmitting antenna 10 and the receiving antenna 20 when the power leaking from the transmitting antenna 10 to the receiving antenna 20 is at its smallest.

[0034] The control unit 32 determines the installation angle of a first antenna of the transmitting antenna 10 and the receiving antenna 20, and then determines the installation angle of a second antenna of the transmitting antenna 10 and the receiving antenna 20. In this embodiment, a case will be described in which the first antenna is the transmitting antenna 10 and the second antenna is the receiving antenna 20, but this is not limiting. The control unit 32 may determine the installation angle of the receiving antenna 20 first, and then determine the installation angle of the transmitting antenna 10.

[0035] The control unit 32 first determines the installation angle of the transmitting antenna 10. The control unit 32 detects the first installation angle at which the received power at the receiving antenna is minimum when the transmitting antenna 10 is rotated in the circumferential direction.

[0036] The control unit 32 inputs an instruction to the transmitting antenna 10 to rotate in the circumferential direction and output radio waves at a predetermined intensity. While the transmitting antenna 10 is rotating, the control unit 32 acquires the received power of the receiving antenna 20 from the receiving antenna 20.

[0037] The control unit 32 controls the rotation angle θ of the transmitting antenna 10. t The control unit 32 obtains the received power of the receiving antenna 20 corresponding to the minimum received power. t The control unit 32 detects the detected rotation angle θ t is determined as the installation angle of the transmitting antenna 10. The control unit 32 sends an instruction to the transmitting antenna 10 to set it to the determined installation angle. At this time, the control unit 32 may confirm that the installation angle of the transmitting antenna 10 is the determined installation angle by, for example, acquiring the installation angle from the transmitting antenna 10.

[0038] After the transmitting antenna 10 is set to the determined installation angle, the control unit 32 determines the installation angle of the receiving antenna 20. The control unit 32 detects the second installation angle at which the received power at the receiving antenna 20 is minimum when the receiving antenna 20 is rotated in the circumferential direction.

[0039] The control unit 32 inputs an instruction to the receiving antenna 20 to rotate in the circumferential direction and to the transmitting antenna 10 to output radio waves at a predetermined intensity. While the receiving antenna 20 is rotating, the control unit 32 inputs an instruction to the receiving antenna 20 to transmit the received power of the receiving antenna 20 to the control device 30.

[0040] Here, the control unit 32 controls the rotation angle θ of the receiving antenna 20. r The control unit 32 obtains the received power of the receiving antenna 20 corresponding to the minimum received power by calculating the rotation angle θ of the receiving antenna 20 corresponding to the minimum received power. r The control unit 32 detects the detected rotation angle θ r is determined as the installation angle of the receiving antenna 20. The control unit 32 sends an instruction to the receiving antenna 20 to set it to the determined installation angle. At this time, the control unit 32 may confirm that the installation angle of the receiving antenna 20 is the determined installation angle by, for example, acquiring the installation angle from the receiving antenna 20.

[0041] Furthermore, the control unit 32 may execute a process for determining the receiving antenna 20 and the setting angle of the receiving antenna 20 when the antenna 1 is first introduced or when the isolation characteristics have deteriorated. Deterioration of the isolation characteristics is detected, for example, by fluctuations in the received power at the receiving antenna 20. The control unit 32 may successively acquire and monitor the received power at the receiving antenna 20. The control unit 32 monitors increases or decreases in the received power and determines the timing for executing the determination process.

[0042] The timing to execute the determination process may be determined based on, for example, (i) fluctuations in received power, (ii) the state after the fluctuations in received power, or (iii) the state before and after the fluctuations in received power.

[0043] First, (i) a case where the timing to execute the determination process is determined based on fluctuations in received power will be described. The control unit 32 executes the determination process when it detects a fluctuation in the received power of the receiving antenna 20 that is equal to or greater than a predetermined value. The received power of the receiving antenna 20 is thought to fluctuate due to various reasons, such as noise. Therefore, the predetermined value is set so that fluctuations in received power during normal operation can be excluded. As a result, the control unit 32 executes a process to determine the receiving antenna 20 and the setting angle of the receiving antenna 20 when the received power fluctuates more than the normal fluctuations in the communication terminal.

[0044] Next, (ii) a case where the timing to execute the determination process is determined based on the state after fluctuations in the received power will be described. After detecting a fluctuation of the received power of the receiving antenna 20 that is equal to or greater than a predetermined value, the control unit 32 executes the determination process if the fluctuation of the received power of the receiving antenna 20 that is equal to or greater than the predetermined value continues for a predetermined period of time. The received power may fluctuate temporarily due to various circumstances. If a long-term fluctuation is expected rather than a temporary fluctuation due to noise or the like in the received power, the control unit 32 can execute a process to determine the receiving antenna 20 and the setting angle of the receiving antenna 20.

[0045] Next, we will explain (iii) a case in which the timing to execute the determination process is determined based on the state before and after a fluctuation in the received power. The control unit 32 executes the determination process when the index value of the received power of the receiving antenna 20 for a predetermined period after detecting a fluctuation of the received power of the receiving antenna 20 of a predetermined value or more fluctuates by a predetermined value or more compared to the index value for the predetermined period before the fluctuation in the received power. For example, the control unit 32 sequentially acquires and stores the received power of the receiving antenna 20 for a predetermined period. When the received power fluctuates by a predetermined value or more, the control unit 32 calculates an index value from the received power for a predetermined period going back from the time of the fluctuation. The control unit 32 also calculates an index value from the received power for a predetermined period going forward from the time of the fluctuation. Here, the index value is a value related to the magnitude of the received power for a predetermined period, such as an average or median. The control unit 32 can execute a process to determine the receiving antenna 20 and the setting angle of the receiving antenna 20 when a long-term fluctuation is expected, rather than a temporary fluctuation due to noise or the like in the received power.

[0046] In this embodiment, three examples (i) to (iii) have been given as examples of the timing to execute the process of determining the receiving antenna 20 and the setting angle of the receiving antenna 20, but the timing is not limited to these. The control unit 32 may also determine the timing to execute the determination process taking other conditions into account.

[0047] A control method by the control unit 32 will be described with reference to Fig. 5. In the example shown in Fig. 5, a case will be described in which the installation angle of the receiving antenna 20 is determined after the installation angle of the transmitting antenna 10 is determined, but this is not limiting. The installation angle of the transmitting antenna 10 may be determined after the installation angle of the receiving antenna 20 is determined.

[0048] In step S1, the control unit 32 determines the conditions for starting the process of determining the installation angles of the transmitting antenna 10 and the receiving antenna 20. If the conditions are not met in step S2, the control unit 32 waits until the conditions are met. If the conditions are met, the control unit 32 proceeds to step S3.

[0049] In step S3, the control unit 32 outputs an instruction to the transmitting antenna 10 to rotate in the circumferential direction while radiating radio waves. In step S4, the control unit 32 controls the rotation angle θ of the transmitting antenna 10. t In step S5, the control unit 32 controls the transmitting antenna 10 to rotate at the angle θ when the received power is minimum. t Outputs an instruction to set

[0050] In step S6, the control unit 32 outputs an instruction to the transmitting antenna 10 to radiate radio waves and an instruction to the receiving antenna 20 to rotate in the circumferential direction. In step S7, the control unit 32 controls the rotation angle θ of the receiving antenna 20. t In step S5, the control unit 32 controls the receiving antenna 20 to rotate at the angle θ when the received power is minimum. r Outputs an instruction to set

[0051] As a result, the transmitting antenna 10 and the receiving antenna 20 are rotated at a rotation angle θ at which the received power is minimized. t and θ r Since it is installed in the vicinity of the sensor, the isolation characteristics are improved.

[0052] The processing of step S1 in Fig. 5 will be described with reference to Fig. 6. Fig. 6 describes a case in which, after detecting (i) a fluctuation in received power, (ii) a state after the fluctuation in received power, or (iii) a state before and after the fluctuation in received power, the control unit 32 determines that the condition is met if (ii) or (iii) is met. As another example, when the control unit 32 detects (i) a fluctuation in received power, the control unit 32 may determine that the condition is met without determining (ii) or (iii).

[0053] First, in step S51, the control unit 32 determines whether or not the received power has fluctuated by a predetermined value or more. If it has not fluctuated, the process proceeds to step S54. If it has fluctuated, the process proceeds to step S52.

[0054] In step S52, the control unit 32 determines whether the fluctuation in received power has continued for a predetermined period after detecting the fluctuation in received power in step S51. If the fluctuation has continued for the predetermined period, the process proceeds to step S55. If the fluctuation has not continued for the predetermined period, the process proceeds to step S53.

[0055] In step S53, the control unit 32 determines whether there is a fluctuation of a predetermined value or more between the index value for the predetermined period before the detection of the fluctuation in received power in step S51 and the index value for the predetermined period after the detection. If there is no fluctuation of a predetermined value or more, the control unit 32 proceeds to step S54. If there is a fluctuation of a predetermined value or more, the control unit 32 proceeds to step S55.

[0056] In step S54, the control unit 32 determines that the condition is not satisfied. In the example shown in Fig. 6, if there is no fluctuation in the received power, or if there is a fluctuation in the received power but the fluctuation does not continue, and if there is no change in the index value before and after detection, the control unit 32 determines that the condition is not satisfied.

[0057] In step S55, the control unit 32 determines that the condition is satisfied. In the example shown in Fig. 6, if there is a fluctuation in the received power and the fluctuation continues, or if there is a fluctuation in the received power and there is a change in the index value before and after detection, the control unit 32 determines that the condition is satisfied.

[0058] In FIG. 6, the predetermined value (threshold) or the predetermined period for determining fluctuations in the received power may be changed as appropriate depending on the environment in which the antenna 1 is installed, etc.

[0059] Here, we will explain the results of the process of determining the set angles by rotating the transmitting antenna 10 and the receiving antenna 20 in a predetermined environment. This predetermined environment is when there are no objects around the antenna 1 that reflect radio waves.

[0060] Table 1 shows the values ​​before and after the control of the rotation angle by the process of determining the setting angle. Each value corresponds to the rotation angle θ of the transmitting antenna 10. t , the rotation angle θ of the receiving antenna 20 r, and isolation value. The values ​​in Table 1 are the results confirmed by electromagnetic field simulation.

[0061] [Table 1]

[0062] Before the control, the rotation angle θ of the transmitting antenna 10 t and the rotation angle θ of the receiving antenna 20 r Both are 0 degrees. Before control, the isolation value is 44.8 dB.

[0063] On the other hand, after the control, the rotation angle θ of the transmitting antenna 10 t is 220 degrees, and the rotation angle θ of the receiving antenna 20 r When the angle is 60 degrees, the received power of the receiving antenna 20 is minimum. After the control, the isolation value is 56.9 dB. This isolation value is improved compared to the isolation value before the control.

[0064] Before control, if the received power at frequency f0 of the receiving antenna 20 fluctuates, the control unit 32 performs processing to determine the set angle using the processing in Fig. 5. Note that although the fluctuation in received power at frequency f0 is used as the trigger here, this is not limiting. For example, the trigger may be a fluctuation in received power at any frequency, such as when fluctuations in received power occur at multiple frequencies, or when fluctuations in received power occur at a predetermined number or more of the multiple frequencies being monitored, or at all frequencies.

[0065] When the transmitting antenna 10 emits radio waves, the transmitting antenna 10 rotates at a rotation angle θ t While the transmitting antenna 10 is rotated by 360 degrees from 0 degrees before the control, the control unit 32 monitors the received power of the receiving antenna 20. As a result, the control unit 32 adjusts the rotation angle θ of the transmitting antenna 10 as shown in FIG. t Here, the isolation value is calculated from the received power of the receiving antenna 20 and the like.

[0066] The control unit 32 determines the rotation angle θ of the transmitting antenna 10 from FIG. 7A. t It is determined that the isolation value is maximized when the installation angle of the transmitting antenna 10 is 220 degrees. Therefore, the control unit 32 determines that the installation angle of the transmitting antenna 10 is 220 degrees. The control unit 32 sends an instruction to the transmitting antenna 10 to change the installation angle to 220 degrees.

[0067] Next, with the transmitting antenna 10 radiating radio waves, the receiving antenna 20 rotates at a rotation angle θ r While the receiving antenna 20 is rotated by 360 degrees from 0 degrees before the control, the control unit 32 monitors the received power of the receiving antenna 20. As a result, the control unit 32 adjusts the rotation angle θ of the receiving antenna 20 as shown in FIG. r Identify the relationship of the isolation value to

[0068] The control unit 32 determines the rotation angle θ of the receiving antenna 20 from FIG. 7B. r It is determined that the isolation value is maximized when the installation angle of the receiving antenna 20 is 60 degrees. Therefore, the control unit 32 determines that the installation angle of the receiving antenna 20 is 60 degrees. The control unit 32 sends an instruction to the receiving antenna 20 to change the installation angle to 60 degrees.

[0069] By this process, the antenna 1 rotates at a rotation angle θ of the transmitting antenna 10. t from 0 degrees to 220 degrees, and the rotation angle θ of the receiving antenna 20 r is changed from 0 degrees to 60 degrees. The isolation value improves from 44.8db before control to 56.9db after control.

[0070] FIG. 8A shows the radiation pattern of the transmitting antenna 10 in the horizontal plane before control. The installation angle of the transmitting antenna 10 is 0 degrees. FIG. 8B shows the radiation pattern of the receiving antenna 20 in the horizontal plane before control. The installation angle of the receiving antenna 20 is 0 degrees. Here, the rotation angle θ of the transmitting antenna 10 is t The receiving antenna 20 is positioned in the direction of 0 degrees. r The receiving antenna 20 is located in the direction of -180 degrees.

[0071] Figure 9A shows the radiation pattern of the horizontal plane of the transmitting antenna 10 after control. The installation angle of the transmitting antenna 10 is 220 degrees. Figure 9B shows the radiation pattern of the horizontal plane of the receiving antenna 20 before control. The installation angle of the receiving antenna 20 is 60 degrees.

[0072] 9B, the conditions under which the best isolation characteristics are obtained when the transmitting antenna 10 and the receiving antenna 20 are installed in an environment where there are no objects that reflect radio waves can be understood. The best isolation characteristics are obtained when the directions of weak radiation from the transmitting antenna 10 and the receiving antenna 20 face each other.

[0073] Here, as shown in Figures 10 and 11, the transmitting antenna 10 and the receiving antenna 20 are placed in an environment where radio waves can be reflected, and the transmitting antenna 10 and the receiving antenna 20 are rotated to determine the set angles. The results of this process will be explained.

[0074] 10 and 11, the transmitting antenna 10 and the receiving antenna 20 are placed near a metal wall 90 having a length of 7.48λ0 and a height of 1.87λ0. The distance from the edge of the dielectric substrate 11 of the transmitting antenna 10 to the metal wall 90, and the distance from the edge of the dielectric substrate 21 of the receiving antenna 20 to the metal wall 90 are both 0.48λ0. Note that although the control device 30 is not shown in FIGS. 10 and 11, the control device 30 is connected to the transmitting antenna 10 and the receiving antenna 20.

[0075] Table 2 shows the values ​​before control and the values ​​in the environments shown in Figures 10 and 11. Each value corresponds to the rotation angle θ of the transmitting antenna 10. t , the rotation angle θ of the receiving antenna 20 r , and isolation value. The values ​​in Table 2 are the results confirmed by electromagnetic field simulation.

[0076] [Table 2]

[0077] In Table 2, before control, the installation angle is optimized in an environment without a metal wall 90, and then the metal wall 90 is installed. t is 220 degrees, and the rotation angle θ of the receiving antenna 20 r is 60 degrees. Before control, the isolation value is 49.2 dB.

[0078] As shown in Table 1, before the metal wall 90 was installed and after the processing shown in Fig. 5 was performed, the isolation value was 56.9 dB. After the metal wall 90 was installed, the isolation value deteriorated to 49.2 dB. The control unit 32 performs processing to determine the set angle by the processing shown in Fig. 5.

[0079] When the transmitting antenna 10 emits radio waves, the transmitting antenna 10 rotates at a rotation angle θ t While the transmitting antenna 10 is rotated from 220 degrees before the control to 360 degrees, the control unit 32 monitors the received power of the receiving antenna 20. As a result, the control unit 32 adjusts the rotation angle θ of the transmitting antenna 10 as shown in FIG. t Identify the relationship of the isolation value to

[0080] The control unit 32 determines the rotation angle θ of the transmitting antenna 10 from FIG. 12A. t It is determined that the isolation value is maximized when the installation angle of the transmitting antenna 10 is 195 degrees. Therefore, the control unit 32 determines that the installation angle of the transmitting antenna 10 is 195 degrees. The control unit 32 sends an instruction to the transmitting antenna 10 to change the installation angle to 195 degrees.

[0081] Next, with the transmitting antenna 10 radiating radio waves, the receiving antenna 20 rotates at a rotation angle θ r While the receiving antenna 20 is rotated from 60 degrees before the control to 360 degrees, the control unit 32 monitors the received power of the receiving antenna 20. As a result, the control unit 32 adjusts the rotation angle θ of the receiving antenna 20 as shown in FIG. r Identify the relationship of the isolation value to

[0082] The control unit 32 determines the rotation angle θ of the receiving antenna 20 from FIG. 12B. r It is determined that the isolation value is maximized when the installation angle of the receiving antenna 20 is 50 degrees. Therefore, the control unit 32 determines that the installation angle of the receiving antenna 20 is 50 degrees. The control unit 32 sends an instruction to the receiving antenna 20 to change the installation angle to 50 degrees.

[0083] By this process, the antenna 1 rotates at a rotation angle θ of the transmitting antenna 10. t from 220 degrees to 195 degrees, and the rotation angle θ of the receiving antenna 20 r is changed from 60 degrees to 50 degrees. The isolation value improves from 49.2db before control to 57.5db after control.

[0084] FIG. 13A shows the radiation pattern of the transmitting antenna 10 in the horizontal plane before control. The installation angle of the transmitting antenna 10 is 220 degrees. FIG. 13B shows the radiation pattern of the receiving antenna 20 in the horizontal plane before control. The installation angle of the receiving antenna 20 is 60 degrees. Here, as in FIGS. 8A and 8B, the rotation angle θ of the transmitting antenna 10 t The receiving antenna 20 is positioned in the direction of 0 degrees. r The receiving antenna 20 is located in the direction of -180 degrees.

[0085] Fig. 14A shows the radiation pattern of the horizontal plane of the transmitting antenna 10 after control. The installation angle of the transmitting antenna 10 is 195 degrees. Fig. 14B shows the radiation pattern of the horizontal plane of the receiving antenna 20 before control. The installation angle of the receiving antenna 20 is 50 degrees.

[0086] 14A and 14B show that when the transmitting antenna 10 and the receiving antenna 20 are installed near a metal wall 90, different isolation characteristics are obtained than those shown in FIGS. 8A and 8B. FIGS. 8A and 8B show that the best isolation characteristics are obtained when the directions of weak radiation of the transmitting and receiving antennas face each other. In contrast, FIGS. 14A and 14B show that when the transmitting antenna 10 and the receiving antenna 20 are installed near a metal wall 90, the best isolation characteristics are not obtained even when the directions of weak radiation of the transmitting and receiving antennas face each other. This is thought to be because installing the transmitting antenna 10 and the receiving antenna 20 near the metal wall 90 creates a path for radio waves to travel from the transmitting antenna 10 to the receiving antenna 20 via reflection from the metal wall 90.

[0087] In this way, the antenna 1 according to this embodiment can determine the optimal antenna installation angle even when the isolation characteristics deteriorate due to the influence of the surrounding environment of the antenna 1. The antenna 1 according to this embodiment can optimize the installation angles of the transmitting antenna 10 and the receiving antenna 20 in any environment, regardless of whether the isolation characteristics are influenced by the surrounding environment of the antenna 1. The antenna 1 according to this embodiment can identify the installation angle that provides the optimal isolation even when the radiation characteristics are unknown.

[0088] In this way, the antenna 1 according to this embodiment can improve isolation characteristics when installed in any environment or even when the radiation characteristics are unknown.

[0089] In this embodiment, the control device 30 detects fluctuations in the amount of power received at the receiving antenna 20 by monitoring the power sneaking into the receiving antenna 20 when the transmitting antenna 10 is communicating data with a communication partner, but this is not limiting. The control device 30 may also detect fluctuations in the amount of power received at the receiving antenna 20 by monitoring the power sneaking into the receiving antenna 20 during communication to check the isolation characteristics between the transmitting antenna 10 and the receiving antenna 20.

[0090] The communication for checking the isolation characteristics between the transmitting antenna 10 and the receiving antenna 20 may be performed manually by an operator or the like at any timing, or may be performed at a predetermined timing. Also, the process shown in Fig. 5 may be performed at any timing.

[0091] In this embodiment, the case where the control device 30 is provided inside the antenna 1 will be described, but this is not limiting. The control device 30 only needs to be connected to the transmitting antenna 10 and the receiving antenna 20, and may be provided outside the housing of the antenna 1.

[0092] As described above, the antenna 1 according to the first aspect of this embodiment comprises a transmitting antenna 10 that transmits radio waves at a predetermined frequency, a receiving antenna 20 that receives radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna, and a control device 30 connected to the transmitting antenna 10 and the receiving antenna 20 and that determines the installation angles of the transmitting antenna 10 and the receiving antenna. The control device 30 detects a first installation angle at which the received power at the receiving antenna 20 is minimized when the first antenna of the transmitting antenna 10 and the receiving antenna 20 is rotated in a circumferential direction, and sends an instruction to the first antenna to set it to the first installation angle. Then, it detects a second installation angle at which the received power at the receiving antenna 20 is minimized when the second antenna of the transmitting antenna 10 and the receiving antenna 20 is rotated in a circumferential direction, and sends an instruction to the second antenna to set it to the second installation angle, thereby determining the installation angles of the transmitting antenna 10 and the receiving antenna 20.

[0093] In the antenna 1, the control device 30 may determine the installation angles of the transmitting antenna 10 and the receiving antenna 20 when it detects a fluctuation in the received power of the receiving antenna 20 that is equal to or greater than a predetermined value.

[0094] In the antenna 1, the control device 30 may determine the installation angle of the transmitting antenna 10 and the installation angle of the receiving antenna 20 if, after detecting a fluctuation in the received power of the receiving antenna 20 that is greater than a predetermined value, the fluctuation in the received power of the receiving antenna 20 that is greater than or equal to the predetermined value continues for a predetermined period of time.

[0095] In the antenna 1, the control device 30 may determine the installation angle of the transmitting antenna 10 and the installation angle of the receiving antenna 20 when the index value of the received power of the receiving antenna 20 for a predetermined period after detecting a fluctuation in the received power of the receiving antenna 20 of a predetermined value or more fluctuates by a predetermined value or more compared to the index value for a predetermined period before the fluctuation in the received power.

[0096] A control device 30 according to a second aspect of this embodiment includes a connecting unit 31 connected to a transmitting antenna 10 that transmits radio waves at a predetermined frequency, a receiving antenna 20 that receives radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna 10, and a control unit 32 that detects a first installation angle at which the received power at the receiving antenna 20 is minimized when a first antenna of the transmitting antenna 10 and the receiving antenna 20 is rotated in a circumferential direction, transmits an instruction to the first antenna to set it to the first installation angle, and then detects a second installation angle at which the received power at the receiving antenna 20 is minimized when a second antenna of the transmitting antenna 10 and the receiving antenna 20 is rotated in a circumferential direction, transmits an instruction to the second antenna to set it to the second installation angle.

[0097] In a control method according to a third aspect of this embodiment, a computer connected to a transmitting antenna 10 that transmits radio waves at a predetermined frequency and a receiving antenna 20 that receives radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna 10 detects a first installation angle at which the received power at the receiving antenna 20 is minimized when a first antenna of the transmitting antenna 10 and the receiving antenna 20 is rotated in a circumferential direction, and sends an instruction to the first antenna to set it to the first installation angle.The computer then detects a second installation angle at which the received power at the receiving antenna 20 is minimized when a second antenna of the transmitting antenna 10 and the receiving antenna 20 is rotated in a circumferential direction, and sends an instruction to the second antenna to set it to the second installation angle.

[0098] A control program according to a fourth aspect of this embodiment causes a computer connected to a transmitting antenna 10 that transmits radio waves at a predetermined frequency and a receiving antenna 20 that receives radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna 10 to function as a control unit 32 that detects a first installation angle at which the received power at the receiving antenna 20 is minimized when a first antenna of the transmitting antenna 10 and the receiving antenna 20 is rotated in a circumferential direction, transmits an instruction to the first antenna to set it to the first installation angle, and then detects a second installation angle at which the received power at the receiving antenna 20 is minimized when a second antenna of the transmitting antenna 10 and the receiving antenna 20 is rotated in a circumferential direction, transmits an instruction to the second antenna to set it to the second installation angle.

[0099] Although the present embodiment has been described above, the present embodiment is not limited to this, and various modifications are possible within the scope of the gist of the present embodiment. [Explanation of symbols]

[0100] 1 antenna 10 transmitting antennas 20 receiving antenna 30 Control device 31 Connection

Claims

1. a transmitting antenna for transmitting radio waves at a predetermined frequency; a receiving antenna that receives radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna; a control device connected to the transmitting antenna and the receiving antenna and configured to determine an installation angle between the transmitting antenna and the receiving antenna; The control device detecting a first installation angle at which a received power is minimum among received powers at the receiving antenna when a first antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction; After transmitting an instruction to set the first antenna to the first installation angle, detecting a second installation angle at which the received power is minimum among the received powers of the receiving antenna when the second antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction; Transmitting an instruction to set the second antenna to the second installation angle, Determine the installation angle between the transmitting antenna and the receiving antenna antenna.

2. The control device When a fluctuation of the received power of the receiving antenna that is equal to or greater than a predetermined value is detected, Determine the installation angle of the transmitting antenna and the installation angle of the receiving antenna 10. The antenna of claim 1.

3. The control device If the fluctuation of the received power of the receiving antenna is equal to or greater than a predetermined value and continues for a predetermined period after detecting the fluctuation of the received power of the receiving antenna equal to or greater than a predetermined value, Determine the installation angle of the transmitting antenna and the installation angle of the receiving antenna 3. The antenna of claim 2.

4. The control device When an index value of the received power of the receiving antenna for a predetermined period after detecting a fluctuation of the received power of the receiving antenna that is equal to or greater than a predetermined value fluctuates by a predetermined value or more compared to an index value for a predetermined period before the fluctuation of the received power, Determine the installation angle of the transmitting antenna and the installation angle of the receiving antenna 3. The antenna of claim 2.

5. a transmitting antenna for transmitting radio waves at a predetermined frequency, and a connecting portion for connecting to a receiving antenna for receiving radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna; detecting a first installation angle at which a received power is minimum among received powers at the receiving antenna when a first antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction; After transmitting an instruction to set the first antenna to the first installation angle, detecting a second installation angle at which the received power is minimum among the received powers of the receiving antenna when the second antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction; a control unit that transmits an instruction to the second antenna to set the second installation angle to the second antenna; A control device comprising:

6. A computer connected to a transmitting antenna that transmits radio waves at a predetermined frequency and a receiving antenna that receives radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna, detecting a first installation angle at which a received power is minimum among received powers at the receiving antenna when a first antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction; After transmitting an instruction to set the first antenna to the first installation angle, detecting a second installation angle at which the received power is minimum among the received powers of the receiving antenna when the second antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction; Transmitting an instruction to set the second antenna to the second installation angle Control method.

7. A computer connected to a transmitting antenna that transmits radio waves at a predetermined frequency and a receiving antenna that receives radio waves at the same frequency as the frequency of the radio waves transmitted by the transmitting antenna, detecting a first installation angle at which a received power is minimum among received powers at the receiving antenna when a first antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction; After transmitting an instruction to set the first antenna to the first installation angle, detecting a second installation angle at which the received power is minimum among the received powers of the receiving antenna when the second antenna of the transmitting antenna and the receiving antenna is rotated in a circumferential direction; a control unit that transmits an instruction to the second antenna to set the second installation angle to the second antenna; A control program that functions as a

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