Antenna device

Abstract

To contribute to suppression of signal interference between two adjacent antennas by a device of a minimum scale.SOLUTION: An antenna device according to the present disclosure includes an element of a first antenna that performs one or both of transmission and reception of a radio signal of a predetermined first frequency, an element of a second antenna that performs one or both of transmission and reception of a radio signal of a second frequency that is the same as or different from the first frequency, and a resonator that is disposed between the element of the first antenna and the element of the second antenna and resonates at a third frequency that is the same as the first frequency or the second frequency or is different from the first frequency or the second frequency.SELECTED DRAWING: Figure 1D

Description

[Technical Field]

[0001] The present disclosure relates to an antenna device. [Background technology]

[0002] A wireless communication system is known that is configured to feed signals to one of two adjacent antennas via a power supply device that includes a plurality of conductors connected via capacitive elements and a plurality of inductive elements that connect the plurality of conductors to the antenna, thereby suppressing signal interference between the two antennas (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-026962 Summary of the Invention [Problem to be solved by the invention]

[0004] The disclosures of the above-mentioned prior art documents are incorporated herein by reference.The following analysis was conducted by the inventors.

[0005] However, in the wireless communication system disclosed in Patent Document 1, the length of the power supply device that supplies a signal to one of the two antennas is approximately the same as the length of this one antenna. In other words, in order to use two antennas in this wireless communication system, a power supply device of the same size as one of the antennas is required in addition to these two antennas, which makes the system larger in size.

[0006] In view of the above-mentioned problems, an object of the present disclosure is to contribute to suppressing signal interference between two nearby antennas using a device with a minimum size. [Means for solving the problem]

[0007] In one aspect of the present disclosure, there is provided an antenna device comprising: a first antenna element that transmits and / or receives radio wave signals at a predetermined first frequency; a second antenna element that transmits and / or receives radio wave signals at a second frequency that is the same as or different from the first frequency; and a resonator disposed between the first antenna element and the second antenna element that resonates at a third frequency that is the same as the first frequency or the second frequency, or that is different from the first frequency or the second frequency. [Effects of the Invention]

[0008] Aspects of the present disclosure can contribute to reducing signal interference between two closely spaced antennas with a device of minimal size. [Brief explanation of the drawings]

[0009] [Figure 1A] FIG. 1A is a diagram illustrating a configuration of a communication system according to an embodiment of the present disclosure. [Figure 1B] FIG. 1B is a diagram illustrating a top view of one configuration of an antenna device of the communication system illustrated in FIG. 1A. [Figure 1C] FIG. 1C is a diagram schematically showing a circuit pattern around the resonator shown in FIGS. 1A and 1B. [Figure 1D] FIG. 1D is a diagram illustrating an example of the relationship between an antenna element and an equivalent circuit of a resonator. [Figure 1E] FIG. 1E is a diagram illustrating one configuration of a resonator in which lumped-constant inductors L1 and L2 are inserted into the circuit pattern of the resonator shown in FIG. 1B. [Figure 1F] FIG. 1F is a diagram illustrating a configuration of a communication system in which the inverted L-shaped antenna of the communication system shown in FIG. 1B is replaced with a monopole antenna such as a λ / 4 type. [Figure 2A] FIG. 2A illustrates one configuration of a resonator according to an embodiment of the present disclosure. [Figure 2B]FIG. 2B is a diagram illustrating one configuration of a control device that outputs a control signal to the resonator shown in FIG. 2A. [Figure 2C] FIG. 2C is a flowchart illustrating one process performed by the control device shown in FIG. 2B. [Figure 3A] FIG. 3A illustrates one configuration of a resonator according to an embodiment of the present disclosure. [Figure 3B] FIG. 3B is a flowchart showing an example of a control process performed on the resonator shown in FIG. 3A by the control device shown in FIG. 2B.

[0010] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. However, the present disclosure is not limited to the embodiments described below. Furthermore, in each drawing, the same or corresponding elements are appropriately designated by the same reference numerals, and the same or corresponding processes are appropriately designated by the same reference numerals. Furthermore, the drawings are schematic, and the dimensional relationships and ratios of each element may differ from the actual relationships. Furthermore, the dimensional relationships and ratios may differ between drawings.

[0011] [Embodiment] First, an example of an embodiment of the present disclosure will be described with reference to Figures 1A to 1F. Figure 1A is a diagram illustrating an example configuration of a communication system 10 according to an embodiment of the present disclosure. Figure 1B is a diagram illustrating a top view of an example configuration of an antenna device 12 of the communication system 10 illustrated in Figure 1A.

[0012] 1A and 1B, a communication system 10 includes an antenna device 12, an antenna base 14, a first wireless communication device 4-1, and a second wireless communication device 4-2. The antenna device 12 is disposed on the surface of the antenna base 14. The antenna device 12 includes an inverted-L-shaped first antenna 3-1 connected to the wireless communication device 4-1 and its antenna element 30-1, a second inverted-L-shaped antenna 3-2 connected to the wireless communication device 4-2 and its antenna element 30-2, a conductive pattern 40, and a resonator 50 formed integrally with the conductive pattern 40.

[0013] When referring to any of the multiple possible components, such as antennas 3-1 and 3-2, without specifying them, the subscripts (-1, -2) of the reference numerals (3-1, 3-2) may be omitted as appropriate, and the component may simply be referred to as antenna 3. 1A and 1B show a specific example in which antenna device 12 includes two antennas 3-1 and 3-2 and one resonator 50, but it will be obvious to those skilled in the art that with appropriate modifications, antenna device 12 may include three or more antennas 3 and two or more resonators 50.

[0014] In the antenna base 14, portions other than the antennas 3-1 and 3-2 and the conductive pattern 40 are formed from an insulator, while the antennas 3-1 and 3-2 and the conductive pattern 40 are formed from a good conductor such as copper or silver. In other words, the antenna base 14 may be configured such that the antennas 3-1 and 3-2 and the conductive pattern 40 are formed from a good conductor on the surface of an insulator such as glass epoxy or ceramic. Therefore, the antenna base 14 may be, for example, a printed circuit board in which a film of a good conductor such as copper or silver is formed on the surface of an insulator such as glass epoxy or ceramic. In this case, the antennas 3-1 and 3-2 and the conductive pattern 40 may be formed by etching the film of the good conductor on the printed circuit board or by making cuts along the shapes of the antennas 3-1 and 3-2 and the conductive pattern 40.

[0015] The resonator 50 is configured, for example, by forming a recess in a part of the conductive pattern 40 so as to resonate at or near the frequency of the radio wave signals transmitted and received by the antenna 3. That is, the resonator 50 is configured as a split ring using a metamaterial. Alternatively, the resonator 50 is configured as a stripline provided on an insulator. The resonator 50 is disposed on the surface of the antenna base 14 between the antenna elements 30-1 and 30-2 of the antennas 3-1 and 3-2, for example, at a position equidistant from both the antenna elements 30-1 and 30-2. That is, the resonator 50 is disposed on the surface of the antenna base 14 approximately at the center of the antenna elements 30-1 and 30-2.

[0016] In the communication system 10, the wireless communication device 4-1 communicates with a wireless communication device (not shown) other than the communication system 10 via an antenna 3-1, for example, at a predetermined frequency f of 500 MHz or higher. tr1 The wireless communication device 4-2 communicates with a wireless communication device (not shown) other than the communication system 10 via the antenna 3-2 using a radio signal of the frequency f tr1 (first frequency) and a frequency f tr2 The radio signals transmitted and received by the wireless communication devices 4-1 and 4-2 are of a frequency f tr1 ,f tr2 When we do not distinguish between these frequencies, we simply refer to them as "frequencies f tr " is written.

[0017] In the communication system 10, the resonator 50 reduces adverse effects on the communications of the wireless communication devices 4-1 and 4-2 caused by interference due to capacitive coupling between the antenna elements 30-1 and 30-2 of the antenna 3-1 and the antenna elements 30-3 and 30-4 of the antenna 3-2.

[0018] 1B , antenna element 30-1 of antenna 3-1 includes feed point 32-1, a portion connected to feed point 32-1 and extending in a direction perpendicular to the side of conductive pattern 40, and a portion extending parallel to the side of conductive pattern 40 toward antenna 3-2. Antenna element 30-2 of antenna 3-2 includes feed point 32-2, a portion connected to feed point 32-2 and extending in a direction perpendicular to the side of conductive pattern 40, and a portion extending parallel to the side of conductive pattern 40 toward antenna 3-1.

[0019] A recess is formed in the conductive pattern 40 to accommodate the feed point 32-1 and a portion of the antenna element 30-1 extending in a direction perpendicular to the side of the conductive pattern 40. Similarly, a recess is formed in the conductive pattern 40 to accommodate the feed point 32-2 and a portion of the antenna element 30-2 extending in a direction perpendicular to the side of the conductive pattern 40.

[0020] For example, the lengths of the antenna elements 30-1 and 30-2 are set to be equal to the wavelength λ of the radio wave signals transmitted and received by the antennas 3-1 and 3-2, respectively. tr (=c / f tr ;c is the speed of light) tr / 4) multiplied by the shortening rate. Wireless communication device 4-1 transmits radio signals via antenna 3-1. Wireless communication device 4-1 also receives radio signals via antenna 3-1, outputs information indicated by the radio signals, and evaluates reception quality such as signal strength and S / N (Signal / Noise) ratio of the received radio signals. Wireless communication device 4-2 also receives radio signals via antenna 3-2, outputs information indicated by the radio signals, and evaluates reception quality such as signal strength and S / N ratio of the received radio signals.

[0021] 1A and 1B. As shown in Fig. 1C, the recess constituting the resonator 50 has circuit patterns 500 and 502 extending along the sides of the conductive pattern 40 with a gap therebetween, circuit patterns 508 and 510 extending perpendicularly to the sides of the conductive pattern 40 and into the recess in the gap between the circuit patterns 500 and 502, and a virtual circuit pattern 504 of the conductive pattern 40 around the recess.

[0022] FIG. 1D is a diagram illustrating an example of the relationship between the antenna elements 30-1 and 30-2 and the equivalent circuit of the resonator 50. Just as the distributed constant capacitance C occurs in the resonator 50, a distributed constant capacitance also occurs between the antenna elements 30-1 and 30-2. However, since this is minute compared to the capacitance C of the resonator 50, it is not shown in FIG. 1D and will not be mentioned in the following description. The resonator 50 is provided in a portion that contacts the side of the conductive pattern 40. The shape of the resonator 50 is such that the distributed constant inductance L generated by the circuit patterns 500, 502, and 504 and the distributed constant capacitance C generated between the circuit patterns 508 and 510 are equal to each other at a frequency f as described above. tr Alternatively, it is designed to form a resonant circuit that resonates at a frequency in this vicinity.

[0023] In reality, distributed constant inductance and capacitance are generated in all of the circuit patterns 500, 502, 504, 508, and 510. However, for the sake of specificity and clarity, in the description of the embodiment, it is assumed that the inductance is generated by the circuit patterns 500, 502, and 504, and the capacitance is generated by the circuit patterns 508 and 510. The resonant frequency f d is [f d =1 / {2π(LC) 1 / 2}] and the resonant frequency f d is the frequency f tr is approximately equal to or the same as (f d ≒f tr or f d =f tr ).

[0024] 1C, GND means ground. Specifically, GND indicates a connection of the circuit pattern 504 to the conductive pattern 40, a connection to a ground terminal (not shown) of the wireless communication device 4 via the conductive pattern 40, or a connection to the earth (not shown) via the conductive pattern 40. As shown in FIG. 1D, the resonator 50 has a resonant frequency f tr or the resonant frequency f trThis parallel resonant circuit has a resonant frequency close to f, as shown by the X in Figure 1D. tr This provides high impedance to the radio wave signals, thereby preventing interference between the antenna element 30-1 and the feed point 32-1 and the antenna element 30-2 and the feed point 32-2.

[0025] Alternatively, for example, if the frequency of the radio signal transmitted and received by the wireless communication device 4-1 connected to the antenna 3-1 is frequency f d (f d ≒f tr ), the resonator 50 operates at a frequency f tr The resonator 50 absorbs the radio wave signals from the antennas 3-1 and 3-2, suppressing interference between the antennas 3-1 and 3-2. In this way, when the resonator 50 is used in the antenna device 12, it is possible to prevent or suppress interference between the antennas 3-1 and 3-2, thereby improving the transmission and reception characteristics, particularly the reception characteristics, of the wireless communication devices 4-1 and 4-2. This improves the reception frequency of the wireless communication devices 4-1 and 4-2.

[0026] According to the resonator 50 of the communication system 10 described above, the distance between the antenna element 30-1 and the feed point 32-1 of the antenna 3-1 and the antenna element 30-2 and the feed point 32-2 of the antenna 3-2 cannot be made sufficiently long. tr Even when the difference between the frequencies of the radio signals used by the wireless communication devices 4-1 and 4-2 is small, the resonator 50 prevents or suppresses interference between the antennas 3-1 and 3-2.

[0027] Furthermore, the resonator 50 can prevent degradation of the reception quality of the wireless communication devices 4-1 and 4-2 without providing a large shield such as a metal plate or radio wave absorbing sheet between the antennas 3-1 and 3-2. Furthermore, the resonator 50 does not cause degradation of reception quality due to the provision of a shield itself. Furthermore, the resonator 50 can prevent or suppress interference between the antennas 3-1 and 3-2 even when a long distance cannot be placed between these antennas. Furthermore, the resonator 50 can prevent or suppress interference between the antennas 3-1 and 3-2 even when the distance between the antennas 3-1 and 3-2 is relatively short and the frequency f of the radio signals of the wireless communication devices 4-1 and 4-2 is relatively short. tr1 ,f tr2 is changed, and the difference between these frequencies Δf (Δf = |f tr1 -f tr2 Even if the distance |) becomes smaller or larger, it is not necessary to provide or remove a large shield between the antennas 3-1 and 3-2.

[0028] Next, a resonator 52 will be described as a modified example of the resonator 50. Fig. 1E is a diagram illustrating one configuration of the resonator 52 in which lumped-constant inductors L1 and L2 are inserted into the circuit patterns 500 and 502 of the resonator 50 shown in Fig. 1B. As shown in Fig. 1E, by inserting the lumped-constant inductors L1 and L2 into the circuit patterns 500 and 502 of the resonator 50 to form the resonator 52, the resonant frequency of the resonator 52 can be shifted downward.

[0029] When the combined inductance of the distributed constant inductances of the circuit patterns 500, 502, and 504 of the resonator 52 and the lumped constant inductors L1 and L2 is L', the resonant frequency f d ' is [f d '=1 / {2π(L'C) 1 / 2 When the size of the resonator 52 is limited, the resonant frequency f d is made closer to the frequency ftr of the radio wave signal transmitted and received by the wireless communication device 4 (f d ≒f tr ), make it the same (f d =f tr) to help.

[0030] Next, modified examples of the antenna 3 will be described. Fig. 1F is a diagram illustrating one configuration of a communication system 16 in which the inverted-L antenna 3 of the communication system 10 shown in Fig. 1B is replaced with a monopole antenna 7 such as a λ / 4 type. As shown in Fig. 1F, the communication system 16 can be obtained by replacing the inverted-L antenna 3 of the communication system 10 with a monopole antenna 7. In this way, the antenna 3 of the communication system 10 can be replaced with various types of antennas.

[0031] Next, another example of an embodiment of the present disclosure will be described with reference to Figures 2A to 2C. Figure 2A is a diagram illustrating a configuration of a resonator 54 according to an embodiment of the present disclosure. Figure 2B is a diagram illustrating a configuration of a control device 6 that outputs a control signal to the resonator 54 shown in Figure 2A. Figure 2C is a flowchart illustrating a process executed by the control device 6 shown in Figure 2B.

[0032] 2A, the resonator 54 has a configuration in which the inductor L1 of the resonator 52 shown in FIG. 1E is replaced with a high-frequency relay 540, and is used in place of the resonator 50 in the communication systems 10, 16 (FIGS. 1A, 1F, etc.). The contacts of the high-frequency relay 540 open and close depending on the value of a control signal. When the contacts of the high-frequency relay 540 are closed, the resonator 54 is enabled and operates as a resonant circuit, and when the contacts of the high-frequency relay 540 are open, the resonator 54 is disabled and does not operate as a resonant circuit.

[0033] 2B, the control device 6 that outputs a control signal to the resonator 54 shown in FIG. 2A includes a CPU (Central Processing Unit; processor) 600, a main memory device 602, an auxiliary memory device 604, and an interface (IF (InterFace)) circuit 606, all of which are connected via a bus or the like so as to be able to input and output data and information from and to each other. The process of opening and closing the contacts of the high-frequency relay 540 of the resonator 54, which will be described later with reference to FIG. 2C, can be realized as a program executed by the control device 6.

[0034] The control device 6 uses these components to open and close the contacts of the high-frequency relay 540 of the resonator 54. However, Fig. 2B does not limit the components that may be included in the control device 6, and the control device 6 may include components other than those shown in Fig. 2B. Furthermore, the auxiliary storage device 604 may be omitted when no program update is performed in the control device 6, and may be removed from the control device 6 by the user after the program update is performed.

[0035] The CPU 600 executes each command included in a control program executed by an information processing device (computer) to control the opening and closing of the contacts of the high-frequency relay 540. The main storage device 602 includes, for example, a volatile memory element such as a RAM (Random Access Memory) and a non-volatile memory element such as a ROM (Read Only Memory). The main storage device 602 temporarily or medium- to long-term stores various programs such as the control program executed by the CPU 600, as well as data and information required for executing the control programs, etc.

[0036] The auxiliary storage device 604 includes, for example, nonvolatile storage devices and storage elements such as a hard disk drive (HDD), a solid state drive (SSD), and a flash memory. The auxiliary storage device 604 temporarily or medium- to long-term stores various programs, such as a control program executed by the CPU 600, and data and information required for executing the control programs. The auxiliary storage device 604 may include a connector, such as a universal serial bus (USB) connector, to which a nonvolatile memory element, such as a USB memory, can be connected. The control program, which performs the processing described below with reference to FIG. 2C, and the like, can be supplied to the control device 6 via the connector included in the auxiliary storage device 604. Note that the various programs, such as the control program, can be provided as a program product recorded on a non-transitory computer-readable storage medium.

[0037] The interface circuit 606 is connected to the wireless communication devices 4-1, 4-2 (e.g., FIG. 1A) and the high-frequency relay 540 of the resonator 54. The interface circuit 606 receives, from the wireless communication devices 4-1, 4-2, communication states indicating whether each is transmitting or receiving a radio wave signal, and quality information indicating the reception quality of the radio wave signal, and outputs these to the CPU 600. The interface circuit 606 also outputs a control signal to the high-frequency relay 540, closing the contacts of the high-frequency relay 540 to enable the resonator 54, or opening the contacts of the high-frequency relay 540 to disable the resonator 54.

[0038] Next, the control of the resonator 54 by the control device 6 will be described. As shown in Fig. 2C, in S100, the control device 6 determines whether the wireless communication device 4 is in a communication state in which it is receiving a radio signal. If the wireless communication device 4 is in a communication state in which it is transmitting and receiving a radio signal (Y in the process of S100), the control device 6 proceeds to the process of S102, and if the wireless communication device 4 is not in a communication state (N in the same process), the control device 6 proceeds to the process of S116.

[0039] In S102, the control device 6 determines whether the difference in frequency between the wireless signals transmitted and received by the wireless communication devices 4-1 and 4-2 is equal to or less than a predetermined value and whether they are adjacent. If the wireless signals transmitted and received by the wireless communication devices 4-1 and 4-2 are adjacent (Y in S102), the control device 6 proceeds to processing in S104. If they are not adjacent (N in S102), the control device 6 proceeds to processing in S116. Note that in the explanation of FIG. 2C and other figures, the predetermined value refers to a value that is preset in the control device 6 by a communication system designer or user before the antenna device 12 is put into use. In this way, the preset value is determined based on actual measurements of the antenna device 12 or the results of computer simulations. Note that in the explanation of FIG. 2C and other figures, there is no substantial difference between "equal to or less than," "less than," and "smaller," and there is no substantial difference between "equal to or greater than" and "greater," etc.

[0040] In S104, the control device 6 determines whether the reception quality detected by the wireless communication device 4 upon receiving the radio signal, for example, the S / N ratio of the radio signal, is lower than a predetermined value (lower than practical reception sensitivity) (whether it is higher than or equal to practical reception sensitivity). If the reception sensitivity of the wireless communication device 4 is lower than the predetermined value (Y in the process of S104), the control device 6 proceeds to the process of S106, and if the reception sensitivity is equal to or higher than the predetermined value (N in the process of S104), the control device 6 proceeds to the process of S116.

[0041] In S106, the control device 6 determines whether the power (transmission power) of the radio wave signal transmitted by the wireless communication device 4 is higher than a predetermined value. If the transmission power of the wireless communication device 4 is higher than the predetermined value (Y in the process of S106), the control device 6 proceeds to the process of S108, and if the transmission power is not higher than the predetermined value (N in the process of S106), the control device 6 proceeds to the process of S116.

[0042] In S108, the control device 6 sets the control signal to a value that closes the contact of the high-frequency relay 540 (FIG. 2A) of the resonator 54 to activate it, causing the high-frequency relay 540 to close the contact and enable the resonator 54. In S110, the control device 6 determines whether the reception quality of the wireless communication device 4 has improved. If the reception quality of the wireless communication device 4 has improved (Y in the process of S110), the control device 6 proceeds to the process of S114, and if the reception quality is not higher than a predetermined value (N in the process of S110), the control device 6 proceeds to the process of S116.

[0043] In S114, the control device 6 leaves the resonator 54 in an activated state. In S116, the control device 6 maintains the control signal at a value that closes the contact of the high-frequency relay 540 ( FIG. 2A ) of the resonator 54 to activate it. In S116, the control device 6 changes the control signal to a value that opens the contact of the high-frequency relay 540 ( FIG. 2A ) of the resonator 54, thereby disabling the resonator 54. Note that whether the control device 6 closes the contact of the high-frequency relay 540 when activating the resonator 54 or opens the contact of the high-frequency relay 540 when disabling the resonator 54 can be changed as appropriate depending on whether the high-frequency relay 540 is normally open or normally closed, for example.

[0044] As described above, the resonator 54 and the control device 6 can activate the resonator 54 under a predetermined condition to suppress interference between the antennas 3-1 and 3-2. The predetermined condition is when the transmission power of the wireless communication device 4 is greater than a predetermined value, when the reception quality of the received signal of the wireless communication device 4 is lower than a predetermined value, or when the frequency ftr of the radio wave signal changes to a lower value, resulting in the distance between the antennas 3-1 and 3-2 decreasing to λ tr On the other hand, with the resonator 54 and the control device 6, when the transmission power of the wireless communication device 4 is smaller than a predetermined value and when the reception quality of the received signal of the wireless communication device 4 is higher than a predetermined value, it is possible to disable the resonator 54, thereby preventing adverse effects such as a decrease in the reception quality of the wireless communication device 4 that may be caused by the resonator 54.

[0045] Next, another example of the embodiment of the present disclosure will be described with reference to Figures 3A and 3B. Figure 3A is a diagram illustrating one configuration of a resonator 56 according to the embodiment of the present disclosure. Figure 3B is a flowchart showing one example of control processing performed on the resonator 56 shown in Figure 3A by the control device 6 shown in Figure 2B.

[0046] As shown in FIG. 3A, the resonator 56 has a configuration in which a variable capacitor (VC) 560, the capacitance of which can be changed in response to a control signal from the control device 6 (FIG. 2B), is connected to the gap between the circuit patterns 500 and 502 of the resonator 54 shown in FIG. 2A, i.e., between the circuit patterns 508 and 510. If the combined capacitance of the capacitance occurring between the circuit patterns 508 and 510 and the capacitance of the variable capacitor (VC) 560 is C", the resonant frequency f of the resonator 56 is d " is [f d ”=1 / {2π(LC) 1 / 2}]. In the communication systems 10, 16 (FIGS. 1A, 1F, etc.), the resonator 50 is replaced with a resonator 56. The variable range of the variable capacitor 560 of the resonator 56 is set in advance before the communication system 10, etc. in which the resonator 56 is used, starts operation. Specifically, the variable range of the variable capacitor (VC) 560 is set to 0 to 50 pF when the frequency of the radio wave signal transmitted and received by the wireless communication device 4 is 1 GHz or less, and set to 0 to 20 pF when the frequency of the radio wave signal is higher than 1 GHz. The variable range of the capacitance of the resonator 56 is also determined based on actual measurements or the results of computer simulations, similar to the predetermined value described with reference to FIG. 2C.

[0047] Next, the control of the resonator 56 by the control device 6 will be described. The process shown in Fig. 3B includes the processes of S100 to S116 shown in Fig. 2C. In S140 following S114, the control device 6 outputs a control signal to the variable capacitor (VC) 560 to minimize the capacitance value of the variable capacitor (VC) 560. The variable capacitor (VC) 560 minimizes its capacitance value in accordance with this control signal.

[0048] In S142, the control device 6 outputs a control signal to the variable capacitor (VC) 560 to increase the capacitance value of the variable capacitor (VC) 560 by a predetermined value, for example, 0.1 pF. The variable capacitor (VC) 560 increases the capacitance by the predetermined value in accordance with the control signal from the control device 6.

[0049] In S144, the control device 6 determines whether the value of the reception quality in the wireless communication device 4 has improved, based on the reception quality detected by the wireless communication device 4. If the value of the reception quality in the wireless communication device 4 has improved (Y in the process of S144), the control device 6 returns to the process of S142, and if the value of the reception quality has not improved (N in the process of S144), the control device 6 proceeds to the process of S146. Note that if the value of the reception quality in one of the wireless communication devices 4-1, 4-2 has improved and the value of the reception quality in the other has not improved or has decreased, the control device 6 may end the process, for example, not proceed to the process of S146, or may end the process by performing a process different from S146.

[0050] In S146, the control device 6 outputs a control signal to the variable capacitor (VC) 560 to reduce the capacitance value of the variable capacitor (VC) 560 by a predetermined value. The variable capacitor (VC) 560 reduces the capacitance by the predetermined value in accordance with the control signal from the control device 6. In other words, the control device 6 adjusts the capacitance value of the variable capacitor (VC) 560 so that the value of the reception quality in the wireless communication device 4-1 and the value of the reception quality in the wireless communication device 4-2 become the best values.

[0051] As the capacitance of the variable capacitor (VC) 560 changes, the resonant frequency f d Therefore, the variable capacitor (VC) 560 and the control device 6 change their resonant frequency f d can be set to a value that most effectively suppresses interference between the antennas 3-1 and 3-2 without adversely affecting the operation of the wireless communication device 4.

[0052] Some or all of the above-described embodiments can be described as, but are not limited to, the following supplementary notes. [Appendix 1] An antenna device comprising: a first antenna element that transmits and / or receives radio wave signals at a predetermined first frequency; a second antenna element that transmits and / or receives radio wave signals at a second frequency that is the same as or different from the first frequency; and a resonator that is disposed between the first antenna element and the second antenna element and that resonates at a third frequency that is the same as the first frequency or the second frequency, or that is different from the first frequency or the second frequency. [Appendix 2] 2. The antenna device according to claim 1, wherein the resonator has an inductance and a capacitance, the resonator has a common ground layer with the first antenna element and the second antenna element, and the third frequency is defined by the inductance and the capacitance. [Appendix 3] 3. The antenna device according to claim 1, wherein the resonator has a circuit pattern that generates distributed constant inductance and capacitance. [Appendix 4] 4. The antenna device according to claim 1, wherein the resonator includes a relay that cuts the circuit pattern to disable the resonator. [Appendix 5] 5. The antenna device according to any one of claims 1 to 4, wherein the circuit pattern has a gap, and further comprises a variable capacitor connected in the gap of the circuit pattern to change the capacitance. [Appendix 6] 6. The antenna device according to any one of Supplementary notes 1 to 5, wherein the first antenna and the second antenna are inverted L-shaped antennas or λ / 4 type monopole antennas. [Appendix 7] The antenna device according to any one of appendices 1 to 6, further comprising a control device that enables the resonator when at least one of the power value of the radio wave signal of the first frequency transmitted from the element of the first antenna and the power value of the radio wave signal of the second frequency transmitted from the element of the second antenna is greater than a predetermined power value, and disables the resonator when both the power value of the radio wave signal of the first frequency transmitted from the element of the first antenna and the power value of the radio wave signal of the second frequency transmitted from the element of the second antenna are equal to or less than the predetermined power value. [Appendix 8] The antenna device according to any one of appendices 1 to 7, wherein the control device enables the resonator when the quality of the radio wave signal of the first frequency received from the element of the first antenna and the quality of the radio wave signal of the second frequency received from the element of the second antenna are lower than a predetermined value, and enables the resonator when at least one of the quality of the radio wave signal of the first frequency received from the element of the first antenna and the quality of the radio wave signal of the second frequency received from the element of the second antenna is lower than a predetermined value. [Appendix 9] The antenna device according to any one of appendices 1 to 8, wherein the control device enables the resonator when the difference between the first frequency and the second frequency is smaller than a predetermined value, and disables the resonator when the difference between the first frequency and the second frequency is equal to or greater than a predetermined value. [Appendix 10] The antenna device according to any one of appendices 1 to 9, further comprising: a variable capacitor connected to a gap in the circuit pattern; and a control device that adjusts the capacitance of the variable capacitor so that the quality of the radio wave signal of the first frequency received from the first antenna element and the quality of the radio wave signal of the second frequency received from the second antenna element are maximized. [Appendix 11] 11. The antenna device according to any one of claims 1 to 10, wherein the resonator is disposed at the center between the elements of the first antenna and the elements of the second antenna. It goes without saying that combinations of the various forms described in the appendix of this disclosure, or any combination of the elements described in each aspect and embodiment (including the non-selection of some elements), can be made at any time by those skilled in the art in accordance with the basic concept of this disclosure.

[0053] The disclosures of the above-cited patent documents and other documents are incorporated herein by reference. Modifications and adjustments of the embodiments and examples are possible within the scope of this disclosure (including the claims), and based on its basic technical concept. Furthermore, various combinations and selections (including partial deletions) of various disclosed elements (including each element of each appendix, each element of each embodiment or example, each element of each drawing, etc.) are possible within the scope of this disclosure. In other words, this disclosure naturally includes various modifications and alterations that would be possible by those skilled in the art in accordance with the entire disclosure and technical concept, including the claims. In particular, the numerical ranges set forth herein should be construed as specifically describing any numerical value or subrange within the range, even if not otherwise specified. Furthermore, the disclosures of the above-cited documents are deemed to be included in the disclosures of this application, in part or in whole, which may be used in combination with the disclosures herein, as part of the spirit of this disclosure, as necessary. [Explanation of symbols]

[0054] 10,16 Communication Systems 12,18 Antenna device 14 Antenna base 3,7 Antenna 30,70 antenna element 32 Power supply point 4. Wireless communication devices 50,52,54,56 resonator 500,502,504,508,510 Circuit patterns 520,522 inductors 506 Distributed constant capacitance 540 High Frequency Relay 560 variable capacitor 6. Control device 600 CPU 602 Main storage 604 Auxiliary storage 606 Interface Circuit

Claims

1. a first antenna element for transmitting and / or receiving radio signals at a predetermined first frequency; a second antenna element for transmitting and / or receiving radio signals at a second frequency that is the same as or different from the first frequency; a resonator disposed between the first antenna element and the second antenna element, resonating at a third frequency that is the same as the first frequency or the second frequency, or different from the first frequency or the second frequency; An antenna device comprising:

2. Inductance and capacitance are generated in the resonator, and a common ground plane is provided between the resonator, the first antenna element, and the second antenna element, and the third frequency is defined by the inductance and the capacitance. The antenna device according to claim 1 .

3. The resonator has a circuit pattern that generates distributed constant inductance and capacitance. The antenna device according to claim 1 .

4. The resonator includes a relay that cuts the circuit pattern to disable the resonator. The antenna device according to claim 3 .

5. the circuit pattern has gaps; a variable capacitor connected between the gaps of the circuit pattern and configured to change the capacitance; The antenna device according to claim 3 .

6. The first antenna and the second antenna are inverted L-type antennas or λ / 4 type monopole antennas. The antenna device according to claim 1 .

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