JP2018023019A - Antenna device, antenna module and electronic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an antenna device where interaction of coil antennas is suppressed, in a constitution including multiple coil antennas used in multiple systems.SOLUTION: An antenna device 101 includes a first coil antenna 1 having a first end E1 and a second end E2, a second coil antenna 2 having a third end E3 and a fourth end E4, and an inductor 5 having a fifth end E5 and a sixth end E6. The second end E2, fourth end E4, and fifth end E5 are connected. When representing the elements of two row by two column impedance matrix of a two terminal pair circuit of a terminal pair by the first end E1, and sixth end E6, and a terminal pair by the third end E3, and sixth end E6 by Z11, Z12, Z21, Z22, and representing the mutual inductance of the first coil antenna 1 and second coil antennas 1 by M12, at least one of |Zii|>|Zij| (i, j)=(1, 2), (2, 1), and |Zij|<|M12| (i, j)=(1, 2), (2, 1) is satisfied.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an antenna device, and more particularly to an antenna device including a plurality of coil antennas, an antenna module including the antenna device, and an electronic apparatus.

  DESCRIPTION OF RELATED ART Conventionally, the antenna apparatus or electronic device provided with the antenna coil for near field communication (NFC: Near Field Communication) systems and the antenna coil for non-contact electric power transmission systems is known (patent document 1).

International Publication No. 2014/167881

  However, in the antenna device disclosed in Patent Document 1, since the NFC coil antenna and the power transmission coil antenna are unnecessarily coupled, both the communication efficiency and the power transmission efficiency are low. For example, magnetic energy generated in the NFC coil antenna is absorbed by the power transmission coil antenna, resulting in a problem that communication efficiency is lowered. Such a problem occurs not only in an antenna device including an NFC coil antenna and a power transmission coil antenna, but also when a plurality of coil antennas respectively used in a plurality of systems are provided.

  An object of the present invention is to provide an antenna device including a plurality of coil antennas respectively used in a plurality of systems, in which unnecessary coupling between the coil antennas is suppressed, and an interaction (interference) between the plurality of coil antennas is suppressed. Is to provide. Another object of the present invention is to provide an antenna module and an electronic device including the antenna device.

(1) The antenna device of the present invention
A first coil antenna having a first end and a second end;
A second coil antenna having a third end and a fourth end;
An inductor having a fifth end and a sixth end;
The second end of the first coil antenna, the fourth end of the second coil antenna, and the fifth end of the inductor are connected to each other;
The elements of 2 rows and 2 columns of the impedance matrix of the two-terminal pair circuit of the terminal pair by the first end and the sixth end, and the terminal pair by the third end and the sixth end are Z11, Z12, Z21, Z22, and when M12 represents a mutual inductor due to magnetic field coupling between the first coil antenna and the second coil antenna,
| Zii |> | Zij | (i, j) = (1,2), (2,1), or | Zij | <| M12 | (i, j) = (1,2), (2,1) It is characterized in that at least one of the following holds.

  With this configuration, unnecessary coupling between the first coil antenna and the second coil antenna is suppressed. Therefore, in the antenna device including the first coil antenna and the second coil antenna respectively used in the two systems, an antenna device in which the interaction (interference) between the first coil antenna and the second coil antenna is suppressed is realized. it can.

(2) In the above (1), the first coil antenna and the second coil antenna may be connected in a Japanese-style manner.

(3) In the above (2), for example, the first coil antenna and the second coil antenna are wound around an axis, and the coil opening of the first coil antenna is viewed from the axial direction of the first coil antenna. Then, at least a portion overlaps the coil opening of the second coil antenna, the winding direction from the first end to the second end of the first coil antenna, and the fourth end of the second coil antenna. The winding direction up to the third end is the same.

(4) In the above (2), for example, the first coil antenna and the second coil antenna are wound around an axis, and the coil opening of the first coil antenna is viewed from the axial direction of the first coil antenna. Thus, at least a portion does not overlap the coil opening of the second coil antenna, the winding direction from the first end of the first coil antenna to the second end, and the fourth of the second coil antenna. The winding direction from the end to the third end is reversed.

(5) In any one of the above (1) to (4), it is preferable that the inductor and the first coil antenna are connected in a Japanese-style manner. With this configuration, the first coil antenna and the inductor are coupled so as to increase the inductance, and the inductor also functions as an antenna, so that the antenna characteristics are improved.

(6) In any one of the above (1) to (5), it is preferable that the inductor and the second coil antenna are connected in a Japanese-style manner. With this configuration, the second coil antenna and the inductor are coupled so as to increase the inductance, and the inductor also functions as an antenna, so that the antenna characteristics are improved.

(7) In any one of the above (1) to (4), the coupling coefficient between the inductor and the first coil antenna and the coupling coefficient between the inductor and the second coil antenna are the same as those in the first coil antenna. It is preferable that the coupling coefficient with the second coil antenna is smaller. In this configuration, the inductor is not coupled to either the first coil antenna or the second coil antenna. Therefore, compared with the case where the inductor and the coil antenna (the first coil antenna and the second coil antenna) are coupled, the circuit configuration is facilitated without complicating the circuit.

(8) In the above (7), the self-inductance of the inductor is preferably equal to the mutual inductance M12. With this configuration, there is no influence of mutual inductance (unnecessary coupling) due to magnetic field coupling between the first coil antenna and the second coil antenna, and there is no interaction (interference) between the first coil antenna and the second coil antenna. Therefore, it is possible to realize an antenna device that can use the first coil antenna and the second coil antenna completely independently.

(9) The antenna device of the present invention
A first coil antenna having a first end and a second end;
A second coil antenna having a third end and a fourth end;
A third coil antenna having a seventh end and an eighth end;
A fourth coil antenna having a ninth end and a tenth end;
An inductor having a fifth end and a sixth end;
The second end of the first coil antenna, the fourth end of the second coil antenna, and the fifth end of the inductor are connected to each other;
The eighth end of the third coil antenna, the tenth end of the fourth coil antenna, and the sixth end of the inductor are connected to each other;
The elements of 2 rows and 2 columns of the impedance matrix of the two-terminal pair circuit by the terminal pair by the first end and the seventh end and the terminal pair by the third end and the ninth end are Z11, Z12, Z21, Z22, a mutual inductor due to magnetic field coupling between the first coil antenna and the second coil antenna is denoted as M12, and a mutual inductor due to magnetic field coupling between the third coil antenna and the fourth coil antenna is denoted as M34.
| Zii |> | Zij | (i, j) = (1,2), (2,1), or | Zij | <| M12 + M34 | (i, j) = (1,2,), (2,1) It is characterized in that at least one of the following holds.

  With this configuration, unnecessary coupling between the first coil antenna and the second coil antenna is suppressed, and unnecessary coupling between the third coil antenna and the fourth coil antenna is suppressed. Therefore, in an antenna device including a plurality of coil antennas respectively used in the two systems, the interaction (interference) between the first coil antenna and the second coil antenna is suppressed, and the third coil antenna and the fourth coil antenna An antenna device in which the interaction (interference) is suppressed can be realized.

(10) In the above (9), the first coil antenna, the second coil antenna, the third coil antenna, and the fourth coil antenna may be connected in Japanese.

(11) In the above (10), for example, the first coil antenna, the second coil antenna, the third coil antenna, and the fourth coil antenna are wound around an axis, and the coil opening of the first coil antenna As viewed from the axial direction of the first coil antenna, at least a portion thereof overlaps with the coil opening of the second coil antenna, and the coil opening of the third coil antenna is viewed from the axial direction of the third coil antenna. , At least a portion overlaps the coil opening of the fourth coil antenna, the winding direction from the first end to the second end of the first coil antenna, and the fourth end of the second coil antenna The winding direction to the third end is the same, the winding direction from the seventh end to the eighth end of the third coil antenna, and the front of the fourth coil antenna Winding direction from the first 10 end to the ninth end is the same.

(12) In the above (10), for example, the first coil antenna, the second coil antenna, the third coil antenna, and the fourth coil antenna are wound around an axis, and the coil opening of the first coil antenna As seen from the axial direction of the first coil antenna, at least a part thereof does not overlap the coil opening of the second coil antenna, and the coil opening of the third coil antenna is from the axial direction of the third coil antenna. When viewed, at least a portion does not overlap the coil opening of the fourth coil antenna, the winding direction from the first end of the first coil antenna to the second end, and the first of the second coil antenna. The winding direction from the 4th end to the 3rd end is reverse, the winding direction from the 7th end of the 3rd coil antenna to the 8th end, and the 4th coil antenna Winding direction from the serial tenth end to the ninth end is reversed.

(13) In any one of the above (9) to (12), the inductor, the first coil antenna, and the third coil antenna are preferably connected in a Japanese-style manner. With this configuration, the inductor, the first coil antenna, and the third coil antenna are coupled so as to increase the inductance, and the inductor also functions as an antenna, so that the antenna characteristics are improved.

(14) In any one of the above (9) to (13), it is preferable that the inductor, the second coil antenna, and the fourth coil antenna are connected in a Japanese-style manner. With this configuration, the inductor, the second coil antenna, and the fourth coil antenna are coupled so as to increase the inductance, and the inductor also functions as an antenna, so that the antenna characteristics are improved.

(15) In any one of (9) to (12), the coupling coefficient between the inductor and the first coil antenna, the coupling coefficient between the inductor and the second coil antenna, the inductor and the third coil antenna And the coupling coefficient between the inductor and the fourth coil antenna are the coupling coefficient between the first coil antenna and the second coil antenna, and the coupling coefficient between the third coil antenna and the fourth coil antenna. It is preferably smaller than the coupling coefficient. In this configuration, the inductor is not coupled to any of the first coil antenna, the second coil antenna, the third coil antenna, and the fourth coil antenna. Therefore, compared with the case where the inductor and the coil antenna (the first coil antenna, the second coil antenna, the third coil antenna, and the fourth coil antenna) are combined, the circuit configuration is easy without being complicated. Become.

(16) In the above (15), the self-inductance of the inductor is preferably equal to the sum of the mutual inductance M12 and the mutual inductance M34. With this configuration, there is no influence of mutual inductance (unnecessary coupling) due to magnetic field coupling between the first coil antenna and the second coil antenna, and there is no interaction (interference) between the first coil antenna and the second coil antenna. At the same time, this configuration eliminates the influence of mutual inductance (unnecessary coupling) due to magnetic field coupling between the third coil antenna and the fourth coil antenna, and eliminates the interaction (interference) between the third coil antenna and the fourth coil antenna. . Therefore, it is possible to realize an antenna device that can use the first system (first coil antenna and third coil antenna) and the second system (second coil antenna and fourth coil antenna) completely independently.

(17) The antenna module of the present invention includes:
Any one of the antenna devices of (1) to (8) above;
A first system circuit connected to the first end of the first coil antenna and the sixth end of the inductor;
A second system circuit connected to the third end of the second coil antenna and the sixth end of the inductor;
It is characterized by providing.

  With this configuration, it is possible to realize an antenna module including an antenna device in which the interaction (interference) between the first coil antenna and the second coil antenna is suppressed.

(18) The antenna module of the present invention includes:
Any one of the antenna devices of (9) to (16) above;
A first system circuit connected to the first end of the first coil antenna and the seventh end of the third coil antenna;
A second system circuit connected to the third end of the second coil antenna and the ninth end of the fourth coil antenna;
It is characterized by providing.

  With this configuration, an antenna module including an antenna device in which the interaction (interference) between the first coil antenna and the second coil antenna is suppressed and the interaction (interference) between the third coil antenna and the fourth coil antenna is suppressed. Can be realized.

(19) In the above (17) or (18), for example, the first system circuit is a circuit for non-contact power transmission.

(20) In any one of (17) to (19), for example, the second system circuit is a near-field communication circuit.

(21) In any one of the above (17) to (20), for example, a use frequency band of the first system circuit is an HF band.

(22) In any one of the above (17) to (21), for example, a use frequency band of the second system circuit is an HF band.

(23) In any one of the above (17) to (22), for example, a center frequency of the used frequency band of the first system circuit is equal to a center frequency band of the used frequency band of the second system circuit. Is different.

(24) The electronic device of the present invention
A housing,
An antenna device housed in the housing;
A first system circuit and a second system circuit housed in the housing;
With
The antenna device is
A first coil antenna having a first end and a second end;
A second coil antenna having a third end and a fourth end;
An inductor having a fifth end and a sixth end;
The second end of the first coil antenna, the fourth end of the second coil antenna, and the fifth end of the inductor are connected to each other;
The elements of 2 rows and 2 columns of the impedance matrix of the two-terminal pair circuit of the terminal pair by the first end and the sixth end, and the terminal pair by the third end and the sixth end are Z11, Z12, Z21, Z22, and when M12 represents a mutual inductor due to magnetic field coupling between the first coil antenna and the second coil antenna,
| Zii |> | Zij | (i, j) = (1,2), (2,1), or | Zij | <| M12 | (i, j) = (1,2), (2,1) At least one of
The first system circuit is connected to the first end of the first coil antenna and the sixth end of the inductor;
The second system circuit is connected to the third end of the second coil antenna and the sixth end of the inductor.

  With this configuration, unnecessary coupling between the first coil antenna and the second coil antenna is suppressed. Therefore, in the configuration including the first coil antenna and the second coil antenna respectively used in the two systems, an electronic device including an antenna device in which the interaction (interference) between the first coil antenna and the second coil antenna is suppressed. Equipment can be realized.

(25) The electronic device of the present invention
A housing,
An antenna device housed in the housing;
A first system circuit and a second system circuit housed in the housing;
With
The antenna device is
A first coil antenna having a first end and a second end;
A second coil antenna having a third end and a fourth end;
A third coil antenna having a seventh end and an eighth end;
A fourth coil antenna having a ninth end and a tenth end;
An inductor having a fifth end and a sixth end;
The second end of the first coil antenna, the fourth end of the second coil antenna, and the fifth end of the inductor are connected to each other;
The eighth end of the third coil antenna, the tenth end of the fourth coil antenna, and the sixth end of the inductor are connected to each other;
The elements of 2 rows and 2 columns of the impedance matrix of the two-terminal pair circuit by the terminal pair by the first end and the seventh end and the terminal pair by the third end and the ninth end are Z11, Z12, Z21, Z22, a mutual inductor due to magnetic field coupling between the first coil antenna and the second coil antenna is denoted as M12, and a mutual inductor due to magnetic field coupling between the third coil antenna and the fourth coil antenna is denoted as M34.
| Zii |> | Zij | (i, j) = (1,2), (2,1), or | Zij | <M12 + M34 | (i, j) = (1,2,), (2,1) At least one of the first system circuits is connected to the first end of the first coil antenna and the seventh end of the third coil antenna,
The second system circuit is connected to the third end of the second coil antenna and the ninth end of the fourth coil antenna.

  With this configuration, unnecessary coupling between the first coil antenna and the second coil antenna is suppressed, and unnecessary coupling between the third coil antenna and the fourth coil antenna is suppressed. Therefore, in a configuration including a plurality of coil antennas respectively used in the two systems, the interaction (interference) between the first coil antenna and the second coil antenna, and the interaction between the third coil antenna and the fourth coil antenna. An electronic device including an antenna device in which (interference) is suppressed can be realized.

  According to the present invention, in an antenna device including a plurality of coil antennas respectively used in a plurality of systems, an unnecessary coupling between the coil antennas is suppressed, and an interaction (interference) of the plurality of coil antennas is suppressed. Can be realized. Moreover, an antenna module and an electronic device including the antenna device can be obtained.

1A is a plan view of an antenna unit 51 that is a part of the antenna device according to the first embodiment, and FIG. 1B is a first coil antenna 1 and a second coil antenna that the antenna unit 51 includes. FIG. FIG. 2 is a plan view of the antenna module 201 according to the first embodiment. FIG. 3 is a circuit diagram of the antenna module 201 according to the first embodiment. FIG. 4A is a plan view of an antenna unit 52 that is a part of the antenna device according to the second embodiment, and FIG. 4B is a first coil antenna 1 and a second coil antenna that the antenna unit 52 includes. FIG. FIG. 5 is a plan view of the antenna module 202 according to the second embodiment. FIG. 6A is a plan view of the antenna unit 53 that is a part of the antenna device according to the third embodiment, and FIG. 6B is a diagram illustrating the first coil antenna 1 and the second coil antenna that the antenna unit 53 includes. FIG. FIG. 7 is a plan view of the antenna module 203 according to the third embodiment. FIG. 8 is a circuit diagram of the antenna module 203 according to the third embodiment. FIG. 9A is a plan view of an antenna unit 54 which is a part of the antenna device according to the fourth embodiment, and FIG. 9B is a first coil antenna 1 and a second coil antenna provided in the antenna unit 54. It is a top view which shows 2 and 5th coil antenna 5A. FIG. 10 is a plan view of an antenna module 204 according to the fourth embodiment. FIG. 11 is a circuit diagram of the antenna module 204 according to the fourth embodiment.

  Hereinafter, several specific examples will be given with reference to the drawings to show a plurality of modes for carrying out the present invention. In each figure, the same reference numerals are assigned to the same portions. In consideration of ease of explanation or understanding of the main points, the embodiments are shown separately for convenience, but the components shown in different embodiments can be partially replaced or combined. In the second and subsequent embodiments, description of matters common to the first embodiment is omitted, and only different points will be described. In particular, the same operation effect by the same configuration will not be sequentially described for each embodiment.

  The “antenna device” in the present invention is an antenna device including a plurality of coil antennas used in a plurality of systems. The “antenna module” in the present invention is a module component including a plurality of power feeding circuits and the like. An “electronic device” in the present invention is a device in which the antenna device and a plurality of power feeding circuits are housed in a housing. For example, a mobile phone terminal, so-called smartphone, tablet terminal, notebook PC or PDA, wearable terminal (so-called smart device) Watches, smart glasses, etc.), cameras, game machines, toys, etc.

<< First Embodiment >>
1A is a plan view of an antenna unit 51 that is a part of the antenna device according to the first embodiment, and FIG. 1B is a first coil antenna 1 and a second coil antenna that the antenna unit 51 includes. FIG. FIG. 2 is a plan view of the antenna module 201 according to the first embodiment. In FIG. 1B and FIG. 2, the first coil antenna 1 is illustrated by a broken line in order to facilitate understanding of the structure of the first coil antenna 1.

  The antenna module 201 includes an antenna device 101, a first system circuit 21, and a second system circuit 22. The “electronic device” in the present invention includes a housing (not shown), an antenna device 101 housed in the housing, a first system circuit 21 housed in the housing, and a first housing housed in the housing. A two-system circuit 22 is provided. This is the same in the embodiments described below.

The first system circuit 21 is a power transmission circuit or a power reception circuit for a magnetic contactless power transmission system such as an electromagnetic induction power transmission system or a magnetic resonance power transmission system. For example, the use frequency band of the magnetic field resonance power transmission system is used in the HF band, particularly in the frequency band near the center frequency of 6.78 MHz. The magnetic field type non-contact power transmission system performs power transmission by magnetic field coupling with a power transmission partner. This power transmission system is used, for example, to charge an electronic device such as a smartphone. The magnetic resonance power transmission system is an example of the “first system” in the present invention.

  The second system circuit 22 is a power supply circuit for a communication system such as NFC, and is a balanced input / output type HF band IC or the like. The short-range wireless communication system is, for example, a system using NFC (Near Field Communication). For example, the use frequency band of the short-range wireless communication system is used in the HF band, particularly in the frequency band near the center frequency of 13.56 MHz. The short-range wireless communication system communicates with a communication partner by magnetic field coupling. A communication system using NFC is an example of the “second system” in the present invention.

  The antenna device 101 includes a first coil antenna 1, a second coil antenna 2, and an inductor 5.

  As shown in FIG. 1A, the first coil antenna 1 is a rectangular spiral conductor pattern of about 2 turns formed on the surface of a base material 11 and wound around an axis. The first coil antenna 1 has a first end E1 and a second end E2. The first end E1 of the first coil antenna 1 is connected to the terminal electrode P1 through a conductor pattern or the like formed on the back surface of the substrate 11. The second end E2 is connected to the terminal electrode P2 via a conductor pattern or the like formed on the back surface of the base material 11. The first coil antenna 1 is, for example, a power receiving antenna or a power transmitting antenna used in a magnetic field type non-contact power transmission system. The substrate 11 is a resin sheet such as polyimide (PI) or liquid crystal polymer (LCP).

  As shown in FIG. 1A, the second coil antenna 2 is a rectangular spiral conductor pattern of about 2 turns formed on the surface of the substrate 11 and wound around the axis. The second coil antenna 2 has a third end E3 and a fourth end E4. The third end E3 of the second coil antenna 2 is connected to the terminal electrode P3. The fourth end E4 of the second coil antenna 2 is connected to the second end E2 of the first coil antenna 1. The fourth end E4 is connected to the terminal electrode P2 through a conductor pattern or the like formed on the back surface of the base material 11. The second coil antenna 2 is an antenna used in a communication system such as NFC, for example.

  In the present embodiment, the first coil antenna 1 and the second coil antenna 2 are connected in a Japanese-style manner. Specifically, as shown in FIG. 1B, the coil opening of the first coil antenna 1 is viewed from the axial direction (Z-axis direction) of the first coil antenna 1, and the coil opening of the second coil antenna 2. Overlapping. Further, the winding direction from the first end E1 to the second end E2 of the first coil antenna 1 (clockwise) and the winding direction from the fourth end E4 to the third end E3 of the second coil antenna 2 (right) Rotation) is the same.

  The inductor 5 has a fifth end E5 and a sixth end E6. The fifth end E5 of the inductor 5 is connected to the terminal electrode P2. That is, the second end E2 of the first coil antenna 1, the fourth end E4 of the second coil antenna 2, and the fifth end E5 of the inductor 5 are connected to each other. The inductor 5 is, for example, a chip inductor.

  The inductor 5 according to this embodiment is not coupled to either the first coil antenna 1 or the second coil antenna 2. For example, the coupling coefficient k 51 between the inductor 5 and the first coil antenna 1 and the coupling coefficient k 52 between the inductor 5 and the second coil antenna 2 are both coupling coefficients k 12 between the first coil antenna 1 and the second coil antenna 2. Smaller than (k51 <k12) (k52 <k12).

  As shown in FIG. 2, the first system circuit 21 is connected to the first end E <b> 1 of the first coil antenna 1 and the sixth end E <b> 6 of the inductor 5. The second system circuit 22 is connected to the third end E3 of the second coil antenna 2 and the sixth end E6 of the inductor 5.

  FIG. 3 is a circuit diagram of the antenna module 201 according to the first embodiment. In FIG. 3, the first coil antenna 1 is represented by an inductor L1, the second coil antenna 2 is represented by an inductor L2, the inductor 5 is represented by an inductor L5, and magnetic field coupling between the first coil antenna 1 and the second coil antenna 2 is performed. The mutual inductance is represented by M12. In FIG. 3, the power supply voltage of the first system circuit 21 is represented by V1, the current flowing through the inductor L1 is represented by I1, the power supply voltage for the second system is represented by V2, and the current flowing through the inductor L2 is represented by I2. Represents. The same applies to the circuit diagrams shown below.

  At this time, an element of 2 rows and 2 columns of an impedance matrix of a two-terminal pair circuit (antenna device 101) including a terminal pair formed by the first end E1 and the sixth end E6 and a terminal pair formed by the third end E3 and the sixth end E6. Is represented by Z11, Z12, Z21, and Z22, the circuit equation is as follows.

  Further, when specific mathematical formulas are substituted into the elements Z11, Z12, Z21, and Z22, the above circuit equations are as follows.

  In the above circuit equation, as the values of the elements Z11 and Z22 are larger, the influence of the mutual inductance M12 (unnecessary coupling) due to the magnetic field coupling between the first coil antenna 1 and the second coil antenna 2 is smaller. Specifically, it is preferable that | Z11 |> | Z12 | and | Z22 |> | Z21 | hold as shown in the following equation.

  In the circuit equation, the smaller the values of the elements Z12 and Z21, the smaller the influence of the mutual inductance M12 (unnecessary coupling) due to the magnetic field coupling between the first coil antenna 1 and the second coil antenna 2. Specifically, it is preferable that | Z12 | <| M12 | and | Z21 | <| M12 |

  In the present embodiment, unnecessary coupling between the first coil antenna 1 and the second coil antenna 2 is suppressed by a structure in which at least one of the two types is established. Therefore, in the configuration including the first coil antenna 1 and the second coil antenna 2 respectively used in the two systems, the antenna in which the interaction (interference) between the first coil antenna 1 and the second coil antenna 2 is suppressed. A device can be realized. Moreover, an antenna module and an electronic device including the antenna device can be obtained.

  Furthermore, the inductor L5 (the self-inductance of the inductor 5) is preferably equal to the mutual inductance M12. That is, it is preferable that | Z12 | = 0 and | Z21 | = 0 hold as shown in the following equation.

  With this configuration, the influence of mutual inductance M12 (unnecessary coupling) due to magnetic field coupling between the first coil antenna 1 and the second coil antenna 2 is eliminated, and the interaction (interference) between the first coil antenna 1 and the second coil antenna 2 is eliminated. Disappears. Therefore, it is possible to realize an antenna device that can use the first system (first coil antenna 1) and the second system (second coil antenna 2) completely independently.

  In the present embodiment, the inductor 5 is not coupled to either the first coil antenna 1 or the second coil antenna 2. Therefore, the circuit is complicated compared with the case where the inductor and the coil antenna (the first coil antenna 1 and the second coil antenna 2) are coupled (the antenna device 104 according to the fourth embodiment described in detail later). Therefore, the circuit configuration is easy.

  In the present embodiment, the coil opening of the first coil antenna 1 overlaps the coil opening of the second coil antenna 2 when viewed from the Z-axis direction. Therefore, the area viewed from the axial direction of the first coil antenna can be reduced, and a small antenna device can be configured.

  In the present embodiment, an example in which the entire coil opening of the second coil antenna 2 overlaps with the coil opening of the first coil antenna 1 as viewed from the Z-axis direction has been described. However, the present invention is not limited to this configuration. . If the first coil antenna 1 and the second coil antenna are connected in a harmonized manner, at least a part of the coil opening of the first coil antenna 1 is a coil opening of the second coil antenna 2 as viewed from the Z-axis direction. The structure which overlaps with may be sufficient.

<< Second Embodiment >>
In the second embodiment, an example in which the structures of the first coil antenna and the second coil antenna are different from those of the antenna device 101 according to the first embodiment will be described.

  FIG. 4A is a plan view of an antenna unit 52 that is a part of the antenna device according to the second embodiment, and FIG. 4B is a first coil antenna 1 and a second coil antenna that the antenna unit 52 includes. FIG. FIG. 5 is a plan view of the antenna module 202 according to the second embodiment. In FIG. 4B and FIG. 5, the first coil antenna 1 is illustrated by a broken line in order to facilitate understanding of the structure of the first coil antenna 1.

  The antenna module 202 includes an antenna device 102, a first system circuit 21, and a second system circuit 22.

  The antenna device 102 is different from the antenna device 101 according to the first embodiment in the structure of the first coil antenna 1 and the second coil antenna 2. Other configurations are substantially the same as those of the antenna device 101. Hereinafter, parts different from the antenna device 101 will be described.

  In the present embodiment, as shown in FIG. 4B, the coil opening of the first coil antenna 1 does not overlap the coil opening of the second coil antenna 2 when viewed from the Z-axis direction. The winding direction from the first end E1 to the second end E2 of the first coil antenna 1 (clockwise) and the winding direction from the fourth end E4 to the third end E3 of the second coil antenna 2 (left) Is the opposite. Even in such a configuration, the first coil antenna 1 and the second coil antenna are connected in a Japanese-style manner.

  Even with such a configuration, the same operation and effect as the antenna device 101 can be obtained.

<< Third Embodiment >>
In the third embodiment, an antenna device including a first coil antenna, a second coil antenna, a third coil antenna, and a fourth coil antenna is shown.

  FIG. 6A is a plan view of the antenna unit 53 that is a part of the antenna device according to the third embodiment, and FIG. 6B is a diagram illustrating the first coil antenna 1 and the second coil antenna that the antenna unit 53 includes. FIG. FIG. 7 is a plan view of the antenna module 203 according to the third embodiment. In FIG. 6B and FIG. 7, the first coil antenna 1 and the fourth coil antenna 4 are illustrated by broken lines in order to facilitate understanding of the structures of the first coil antenna 1 and the fourth coil antenna 4.

  The antenna module 203 includes an antenna device 103, a first system circuit 21, and a second system circuit 22.

  The antenna device 103 includes a first coil antenna 1, a second coil antenna 2, a third coil antenna 3, a fourth coil antenna 4, and an inductor 5. The first coil antenna 1 and the third coil antenna 3 are, for example, a power receiving antenna or a power transmitting antenna used in a magnetic field type non-contact power transmission system. The 2nd coil antenna 2 and the 4th coil antenna 4 are antennas used for communication systems, such as NFC, for example.

  As shown in FIG. 6 (A), the first coil antenna 1 is a rectangular spiral conductor pattern of less than two turns formed on the surface of the base material 13 and wound around the axis. The first coil antenna 1 has a first end E1 and a second end E2. The first end E1 of the first coil antenna 1 is connected to the terminal electrode P1 via a conductor pattern or the like formed on the back surface of the base material 13. The second end E2 is connected to the terminal electrode P2 through a conductor pattern or the like formed on the back surface of the substrate 13.

  As shown in FIG. 6 (A), the second coil antenna 2 is a rectangular spiral conductor pattern of less than two turns formed on the surface of the base material 13 and wound around the axis. The second coil antenna 2 has a third end E3 and a fourth end E4. The third end E3 of the second coil antenna 2 is connected to the terminal electrode P3 via a conductor pattern or the like formed on the back surface of the substrate 13. The fourth end E4 of the second coil antenna 2 is connected to the second end E2 of the first coil antenna 1. The fourth end E4 is connected to the terminal electrode P2 through a conductor pattern or the like formed on the back surface of the substrate 13.

  As shown in FIG. 6A, the third coil antenna 3 is a rectangular spiral conductor pattern of about 2 turns formed on the surface of the base material 13 and wound around the axis. The third coil antenna 3 has a seventh end E7 and an eighth end E8. The seventh end E7 of the third coil antenna 3 is connected to the terminal electrode P4. The eighth end E8 is connected to the terminal electrode P5 through a conductor pattern or the like formed on the back surface of the substrate 13.

  As shown in FIG. 6A, the fourth coil antenna 4 is a rectangular spiral conductor pattern of about 2 turns formed on the surface of the base material 13 and wound around the axis. The fourth coil antenna 4 has a ninth end E9 and a tenth end E10. The ninth end E9 of the fourth coil antenna 4 is connected to the terminal electrode P6 via a conductor pattern or the like formed on the back surface of the substrate 13. The tenth end E10 of the fourth coil antenna 4 is connected to the eighth end E8 of the third coil antenna 3. The tenth end E10 is connected to the terminal electrode P5 through a conductor pattern or the like formed on the back surface of the base material 13.

  In the present embodiment, the first coil antenna 1 and the second coil antenna 2 are connected in a Japanese-style manner, and the third coil antenna 3 and the fourth coil antenna 4 are connected in a Japanese-style manner. Specifically, as shown in FIG. 6B, the coil opening of the first coil antenna 1 overlaps the coil opening of the second coil antenna 2 when viewed from the Z-axis direction. The coil opening of the third coil antenna 3 overlaps the coil opening of the fourth coil antenna 4 when viewed from the axial direction (Z-axis direction) of the third coil antenna. Further, the winding direction from the first end E1 to the second end E2 of the first coil antenna 1 (clockwise) and the winding direction from the fourth end E4 to the third end E3 of the second coil antenna 2 (right) Rotation) is the same. Further, the winding direction from the seventh end E7 to the eighth end E8 of the third coil antenna 3 (counterclockwise) and the winding direction from the tenth end E10 to the ninth end E9 of the fourth coil antenna 4 ( Is counterclockwise).

  The inductor 5 has a fifth end E5 and a sixth end E6. The fifth end E5 of the inductor 5 is connected to the terminal electrode P2, and the sixth end E6 of the inductor 5 is connected to the terminal electrode P5. That is, the second end E2 of the first coil antenna 1, the fourth end E4 of the second coil antenna 2, and the fifth end E5 of the inductor 5 are connected. The eighth end E8 of the third coil antenna 3, the tenth end E10 of the fourth coil antenna 4, and the sixth end E6 of the inductor 5 are connected.

  The inductor 5 according to this embodiment is not coupled to any of the first coil antenna 1, the second coil antenna 2, the third coil antenna 3, and the fourth coil antenna 4. For example, the coupling coefficient k51 between the inductor 5 and the first coil antenna 1, the coupling coefficient k52 between the inductor 5 and the second coil antenna 2, the coupling coefficient k53 between the inductor 5 and the third coil antenna 3, and the inductor 5 and the first The coupling coefficient k54 with the 4-coil antenna 4 is smaller than the coupling coefficient k12 between the first coil antenna 1 and the second coil antenna 2 (k51 <k12) (k52 <k12) (k53 <k12) (k54 < k12).

  As shown in FIG. 7, the first system circuit 21 is connected to the first end E <b> 1 of the first coil antenna 1 and the seventh end E <b> 7 of the third coil antenna 3. The second system circuit 22 is connected to the third end E3 of the second coil antenna 2 and the ninth end E9 of the fourth coil antenna 4.

  FIG. 8 is a circuit diagram of the antenna module 203 according to the third embodiment. In FIG. 8, the third coil antenna 3 is represented by an inductor L3, the fourth coil antenna 4 is represented by an inductor L4, and the mutual inductance due to magnetic field coupling between the third coil antenna 3 and the fourth coil antenna 4 is represented by M34. .

  At this time, an element of 2 rows and 2 columns of an impedance matrix of a two-terminal pair circuit (antenna device 103) including a terminal pair by the first end E1 and the seventh end E7 and a terminal pair by the third end E3 and the ninth end E9 Is represented by Z11, Z12, Z21, and Z22, the circuit equation is as follows.

  In the above circuit equation, the larger the value of the element Z11, the smaller the influence of the mutual inductance M12 due to the magnetic field coupling between the first coil antenna 1 and the second coil antenna 2. In the circuit equation, the larger the value of the element Z22, the smaller the influence of the mutual inductance M34 due to the magnetic field coupling between the third coil antenna 3 and the fourth coil antenna 4. Specifically, it is preferable that | Z11 |> | Z12 | and | Z22 |> | Z21 | hold as shown in the following equation.

  In the above circuit equation, the smaller the value of the element Z12, the smaller the influence of the mutual inductance M12 due to the magnetic field coupling between the first coil antenna 1 and the second coil antenna 2. In the circuit equation, the smaller the value of the element Z21, the smaller the influence of the mutual inductance M34 due to magnetic field coupling between the third coil antenna 3 and the fourth coil antenna 4. Specifically, it is preferable that | Z12 | <| M12 + M34 | and | Z21 | <| M12 + M34 |

  In the present embodiment, unnecessary coupling between the first coil antenna 1 and the second coil antenna 2 and unnecessary coupling between the third coil antenna 3 and the fourth coil antenna are suppressed by a structure in which at least one of the two types is established. Is done. Therefore, in a configuration including a plurality of coil antennas respectively used in the two systems, the interaction (interference) between the first coil antenna 1 and the second coil antenna 2, and the third coil antenna 3 and the fourth coil antenna 4. An antenna device in which interaction (interference) with the antenna is suppressed can be realized. Moreover, an antenna module and an electronic device including the antenna device can be obtained.

  Furthermore, the inductor L5 (the self-inductance of the inductor 5) is preferably equal to the sum of the mutual inductance M12 and the mutual inductance M34. That is, it is preferable that | Z12 | = 0 and | Z21 | = 0 hold as shown in the following equation.

  With this configuration, the influence of mutual inductance M12 (unnecessary coupling) due to magnetic field coupling between the first coil antenna 1 and the second coil antenna 2 is eliminated, and the interaction (interference) between the first coil antenna 1 and the second coil antenna 2 is eliminated. Disappears. At the same time, this configuration eliminates the influence of the mutual inductance M34 (unnecessary coupling) due to the magnetic field coupling between the third coil antenna 3 and the fourth coil antenna 4, and the interaction between the third coil antenna 3 and the fourth coil antenna 4. (Interference) disappears. Therefore, it is possible to realize an antenna device that can use the first system (first coil antenna 1 and third coil antenna 3) and the second system (second coil antenna 2 and fourth coil antenna 4) completely independently. .

  In the present embodiment, the inductor 5 is not coupled to any of the first coil antenna 1, the second coil antenna 2, the third coil antenna 3, and the fourth coil antenna 4. Therefore, compared with the case where the inductor and the coil antenna (the first coil antenna 1, the second coil antenna 2, the third coil antenna 3, and the fourth coil antenna 4) are coupled, the circuit is not complicated. Configuration becomes easy.

  In the present embodiment, when viewed from the Z-axis direction, the coil opening of the first coil antenna 1 overlaps the coil opening of the second coil antenna 2, and the coil opening of the third coil antenna 3 overlaps the fourth coil opening. Therefore, the area viewed from the axial direction of the first coil antenna can be reduced, and a small antenna device can be configured.

  In the present embodiment, the coil opening of the first coil antenna 1, the coil opening of the second coil antenna 2, the coil opening of the third coil antenna 3, and the coil opening of the fourth coil antenna 4 are viewed from the Z-axis direction. In this example, the examples overlap each other, but the present invention is not limited to this configuration. If the first coil antenna 1 and the second coil antenna 2 are connected in a harmonized manner, at least a part of the coil opening of the first coil antenna 1 is a coil of the second coil antenna 2 when viewed from the Z-axis direction. The structure which overlaps with opening may be sufficient. Further, if the third coil antenna 3 and the fourth coil antenna 4 are connected in a Japanese-style manner, at least a part of the coil opening of the third coil antenna 3 is the fourth coil antenna 4 as viewed from the Z-axis direction. It may be configured to overlap the coil opening.

  Further, if the first coil antenna 1 and the second coil antenna 2 are connected in a harmonized manner, the coil opening of the first coil antenna 1 is the coil opening of the second coil antenna 2 as viewed from the Z-axis direction. It does not have to overlap. In that case, the winding direction (clockwise) from the first end E1 to the second end E2 of the first coil antenna 1 and the winding direction from the fourth end E4 to the third end E3 of the second coil antenna 2. (Counterclockwise) is reversed. Similarly, if the third coil antenna 3 and the fourth coil antenna 4 are connected in a harmonized manner, the coil opening of the third coil antenna 3 is the coil opening of the fourth coil antenna 4 as viewed from the Z-axis direction. It does not have to overlap. In that case, the winding direction from the seventh end E7 to the eighth end E8 of the third coil antenna 3 (counterclockwise) and the winding direction from the tenth end E10 to the ninth end E9 of the fourth coil antenna 4 (Clockwise) is the opposite.

<< Fourth Embodiment >>
In the fourth embodiment, an antenna device in which an inductor is coupled to both the first coil antenna and the second coil antenna will be described.

  FIG. 9A is a plan view of an antenna unit 54 which is a part of the antenna device according to the fourth embodiment, and FIG. 9B is a first coil antenna 1 and a second coil antenna provided in the antenna unit 54. It is a top view which shows 2 and 5th coil antenna 5A. FIG. 10 is a plan view of an antenna module 204 according to the fourth embodiment. In FIG. 9B and FIG. 10, the fifth coil antenna 5 </ b> A is indicated by a broken line in order to facilitate understanding of the structure of the fifth coil antenna 5 </ b> A.

  The antenna module 204 includes the antenna device 104, the first system circuit 21, and the second system circuit 22.

  The antenna device 104 is different from the antenna device 102 according to the second embodiment in that it includes a fifth coil antenna 5A. Other configurations are substantially the same as those of the antenna device 102. Hereinafter, parts different from the antenna device 102 will be described.

  As shown in FIG. 9A, the fifth coil antenna 5A is a rectangular spiral conductor pattern of about 2 turns formed on the surface of the base material 14 and wound around the axis. The fifth coil antenna 5A has a fifth end E5 and a sixth end E6. A fifth end E5 of the fifth coil antenna 5A is connected to a second end E2 of the first coil antenna 1 and a fourth end E4 of the second coil antenna 2. The sixth end E6 of the fifth coil antenna 5A is connected to the terminal electrode P2.

  In the present embodiment, the fifth coil antenna 5A corresponds to an “inductor” in the present invention.

  The fifth coil antenna 5 A is coupled to both the first coil antenna 1 and the second coil antenna 2. Specifically, as shown in FIG. 9B, the coil opening of the fifth coil antenna 5 </ b> A is the same as the coil opening of the first coil antenna 1 and the coil opening of the second coil antenna 2 as viewed from the Z-axis direction. It overlaps with both. Further, the winding direction (clockwise) from the first end E1 to the second end E2 of the first coil antenna 1 and the winding direction (rightward) from the fifth end E5 to the sixth end E6 of the fifth coil antenna 5A. Rotation) is the same. In this way, in the present embodiment, the first coil antenna 1 and the fifth coil antenna 5A are connected in a Japanese-style manner. On the other hand, the winding direction (counterclockwise) from the fourth end E4 to the third end E3 of the second coil antenna 2 and the winding direction (right) from the fifth end E5 to the sixth end E6 of the fifth coil antenna 5A. This is the opposite of (around). Therefore, in the present embodiment, the second coil antenna 2 and the fifth coil antenna 5A are differentially connected.

  Further, as shown in the second embodiment, the first coil antenna 1 and the second coil antenna 2 are connected in a Japanese-style manner.

  As shown in FIG. 10, the first system circuit 21 is connected to the first end E1 of the first coil antenna 1 and the sixth end E6 of the fifth coil antenna 5A (inductor). The second system circuit 22 is connected to the third end E3 of the second coil antenna 2 and the sixth end E6 of the fifth coil antenna 5A (inductor).

  FIG. 11 is a circuit diagram of the antenna module 204 or the electronic device 304 according to the fourth embodiment. In FIG. 11, the fifth coil antenna 5A is represented by an inductor L5, the mutual inductance due to magnetic field coupling between the first coil antenna 1 and the fifth coil antenna 5A is represented by M15, and the second coil antenna 2 and the fifth coil antenna 5A The mutual inductance due to the magnetic field coupling is represented by M25.

  At this time, the element of 2 rows and 2 columns of the impedance matrix of the two-terminal pair circuit (antenna device 104) by the terminal pair by the first end E1 and the sixth end E6 and the terminal pair by the third end E3 and the sixth end E6 Is represented by Z11, Z12, Z21, and Z22, the circuit equation is as follows.

  In the above circuit equation, as the values of the elements Z11 and Z22 are larger, the influence of the mutual inductance M12 due to the magnetic field coupling between the first coil antenna 1 and the second coil antenna 2 is smaller. Specifically, it is preferable that | Z11 |> | Z12 | and | Z22 |> | Z21 | hold as shown in the following equation.

  In the circuit equation, the smaller the values of the elements Z12 and M21, the smaller the influence of the mutual inductance M12 due to the magnetic coupling between the first coil antenna 1 and the second coil antenna 2. Specifically, it is preferable that | Z12 | <| M12 | and | Z21 | <| M12 |

  In the present embodiment, unnecessary coupling between the first coil antenna 1 and the second coil antenna 2 is suppressed by a structure in which at least one of the two types is established. Therefore, even when the fifth coil antenna 5A (“inductor” in the present invention) is coupled to the coil antennas (the first coil antenna 1 and the second coil antenna 2), the first coil antenna 1 and the second coil antenna 2 An antenna device in which interaction (interference) is suppressed can be realized.

  Further, the inductor L5 (the self-inductance of the fifth coil antenna 5A) is preferably equal to a value obtained by subtracting the mutual inductance M12 from the sum of the mutual inductance M15 and the mutual inductance M25. That is, it is preferable that | Z12 | = 0 and | Z21 | = 0 hold as shown in the following equation.

  With this configuration, it is possible to realize an antenna device that can use the first system (first coil antenna 1) and the second system (second coil antenna 2) completely independently.

  In the present embodiment, the first coil antenna 1 and the fifth coil antenna 5A (“inductor” in the present invention) are connected in a Japanese-style manner. With this configuration, the first coil antenna 1 and the fifth coil antenna 5A are coupled so as to increase the inductance of each other, and the fifth coil antenna 5A also functions as an antenna for the first system. The characteristics are improved. In order to improve the antenna characteristics for the second system, the second coil antenna 2 and the fifth coil antenna 5A may be connected in Japanese.

  In the case where the first coil antenna and the third coil antenna for the first system and the second coil antenna and the fourth coil antenna for the second system are provided as shown in the fourth embodiment, the fifth coil is provided. It is preferable that the antenna 5A (“inductor” in the present invention), the first coil antenna, and the third coil antenna are connected in a Japanese-style manner. With this configuration, the fifth coil antenna 5A, the first coil antenna, and the third coil antenna are coupled so as to increase the inductance, and the fifth coil antenna 5A also functions as an antenna for the first system. The antenna characteristics for the system are improved. Similarly, it is preferable that the fifth coil antenna 5A, the second coil antenna, and the fourth coil antenna are connected in a Japanese-style manner. With this configuration, the antenna characteristics for the second system are improved.

  If at least one of the above two expressions | Zii |> | Zij | or | Zij | <| M12 | (i, j) = (1,2) (2,1) holds, a plurality of coil antennas ( The coupling method between the first coil antenna 1, the second coil antenna 2, and the fifth coil antenna 5A) can be arbitrarily changed. That is, as long as at least one of the above two formulas is established, any of the plurality of coil antennas may be connected in a summing manner or a differential connection, and any of the plurality of coil antennas may not be coupled. However, as described above, in order to improve antenna characteristics, it is desirable that the fifth coil antenna 5A and the first coil antenna (or the second coil antenna) be connected in a Japanese-style manner (mutual inductance M15> 0, Or mutual inductance M25> 0). In the case of mutual inductance M15> 0 and mutual inductance M25> 0, the first coil antenna 1 and the second coil antenna 2 need to be connected in a Japanese-style manner (mutual inductance M12> 0).

<< Other Embodiments >>
In each of the embodiments described above, a plurality of coil antennas (the first coil antenna 1, the second coil antenna 2, the third coil antenna 3, the fourth coil antenna 4, and the fifth coil antenna 5A) are provided on the surface of the base material. Although an example of a rectangular spiral conductive pattern of about 2 turns formed in FIG. 1 is shown, the present invention is not limited to this configuration. The general shape of the plurality of coil antennas can be appropriately changed to a circular shape, an elliptical shape, a polygonal shape, or the like as viewed from the axial direction (Z-axis direction). Further, the plurality of coil antennas may be a looped conductor, a helical conductor, or the like, or may be a helical laminated coil antenna in which a base material on which a looped or spiral conductor is formed is laminated. Good. It is not limited to a configuration in which all of the plurality of coil antennas are formed on the same plane. For example, when a plurality of coil antennas are provided in a base material (stacked body) formed by stacking a plurality of insulating layers. The first coil antenna 1 and the second coil antenna 2 may be formed in different insulating layers. That is, the plurality of coil antennas may be formed on the front surface, the back surface, or the inside of the base material. Furthermore, the number of turns of the plurality of coil antennas can be changed as appropriate within the range where the functions and effects of the present invention are achieved. The plurality of coil antennas may be wound coils. That is, the base material is not essential in the plurality of coil antennas.

  In each of the embodiments described above, the first system is a power transmission system such as an electromagnetic induction power transmission system or a magnetic resonance power transmission system, and the second system is a communication system such as a short-range wireless communication system. However, the present invention is not limited to this. The first system and the second system may be different systems other than the communication system and the power transmission system.

  Finally, the description of the above embodiment is illustrative in all respects and not restrictive. Modifications and changes can be made as appropriate by those skilled in the art. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention includes modifications from the embodiments within the scope equivalent to the claims.

DESCRIPTION OF SYMBOLS 1 ... 1st coil antenna 2 ... 2nd coil antenna 3 ... 3rd coil antenna 4 ... 4th coil antenna 5 ... Inductor 5A ... 5th coil antenna (inductor)
E1 ... first end E1 of the first coil antenna ... second end E3 of the first coil antenna ... third end E4 of the second coil antenna ... fourth end E5 of the second coil antenna ... fifth end E6 of the inductor ... inductor The sixth end E7 of the third coil antenna, the seventh end E8, the eighth end E9 of the third coil antenna, the ninth end E10 of the fourth coil antenna, and the tenth ends k12, k51, k52 of the fourth coil antenna. k53, k54 ... Coupling coefficients L1, L2, L3, L4, L5 ... Inductors M12, M15, M25, M34 ... Mutual inductances P1, P2, P3, P4, P5, P6 ... Terminal electrodes 11, 12, 13, 14 ... Material 21 ... First system circuit 22 ... Second system circuit 51, 52, 53, 54 ... Antenna portions 101, 102, 103, 104 ... Antenna devices 201, 202, 203 204 ... antenna module

Claims (25)

A first coil antenna having a first end and a second end;
A second coil antenna having a third end and a fourth end;
An inductor having a fifth end and a sixth end;
The second end of the first coil antenna, the fourth end of the second coil antenna, and the fifth end of the inductor are connected to each other;
The elements of 2 rows and 2 columns of the impedance matrix of the two-terminal pair circuit of the terminal pair by the first end and the sixth end, and the terminal pair by the third end and the sixth end are Z11, Z12, Z21, Z22, and when M12 represents a mutual inductor due to magnetic field coupling between the first coil antenna and the second coil antenna,
| Zii |> | Zij | (i, j) = (1,2), (2,1), or | Zij | <| M12 | (i, j) = (1,2), (2,1) An antenna device in which at least one of the above holds.   The antenna device according to claim 1, wherein the first coil antenna and the second coil antenna are connected in a Japanese-style manner. The first coil antenna and the second coil antenna are wound around an axis;
The coil opening of the first coil antenna is at least partially overlapped with the coil opening of the second coil antenna when viewed from the axial direction of the first coil antenna.
The winding direction from the first end to the second end of the first coil antenna and the winding direction from the fourth end to the third end of the second coil antenna are the same. The antenna device according to 1. The first coil antenna and the second coil antenna are wound around an axis;
The coil opening of the first coil antenna is not at least partially overlapped with the coil opening of the second coil antenna when viewed from the axial direction of the first coil antenna.
The winding direction from the first end to the second end of the first coil antenna is opposite to the winding direction from the fourth end to the third end of the second coil antenna. The antenna device according to 1.   The antenna device according to any one of claims 1 to 4, wherein the inductor and the first coil antenna are connected in a Japanese-style manner.   The antenna device according to claim 1, wherein the inductor and the second coil antenna are connected in a Japanese-style manner.   The coupling coefficient between the inductor and the first coil antenna and the coupling coefficient between the inductor and the second coil antenna are smaller than the coupling coefficient between the first coil antenna and the second coil antenna. 5. The antenna device according to any one of 4. to 4.   The antenna device according to claim 7, wherein a self-inductance of the inductor is equal to the mutual inductance M12. A first coil antenna having a first end and a second end;
A second coil antenna having a third end and a fourth end;
A third coil antenna having a seventh end and an eighth end;
A fourth coil antenna having a ninth end and a tenth end;
An inductor having a fifth end and a sixth end;
The second end of the first coil antenna, the third end of the second coil antenna, and the fifth end of the inductor are connected to each other;
The eighth end of the third coil antenna, the tenth end of the fourth coil antenna, and the sixth end of the inductor are connected to each other;
The elements of 2 rows and 2 columns of the impedance matrix of the two-terminal pair circuit by the terminal pair by the first end and the seventh end and the terminal pair by the third end and the ninth end are Z11, Z12, Z21, Z22, a mutual inductor due to magnetic field coupling between the first coil antenna and the second coil antenna is denoted as M12, and a mutual inductor due to magnetic field coupling between the third coil antenna and the fourth coil antenna is denoted as M34.
| Zii |> | Zij | (i, j) = (1,2), (2,1), or | Zij | <| M12 + M34 | (i, j) = (1,2,), (2,1) An antenna device in which at least one of the above holds.   The antenna device according to claim 9, wherein the first coil antenna, the second coil antenna, the third coil antenna, and the fourth coil antenna are connected in a Japanese-style manner. The first coil antenna, the second coil antenna, the third coil antenna, and the fourth coil antenna are wound around an axis,
The coil opening of the first coil antenna is at least partially overlapped with the coil opening of the second coil antenna when viewed from the axial direction of the first coil antenna.
The coil opening of the third coil antenna is at least partially overlapped with the coil opening of the fourth coil antenna when viewed from the axial direction of the third coil antenna.
The winding direction from the first end to the second end of the first coil antenna and the winding direction from the fourth end to the third end of the second coil antenna are the same,
The winding direction from the seventh end to the eighth end of the third coil antenna is the same as the winding direction from the tenth end to the ninth end of the fourth coil antenna. The antenna device according to 1. The first coil antenna, the second coil antenna, the third coil antenna, and the fourth coil antenna are wound around an axis,
The coil opening of the first coil antenna is not at least partially overlapped with the coil opening of the second coil antenna when viewed from the axial direction of the first coil antenna.
The coil opening of the third coil antenna is not at least partially overlapped with the coil opening of the fourth coil antenna when viewed from the axial direction of the third coil antenna.
The winding direction from the first end to the second end of the first coil antenna is opposite to the winding direction from the fourth end to the third end of the second coil antenna;
The winding direction from the seventh end to the eighth end of the third coil antenna is opposite to the winding direction from the tenth end to the ninth end of the fourth coil antenna. The antenna device according to 1.   The antenna device according to claim 9, wherein the inductor, the first coil antenna, and the third coil antenna are connected in a Japanese-style manner.   The antenna device according to claim 9, wherein the inductor, the second coil antenna, and the fourth coil antenna are connected in a Japanese-style manner.   A coupling coefficient between the inductor and the first coil antenna, a coupling coefficient between the inductor and the second coil antenna, a coupling coefficient between the inductor and the third coil antenna, and the inductor and the fourth coil antenna. The coupling coefficient is smaller than the coupling coefficient between the first coil antenna and the second coil antenna and the coupling coefficient between the third coil antenna and the fourth coil antenna. Antenna device.   The antenna device according to claim 15, wherein a self-inductance of the inductor is equal to a sum of the mutual inductance M12 and the mutual inductance M34. The antenna device according to any one of claims 1 to 8,
A first system circuit connected to the first end of the first coil antenna and the sixth end of the inductor;
A second system circuit connected to the third end of the second coil antenna and the sixth end of the inductor;
An antenna module comprising: An antenna device according to any one of claims 9 to 16,
A first system circuit connected to the first end of the first coil antenna and the seventh end of the third coil antenna;
A second system circuit connected to the third end of the second coil antenna and the ninth end of the fourth coil antenna;
An antenna module comprising:   The antenna module according to claim 17 or 18, wherein the first system circuit is a circuit for contactless power transmission.   The antenna module according to claim 17, wherein the second system circuit is a near-field communication circuit.   21. The antenna module according to claim 17, wherein a use frequency band of the first system circuit is an HF band.   The antenna module according to any one of claims 17 to 21, wherein a frequency band used by the circuit for the second system is an HF band.   23. The antenna module according to claim 17, wherein a center frequency of the use frequency band of the first system circuit is different from a center frequency band of the use frequency band of the second system circuit. A housing,
An antenna device housed in the housing;
A first system circuit and a second system circuit housed in the housing;
With
The antenna device is
A first coil antenna having a first end and a second end;
A second coil antenna having a third end and a fourth end;
An inductor having a fifth end and a sixth end;
The second end of the first coil antenna, the fourth end of the second coil antenna, and the fifth end of the inductor are connected to each other;
The elements of 2 rows and 2 columns of the impedance matrix of the two-terminal pair circuit of the terminal pair by the first end and the sixth end, and the terminal pair by the third end and the sixth end are Z11, Z12, Z21, Z22, and when M12 represents a mutual inductor due to magnetic field coupling between the first coil antenna and the second coil antenna,
| Zii |> | Zij | (i, j) = (1,2), (2,1), or | Zij | <| M12 | (i, j) = (1,2), (2,1) At least one of
The first system circuit is connected to the first end of the first coil antenna and the sixth end of the inductor;
The second system circuit is an electronic device connected to the third end of the second coil antenna and the sixth end of the inductor. A housing,
An antenna device housed in the housing;
A first system circuit and a second system circuit housed in the housing;
With
The antenna device is
A first coil antenna having a first end and a second end;
A second coil antenna having a third end and a fourth end;
A third coil antenna having a seventh end and an eighth end;
A fourth coil antenna having a ninth end and a tenth end;
An inductor having a fifth end and a sixth end;
The second end of the first coil antenna, the fourth end of the second coil antenna, and the fifth end of the inductor are connected to each other;
The eighth end of the third coil antenna, the tenth end of the fourth coil antenna, and the sixth end of the inductor are connected to each other;
The elements of 2 rows and 2 columns of the impedance matrix of the two-terminal pair circuit by the terminal pair by the first end and the seventh end and the terminal pair by the third end and the ninth end are Z11, Z12, Z21, Z22, a mutual inductor due to magnetic field coupling between the first coil antenna and the second coil antenna is denoted as M12, and a mutual inductor due to magnetic field coupling between the third coil antenna and the fourth coil antenna is denoted as M34.
| Zii |> | Zij | (i, j) = (1,2), (2,1), or | Zij | <M12 + M34 | (i, j) = (1,2,), (2,1) At least one of the first system circuits is connected to the first end of the first coil antenna and the seventh end of the third coil antenna,
The second system circuit is an electronic device connected to the third end of the second coil antenna and the ninth end of the fourth coil antenna.

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