Electronic devices

Abstract

An electronic device includes one or more zero-order resonant antennas (20) and a metal body (100, 100a, 112, 112). Each zero-order resonant antenna includes: a ground plate (40) configured to provide a ground potential; a relative conductor (50) disposed at a predetermined distance from the ground plate in the plate thickness direction of the ground plate; a power supply line (70) electrically connected to the relative conductor, and a short-circuit portion (60) electrically connecting the relative conductor and the ground plate. The metal body is configured to limit the propagation direction of radio waves transmitted or received by the one or more zero-order resonant antennas, and has an opening. The power supply line extends from an edge of the relative conductor toward the opening on a plane orthogonal to the plate thickness direction.

Description

Technical Field

[0001] The present disclosure relates to an electronic device. Background Art

[0002] JP2016-181755A discloses an electronic device including a zero-order resonant antenna. The contents disclosed in JP2016-181755A are incorporated herein by reference as an explanation of the technical elements of the present disclosure.

[0003] In JP2016-181755A, the zero-order resonant antenna has the following structure, in which the ground plate and the relative conductor facing each other are connected by a short-circuit portion. The power supply line (power supply unit) for supplying power to the relative conductor is connected to the central portion of the relative conductor. The zero-order resonant antenna has a circular radiation characteristic, that is, non-directional, and its center is a zero point (NULL) on a plane orthogonal to the thickness direction of the ground plate. When a metal body is arranged near the zero-order resonant antenna, since radio waves are also radiated to the metal body, the influence of reflection causes the reflection characteristics to deteriorate. From the above viewpoints or other viewpoints not mentioned, it is necessary to further improve the electronic device having a zero-order resonant antenna. Summary of the invention

[0004] An object of the present disclosure is to provide an electronic device capable of suppressing degradation of reflection characteristics due to a metal body.

[0005] An electronic device according to one aspect of the present disclosure includes one or more zero-order resonant antennas and a metal body. Each zero-order resonant antenna includes: a ground plate configured to provide a ground potential; a relative conductor arranged at a predetermined distance from the ground plate in the plate thickness direction of the ground plate; a power supply line electrically connected to the relative conductor; and a short-circuit portion electrically connecting the relative conductor and the ground plate. The metal body is configured to limit the propagation direction of radio waves sent or received from the one or more zero-order resonant antennas, and has an opening.

[0006] The feed line of the zero-order resonant antenna extends from the edge of the opposing conductor toward the opening on a plane orthogonal to the plate thickness direction.

[0007] In the above electronic device, the metal body restricts the propagation direction of the radio wave transmitted or received from the zero-order resonant antenna. The metal body has an opening, and the power supply line extends in the direction toward the opening. Therefore, the directivity of the zero-order resonant antenna is biased in the direction in which the power supply line extends, that is, in the direction toward the opening. As a result, the degradation of the reflection characteristics due to the metal body can be suppressed.

[0008] An electronic device according to another aspect of the present disclosure includes one or more zero-order resonant antennas and a metal body. Each zero-order resonant antenna includes: a ground plate configured to provide a ground potential; a relative conductor arranged at a predetermined distance from the ground plate in the plate thickness direction of the ground plate; a plurality of power supply lines electrically connected to the relative conductor, extending from different positions of the edge of the relative conductor in different directions to surround the relative conductor in a plane orthogonal to the plate thickness direction; a short-circuit portion electrically connecting the relative conductor and the ground plate; and a power supply controller configured to control the power supply to the power supply line. The metal body is configured to limit the propagation direction of the radio waves sent or received from the one or more zero-order resonant antennas, and has an opening.

[0009] The power supply controller is configured to supply power to a portion of the power supply lines, including a power supply line extending closest to a direction from the opposing conductor toward the opening, or two power supply lines sandwiching a direction toward the opening in the plane.

[0010] In the above electronic device, the zero-order resonant antenna includes a plurality of power supply lines, and the power supply controller controls the power supply to the plurality of power supply lines. The power supply controller supplies power to only a portion of the plurality of power supply lines, and does not supply power to the remaining power supply lines. The portion of the power supply lines that supply power includes at least a power supply line whose extension direction is closest to the opening, or at least two power supply lines that sandwich the direction toward the opening in the plan view. The directivity of the zero-order resonant antenna is biased in the extension direction of the power supply line to be powered. As a result, the degradation of the reflection characteristics due to the metal body can be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description made with reference to the accompanying drawings. In the accompanying drawings:

[0012] Figure 1 is a perspective view of a zero-order resonant antenna provided in the electronic device of the first embodiment;

[0013] Figure 2 It is along Figure 1 A cross-sectional view of the zero-order resonant antenna taken along line II-II;

[0014] Figure 3 is a perspective view of a zero-order resonant antenna according to a reference example;

[0015] Figure 4 It is along Figure 3 A cross-sectional view of the zero-order resonant antenna taken along line IV-IV;

[0016] Figure 5A and Figure 5B is a diagram showing radiation characteristics of a zero-order resonant antenna according to a reference example;

[0017] Fig. 6A It is shown Figure 1 A diagram showing the extension direction of the power supply line in the zero-order resonant antenna shown; Figure 6B It is shown Fig. 6A A diagram of the radiation characteristics of the zero-order resonant antenna shown;

[0018] Fig. 7A is a diagram showing the extending direction of the feed line in the zero-order resonant antenna; Figure 7B It is shown Fig. 7A A diagram of the radiation characteristics of the zero-order resonant antenna shown;

[0019] Fig. 8A is a diagram showing the extending direction of the feed line in the zero-order resonant antenna; Figure 8B It is shown Fig. 8A A diagram of the radiation characteristics of the zero-order resonant antenna shown;

[0020] Fig.9A is a diagram showing the extending direction of the feed line in the zero-order resonant antenna; Fig. 9B It is shown Fig.9A A diagram of the radiation characteristics of the zero-order resonant antenna shown;

[0021] Fig. 10A is a diagram showing the extending direction of the feed line in the zero-order resonant antenna; Fig. 10B It is shown Fig. 10A A diagram of the radiation characteristics of the zero-order resonant antenna shown;

[0022] Fig.11 is a transparent perspective view showing an electronic device according to a first embodiment;

[0023] Fig.12 is a plan view showing a zeroth-order resonant antenna in an electronic device according to a second embodiment.

[0024] Fig.13 is the equivalent circuit diagram of the zero-order resonant antenna;

[0025] Fig.14 is a plan view showing an electronic device according to a third embodiment;

[0026] Fig.15 is from Fig.14 A side view of the electronic device viewed in the direction X1 shown;

[0027] Fig.16A is a diagram showing the extending direction of the feed line in the zero-order resonant antenna; Fig. 16B It is shown Fig.16A A diagram of the radiation characteristics of the zero-order resonant antenna shown;

[0028] Fig.17 is a diagram showing a zero-order resonant antenna in an electronic device according to a fourth embodiment;

[0029] Fig.18 is a plan view showing an electronic device; and

[0030] Fig.19 is a diagram showing a modified example of the zero-order resonant antenna. DETAILED DESCRIPTION

[0031] The embodiments will be described with reference to the accompanying drawings. In the following embodiments, components having corresponding functions or structures are assigned the same reference numerals.

[0032] (First embodiment)

[0033] First, refer to Figure 1 and Figure 2 The structure of the zero-order resonant antenna 20 included in the electronic device 10 of the first embodiment is described.

[0034] <Structure of the Zero-Order Resonance Antenna>

[0035] like Figure 1 and Figure 2 As shown, the zero-order resonant antenna 20 includes a base member 30, a ground plate 40, a relative conductor 50, a short-circuit portion 60, and a power supply line 70. In the following, the plate thickness direction of the ground plate 40 is defined as the Z direction, and a direction orthogonal to the Z direction is defined as the X direction. The direction orthogonal to the Z direction and the X direction is defined as the Y direction. Unless otherwise specified, the shape observed in a plane from the Z direction, that is, the shape along the XY plane defined by the X and Y directions is referred to as a plane shape. For convenience, the direction from the ground plate 40 toward the relative conductor 50 is defined as upward, and the direction from the relative conductor 50 toward the ground plate 40 is defined as downward.

[0036] The zero-order resonant antenna 20 is configured to transmit and / or receive radio waves of a predetermined operating frequency. An example of the operating frequency is 2.4 GHz. The zero-order resonant antenna 20 is configured to be able to transmit and / or receive radio waves in a frequency band used in short-range wireless communications. The operating frequency can be appropriately designed, and the operating frequency can be another frequency (e.g., 5 GHz).

[0037] The base member 30 is made of a dielectric material such as a resin. By using the base member 30, a wavelength shortening effect caused by the dielectric material can be expected. As the base member 30, for example, a member made of only resin, or a combination of resin and glass cloth, non-woven fabric or the like can be used. The base member 30 serves as a holding portion that holds the ground plate 40 and the relative conductor 50 in a predetermined positional relationship. According to the thickness of the base member 30, the relative distance between the ground plate 40 and the relative conductor 50 and the length of the short-circuit portion 60 in the Z direction can be adjusted. The base member 30 may have a single-layer structure or a multi-layer structure.

[0038] The ground plate 40 is connected to a power supply circuit (not shown) to provide a ground potential in the zero-order resonant antenna 20. The ground plate 40 is a flat conductor made of copper or the like. The direction perpendicular to the plate surface of the ground plate 40 is also substantially parallel to the Z direction. In a plan view, the area of ​​the ground plate 40 is larger than the area of ​​the relative conductor 50. The ground plate 40 has a size that includes the entire relative conductor 50. The ground plate 40 preferably has a size required for the zero-order resonant antenna 20 to operate stably. The ground plate 40 has, for example, a planar square shape. The length of each side of the ground plate 40 is, for example, more than one times the wavelength of the radio wave of the operating frequency, that is, more than one wavelength.

[0039] The ground plate 40 of the present embodiment is provided on the lower surface of the base member 30. The ground plate 40 is formed by patterning a metal foil provided on the lower surface of the base member 30. The ground plate 40 is electrically connected to the ground conductor 41 located on the upper surface of the base member 30 via the connection portion 42. As described above, the zero-order resonant antenna 20 is configured to be able to supply power on the upper surface side of the base member 30.

[0040] The ground conductor 41 is formed by patterning a metal foil provided on the upper surface of the base member 30. The ground conductor 41 extends in the X direction. The connection portion 42 is a via conductor provided in a through hole of the base member 30. The ground plate 40 provides a ground potential by electrically connecting, for example, an outer conductor of a coaxial cable to the ground conductor 41.

[0041] The plane shape of the ground plate 40 can be changed appropriately. In the present embodiment, as an example, the plane shape of the ground plate 40 is a square, but as another configuration, the plane shape of the ground plate 40 may be a rectangle or other polygons. In addition, the plane shape of the ground plate 40 may be a circle (including an ellipse). The ground plate 40 is preferably formed to have a size larger than a circle having a diameter of one wavelength.

[0042] The relative conductor 50 is a plate-shaped conductor made of copper or the like. The relative conductor 50 is arranged as a conductor facing the ground plane 40 at a predetermined distance from the ground plane 40 in the Z direction. The relative conductor 50 is sometimes referred to as a patch portion or a radiating element. In a plan view, the entire relative conductor 50 overlaps with the ground plane 40. That is, the entire plate surface (lower surface) of the relative conductor 50 faces the ground plane 40 in the Z direction. The relative conductor 50 is arranged to be substantially parallel to the ground plane 40. Substantially parallel is not limited to completely parallel. For example, the relative conductor 50 may be tilted from a few degrees to ten degrees relative to the ground plane 40.

[0043] The opposing conductor 50 of this embodiment is provided on the upper surface of the base member 30. The opposing conductor 50 is formed by patterning a metal foil provided on the upper surface of the base member 30. The opposing conductor 50 has a square shape in a plan view. The edge portion of the opposing conductor 50 has one side substantially parallel to the X direction and one side substantially parallel to the Y direction.

[0044] By arranging the opposing conductor 50 and the ground plate 40 to face each other, capacitance is formed according to the area of ​​the opposing conductor 50 and the distance between the opposing conductor 50 and the ground plate 40. The opposing conductor 50 is formed to have a size that forms capacitance that resonates in parallel with the inductance of the short-circuit portion 60 at a target frequency. The area of ​​the opposing conductor 50 is appropriately designed to provide a desired capacitance and thereby operate at an operating frequency.

[0045] In the present embodiment, as an example, the plane shape of the relative conductor 50 is a square, but as another configuration, the plane shape of the relative conductor 50 may be a circle, a regular octagon, a regular hexagon, etc. The relative conductor 50 preferably has a line-symmetrical shape, that is, a bidirectional line-symmetrical shape, with each of two straight lines orthogonal to each other as an axis of symmetry. A bidirectional line-symmetrical shape refers to a figure that is line-symmetrical with a first straight line as an axis of symmetry and is also line-symmetrical with respect to a second straight line orthogonal to the first straight line. The bidirectional line-symmetrical shape corresponds to, for example, an ellipse, a rectangle, a circle, a square, a regular hexagon, a regular octagon, a rhombus, etc. In addition, the relative conductor 50 is more preferably a point-symmetrical figure, such as a circle, a square, a rectangle, or a parallelogram.

[0046] The short-circuit portion 60 electrically connects the ground plate 40 and the opposite conductor 50, i.e., short-circuits. The short-circuit portion 60 is a columnar conductor, one end of which is connected to the ground plate 40 and the other end is connected to the opposite conductor 50. The short-circuit portion 60 has, for example, a substantially circular plane. By adjusting the diameter and length of the short-circuit portion 60, the inductance provided in the short-circuit portion 60 can be adjusted. In a plan view, the short-circuit portion 60 is connected to the substantial center of the opposite conductor 50. The center of the opposite conductor 50 corresponds to the center of gravity of the opposite conductor 50.

[0047] Since the opposing conductor 50 of the present embodiment has a planar square shape, the center corresponds to the intersection of the two diagonal lines of the opposing conductor 50. The short-circuit portion 60 is a via conductor provided in the through hole of the base member 30. The number of via conductors constituting the short-circuit portion 60 is not particularly limited. The short-circuit portion 60 may be formed by a plurality of via conductors provided in parallel between the ground plate 40 and the opposing conductor 50.

[0048] The power supply line 70 is a conductor for supplying power to the relative conductor 50. The power supply line 70 extends from the edge portion of the relative conductor 50 in a direction orthogonal to the Z direction. The power supply line 70 includes a portion extending from a power supply point along a virtual straight line connecting the basic center of the relative conductor 50 and the power supply point. One end of the power supply line 70 is connected to the edge portion of the relative conductor 50, and the other end is electrically connected to the inner conductor of the coaxial cable. The connection portion between the power supply line 70 and the relative conductor 50 corresponds to the power supply point. The current input to the power supply line 70 via the coaxial cable propagates to the relative conductor 50 and excites the relative conductor 50. The power supply method is not limited to the direct power supply method. A power supply method in which the power supply line 70 and the relative conductor 50 are electromagnetically coupled can also be adopted. The extension length and width of the power supply line 70 are set in consideration of impedance matching, etc.

[0049] The power supply line 70 of the present embodiment is a conductor provided on the upper surface of the base member 30. This conductor is sometimes referred to as a microstrip line. The power supply line 70 extends in the X direction from one side of the relative conductor 50 which is substantially parallel to the Y direction. The power supply line 70 is connected to the substantially central portion of the relative conductor 50 in the Y direction. The power supply line 70 and the relative conductor 50 are provided symmetrically with respect to the X-axis line. A predetermined gap is provided between the power supply line 70 and the ground conductor 41. The power supply line 70 is provided to face the ground plate 40 in the Z direction.

[0050] The zero-order resonant antenna 20 configured in this manner has a structure in which the ground plate 40 and the opposing conductor 50 facing each other are connected by a short-circuit portion 60. This structure is a so-called mushroom structure, which is the same as the basic structure of a metamaterial. Since the zero-order resonant antenna 20 is an antenna to which the metamaterial technology is applied, the zero-order resonant antenna 20 is sometimes referred to as a metamaterial antenna.

[0051] The zero-order resonant antenna 20 is designed to operate in a zero-order resonant mode at a desired operating frequency. In the dispersion characteristics of the metamaterial, the resonance phenomenon at a frequency at which the phase constant β becomes zero (0) is the zero-order resonance. The phase constant β is the imaginary part of the propagation coefficient γ of the electric wave propagating on the transmission line. The zero-order resonant antenna 20 can satisfactorily transmit and / or receive radio waves in a predetermined frequency band including the frequency at which the zero-order resonance occurs.

[0052] The connection between the zero-order resonant antenna 20 and the power supply circuit (wireless device) is not limited to the coaxial cable. The zero-order resonant antenna 20 and the power supply circuit can be connected by using another communication cable such as a power supply line. In addition, in addition to the coaxial cable, the zero-order resonant antenna 20 and the power supply circuit can also be connected through a matching circuit, a filter circuit, etc. The zero-order resonant antenna 20 can be set integrally with the power supply circuit.

[0053] <Antenna Operation>

[0054] Next, the operation of the zero-order resonant antenna 20 will be described. The zero-order resonant antenna 20 operates by LC parallel resonance of the capacitance formed between the ground plate 40 and the opposing conductor 50 and the inductance provided in the short-circuit portion 60. In the zero-order resonant antenna 20, the opposing conductor 50 is short-circuited to the ground plate 40 by the short-circuit portion 60 provided in the center area of ​​the opposing conductor 50. The area of ​​the opposing conductor 50 is an area that forms a capacitance that resonates in parallel with the inductance of the short-circuit portion 60 at a desired frequency (operating frequency).

[0055] Therefore, when power of the operating frequency is supplied, parallel resonance is generated due to the energy exchange between the inductor and the capacitor, and an electric field perpendicular to the ground plate 40 and the relative conductor 50 is generated between the ground plate 40 and the relative conductor 50. That is, an electric field is generated in the Z direction. The vertical electric field propagates from the short-circuit portion 60 toward the edge portion of the relative conductor 50, is vertically polarized at the edge of the relative conductor 50, and propagates in space. The vertically polarized wave here refers to a radio wave whose vibration direction of the electric field is perpendicular to the ground plate 40 and the relative conductor 50. In addition, the zero-order resonant antenna 20 receives a vertically polarized wave from the outside of the zero-order resonant antenna 20 through LC parallel resonance.

[0056] The resonant frequency of the zero-order resonance does not depend on the antenna size. Therefore, the length of one side of the relative conductor 50 can be made shorter than 1 / 2 wavelength of the zero-order resonance frequency (operating frequency). For example, even if one side has a length equal to 1 / 4 wavelength, zero-order resonance can be generated. For example, in the case where the operating frequency is 2.4 GHz, in a structure including a base member 30, the wavelength λε can be obtained by (300 [mm / s] / 2.4 [GHz]) / square root of the dielectric constant of the base member 30.

[0057] <Directional adjustment method>

[0058] Next, a method of adjusting the directivity of the zero-order resonant antenna 20 will be described. Figure 3 and Figure 4 A zero-order resonant antenna 20R according to a reference example is shown. Figure 5A , 5B6A and 6B show the results of electromagnetic field simulation (radiation characteristics) between the reference example and the present embodiment. In the reference example and the present embodiment, the operating frequency, the configuration (dielectric constant and thickness) of the base member 30, and the diameter of the short-circuit portion 60 are the same. Then, the design optimization is performed according to the size (area) of the relative conductor 50.

[0059] As a reference example, Figure 3 and Figure 4 The zero-order resonant antenna 20R shown in FIG. 1 is configured to be powered on the lower surface side of the base member 30. In other words, the power supply line 70 is not connected to the edge portion of the opposing conductor 50 but to the center portion surrounded by the edge portion. In the reference example, portions corresponding in function and / or structure to the zero-order resonant antenna 20 shown in the present embodiment are given the same reference numerals.

[0060] The power supply line 70 extends in the Z direction. One end of the power supply line 70 is connected to the lower surface of the opposing conductor 50, and the other end is exposed to the lower surface side of the base member 30, so that the power supply line 70 can be connected to a communication cable (for example, a coaxial cable). On the lower surface of the base member 30, the ground plate 40 is not provided to surround the power supply line 70. A predetermined gap is provided between the power supply line 70 and the ground plate 40. The power supply line 70 is provided by a via conductor, a metal pin, etc. provided in a through hole of the base member 30. The other configurations are the same as those of the zero-order resonant antenna 20.

[0061] Figure 5A and Figure 5B 5 shows the radiation characteristics of the zero-order resonant antenna 20R. The vertical electric field generated by the LC parallel resonance propagates in all directions of the edge portion of the relative conductor 50 with the short-circuit portion 60 as the center. Since the propagation direction of the vertical electric field is symmetrical with respect to the short-circuit portion 60, the zero-order resonant antenna 20R has directivity in all directions from the substantially center of the relative conductor 50 toward the edge portion at the operating frequency. As shown in FIG. 5, the zero-order resonant antenna 20R has a ring-shaped (donut-shaped) radiation characteristic with a zero point, that is, it is non-directional in the XY plane.

[0062] Fig. 6A and Figure 6B The zero-order resonant antenna 20 (see Figure 1 ) radiation characteristics. As described above, in the zero-order resonant antenna 20, the power supply line 70 extends from the edge portion of the opposing conductor 50 in the direction perpendicular to the Z axis (X direction). Due to the influence of the power supply line 70 arranged to face the ground plate 40, in the zero-order resonant antenna 20, the null point (NULL) is tilted to the side opposite to the power supply line 70, and the directivity is biased to the side where the power supply line 70 is provided. In this way, the zero-order resonant antenna 20 has directivity in the extending direction of the power supply line 70.

[0063] 7A to 10B is shown relative to 6A and Figure 6B , a diagram showing how the radiation characteristics vary depending on the extending direction of the power supply line 70. 7A to 10B It shows that Fig. 6A and 6B The results of the electromagnetic field simulation (radiation characteristics) of the zero-order resonant antenna 20 in FIG. 2 are shown in FIG. 2 . In the electromagnetic field simulation, only the extension direction of the power supply line 70 is different from the Figure 1 The extension direction of the power supply line 70 is different, and other conditions are the same. Fig. 7A , Fig. 8A , Fig.9A and Fig. 10A , for the sake of convenience, the zero-order resonant antenna 20 is shown without the base member 30 .

[0064] exist Fig. 7A In the embodiment, the power supply line 70 extends in the Y direction. The power supply line 70 extends in the Y direction from one side of the relative conductor 50 which is substantially parallel to the X direction. Figure 7B As shown, in the extending direction of the power supply line 70, the null point (NULL) is inclined to the side opposite to the power supply line 70, and the directivity is biased to the side where the power supply line 70 is provided. Fig. 7A The illustrated zero-order resonant antenna 20 has directivity in the extending direction of the power supply line 70 .

[0065] exist Fig. 8A In the embodiment, the power supply line 70 is Figure 1 The side opposite to the extending direction shown extends in the X direction. Figure 8B As shown, in the extension direction of the power supply line 70, the zero point (NULL) is inclined to Figure 6B The opposite side, and the directionality is biased to the side where the power supply line 70 is provided. Fig. 8A The zero-order resonant antenna 20 shown has a direction in which the power supply line 70 extends, that is, in the direction in which the power supply line 70 extends. Figure 6B Directionality in the opposite direction.

[0066] exist Fig.9A In the embodiment, the power supply line 70 is Fig. 7A The y-direction is extended on the opposite side of the extension direction shown. Fig. 9B As shown, in the extension direction of the power supply line 70, the zero point (NULL) is inclined to Figure 7B The opposite side, and the directionality is biased to the side where the power supply line 70 is provided. Fig.9A The zero-order resonant antenna 20 shown has a direction in which the power supply line 70 extends, that is, in the direction in which the power supply line 70 extends. Figure 7B Directionality in the opposite direction.

[0067] exist Fig. 10AIn the embodiment, the power supply line 70 extends diagonally. The power supply line 70 has an X-direction component and a Y-direction component. The angle formed by the power supply line 70 and a virtual straight line substantially parallel to the X direction and the angle formed by the virtual straight line substantially parallel to the Y direction are acute angles. The power supply line 70 extends from one of the corners of the relative conductor 50. Fig. 10B As shown, in the extending direction of the power supply line 70, the null point (NULL) is inclined to the side opposite to the power supply line 70, and the directivity is biased to the side where the power supply line 70 is provided. Fig. 10A The illustrated zero-order resonant antenna 20 has directivity in the extending direction of the power supply line 70 .

[0068] like FIG. 6A to FIG. 10B As shown, the zero-order resonant antenna 20 that initially has non-directivity on the XY plane can be provided with directivity in a predetermined direction. The directivity of the zero-order resonant antenna 20 can be adjusted in a desired direction according to the extending direction of the power supply line 70.

[0069] <Electronic equipment>

[0070] Next, we will refer to Fig.11 An electronic device 10 is described. Fig.11 1 is a transparent perspective view, and the elements accommodated in the housing 100 are shown in solid lines. Fig.11 As shown, the electronic device 10 includes the above-mentioned zero-order resonant antenna 20 and a housing 100. The electronic device 10 is installed on a moving body such as a vehicle. The electronic device 10 can perform wireless communication with another electronic device set in the moving body. The electronic device 10 of this embodiment is configured to perform wireless communication with another electronic device set outside the housing 100.

[0071] The electronic device 10 is, for example, an antenna device that provides a wireless communication function or an electronic control device (ECU) that has a wireless communication function. The electronic device 10 of this embodiment is an electronic control device installed in a vehicle. In addition to having a wireless communication function, the electronic device 10 also has a function of performing vehicle-related control.

[0072] like Figure 1 As shown, the power supply line 70 of the zero-order resonant antenna 20 extends from the edge portion of the opposing conductor 50 in the X direction. The zero-order resonant antenna 20 is arranged in a part of the base member 30. In another area of ​​the base member 30, wiring (not shown) is provided, and electronic components are mounted to form a circuit. In another area, a power supply circuit, a power supply circuit, and a circuit for providing a control function of the zero-order resonant antenna 20 are formed. The base member 30 is an insulating base member constituting the circuit board 11. The zero-order resonant antenna 20 is formed on a part of the circuit board 11.

[0073] The housing 100 accommodates other elements of the electronic device 10 including the zero-order resonant antenna 20. The housing 100 is configured so that at least a portion of the wall defining the accommodation space transmits radio waves. In other words, a portion of the wall is configured to reflect radio waves. The housing 100 is formed of, for example, a resin material and a metal material.

[0074] The housing 100 of the present embodiment has a substantially rectangular shape in a plane, and has four side walls 101 to 104, a lower wall 105, and an upper wall 106. The side walls 101 and 102 are walls in the X direction, and the side walls 103 and 104 are walls in the Y direction. At least a portion of the side wall 102 close to the power supply line 70 relative to the relative conductor 50 is formed using a resin material. The side walls 101, 103, 104 are formed using a metal material. The housing 100 is constructed by assembling a resin cover 100b having a side wall 102 to a bottomed tubular metal shell 100a having side walls 101, 103, 104, a lower wall 105, and an upper wall 106. The entire resin cover 100b may be made of a resin material, or a metal member may be included in a portion of the resin cover 100b by insert molding or the like.

[0075] <Overview of First Embodiment>

[0076] When the non-directional zero-order resonant antenna 20R shown in the reference example is applied to Fig.11 In the illustrated electronic device 10 , the reflection characteristics of the zero-order resonant antenna 20R are affected by reflection from the metal portion of the housing 100 .

[0077] The metal shell 100a provides a small space for setting the zero-order resonant antenna 20. The metal shell 100a has an opening 100c at one end in the X direction. Metal reflects radio waves. The metal shell 100a is a metal body that limits the propagation direction of radio waves to the direction shown by the white arrow, that is, the direction toward the opening 100c. Radio waves are transmitted and / or received from the outside of the electronic device 10 through the opening 100c formed at the end of the metal body.

[0078] In the present embodiment, in the zero-order resonant antenna 20 provided in the housing 100, the power supply line 70 extends in a direction from the edge portion of the relative conductor 50 toward the opening 100c. Specifically, in a plan view, the power supply line 70 extends along a virtual straight line connecting the basic center of the relative conductor 50 in the Y direction and the basic center of the width of the opening 100c in the Y direction. As a result, the zero-order resonant antenna 20 is not non-directional in the XY plane, but has a directivity biased toward the opening 100c. For example, the zero-order resonant antenna 20 radiates radio waves mainly toward the opening 100c (resin cover 100b). Therefore, the degradation of the reflection characteristics due to the metal shell 100a can be suppressed.

[0079] The extending direction of the power supply line 70 is not limited to Fig.11 The extending direction can be appropriately set according to the positional relationship with the opening 100c. 7A to 10B As shown, directivity can be provided in the extending direction of the power supply line 70. According to this embodiment, the extending direction of the power supply line 70 can be set to the direction from the opposing conductor 50 toward the opening 100c, so that the design of the zero-order resonant antenna 20 can be simplified.

[0080] The housing 100 in which the propagation direction is restricted by the local arrangement of metal is not limited to the above example. For example, the housing 100 in which a metal film or the like is partially formed on the inner surface and / or the outer surface of a resin molded body may also be adopted.

[0081] (Second embodiment)

[0082] The second embodiment is a modification of the previous embodiment as a basic configuration, and the description of the previous embodiment can be incorporated. In the previous embodiment, the opposing conductor 50 has a square shape. Instead of this, a slit may be provided in the opposing conductor 50.

[0083] Fig.12 1 is a plan view showing the zero-order resonant antenna 20 in the electronic device 10 of the present embodiment. Fig.12 In the figure, for convenience, the base member 30 is omitted. Fig.12 As shown, at least one slit 51 is provided in the opposing conductor 50. The slit 51 has a predetermined depth in the Z direction and opens at an edge of the opposing conductor 50.

[0084] The slit 51 of the present embodiment penetrates the opposing conductor 50 in the Z direction. The opposing conductor 50 has two slits 51. The two slits 51 are provided so that the opposing conductor 50 has double symmetry around the Z axis. The two slits 51 are provided so as to sandwich the short-circuit portion 60 in the plan view, in other words, sandwich the substantial center of the opposing conductor 50 in the Y direction. The slits 51 are open on two opposite sides to which the power supply line 70 is not connected.

[0085] The extension length and width of the two slits 51 are equal to each other. The slit 51 divides the relative conductor 50 into a first relative portion 50a and a second relative portion 50b. The first relative portion 50a and the second relative portion 50b have the same shape and area. The part sandwiched by the two slits 51 forms a connecting portion 50c connecting the first relative portion 50a and the second relative portion 50b. The relative conductor 50 includes the first relative portion 50a, the second relative portion 50b and the connecting portion 50c. The extension length of the slit 51 in the Y direction is longer than the length of the connecting portion 50c, and the width of the slit 51 is shorter than the width of the first relative portion 50a and the second relative portion 50b. The relative conductor 50 forms a substantially square plane, wherein each part of the slit 51 is removed from the square.

[0086] Fig.13 is an equivalent circuit diagram of the zero-order resonant antenna 20. Fig.13 In the figure, for convenience, some circuit elements are omitted, for example, an inductor included in the relative conductor 50. Fig.13 As shown, the zero-order resonant antenna 20 has a parallel resonant structure of an inductor L1 included in the short-circuit portion 60 and a capacitor C1 formed between the ground plate 40 and the opposing conductor 50. A capacitor C2 is formed between the first opposing portion 50a and the second opposing portion 50b by providing the slits 51. The capacitor C2 is a parallel circuit of capacitors formed in each of the two slits 51. The capacitor C2 is connected in series with the capacitor C1.

[0087] <Overview of Second Embodiment>

[0088] In the present embodiment, by providing the slit 51 in the opposing conductor 50, the area of ​​the opposing conductor 50 is reduced, and the capacitance of the capacitor C1 is reduced. On the other hand, due to the slit 51, the capacitor C2 is connected in series with the capacitor C1. Therefore, the number of variables determining the total capacitance increases. The capacitance of the capacitor C2 can be set by, for example, at least one of the extension length, width, and depth of the slit 51.

[0089] By providing the capacitor C2 in this manner, the degree of freedom in designing the zero-order resonant antenna 20 is improved. Therefore, the reflection characteristics can be improved compared to a configuration without the slit 51. In addition, the relative conductor 50 can be miniaturized. By, for example, miniaturizing the circuit board, the degree of freedom in setting the relative conductor 50 can be increased. Specifically, the relative conductor 50 can be set in a narrower space.

[0090] The shape, size, arrangement and number of the slits 51 are not limited to the above examples. For example, the positions of the two slits 51 may be offset from each other. The slits 51 may be arranged to open on one side substantially parallel to the Y direction. Only one slit 51 may be arranged, or three or more slits 51 may be arranged. The slits 51 are not limited to straight lines. For example, a slit 51 having a substantially L-shape in a plan view may be adopted. As described above, when the slits 51 are arranged so as to have a double symmetry relative to the conductor 50, the bias of the electric field distribution can be suppressed. Fig.12 The zero-order resonant antenna 20 of the structure shown has a radiation characteristic, that is, directivity in the X direction, which is the extending direction of the power supply line 70, in the same manner as in the previous embodiment. Figure 1 The construction shown is similar.

[0091] In the above example, the slit 51 penetrates the opposing conductor 50 in the Z direction. However, the structure of the slit 51 is not limited to the above example. The slit 51 may have a groove shape, which is provided midway in the depth of the opposing conductor 50. Even in this structure, the capacitor C2 is formed between the opposing surfaces of the first opposing portion 50a and the second opposing portion 50b.

[0092] As described in the previous embodiment, the planar shape of the opposing conductor 50 is not limited to a square. The slit 51 may also be combined with an opposing conductor 50 other than a square shape.

[0093] (Third Embodiment)

[0094] The third embodiment is a modification of the previous embodiment as a basic configuration, and can be incorporated into the description of the previous embodiment. In the previous embodiment, an example of performing wireless communication with the outside of the housing has been described. Instead of this, the present disclosure can be applied to a configuration in which wireless communication is performed inside the housing.

[0095] The electronic device 10 of the present embodiment is a battery module applied to an electric vehicle such as an electric vehicle and a plug-in hybrid vehicle. The electronic device 10 constitutes an on-board power supply device. The electronic device 10 supplies power to the electrical load of the vehicle. The battery module is sometimes referred to as a battery pack. In the vehicle, the electronic device 10 can be set, for example, in the space under the front seats, the space under the rear seats, the space between the rear seats and the trunk, etc.

[0096] <Battery Module>

[0097] First, refer to Fig.14 and Fig.15 A schematic configuration of a battery module (electronic device 10) is described. Fig.14 In the figure, for the sake of convenience, the elements inside the housing 100 are shown with solid lines. Fig.15 Viewed from the X1 direction Fig.14 Side view of.

[0098] The electronic device 10 (battery module) includes a housing 100, a plurality of battery stacks 110, a plurality of individual monitors 114, and an integrated monitor 115. The housing 100 is a metal housing formed of a metal such as aluminum. All walls, namely the side walls 101-104, the lower wall 105, and the upper wall 106 are made of metal. The housing 100 accommodates the battery stacks 110, the individual monitors 114, and the integrated monitor 115. The housing 100 has a substantially rectangular shape in a plan view.

[0099] The electronic device 10 includes two battery stacks 110. Each battery stack 110 has a plurality of battery cells 111, a battery box 112, and a plurality of bus bars 113. The battery box 112 accommodates the battery cells 111. The battery box 112 is formed of metal, for example. The battery box 112 has a box shape with one surface open. The battery box 112 has a substantially rectangular shape in a plan view, and is open on one side in the Z direction.

[0100] Each battery cell 111 is a secondary battery that generates an electric voltage through a chemical reaction. As a secondary battery, for example, a lithium-ion secondary battery can be used. The battery cells 111 are stacked and arranged in a direction orthogonal to the Z direction. In this embodiment, the battery cells 111 are stacked in the X direction. Each battery cell 111 has electrode terminals (not shown) near both ends in the Y direction on the upper surface. Fig.14 , for convenience, the battery unit 111 accommodated in the battery box 112 is shown integrally.

[0101] Each bus bar 113 is a plate-shaped metal member made of copper or the like. Each bus bar 113 is connected to an electrode terminal of a battery cell 111. The bus bars 113 include bus bars 113a, 113b, and 113c. Most of the bus bars 113 are bus bars 113a. Each bus bar 113a electrically connects the electrode terminals of two adjacent battery cells 111 in the X direction. The battery cells 111 housed in the common battery case 112 are electrically connected in series through the bus bars 113a to form an assembled battery. Although a gap is provided between adjacent bus bars 113a in the X direction, for convenience, the bus bars 113a are spaced apart from each other. Fig.14 The bus bar 113a is shown as a whole in FIG.

[0102] The bus bar 113b electrically connects the battery cells 111 of different battery stacks 110. The bus bar 113b of the present embodiment electrically connects the battery cells 111 disposed at the ends close to the side wall 102 in two battery stacks 110 adjacent to each other in the Y direction. The assembled batteries included in each battery stack 110 are electrically connected in series through the bus bar 113b. The bus bar 113b is a common bus bar 113 in the two battery stacks 110.

[0103] The bus bar 113c is electrically connected to power supply lines (positive line, negative line) not shown. The bus bar 113c also extends in the X direction. The power supply lines not shown are connected to the battery stack 110 with the highest potential and the battery stack 110 with the lowest potential via the bus bar 113c, respectively. In the present embodiment, one of the battery stacks 110 is the battery stack with the highest potential, and the other battery stack 110 is the battery stack with the lowest potential. The bus bars 113c are respectively connected to the battery cells 111 arranged at the ends near the side walls 101 in the two battery stacks 110. A gap is provided between the adjacent bus bars 113a and 113c in the X direction, but Fig.14 , for convenience, the bus bars 113a and 113c are shown integrally.

[0104] Each battery stack 110 has a substantially planar shape, wherein the X direction is the stacking direction of the battery cells 111, the X direction is the longitudinal direction, and the Y direction is the transverse direction. The battery stack 110 is fixed to, for example, the lower wall 105 of the housing 100. Two battery stacks 110 are arranged side by side in the Y direction as the transverse direction. One of the battery stacks 110 is arranged near the side wall 103 in the Y direction. In the Y direction, one end of each battery stack 110 is located near the side wall 101, and the other end is located near the side wall 102.

[0105] Individual monitors 114 are provided for the respective battery stacks 110. The individual monitors 114 have a function of acquiring physical quantities of the battery cells 111 and outputting the physical quantities to the integrated monitor 115. The individual monitors 114 have a function of performing equalization processing. The individual monitors 114 are provided on the corresponding battery stacks 110, respectively.

[0106] The electronic device 10 includes a sensor (not shown) that detects a physical quantity of each battery cell 111. Examples of the sensor include a voltage sensor, a temperature sensor, and a current sensor. The voltage sensor detects an output voltage of each battery cell 111. The temperature sensor detects a temperature of at least one battery cell 111. The current sensor detects a current that flows commonly to the battery cells 111 connected in series.

[0107] Each individual monitor 114 acquires the detection result of the sensor, assigns an identification code for identifying which battery stack 110 is to be detected to the acquired detection result, and generates a monitoring signal. Each individual monitor 114 includes a zero-order resonant antenna 20 and a power supply circuit, that is, the wireless device described in the previous embodiment. Hereinafter, the zero-order resonant antenna 20 included in each individual monitor 114 may be referred to as a zero-order resonant antenna 20S. The monitoring signal is modulated in the power supply circuit and radiated (transmitted) from the zero-order resonant antenna 20S to the accommodation space of the housing 100 as a radio wave carrying the signal. The two individual monitors 114 respectively transmit monitoring signals for the corresponding battery stacks 110. The individual monitor 114 corresponds to the second wireless device.

[0108] The integrated monitor 115 also includes a zero-order resonant antenna 20 and a power supply circuit. Hereinafter, the zero-order resonant antenna 20 included in the integrated monitor 115 may be referred to as a zero-order resonant antenna 20M. The zero-order resonant antenna 20M receives the radio waves radiated by each zero-order resonant antenna 20S. The radio waves are demodulated and converted into digital signals in the power supply circuit. In this way, the integrated monitor 115 converts the radio waves output from the individual monitors 114 into digital signals. The integrated monitor 115 corresponds to a first wireless device. The integrated monitor 115 outputs the converted digital signal to the battery ECU 200. The integrated monitor 115 and the battery ECU 200 are configured to be able to communicate with each other via the bus 201.

[0109] The integrated monitor 115 is disposed side by side with the battery stack 110 in the Y direction. The integrated monitor 115 is disposed near the corner of the side walls 102 and 104. The integrated monitor 115 is fixed to the lower wall 105 of the housing 100 via a support member 107, for example.

[0110] The battery ECU 200 calculates the state of charge (SOC) of the electronic device 10 (battery module) based on the input digital signal. The battery ECU 200 determines the charge or discharge state of the electronic device 10 based on the detected SOC and vehicle information input from other vehicle ECUs, vehicle sensors, etc.

[0111] Furthermore, the battery ECU 200 calculates the SOC of each battery cell 111 included in each battery stack 110. Then, the battery ECU 200 determines whether it is possible to perform the SOC equalization process of each battery cell 111. The battery ECU 200 outputs a command signal to the integrated monitor 115 based on the confirmation of the equalization process.

[0112] The integrated monitor 115 radiates the input command signal into the accommodation space of the housing 100 via the zero-order resonant antenna 20M. The command signal includes the above-mentioned identification code. Therefore, in the individual monitor 114, only the individual monitor 114 corresponding to the identification code receives the radio wave. The individual monitor 114 includes a switching element (not shown) for charging and discharging each battery cell 111 individually. The individual monitor 114 controls the driving of the switching element based on the command signal. Therefore, the battery cells 111 are charged and discharged individually. As a result, the SOCs of the plurality of battery cells 111 are balanced.

[0113] <Zero-order resonant antenna and directivity>

[0114] Will refer to Figures 14 to 16B The installation and directivity of the zero-order resonant antennas 20M and 20S will be described. Fig.16A and Fig. 16B 2 is a diagram showing the relationship between the extending direction of the feed line 70 of the zero-order resonant antenna 20M and the radiation characteristics.

[0115] In the battery stack 110, the bus bar 113 is arranged so that radio waves of the operating frequency do not leak from portions adjacent to each other in the X direction. The bus bar row 113L in which the bus bar 113 is arranged in the X direction acts as one metal body in terms of electromagnetics. Therefore, the bus bar row 113L (bus bar 113) limits the direction in which radio waves propagate.

[0116] Each battery stack 110 includes two bus bars 113L. The zero-order resonant antenna 20S is provided between the bus bars 113L on the upper surface of the corresponding battery stack 110. The bus bar 113L (bus bar 113) corresponds to a metal body and a metal member accommodated in a case.

[0117] In this way, the bus bar 113L (bus bar 113) is arranged on both sides of the zero-order resonant antenna 20S in the Y direction to sandwich the zero-order resonant antenna 20S. A separate monitor 114 including the zero-order resonant antenna 20S is arranged on the upper surface of the battery stack 110. The height of the electronic device 10 in the Z direction is low. In the thin electronic device 10, the distance between the zero-order resonant antenna 20S and the upper wall 106 of the shell 100 is narrow. The zero-order resonant antenna 20S is arranged in a space 120 formed by the shell 100 (upper wall 106) and the two bus bars 113L (bus bar 113). Fig.15 In FIG. 1 , a region surrounded by a dashed line is a space 120. The space 120 extends in the X direction along the bus bar 113L. The X direction corresponds to the first direction.

[0118] In the space 120, the direction in which the radio waves propagate is limited by the metal body including the bus bar 113L and the housing 100. Specifically, the direction in which the radio waves propagate is limited at the end of the space 120. The metal body has an opening 120a, which is one of the ends of the space 120. The opening 120a is formed at the end of the bus bar 113L (bus bar 113) in the extension direction, specifically at the end close to the side wall 102. Fig.14 , the opening 120a is indicated by a double-dashed dashed line.

[0119] The zero-order resonant antenna 20S has the same configuration as that of the second embodiment. The opposing conductor 50 has a substantially square shape provided with a slit 51. The power supply line 70 extends from the edge of the opposing conductor 50 in a direction toward the opening 120a. Specifically, in a plan view, the power supply line 70 extends along a virtual straight line connecting the substantial center of the opposing conductor 50 in the Y direction and the substantial center of the width of the opening 120a in the Y direction. The extending direction of the power supply line 70 is substantially parallel to the X direction. Therefore, each zero-order resonant antenna 20S has directivity in a direction toward the opening 120a. Fig.14 The dashed-dotted arrows shown indicate the direction of directivity of the zero-order resonant antenna 20S.

[0120] For example, the radio waves radiated from the zero-order resonant antenna 20S travel along the Fig.14 The radio waves propagate in the direction indicated by the dashed dotted arrow in the figure and are radiated to the outside from the opening 120a. Since the radio waves are reflected by the side walls 102 and 103, the radio waves radiated from the opening 120a propagate toward the side wall 104 through the gap (space) between the battery stack 110 and the side wall 102 and are received by the zero-order resonant antenna 20M.

[0121] In the Y direction, the battery box 112 and the bus bar 113L as metal bodies are arranged between the integrated monitor 115 (i.e., the zero-order resonant antenna 20M) and the zero-order resonant antenna 20S. Therefore, the propagation direction of the radio waves is limited. The Y direction corresponds to the second direction. For example, a gap is provided between the end face of the metal body (battery box 112) closest to the zero-order resonant antenna 20M in the Y direction and the side wall 102. In this way, the battery box 112 and the housing 100 including the side wall 102 form a space 121 capable of propagating radio waves.

[0122] The space 121 extends in the Y direction along the end surface of the battery box 112. In the space 121, the propagation direction of the radio wave is limited by the metal body including the battery box 112 and the housing 100. Specifically, the propagation direction of the radio wave is limited to the end of the space 121. The metal body has an opening 121a as one of the ends of the space 121. The opening 121a is provided at the end of the side of the battery box 112 close to the side wall 104. Fig.14 In FIG. 1 , the opening 121 a is indicated by a two-dot chain dashed line.

[0123] like Fig.14 and 16A As shown, the zero-order resonant antenna 20M includes a counter conductor 50 having a substantially square shape, which is provided with a slit 51 in a similar manner to the zero-order resonant antenna 20S. A power supply line 70 extends from the edge of the counter conductor 50 in a direction toward the opening 121a. The zero-order resonant antenna 20M is disposed closer to the side wall 104 than the two zero-order resonant antennas 20S. In a plan view, the basic center of the counter conductor 50 and the basic center of the width of the opening 121a are offset in the X direction. Therefore, the power supply line 70 extends to have an X-direction component and a Y-direction component. The power supply line 70 has an X-direction extending portion and a Y-direction extending portion, and a combination of the X-direction extending portion and the Y-direction extending portion extends in the direction of the opening 121a.

[0124] The power supply line 70 has a substantially L-shaped shape in a plan view. The power supply line 70 extends from the edge of the opposite conductor 50 toward the side wall 103 in the Y direction, and extends toward the side wall 101 in the X direction on the way. Fig. 16B As shown, the zero-order resonant antenna 20M has an inclined directivity with an X-direction component and a Y-direction component. Fig.14 The dashed double-dashed line arrows shown indicate the direction of directivity of the zero-order resonant antenna 20M. The null point (NULL) is inclined to the opposite side of the power supply line 70. The zero-order resonant antenna 20M has directivity biased toward the opening 121a.

[0125] For example, the radio waves radiated from the zero-order resonant antenna 20M are Fig.14 The radio waves propagate in the direction indicated by the double-dashed dashed arrow in FIG. 1 and propagate through the opening 121a to the gap (space) between the battery stack 110 and the side wall 102. The radio waves propagate in the space 120 connected to the gap and are received by the zero-order resonant antenna 20S.

[0126] <Overview of Third Embodiment>

[0127] When the above-described non-directional zero-order resonant antenna 20R is used, the reflection characteristics of both the individual monitor 114 and the integrated monitor 115 are deteriorated due to the influence of reflection by the housing 100 made of metal.

[0128] In the present embodiment, in each of the zero-order resonant antennas 20M and 20S, the power supply line 70 extends in a direction from the opposing conductor 50 toward the opening of the metal body. Therefore, the zero-order resonant antennas 20M and 20S have directivities biased toward the corresponding openings. Therefore, in a configuration in which a plurality of wireless devices perform wireless communication in the housing 100 made of metal, degradation of reflection characteristics can be suppressed.

[0129] In the present embodiment, a zero-order resonant antenna 20S of a separate monitor 114 is provided in a space 120 defined by a bus bar 113L (bus bar 113) and a housing 100 (upper wall 106). In this configuration, a power supply line 70 of the zero-order resonant antenna 20S extends in a direction from the opposing conductor 50 toward the opening 120a. Therefore, the zero-order resonant antenna 20S has directivity in the direction of the opening 120a. Therefore, degradation of the reflection characteristic of the zero-order resonant antenna 20S can be suppressed.

[0130] In the present embodiment, a battery box 112 and a bus bar 113L (bus bar 113) as a metal body are provided between the zero-order resonant antenna 20M and the zero-order resonant antenna 20S of the integrated monitor 115, and the propagation direction of the radio wave is restricted. In this configuration, the power supply line 70 of the zero-order resonant antenna 20M extends toward the opening 121a formed by providing an opening for the battery box 112 (metal body). Therefore, the zero-order resonant antenna 20M has directivity in the direction of the opening 121a. Therefore, the degradation of the reflection characteristics of the zero-order resonant antenna 20M can be suppressed.

[0131] As in the previous examples (see Fig. 10A ), directivity in the oblique direction can be set for the zero-order resonant antenna 20M by extending the power supply line 70 in the oblique direction from the corner portion of the relative conductor 50. In this case, the power supply line 70 can be set along a virtual straight line in a plan view, which connects the basic center of the relative conductor 50 and the basic center of the width of the opening 121a. However, as in the present embodiment, by setting the power supply line 70 in a manner having an X-direction extending portion and a Y-direction extending portion, the degree of freedom of design can be improved. For example, even when the power supply line 70 cannot be extended in the oblique direction due to power supply, power supply can be performed. The directivity can be adjusted by balancing the lengths of the X-direction extending portion and the Y-direction extending portion.

[0132] The configuration of the electronic device 10 (battery module) is not limited to the above example. For example, the number of battery stacks 110, the arrangement of battery stacks 110, the number of battery cells 111, the electrical connection structure of battery cells 111, etc. are not limited to the above example. The number of individual monitors 114 is also not limited to the above example.

[0133] An example has been described in which the opposing conductor 50 is provided with the slit 51, but the opposing conductor 50 may have a different structure. The zero-order resonant antenna 20 shown in the first embodiment which does not have the slit 51 may also be employed.

[0134] An example of applying the electronic device 10 to a battery module has been described, but the application of the present disclosure is not limited to a battery module. The present disclosure can be applied to any electronic device having a configuration for performing wireless communication in a housing 100 made of metal. In addition, an example of a bus bar 113L in which bus bars 113 are arranged side by side has been described as a metal member provided in a housing 100 made of metal, and the metal member is not limited to the bus bar 113L. The metal member may be composed of one member. In addition, a metal shell of an electronic component provided in the housing 100, a wiring member, etc. may be used as the metal member.

[0135] (Fourth embodiment)

[0136] The fourth embodiment is a modification of the previous embodiment as a basic configuration, and can be incorporated into the description of the previous embodiment. In the previous embodiment, each zero-order resonant antenna 20 has only one power supply line. The zero-order resonant antenna 20 may have a plurality of power supply lines.

[0137] Fig.17 FIG. 2 shows the zero-order resonant antenna 20 of this embodiment. Fig.17 , for convenience, the base member 30 is omitted. The zero-order resonant antenna 20 has a plurality of power supply lines 70. In a plan view, the plurality of power supply lines 70 extend in different directions from different positions on the edge of the opposing conductor 50 to surround the opposing conductor 50.

[0138] Specifically, the power supply line 70 includes four power supply lines 70a, 70b, 70c and 70d. Each power supply line 70 extends along a virtual straight line connecting the basic center of the opposite conductor 50 and the basic center of each side of the square. The power supply line 70a extends in the X direction from one of the sides substantially parallel to the Y direction, and the power supply line 70b extends from the opposite side of the Y direction to the side opposite to the power supply line 70a. The power supply line 70c extends in the Y direction from one of the sides substantially parallel to the X direction, and the power supply line 70d extends from the opposite side of the X direction to the side opposite to the power supply line 70c. The plurality of power supply lines 70 are arranged radially.

[0139] The zero-order resonant antenna 20 also includes a power supply controller 80. The configuration other than the number of power supply lines 70 and the power supply controller 80 is the same as that of the zero-order resonant antenna 20 described in the previous embodiment. The power supply controller 80 controls the power supply to the plurality of power supply lines 70. The power supply controller 80 includes a plurality of switches 81 and a switch controller 82. Each switch 81 switches the connection state between the corresponding power supply line 70 and the power supply circuit to on or off. When each switch 81 is turned on, the corresponding power supply line 70 becomes conductive with the power supply circuit, and current is input from the power supply circuit to the corresponding power supply line 70. When each switch 81 is turned off, the power supply from the power supply circuit to the corresponding power supply line 70 is cut off.

[0140] The switches 81 are provided for the power supply lines 70, respectively. The power supply controller 80 has switches 81a, 81b, 81c, and 81d. The switch 81a is provided corresponding to the power supply line 70a, and the switch 81b is provided corresponding to the power supply line 70b. The switch 81c is provided corresponding to the power supply line 70c, and the switch 81d is provided corresponding to the power supply line 70d. As each switch 81, for example, a MOSFET or the like can be used.

[0141] The switch controller 82 controls the on-off state of each switch 81. The switch controller 82 controls the on-off state of all switches 81, and in response to an external command signal, makes a part of the switches 81 turned on and the rest of the switches 81 turned off. Fig.17 When the directivity is biased in the direction indicated by the white arrow, the switch controller 82 controls the switches 81a and 81c to be in the on state and controls the switches 81b and 81d to be in the off state through the command signal. Therefore, in the power supply line 70, power is supplied to the relative conductor 50 via the power supply lines 70a and 70c, and power is not supplied from the power supply lines 70b and 70d. In the power supply line 70, the power supply lines 70a and 70c are used as basic power supply lines. The power supply line 70a extends in the X direction, and the power supply line 70c extends in the Y direction. Therefore, the combination of the X-direction component and the Y-direction component provided by the two power supply lines 70a and 70c can provide directivity in the direction of the white arrow.

[0142] Fig.18 An example of an electronic device 10 provided with the above-described zero-order resonant antenna 20 is shown. The electronic device 10 includes a housing 100 made of metal, two wireless devices, and a metal member 122. The wireless devices and the metal member 122 are accommodated in the housing 100. Each wireless device includes the zero-order resonant antenna 20 having the above-described configuration. Fig.18 In the figure, for convenience, only the zero-order resonant antenna 20 in the wireless device is drawn. Fig.17 In a similar manner, the base member 30 is omitted. Two zero-order resonant antennas 20 (wireless devices) are arranged side by side in the Y direction. The structure and arrangement of the zero-order resonant antenna 20 are similar to Fig.17 Hereinafter, the zero-order resonant antenna 20 close to the side wall 103 may be referred to as a zero-order resonant antenna 20A, and the zero-order resonant antenna 20 close to the side wall 104 may be referred to as a zero-order resonant antenna 20B.

[0143] The metal member 122 is, for example, a metal shell of an electronic component disposed in the housing 100, such as a wiring member of a bus bar, etc. In a plan view, the metal member 122 is disposed between the two zero-order resonant antennas 20. The metal member 122 extends in the X direction and limits the propagation direction of the radio wave. A space 123 is provided between the end surface of the metal member 122 and the housing 100 including the side wall 101.

[0144] The space 123 extends in the Y direction along the end surface of the metal member 122. In the space 123, the propagation direction of the radio waves is limited by the metal body including the metal member 122 and the housing 100. Specifically, the propagation direction of the radio waves is limited to the end of the space 123. The metal body has openings 123a and 123b as the ends of the space 123. The opening 123a is provided at the end of the side of the metal member 122 close to the side wall 103. The opening 123b is provided at the end of the side of the metal member 122 close to the side wall 104. Fig.18 In FIG. 1 , the openings 123 a and 123 b are shown by double-dashed dashed lines.

[0145] The relative conductor 50 and the opening 123a of the zero-order resonant antenna 20A are offset in the X and Y directions. In the plan view, the direction from the relative conductor 50 toward the opening 123a is located between the two power supply lines 70a and 70d. In other words, in the plan view, a virtual straight line connecting the basic center of the relative conductor 50 and the basic center of the width of the opening 123a is located between the power supply lines 70a and 70d. In this case, the command signal for turning on the switches 81a and 81d and turning off the switches 81b and 81c is input to the switch controller 82.

[0146] When receiving the instruction signal, the switch controller 82 controls the switches 81a and 81d to be in the on state and the switches 81b and 81c to be in the off state. Therefore, power is supplied from the power supply lines 70a and 70d, and power is not supplied from the power supply lines 70b and 70c. Due to the combination of the X-direction component and the Y-direction component provided by the two power supply lines 70a and 70d, the zero-order resonant antenna 20A has a directivity biased in the direction of the dashed-dotted arrow, that is, a directivity biased in the direction toward the opening 123a.

[0147] Similarly, the relative conductor 50 and the opening 123b of the zero-order resonant antenna 20B are offset in the X and Y directions. In the plan view, the direction from the relative conductor 50 toward the opening 123b is located between the two power supply lines 70a and 70c. In other words, in the plan view, a virtual straight line connecting the basic center of the relative conductor 50 and the basic center of the width of the opening 123b is located between the power supply lines 70a and 70c. In this case, the command signal for turning on the switches 81a and 81c and turning off the switches 81b and 81d is input to the switch controller 82.

[0148] When receiving the instruction signal, the switch controller 82 controls the switches 81a and 81c to be in the on state, and the switches 81b and 81d to be in the off state. Therefore, power is supplied from the power supply lines 70a and 70c, and power is not supplied from the power supply lines 70b and 70d. Due to the combination of the X-direction component and the Y-direction component provided by the two power supply lines 70a and 70c, the zero-order resonant antenna 20B has a directivity biased in the direction of the arrow of the double-dashed dashed line, that is, a directivity biased in the direction toward the opening 123b.

[0149] <Overview of Fourth Embodiment>

[0150] According to the present embodiment, the power supply controller 80 can select a portion of the power supply line 70 to supply power to the opposing conductor 50, thereby having directivity in the direction toward the opening. Therefore, it is not necessary to pattern the power supply line 70 according to the positional relationship between the opposing conductor 50 of the zero-order resonant antenna 20 and the opening of the metal body. For example, in a configuration in which wireless communication is performed within the housing 100 as in the present embodiment, the zero-order resonant antennas 20A and 20B can be formed to have a common configuration.

[0151] In the present embodiment, two power supply lines 70 sandwiched in the direction from the opposing conductor 50 toward the corresponding openings 123a, 123b in a plan view are powered, and the remaining two power supply lines 70 are not powered, so as to achieve the desired directivity. However, in another example, power may be supplied only to the power supply line 70 whose extending direction is closest to the direction from the opposing conductor 50 toward the corresponding openings 123a and 123b, and power may not be supplied to the remaining three power supply lines 70. For example, when the direction from the opposing conductor 50 toward the corresponding openings 123a and 123b, that is, the extending direction of the above-mentioned virtual straight line and one of the power supply lines 70 substantially coincide with each other, power may be supplied only to one of the power supply lines 70.

[0152] The number of power supply lines 70 is not limited to the above examples. Fig.19 In the modification shown, 16 power supply lines 70 are electrically connected to the opposite conductor 50 having a rectangular shape. In a plan view, the power supply lines 70 extend in different directions from different positions on the edge of the opposite conductor 50 to surround the opposite conductor 50. Specifically, the power supply lines 70 extend along a virtual straight line that passes through the substantial center of the opposite conductor 50. The power supply lines 70 are arranged in a radial direction with respect to the opposite conductor 50. Switches 81 are provided for the power supply lines 70, respectively. A switch controller 82 (not shown) controls the on-off state of all the switches 81.

[0153] As described above, as the number of power supply lines 70 increases, the possibility of one of the power supply lines 70 and the direction from the opposite conductor 50 toward the opening coinciding with each other increases. Therefore, desired directivity can be obtained by supplying power to a small number of power supply lines 70, preferably only one of them.

[0154] As described above, the planar shape of the opposing conductor 50 is not limited to a rectangle. In the case of an equilateral triangle or a circle, at least three power supply lines 70 may be provided. By arranging the three power supply lines 70 so that the central angle is about 120 degrees relative to the substantial center of the opposing conductor 50, directivity may be provided in any direction orthogonal to the Z direction.

[0155] (Other embodiments)

[0156] The contents disclosed in the specification and drawings, etc. are not limited to the above-mentioned embodiments. The present disclosure covers the above-mentioned embodiments and modifications based on the above-mentioned embodiments by those skilled in the art. For example, the present disclosure is not limited to the combination of parts and components shown in the embodiments. The present disclosure can be implemented in various combinations. The present disclosure may have additional components added to the embodiments. The present disclosure covers the omission of components and elements of the embodiments. The present disclosure covers the replacement or combination of parts, elements of one of the embodiments with other embodiments. The disclosed technical scope is not limited to the description of the embodiments. The several disclosed technical scopes are represented by the description of the claims and should be interpreted as including all modifications within the meaning and scope equivalent to the description of the claims.

[0157] The disclosure of the specification, drawings, etc. is not limited by the description of the claims. The disclosure of the specification, drawings, etc. covers the technical concepts described in the claims, and further extends to technical concepts that are broader than the technical concepts in the claims. Therefore, various technical concepts can be extracted from the disclosure of the specification, drawings, etc. without being limited to the description of the claims.

[0158] When an element or layer is described as "placed above" or "connected", the element or layer may be directly placed above another element or another layer or directly connected to another element or another layer, or there may be an intermediate element or intermediate layer. On the contrary, when an element or layer is described as "directly located above" or "directly connected", there is no intermediate element or intermediate layer. Other terms used to describe the relationship between elements (for example, "between..." and "directly between...", and "adjacent" and "directly adjacent") should also be interpreted similarly. As used herein, the term "and / or" includes any combination and all combinations of one or more related listed items. For example, the term A and / or B includes only A, only B, or both A and B.

[0159] Spatially relative terms such as "inside," "outside," "back," "bottom," "lower," "upper," "higher," and the like are used herein to help describe the relationship between one element or feature and another element or feature. In addition to the orientation depicted in the drawings, the spatially relative terms may be intended to include different orientations of the device in use or operation. For example, when the device in the drawings is turned over, an element or feature described as being "below" or "directly below" another element or feature is oriented as being "above" the other element or feature. Thus, the term "below" may include above and below. The device may be oriented in another orientation (rotated 90 degrees or in any other orientation), and the spatially relative terms used herein should be interpreted accordingly.

[0160] An example has been described in which the zero-order resonant antenna 20 includes the base member 30 , but the present disclosure is not limited thereto. The zero-order resonant antenna 20 may also have a configuration without the base member 30 .

Claims

1. An electronic device, comprising: One or more zero-order resonant antennas (20), each zero-order resonant antenna comprising: a ground plate (40) configured to provide a ground potential; a counter conductor (50) arranged at a predetermined distance from the ground plate in a plate thickness direction of the ground plate; a power supply line (70) electrically connected to the opposing conductors; and a short-circuit portion (60) electrically connecting the opposing conductors and the ground plate; and a metal body configured to limit the propagation direction of radio waves transmitted or received by the one or more zero-order resonant antennas and having an opening, wherein In a plane orthogonal to the plate thickness direction, the feed line extends from an edge of the opposing conductor toward the opening so that the directivity of the zero-order resonant antenna is biased in the direction in which the feed line extends.

2. The electronic device according to claim 1, further comprising A housing (100) accommodating the one or more zero-order resonant antennas, wherein The housing includes a shell as the metal body which is made of metal and has the opening.

3. The electronic device according to claim 1, further comprising: A first wireless device (114) comprising one of the zero-order resonant antennas; a second wireless device (115) comprising another of the zero-order resonant antennas and configured to perform wireless communication with the first wireless device; a housing (100) made of metal and accommodating the first wireless device and the second wireless device; and A metal member (113) housed in the housing, wherein The metal body is at least one of the housing and the metal member.

4. The electronic device according to claim 3, wherein The metal member extends in a first direction perpendicular to the plate thickness direction and is located between the first wireless device and the second wireless device in a second direction perpendicular to the first direction and the plate thickness direction. The opening is provided between an end portion of the metal member and the housing facing the end portion, and In the zero-order resonant antenna in the first wireless device, the power supply line extends toward the opening.

5. The electronic device according to claim 3 or 4, wherein The metal member extends in a first direction orthogonal to the plate thickness direction, The zero-order resonant antenna in the second wireless device is arranged in a middle portion of a space (120) defined by the metal member and the housing and extending in the first direction, The opening is provided at an end of the metal member, and In the zero-order resonant antenna in the second wireless device, the power supply line extends toward the opening.

6. The electronic device according to any one of claims 1 to 4, wherein The power supply line includes a portion extending in a first direction orthogonal to the plate thickness direction and a portion extending in a second direction orthogonal to the plate thickness direction and the first direction.

7. An electronic device comprising: One or more zero-order resonant antennas (20), each zero-order resonant antenna comprising: a ground plate (40) configured to provide a ground potential; a counter conductor (50) arranged at a predetermined distance from the ground plate in a plate thickness direction of the ground plate; a plurality of power supply lines (70) electrically connected to the opposing conductor and extending from different positions of an edge of the opposing conductor in different directions to surround the opposing conductor in a plane orthogonal to the plate thickness direction; a short-circuit portion (60) electrically connecting the opposing conductors and the ground plate; and a power supply controller (80) configured to control power supply to the power supply line; and a metal body configured to limit the propagation direction of radio waves transmitted or received by the one or more zero-order resonant antennas and having an opening, wherein The power supply controller is configured to supply power to a portion of the power supply lines, the portion of the power supply lines including a power supply line extending closest to a direction from the opposing conductor toward the opening, or two power supply lines sandwiching the direction toward the opening in the plane.

Images