Antenna Device

Abstract

To provide an antenna device that resonates at a plurality of frequencies and has broadband radiation characteristics.SOLUTION: An antenna device operating at first and second operation frequencies comprises: a first conductor that has an opening having first and second sides substantially parallel to each other; and a feed line that is arranged separate from the opening. When seen from a lamination direction of the opening and the feed line, the feed line includes a first portion including an area from a first intersection between the first side and the feed line to an open end of the feed line, a second portion connecting a second intersection between the second side and the feed line and a power supply part to each other, and a third portion connecting the first intersection and the second intersection to each other to cross the opening obliquely. The distance from the second intersection to one end of the second side and the distance from the second intersection to the other end of the second side are different from each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] In recent years, there has been a remarkable trend toward using higher frequency bands and expanding bandwidth to handle large-volume data communications. Broadband antennas are required to support standards with these functions (such as wireless LAN).

[0003] As a slot antenna capable of handling a plurality of frequencies, for example, a dual-band slot antenna using a feed line and a shorting pin, as shown in Patent Document 1, is known. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2005-167827 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, these dual-band slot antennas have high frequency dependency and narrow-band antenna characteristics, which means that when wide frequencies such as the 2.4 GHz band and 5 to 7 GHz band are required for Wi-Fi 6E, it is difficult to obtain sufficient radiation efficiency characteristics in the corresponding frequency bands.

[0006] The present invention has been made in consideration of the above-mentioned problems, and has an object to provide an antenna device having wideband radiation characteristics that can operate at a plurality of frequencies. [Means for solving the problem]

[0007] In order to solve the above problems, the antenna device of the present invention comprises: 1. An antenna apparatus operating at first and second operating frequencies, comprising: a first conductor having an opening with first and second sides that are generally parallel; a feed line disposed apart from the opening; Equipped with When viewed from the lamination direction of the opening and the power supply line, the power supply line is a first portion including a first intersection between the first side and the power supply line and an open end of the power supply line; a second portion connecting a second intersection between the second side and the power supply line and a power supply portion; The opening At least a part of a third portion connecting the first intersection portion and the second intersection portion so as to diagonally straddle the Equipped with The distance from the second intersection to one end of the second side is different from the distance from the second intersection to the other end of the second side. Effect of the Invention

[0008] According to the present invention, it is possible to provide an antenna device having wideband radiation characteristics that can operate at a plurality of frequencies. [Brief description of the drawings]

[0009] [Figure 1] 1A and 1B are diagrams illustrating the overall configuration of an antenna device according to an embodiment of the present invention. [Diagram 2] (A) and (B) are schematic diagrams of a conventional antenna device. [Diagram 3] A comparison diagram of the radiation characteristics of the antenna devices shown in FIG. 1(A) and FIG. 2(A). [Figure 4] FIG. 1 is a diagram showing an example of an antenna device according to an embodiment of the present invention; [Diagram 5] 1A to 1C are diagrams showing an example of an antenna device according to an embodiment of the present invention. [Figure 6] FIG. 1 is a diagram showing an example of an antenna device according to an embodiment of the present invention; [Figure 7]1A and 1B are diagrams showing an example of an antenna device according to an embodiment of the present invention. [Figure 8] FIG. 1 is a diagram showing an example of an antenna device according to an embodiment of the present invention; [Figure 9] 1A and 1B are diagrams showing an example of an antenna device according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings. Note that the configurations shown in the following embodiments are merely examples, and the present invention is not limited to the illustrated configurations.

[0011] First Embodiment 1(A) and 1(B) are diagrams showing the overall configuration of an antenna device 1 according to this embodiment. Fig. 1(B) is a cross-sectional view of the YZ plane taken along dashed line AA' in Fig. 1(A).

[0012] The antenna device 1 includes a first conductor 101 , a dielectric material 105 , a feed line 106 and a feed portion 107 .

[0013] The first conductor 101 is provided with an opening 102 that functions as a radiating element of the slot antenna. The opening 102 has a first side 103 and a second side 104 in the longitudinal direction. In this embodiment, the opening 102 has a rectangular opening surface. At least one of the first side 103 and the second side 104 has a length equal to a half wavelength (λ1 / 2) of an electromagnetic wave of a first frequency f1 that is a resonant frequency.

[0014] A substrate 105 made of a dielectric is disposed at a position facing the opening 102, and a power feeder 106 and a power supply unit 107 are disposed on the substrate 105. The ground (GND) of the power supply unit 107 is electrically connected to the first conductor 101. In this embodiment, the power feeder 106 and the first conductor 101 are stacked in the Z direction. Here, as shown in FIG. 1B, the first conductor 101, the dielectric 105, and the power feeder 106 are illustrated as being stacked with a gap therebetween, but as long as the power feeder 106 and the first conductor 101 are spaced apart, a gap may be provided between them. In this embodiment, the Z direction is the stacking direction, which is a direction perpendicular to the opening surface of the opening 102. The Z direction may also be referred to as the direction penetrating the opening surface. In this specification, unless otherwise specified, the dielectric is 1 mm thick FR4-epoxy, and the power feeder is a 35 um thick copper thin film.

[0015] The feeder line 106 is a conductor disposed opposite the opening 102 so as to straddle the opening 102. The feeder line 106 includes a first portion (partial line) 108, a second portion 109, and a third portion 110, as viewed from the stacking direction. The first portion 108 is a partial line of the feeder line 106 including from an intersection 1081 where the first side 103 and the feeder line 106 intersect to an open end of the feeder line 106, as viewed from the stacking direction. The second portion 109 is a partial line of the feeder line 106 including from an intersection 1091 where the second side 104 and the feeder line 106 intersect to a feeding end, as viewed from the stacking direction. The third portion 110 is a partial line of the feeder line 106 that straddles the opening 102 diagonally, as viewed from the stacking direction. Here, the intersection 1091 is disposed at a position where the distance from one end of the second side 104 to the intersection 1091 is different from the distance from the other end of the second side 104 to the intersection 1091. In other words, the third portion 110 is disposed at a position shifted so as not to pass through the center of the opening 102.

[0016] Here, the first portion 108 has an electrical length equal to one-quarter (λ1 / 4) of the wavelength λ1 of the first frequency f1. The second portion 109 is disposed at a position one-half (λ2 / 2) of the wavelength λ2 of the resonating second frequency f2 from one vertex of the second side 104. Since the line length of the first portion 108 has an electrical length equal to λ1 / 4, the feeder line 106 and the opening 102 are electrically connected.

[0017] In this embodiment, if the first frequency f1, which is the first operating frequency of the antenna device 1, is 2.4 GHz, then λ1 / 2=49 mm and λ1 / 4=25 mm. In this case, the antenna device 1 functions as a slot antenna that operates in the 2.4 GHz band. If the second frequency f2, which is the second operating frequency of the antenna device 1, is 5.0 GHz, then λ2 / 2=32.5 mm. In this case, the antenna device functions as a dual-band slot antenna that also operates in the 5 GHz band. That is, the antenna device 1 functions as a dual-band antenna device that can operate at the first and second operating frequencies.

[0018] The first frequency f1 and the second frequency f2 can be changed as appropriate according to the operating frequency of the antenna device 1. The wavelength λ2 of the second frequency f2 only needs to be shorter than the wavelength λ1 of the first frequency f1.

[0019] When a signal is input from the power supply portion 107 to the power supply line 106, an electromagnetic field is formed at the opening 102 by the current propagating through the power supply line 106. As a result, a current path is generated along the periphery of the opening 102 at the first frequency f1, and a current path is generated from one vertex of the opening 102 to the periphery of the third portion 110 at the second frequency f2. In this manner, power is supplied from the power supply line 106 to the first conductor 101.

[0020] The feed line 106 has a third portion 110 that diagonally straddles the opening 102. The length from the intersection 1081 to the end of the first side 103 is different from the length from the intersection 1091 to the end of the second side 104. For this reason, when resonating at the second frequency f2, the frequency dependency is lower than that at the first frequency f1.

[0021] 2(A) and 2(B) show a configuration in which the third portion 110 of the feed line 106 is arranged so as to be perpendicular to the first side 103 and the second side 104 of the opening 102 when viewed from the Z direction. The first conductor 201 corresponds to the first conductor 101 in FIG. 1(A), the opening 202 corresponds to the opening 102 in FIG. 1(A), the first side 203 corresponds to the first side 103 in FIG. 1(A), and the second side 204 corresponds to the second side 104 in FIG. 1(A). The dielectric 205 corresponds to the dielectric 105 in FIG. 1(A), and the power supply portion 207 corresponds to the power supply portion 107 in FIG. 1(A). The power supply line 206 includes a first portion 208, a second portion 209, and a third portion 210. The configuration other than the third portion 210 is the same as that in FIG. 1(A) and FIG. 1(B), and therefore will not be described.

[0022] 2(A) and 2(B), when an electromagnetic wave of the first frequency f1 is fed from the power feed line 206, a current path is generated along the periphery of the opening 202. On the other hand, when an electromagnetic wave of the second frequency f2 is fed from the power feed line 206, a current path is generated from one vertex of the opening 202 to the periphery of the third portion 210.

[0023] However, since the feed line 206 has a third portion 210 that is perpendicular to the opening 202 when viewed from the stacking direction, the electrical path lengths are the same on the first side 203 and the second side 204. For this reason, the radiation efficiency characteristic of the antenna device at the second frequency f2 is narrower in band than the radiation efficiency characteristic of the antenna device 1 having the configuration in FIG.

[0024] The radiation efficiency characteristics calculated by simulation for each frequency for each of the antenna devices in Fig. 1(A) and Fig. 2(A) are shown in Fig. 3. In Fig. 3, the radiation efficiency characteristics of the antenna device 1 shown in Fig. 1(A) are shown by a solid line, and the radiation efficiency characteristics of the antenna device shown in Fig. 2(A) are shown by a dashed line.

[0025] As can be seen from FIG. 3, the bandwidth of the radiation efficiency characteristics in the low band (around 2.4 GHz) is almost the same, but in the high band (around 5 to 7 GHz), the bandwidth where a radiation efficiency of -3 dB or more can be obtained is about twice as large for the configuration in FIG. 1(A) compared to the configuration in FIG. 2(A).

[0026] As described above, according to this embodiment, the antenna device 1 resonates in different frequency bands corresponding to the respective current paths. In addition, by disposing the feeder line diagonally across the opening 102, the antenna device 1 can operate as a dual-band antenna that can obtain wideband radiation efficiency characteristics at the second frequency f2 that is higher than the first frequency f1.

[0027] In the present embodiment, the power feed line 106 is described as a strip line, but it may include a thin coaxial cable or a balun that converts an unbalanced connection to a balanced connection, or the power feed line 106 may be connected to the first conductor 101. In the present embodiment, the antenna device 1 is described as a transmitting antenna that transmits electromagnetic waves supplied from the power feed unit 107, but the antenna device 1 may be a receiving antenna that receives electromagnetic waves. In this case, the power feed unit 107 may be replaced with a high-frequency receiving circuit.

[0028] The materials, material thicknesses, shapes and other parameters shown here are merely examples, and all conditions that can obtain the same effects are included in the embodiments.

[0029] Second Embodiment FIG. 4 and FIG. 5(A) to FIG. 5(C) show an example of an antenna device according to this embodiment.

[0030] 4, an opening 402 that serves as a slot antenna element is provided in a housing 401 of an imaging device, which is a conductor having a space inside. The housing 401 is a conductor that forms a closed space inside, and may be formed by engaging, adhering, or joining a plurality of conductors. Note that, in this embodiment, the housing 401 is illustrated as the housing of the imaging device, but the antenna device according to this embodiment can be applied to the housing of a different device.

[0031] Fig. 5(A) shows a part of the housing 401 where the opening 402 is arranged. Fig. 5(B) is a cross-sectional view of the antenna device including the housing 401 in the YZ plane passing through the dashed line A-A' in Fig. 5(A). Fig. 5(C) is a cross-sectional view of the antenna device including the housing 401 in the XZ plane passing through the dashed line B-B' in Fig. 5(A).

[0032] The opening 402 has a first side 403 and a second side 404 in the longitudinal direction, and has an electrical length approximately equal to half (λ1 / 2) the wavelength λ1 of the first frequency f1. For example, when the first frequency is 2.4 GHz, λ1 / 2=49 mm, and λ1 / 4=25 mm. The first side 403 and the second side 404 of the opening 402 are approximately parallel to each other.

[0033] Inside the housing 401, a substrate 405 made of a dielectric material and built-in components 406 which are conductors are arranged at a position facing the opening surface of the opening 402. A power feed line 407, a power feed section 408, and a ground (GND) 409 of the power feed section are arranged on the substrate 405. Here, built-in components such as an imaging unit for functioning as an imaging device, including the power feed line 407 and the power feed section 408, can be arranged in the internal space of the housing 401.

[0034] Furthermore, the housing 401 and the GND 409 of the power supply unit are electrically connected, and the housing 401 and the board 405 are connected at the position of the GND 409 of the power supply unit by a fixing member 410 such as a screw. In one example, the fixing member 410 may be a conductor, which allows the housing 401 and the GND of the power supply unit 408 to be electrically connected.

[0035] The feeder line 407 includes a first portion 411, a second portion 412, and a third portion 413 as viewed from the stacking direction. The first portion 411 is a part of the line of the feeder line 407 including from an intersection 4111 where the first side 403 and the feeder line 407 intersect to an open end of the feeder line 407 as viewed from the stacking direction. The second portion 412 is a part of the line of the feeder line 407 including from an intersection 4121 where the second side 404 and the feeder line 407 intersect to the feeding end as viewed from the stacking direction. The third portion 413 is a part of the feeder line 407 that diagonally straddles the opening 402 as viewed from the stacking direction. The operating principle of the slot antenna is the same as that of the first embodiment, and therefore will not be described.

[0036] Here, the first portion 411 has an electrical length equal to the wavelength λ1 / 4 of the first frequency f1, and the second portion 412 is disposed at a position half the wavelength λ2 (λ2 / 2) of the second frequency f2 from one end of the second side 404. In this embodiment, at the second frequency of 5 GHz, half the wavelength λ2 / 2=32.5 mm.

[0037] In order to reduce the size of the substrate 405, a part of the first portion 411 is disposed so as to extend parallel to the first side 403 of the opening 402. However, similarly to Fig. 1(A), the first portion 411 may be disposed so as to be perpendicular to the first side 403 of the opening 402 when viewed from the stacking direction, or may be disposed obliquely.

[0038] 5A, the orientation of third portion 413 of feeder line 407 is determined in the XY plane such that the distance from built-in component 406 to intersection 4111 is shorter than the distance from built-in component 406 to intersection 4121. This makes it possible to suppress coupling between built-in component 406 and second portion 412 of feeder line 407 and reduce the influence of built-in component 406.

[0039] A non-conductive resin cover or the like (not shown) may be arranged on the outside of housing 401 at opening 402 for dust-proofing, drip-proofing, etc. The non-conductor may be arranged so as to cover the opening surface of opening 402.

[0040] As described above, according to this embodiment, the antenna device is incorporated into the housing of the imaging device, and a dual-band slot antenna having wideband radiation efficiency characteristics can be implemented even if conductors such as built-in components are present near the opening inside the housing.

[0041] In the present embodiment, the power feed line 407 is described as being a strip line, but it may include a thin coaxial cable or a balun that converts an unbalanced connection to a balanced connection, or the power feed line 407 may be connected to the first conductor 401. In the present embodiment, the antenna device 1 is described as being a transmitting antenna that transmits electromagnetic waves supplied from the power feed unit 408, but the antenna device 1 may be a receiving antenna that receives electromagnetic waves. In this case, the power feed unit 107 may be replaced with a high-frequency receiving circuit. Also, the power feed unit 107 may include a receiving circuit.

[0042] The materials, material thicknesses, shapes and other parameters shown here are merely examples, and all conditions that can obtain the same effects are included in the embodiments.

[0043] <Third embodiment> Fig. 6 shows an external view of a medical peripheral device to which the antenna device according to this embodiment is applied. Fig. 7(A) and Fig. 7(B) show a part of a housing 501 of the medical peripheral device.

[0044] The housing 501 of the medical peripheral device in Fig. 6 has a first opening 502 and a second opening 503 functioning as slot antenna elements on different surfaces, that is, two slot antennas are formed. Fig. 7(A) is an enlarged view of the periphery of the first opening 502 in Fig. 6.

[0045] Housing 501 includes a conductor that forms a closed space inside. Housing 501 may be formed by engaging, adhering, or joining a plurality of conductors. In the closed space, a high-frequency circuit including a core wire 506, a fine coaxial cable including an outer cover 507, a power supply unit 508, and a GND line 509, and other units for realizing the function of a medical peripheral device are arranged.

[0046] Aperture 502 has first side 504 and second side 505 in the longitudinal direction, and has an electrical length equal to half (λ1 / 2) the wavelength λ1 of the first resonating frequency f1. In this configuration, if the first frequency is 2.4 GHz, then λ1 / 2=49 mm and λ1 / 4=25 mm.

[0047] A thin coaxial cable is mounted inside the housing 501 of the medical peripheral device so as to face the surface where the opening 502 is provided.

[0048] The thin-coaxial cable is composed of a core 506 that functions as a power feed line and an outer sheath 507 that functions as a GND. The core 506 has a first portion 510 including from the intersection with the first side 504 to the open end, a second portion 511 including from the intersection with the second side 505 to the power feed end, and a third portion 512 that diagonally straddles the opening 502. The outer sheath 507 that is the GND of the thin-coaxial cable is electrically connected to the housing 501 of the medical peripheral device. The GND line 509 that is the GND of the power feed unit 508 is also electrically connected to the housing 501.

[0049] Here, the first portion 510 has an electrical length equal to the wavelength λ1 / 4 of the first frequency f1. The second portion 511 is disposed at a distance of the wavelength λ2 / 2 of the second frequency f2 from one end of the second side 505, and the wavelength λ2 of the second frequency f2 is shorter than the wavelength λ1 of the first frequency f1. In this embodiment, when the second frequency is 5 GHz, the wavelength λ2 / 2=32.5 mm.

[0050] Since the electrical length of the first portion 510 is equal to the wavelength λ1 / 4 of the first frequency f1, the core wire 506 and the opening 502 are electrically coupled. Therefore, when electromagnetic waves including the first frequency or the second frequency are input from the thin coaxial cable to the core wire 506, power is supplied from the core wire 506 to the opening 502, and the slot antenna can function as such. The operating principle of the slot antenna is similar to that of the first embodiment, and therefore a description thereof will be omitted.

[0051] Moreover, the antenna having the second opening 503 has a configuration similar to that of the antenna having the opening 502 as an antenna element shown in Fig. 7. The thin coaxial cable for feeding power to the opening 502 and the thin coaxial cable for feeding power to the opening 503 are arranged so as not to electrically affect each other.

[0052] In this embodiment, the openings 502 and 503 have the same size, but the openings 502 and 503 may have different sizes. For example, by designing the opening 502 to resonate at the third frequency f3 and the opening 503 to resonate at the fourth frequency f4, the antenna device can cover even more frequency bands.

[0053] In this embodiment, the opening is powered by a thin coaxial cable, but a balun may be provided to convert the unbalanced connection to a balanced connection, or the opening may be directly connected to the antenna. The materials, material thicknesses, shapes, and other parameters shown here are merely examples and are not limited to this embodiment.

[0054] <Fourth embodiment> Fig. 8 shows an external view of a medical imaging device to which the antenna device according to this embodiment is applied. Fig. 9(A) and Fig. 9(B) show a part of a housing 601 of the medical imaging device.

[0055] The housing 601 of the medical imaging device in Fig. 8 has a first opening 602 that functions as a slot antenna element. Fig. 9(B) is an enlarged view of the periphery of the first opening 602 in Fig. 8. The housing 601 has a conductor that forms a closed space inside. The housing 601 may be formed by engaging, adhering, or joining a plurality of conductors. In the closed space, a high-frequency circuit including a core wire 606, a thin coaxial cable including an outer cover 607, a power supply unit 608, and a GND line 609, and other units for realizing the function of the medical imaging device are arranged.

[0056] The opening 602 has a first side 604 and a second side 605 in the longitudinal direction, and has an electrical length equal to half (λ1 / 2) the wavelength λ1 of the first resonating frequency f1. In this configuration, if the first frequency is 2.4 GHz, then λ1 / 2=49 mm and λ1 / 4=25 mm.

[0057] A thin coaxial cable is mounted inside a housing 601 of the medical peripheral device so as to face the surface where an opening 602 is provided.

[0058] The thin-coaxial cable is composed of a core 606 that functions as a feeder and an outer sheath 607 that functions as a GND. The core 606 has a first portion 610 that includes from the intersection with the first side 604 to the open end, a second portion 611 that includes from the intersection with the second side 605 to the feed end, and a third portion 612 that straddles the opening 602 diagonally.

[0059] The first portion 610 has an electrical length equal to the wavelength λ1 / 4 of the first frequency f1. The second portion 611 is disposed at a distance of the wavelength λ2 / 2 of the second frequency f2 from one end of the second side 605, and the wavelength λ2 of the second frequency f2 is shorter than the wavelength λ1 of the first frequency f1. In this embodiment, when the second frequency is 5 GHz, the wavelength λ2 / 2=32.5 mm.

[0060] Here, the outer cover 607 functioning as the GND of the power supply line is not electrically connected to the housing 601 of the medical imaging device, that is, is insulated. For example, the outer cover 607 and the housing 601 can be insulated from each other by disposing an insulating structure including an insulator and a dielectric between the housing 601 and the outer cover 607. In another example, the outer cover 607 and the housing 601 can be insulated from each other by separating the housing 601 and the outer cover 607. In addition, the GND line 609 of the power supply unit 608 is also not electrically connected to the housing 601. For example, the GND line 609 can be insulated from the housing 601 by connecting the GND line 609 to a GND that is not connected to the housing 601.

[0061] With this configuration, static electricity and noise flowing through the housing 601 are not superimposed on the outer cover 607 and GND line 609 connected to the high-frequency circuit unit, which is expected to prevent malfunctions due to static electricity and suppress noise in captured images.

[0062] In addition, in order to prevent unintended and unnecessary radiation from the outer cover 607, the outer cover 607, which is the GND of the fine coaxial cable, has a length and shape that does not resonate at the first frequency f1 and the second frequency f2. For example, the length of the outer cover 607 may be a length that does not include the wavelength λ1 / 4 and the wavelength λ2 / 4. In another example, the outer cover 607 may have a shape that allows it to be placed at a position where it is electrically coupled to another conductor different from the housing 601. For example, it may be connected to the GND line 609 of the power supply unit 608. This makes it possible to increase the area of ​​the conductor of the outer cover 607 as the GND, and to prevent unnecessary radiation of electromagnetic waves from the outer cover 607. .

[0063] Moreover, since the electrical length of the first portion 610 is equal to the wavelength λ1 / 4 of the first frequency f1, the core wire 606 and the opening 602 are electrically coupled. Therefore, when electromagnetic waves including the first frequency f1 or the second frequency f2 are input from the thin coaxial cable to the core wire 606, power is supplied from the core wire 606 to the opening 602, and the slot antenna can function as such. The operating principle of the slot antenna is the same as that of the first embodiment, and therefore a description thereof will be omitted.

[0064] In this embodiment, the core 606 and the outer cover 607 are described as being fine coaxial cables that serve as the power supply section. However, the power supply line and the power supply section may be formed by a microstrip line as in the first embodiment, and the power supply section may include a balun that converts an unbalanced connection into a balanced connection. In this case, as described above, the length and shape of either the outer cover 607 or the GND line 609 are set so that they do not resonate at the first frequency f1 and the second frequency f2, so as not to cause unintended and unnecessary radiation. For example, the length of each of the outer cover 607 and the GND line 609 is different from both the wavelength λ1 / 4 and the wavelength λ2 / 4.

[0065] The materials, material thicknesses, shapes and other parameters shown here are merely examples, and all conditions that can obtain the same effects are included in the embodiments.

[0066] As described above, according to this embodiment, the power feed line and the GND of the power feed unit are not electrically connected to the housing, and therefore static electricity and noise that have flowed through the housing are not superimposed on the power feed line and power feed unit connected to the high-frequency circuit unit, which is expected to prevent failures due to static electricity and suppress noise in captured images.

[0067] <Other embodiments> The present invention can also be realized by a process in which a program for implementing one or more of the functions of the above-described embodiments is supplied to a system or device via a network or a storage medium, and one or more processors in a computer of the system or device read and execute the program. The present invention can also be realized by a circuit (e.g., ASIC) that implements one or more of the functions.

[0068] In the present embodiment, the antenna device forming the housing has been described as an imaging device or a medical peripheral device, but the present invention can also be applied to the housing of other devices, such as a personal computer or a communication device such as a smartphone.

[0069] In this embodiment, the dielectric material is 1 mm thick FR4-epoxy, but it may be a ferroelectric material. In this case, the size of the feeder line 106 can be reduced by the wavelength shortening effect.

[0070] In this embodiment, the opening 102 has been described as being rectangular. However, the opening may be of a shape other than a rectangle, such as an ellipse, a trapezoid, or a parallelogram, and any opening having two approximately parallel sides is applicable to this embodiment. Depending on the shape of the housing, the opening may have a three-dimensional shape rather than on the XY plane.

[0071] <Summary of the embodiment> The disclosure of this embodiment is as follows.

[0072] (Item 1) 1. An antenna apparatus operating at first and second operating frequencies, comprising: a first conductor having an opening with first and second sides that are generally parallel; a feed line disposed apart from the opening; Equipped with When viewed from the lamination direction of the opening and the power supply line, the power supply line is a first portion including a first intersection between the first side and the power supply line and an open end of the power supply line; a second portion connecting a second intersection between the second side and the feed line and a feed portion; and a third portion connecting the first intersection and the second intersection so as to straddle the opening diagonally. Equipped with An antenna device, characterized in that a distance from the second intersection to one end of the second side is different from a distance from the second intersection to the other end of the second side.

[0073] (Item 2) 2. The antenna device according to item 1, wherein an electrical length from the first intersection to the open end is approximately equal to half the length of at least one of the first side and the second side.

[0074] (Item 3) 3. The antenna device according to item 1 or 2, wherein an electrical length from the first intersection to the open end is approximately equal to half the wavelength of an electromagnetic wave of the first operating frequency.

[0075] (Item 4) 4. The antenna device according to any one of items 1 to 3, wherein a length from the second intersection to one end of the second side is approximately equal to half the wavelength of an electromagnetic wave of the second operating frequency.

[0076] (Item 5) 5. The antenna device according to any one of claims 1 to 4, wherein the first portion includes a line extending parallel to the first side.

[0077] (Item 6) 6. The antenna device according to claim 1, further comprising a dielectric material disposed between the opening and the third portion.

[0078] (Item 7) 7. The antenna device according to claim 1, wherein the ground of the power supply portion and the first conductor are electrically connected to each other.

[0079] (Item 8) 8. The antenna device according to claim 1, wherein the opening is rectangular.

[0080] (Item 9) 9. The antenna device according to any one of claims 1 to 8, wherein the first conductor forms a closed space, and the feed line is disposed within the closed space.

[0081] (Item 10) 10. The antenna device according to any one of items 1 to 9, further comprising a second conductor arranged at a position opposite to an opening surface of the opening, wherein a distance from the first intersection to the second conductor is shorter than a distance from the second intersection to the second conductor.

[0082] (Item 11) 11. The antenna device according to any one of items 1 to 10, wherein at least one surface of the opening is covered by a non-conductor.

[0083] (Item 12) the first conductor forms at least a portion of a housing; The opening is provided on a first surface of the housing, a second opening having a third side and a fourth side that are substantially parallel to each other is provided on a second surface different from the first surface; a second feed line disposed apart from the second opening; 12. The antenna device according to any one of items 1 to 11, wherein, when viewed from a stacking direction of the second opening and the second feed line, the second feed line is arranged so as to diagonally straddle the third side and the fourth side of the second opening.

[0084] (Item 13) 13. The antenna device according to any one of claims 1 to 12, wherein the first operating frequency is lower than the second operating frequency.

[0085] (Item 14) the first operating frequency is in the 2.4 GHz band; 14. The antenna device according to item 13, wherein the second operating frequency is included in the 5 GHz band.

[0086] (Item 15) 2. The antenna device according to item 1, wherein the ground of the power supply portion and the first conductor are not electrically connected.

[0087] (Item 16) 16. The antenna device according to item 15, wherein a conductor on the ground side of the power supply portion does not resonate at the first and second operating frequencies.

[0088] The invention is not limited to the above-described embodiments, and various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0089] 1 Antenna device, 101 Conductor, 102 Opening, 103 First side, 104 Second side, 106 Power supply line, 107 Power supply section

Claims

1. 1. An antenna apparatus operating at first and second operating frequencies, comprising: a first conductor having an opening with first and second sides that are generally parallel; a feed line disposed apart from the opening; Equipped with When viewed from the lamination direction of the opening and the power supply line, the power supply line is a first portion including a first intersection between the first side and the power supply line and an open end of the power supply line; a second portion connecting a second intersection between the second side and the power supply line and a power supply portion; a third portion connecting the first intersection portion and the second intersection portion so as to diagonally straddle at least a portion of the opening; Equipped with An antenna device, characterized in that a distance from the second intersection to one end of the second side is different from a distance from the second intersection to the other end of the second side.

2. 2. The antenna device according to claim 1, wherein an electrical length from the first intersection to the open end is approximately equal to half the length of at least one of the first side and the second side.

3. 2. The antenna device according to claim 1, wherein an electrical length from the first intersection to the open end is approximately equal to one-half the wavelength of an electromagnetic wave at the first operating frequency.

4. 2. The antenna device according to claim 1, wherein a length from the second intersection to one end of the second side is approximately equal to half the wavelength of an electromagnetic wave of the second operating frequency.

5. 2. The antenna device according to claim 1, wherein the first portion includes a line extending parallel to the first side.

6. The antenna device according to claim 1 , further comprising a dielectric disposed between the opening and the third portion.

7. 2. The antenna device according to claim 1, wherein a ground of the power supply portion and the first conductor are electrically connected to each other.

8. The antenna device according to claim 1 , wherein the opening is rectangular.

9. 2. The antenna device according to claim 1, wherein the first conductor defines a closed space, and the feed line is disposed within the closed space.

10. 2. The antenna device according to claim 1, further comprising a second conductor arranged at a position opposite to an opening surface of the opening, wherein a distance from the first intersection to the second conductor is shorter than a distance from the second intersection to the second conductor.

11. 2. The antenna device according to claim 1, wherein at least one surface of the opening is covered with a non-conductor.

12. the first conductor forms a housing; The opening is provided on a first surface of the housing, a second opening having a third side and a fourth side that are substantially parallel to each other is provided on a second surface different from the first surface; a second feed line disposed apart from the second opening; 2. The antenna device according to claim 1, wherein, when viewed from a stacking direction of the second opening and the second feed line, the second feed line is arranged so as to diagonally straddle the third side and the fourth side of the second opening.

13. 2. The antenna device according to claim 1, wherein the first operating frequency is lower than the second operating frequency.

14. the first operating frequency is in the 2.4 GHz band; 14. The antenna arrangement according to claim 13, wherein the second operating frequency is included in the 5 GHz band.

15. 2. The antenna device according to claim 1, wherein the ground of the power supply portion and the first conductor are not electrically connected to each other.

16. 16. The antenna device according to claim 15, wherein a conductor on the ground side of the power supply portion does not resonate at the first and second operating frequencies.

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