Antenna device

Abstract

An antenna device according to the present invention is provided with: a radiator which has a plurality of conductor parts which are laminated in different layers inside a laminated substrate and which extend in a first direction, and a through-hole which extends in a second direction and connects the plurality of conductor parts, and which radiates radio waves in a direction centered on a third direction, the second direction is orthogonal to a plane along each of the plurality of conductor parts, and the third direction is orthogonal to the first direction and the second direction; a reflector provided opposite to the radiator in a direction opposite to the third direction; and a power feeding unit that is connected to a first conductor section, which is located at the center in the second direction, among the plurality of conductor sections, and that feeds power to the radiator.

Description

Technical Field

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

[0002] In recent years, research has been underway to form antennas for mobile communication terminals using high-frequency signals such as millimeter waves and sub-terahertz waves within a multilayer substrate.

[0003] For example, Non-Patent Document 1 describes an antenna structure in which a loop-shaped antenna for differential feeding is formed inside a multi-layer substrate and radiates in the end-fire direction of the substrate.

[0004] For example, Patent Document 1 describes an antenna structure of an antenna array using non-conductive through-holes in a communication device.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application No. 2019-536377

[0008] Non-patent literature

[0009] Non-patent document 1: J. Seo et al., "Miniaturized Dual-Band Broadside / EndfireAntenna-in-Package for 5G Smartphone," in IEEE Transactions on Antennas andPropagation, vol. 69, no. 12, pp. 8100-8114, Dec. 2021 Summary of the Invention

[0010] However, the miniaturization of antennas within multilayer substrates remains to be investigated.

[0011] Non-limiting embodiments of the present disclosure contribute to providing an antenna device capable of miniaturizing the antenna.

[0012] An antenna device according to one embodiment of the present disclosure includes: a radiator having a plurality of conductor layers stacked on different layers within a laminate substrate and extending in a first direction, and through holes connecting the plurality of conductor layers and extending in a second direction, and radiating radio waves in a direction centered in a third direction, wherein the second direction is perpendicular to a plane along each of the plurality of conductor layers, and the third direction is perpendicular to the first direction and the second direction; a reflector disposed opposite the radiator in a direction opposite to the third direction; and a feeder connected to a first conductor layer located at the center of the plurality of conductor layers in the second direction, for feeding power to the radiator.

[0013] According to one embodiment of the present disclosure, it is possible to achieve miniaturization of the antenna.

[0014] Further advantages and effects of an embodiment of the present disclosure will be clarified through the description and drawings. These advantages and / or effects are provided by several embodiments and the features described in the description and drawings, but not all of them need to be provided in order to obtain one or more of the same features. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a diagram showing an example of communication between a terminal and an access point.

[0016] Figure 2 This is a diagram showing an example of an antenna mounted on a terminal.

[0017] Figure 3 This is a diagram showing an example of a substrate including an antenna.

[0018] Figure 4 This is a diagram showing an example of a differential line.

[0019] Figure 5 This is a perspective view showing an example of an antenna device according to one embodiment of the present disclosure.

[0020] Figure 6 This is a side view of an example of the antenna device according to one embodiment of the present disclosure as viewed from the positive direction of the Y axis.

[0021] Figure 7 This is a diagram of an example of a radiator of an antenna device according to an embodiment of the present disclosure as viewed from the positive direction of the X-axis.

[0022] Figure 8 This is a diagram of an example of the antenna device according to one embodiment of the present disclosure as viewed from the positive Z-axis direction.

[0023] Figure 9 This is a diagram showing an example of the input impedance of a radiator when the length of the dielectric is changed.

[0024] Figure 10A This is a perspective view showing an example of impedance adjustment of the antenna device according to one embodiment of the present disclosure.

[0025] Figure 10B Observed from the positive direction of the X axis Figure 10A FIG. 1 is a diagram showing an example of a radiator of an antenna device shown.

[0026] Figure 10C Observed from the positive direction of the Z axis Figure 10A FIG. 1 is a diagram showing an example of a radiator of an antenna device shown.

[0027] Figure 11 This is a diagram showing an example of impedance change associated with a shift in the power feeding position.

[0028] Figure 12A This is a diagram of the first comparative example of single-ended feeding as viewed from the positive direction of the Z axis.

[0029] Figure 12B Observed from the positive direction of the X axis Figure 12A Diagram of the radiator shown.

[0030] Figure 13 This is a diagram showing an example of the directional gain of the antenna device according to one embodiment of the present disclosure and a first comparative example.

[0031] Figure 14 This is a perspective view showing an example of an antenna device corresponding to a second comparative example of the antenna device according to one embodiment of the present disclosure.

[0032] Figure 15 This is a diagram showing an example of frequency response of reflection characteristics of the antenna device according to one embodiment of the present disclosure and a second comparative example. DETAILED DESCRIPTION

[0033] The embodiments of the present disclosure are described in detail below, with appropriate reference to the accompanying drawings. However, overly detailed descriptions may be omitted. For example, detailed descriptions of well-known matters or repeated descriptions of substantially identical structures may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

[0034] In addition, the drawings and the following description are provided for the purpose of enabling those skilled in the art to fully understand the present disclosure, and are not intended to limit the subject matter described in the claims.

[0035] In the various drawings, some elements are omitted for ease of viewing, and some elements may not be drawn to scale.

[0036] (Technical insights on which this disclosure is based)

[0037] In recent years, mobile communications using high-frequency signals such as millimeter waves and sub-terahertz waves have been studied.

[0038] In the case of millimeter and sub-terahertz waves, since the wavelength of radio waves is less than a few millimeters, the radio waves attenuate significantly over distance. When devices such as smartphones have directional antennas inside, it may be impossible to consistently determine the direction of the main beam.

[0039] Figure 1 This is a diagram showing an example of communication between a terminal and an access point. Figure 1 shows an example in which, in an indoor environment, terminal #1, terminal #2, and an access point (AP) each form a beam through directivity control and transmit or receive signals using the formed beam.

[0040] like Figure 1 As shown, the beam formed by terminal #1 is aligned with the beam formed by the access point, allowing communication between terminal #1 and the access point to proceed smoothly. The beam formed by terminal #2 is oriented in a different direction from the beam formed by the access point, and the beams are not aligned. In the case of terminal #2, communication may become difficult. Therefore, it is desirable for the antennas installed on the terminals to provide coverage in various directions.

[0041] Figure 2 FIG is a diagram showing an example of an antenna installed on a terminal. Figure 2 As shown, multiple antennas are installed inside the terminal ( Figure 2 (Exemplarily, four antennas are used in the figure) It is desirable to use multiple antennas to cover various directions in three dimensions. The multiple antennas include antennas that form beams in the end-fire direction and radiate radio waves.

[0042] Figure 3 This is a diagram showing an example of a substrate including an antenna. The antenna of the terminal is included in a multilayer substrate together with other circuit structures other than the antenna. Figure 3 In the example, the antenna is included in the laminate substrate together with the RF-IC (Radio Frequency – Integrated Circuit). Figure 3 The antenna transmits a signal input from the RF-IC through the transmission line, or outputs a received signal to the RF-IC through the transmission line. Figure 3 The antenna radiates radio waves in a horizontal direction (eg, a direction along the substrates in the stacked substrates) relative to the stacked substrates.

[0043] In order to reduce the size of the terminal, it is desirable to reduce the size of the antenna formed on the multilayer substrate. In addition, a dipole-type element is used as an antenna element that radiates radio waves in the horizontal direction of the multilayer substrate corresponding to the end-fire direction.

[0044] As an example of an antenna structure formed on a multilayer substrate, Non-Patent Document 1 describes an antenna structure comprising an antenna within the multilayer substrate and a base plate disposed on the backside of the antenna. This antenna is a loop-shaped antenna composed of copper foil and through-holes, fed via differential lines. The antenna structure in Non-Patent Document 1 radiates radio waves in the end-fire direction of the substrate.

[0045] In addition, as an example of an antenna structure formed on a multilayer substrate, Patent Document 1 describes an antenna structure having a patch-shaped antenna formed of a through hole and copper foil inside the multilayer substrate and an antenna array with a depletion region provided near the antenna.

[0046] However, in the antenna structure of Non-Patent Document 1, since the feed line is a differential line, the size of the antenna structure becomes large.

[0047] Figure 4 This is a diagram showing an example of a differential line. Figure 4 As shown in FIG, since a differential line is configured by providing a width between two lines, the width between the two lines increases the wiring area and the size of the antenna structure increases. In addition, the differential line connects the antenna and the signal supply source, so when the antenna and the signal supply source (for example, Figure 3 When the RF-IC in the Figure 4 As shown in the figure, the differential line bends midway. At the bend in the differential line, the wiring area is expanded, and the size of the antenna structure increases.

[0048] Furthermore, in the antenna structure of Non-Patent Document 1, the antenna's feed point is limited to the loop end of the loop-shaped antenna, making impedance adjustment difficult. Furthermore, when the feed line is changed from a differential line to a single-ended line, the feed line itself radiates, causing the antenna's radiation to deviate from the desired direction, disrupting the beam pattern and degrading electrical characteristics.

[0049] Furthermore, in the antenna structure of Patent Document 1, since a probe is used for feeding and through holes are densely arranged, the size of the antenna structure becomes large.

[0050] Therefore, the following embodiments describe an antenna device that can miniaturize an antenna within a multilayer substrate. Furthermore, the following embodiments describe an antenna device that can miniaturize an antenna and improve the electrical characteristics of the antenna.

[0051] (One implementation method)

[0052] Figure 5 It is a perspective view showing an example of the antenna device 10 according to the present embodiment. Figure 5, the antenna device 10 and the X-axis, Y-axis, and Z-axis defined for the antenna device 10 are shown. Figure 5 2 shows the antenna device 10 with a portion of the dielectric 11 being transparent. The dielectric 11 may be composed of a plurality of layers (a plurality of dielectric layers).

[0053] The antenna device 10 is formed inside the laminate substrate and includes a radiator 15, a reflector 16, and a feeder line 14. The radiator 15 and the reflector 16 may be arranged substantially in parallel.

[0054] The laminate substrate has a structure composed of a dielectric 11 and copper foil stacked together. The plane along the surface where the copper foil is provided is defined as the XY plane. The XY plane is defined by the X-axis and the Y-axis. In this case, the dielectric layers and the copper foil layers are arranged along the XY plane.

[0055] The Z-axis represents an axis along the thickness direction of the laminated substrate, perpendicular to the X-axis and the Y-axis. The thickness direction may also be referred to as the height direction or the stacking direction. In the following description, the positive Z-axis direction corresponds to "up" or "above," and the negative Z-axis direction corresponds to "down" or "below."

[0056] The X-axis represents the axis along the installation direction of radiator 15 of antenna device 10. Here, the X-axis represents the axis along the main beam direction of the radio waves radiated from antenna device 10. For example, antenna device 10 radiates radio waves in a direction centered on the positive X-axis. Furthermore, the negative X-axis direction corresponds to the "depth direction."

[0057] The Y axis represents an axis perpendicular to the X axis and the Z axis. In the following description, the Y axis corresponds to the "horizontal direction," the positive direction of the Y axis corresponds to the "right" or "rightward," and the negative direction of the Y axis corresponds to the "left" or "leftward."

[0058] In addition, hereinafter, a plane defined by the X-axis and the Z-axis is referred to as an XZ plane, and a plane defined by the Y-axis and the Z-axis is referred to as a YZ plane.

[0059] In addition, although Figure 5 Although not shown in the figure, the laminated substrate may also include Figure 5 For example, it is also possible to Figure 3 Similarly to the example, the RF-IC is included in the laminate substrate.

[0060] Figure 6 This is a side view of an example of the antenna device 10 according to the present embodiment as viewed from the positive direction of the Y axis. Figure 7 This is a diagram showing an example of the radiator 15 of the antenna device 10 according to the present embodiment as viewed from the positive direction of the X-axis. Figure 8This is a diagram showing a portion of the antenna device 10 according to this embodiment as viewed from the positive direction of the Z axis. Figures 5 to 8 The antenna device 10 will be described.

[0061] The radiator 15 is provided on a side surface along the YZ plane of the reflector 16. The radiator 15 includes a copper foil 12A, a copper foil 12B, a copper foil 12C, a through hole 13A, and a through hole 13B.

[0062] Copper foils 12A through 12C are stacked in different layers. Each of copper foils 12A through 12C has a shape extending in the Y-axis direction. Assuming the effective wavelength of the radio waves radiated by radiator 15 is λ, the length of copper foils 12A through 12C in the Y-axis direction can be λ / 4 to λ / 2. The effective wavelength is determined, for example, by the wavelength of the radio waves radiated by radiator 15 in a vacuum and the dielectric constant of dielectric 11.

[0063] In the present embodiment, copper foil is used as an example of the conductor portion (a plurality of conductor layers) forming the radiator 15 . However, the conductor portion is not limited to copper foil, and may be a foil (or layer) formed of other metals or conductors.

[0064] Through-hole 13A and through-hole 13B each extend in the Z-axis direction. Through-hole 13A is located to the left (negative Y-axis direction) of through-hole 13B, passing through copper foil 12B and connecting copper foil 12A and copper foil 12C. Through-hole 13B is located to the right (positive Y-axis direction) of through-hole 13A, passing through copper foil 12B and connecting copper foil 12A and copper foil 12C. Thus, radiator 15 is formed in a closed loop by copper foil 12A, copper foil 12C, through-hole 13A, and through-hole 13B.

[0065] The reflector 16 includes a plurality of copper foils 12D stacked in the stacking direction and a through hole 13C connecting the plurality of copper foils 12D. The reflector 16 may be a ground conductor. The reflector 16 is formed in a wall shape in the stacking direction.

[0066] also, Figures 5 to 8 While the reflector 16 illustrated in the figure is formed from multiple copper foils and through-holes, the present disclosure is not limited thereto. For example, the reflector 16 may be formed from multiple copper foils without through-holes. Since the reflector is formed from multiple copper foils without through-holes, through-holes are not required, simplifying the manufacture of the reflector. Alternatively, the reflector 16 may be formed from a metal housing. Since the reflector is formed from a metal housing, it can be formed into a plate shape, thereby improving antenna characteristics.

[0067] Feeder line 14 is a single line that provides single-ended power feeding to radiator 15. Feeder line 14 is connected to copper foil 12B included in radiator 15 to feed radiator 15. In this embodiment, feeder line 14 is connected to position P1, where copper foil 12B connects to through-hole 13B. Position P1, where feeder line 14 connects to radiator 15, is sometimes referred to as the "feeding position." Copper foil 12B is located in the center of the stacking direction among copper foils 12A, 12B, and 12C.

[0068] In this embodiment, the feeding position is set at the copper foil 12B existing at the position dividing the radiator 15 into two, and power is fed from the feeding position through the feeder line 14, thereby feeding the loop antenna similarly to the case of differential line feeding.

[0069] The feeding position can be determined based on the position where copper foil 12A is connected to through-hole 13A and the wavelength of the radio wave radiated by radiator 15. For example, the length along the conductor portion between the position where copper foil 12A and through-hole 13A are connected and the feeding position can be approximately half the effective wavelength of the radio wave determined by the dielectric constant of dielectric 11.

[0070] Furthermore, by adjusting the position of the feeding position in the Y-axis direction, the impedance of the radiator 15 can be adjusted.

[0071] According to the structure of antenna device 10 , radiator 15 can be formed by through-holes 13A and 13B and copper foils 12A, 12B, and 12C, so the antenna can be miniaturized.

[0072] Figure 8 An example of the dimensions of the antenna device 10 according to this embodiment is shown in FIG. Figure 8 The figure shows the dimensions of the radiator 15 of the antenna device 10 when radiating radio waves with a center frequency of 160 GHz. As an example, the dimensions of the radiator 15 are 0.13 mm in the depth direction, 0.37 mm in the lateral direction, and 0.19 mm in the thickness direction. When these dimensions are converted to the dimensions of a 40 GHz antenna, the dimensions of the antenna device 10 (for example, the dimensions of the radiator 15) obtained by multiplying the three-dimensional lengths are 1.48 mm × 0.52 mm × 0.76 mm = 0.58. On the other hand, the dimensions of the antenna structure described in Non-Patent Document 1 are 2.0 mm × 0.8 mm × 0.76 mm = 1.2. As described above, the dimensions of the antenna device 10 of this embodiment are approximately 50% smaller than those in Non-Patent Document 1.

[0073] Furthermore, according to the configuration of the antenna device 10 , the impedance of the antenna device 10 can be flexibly adjusted by adjusting the feeding position of the feed line 14 .

[0074] Next, an example of the impedance of the antenna device 10 will be described.

[0075] Figure 9 This is a diagram showing an example of the input impedance of the antenna device 10 according to the present embodiment when the length of the dielectric is changed. Figure 9 The horizontal axis represents the length of the dielectric in the setting direction (positive direction of the X axis) of the radiator 15. Figure 9 In the horizontal axis of , the length of the dielectric in the radiation direction (positive direction of the X axis) is normalized by the wavelength λ. As an example, Figure 9 In the example, λ is the wavelength corresponding to a frequency of 157 GHz. Figure 9 The vertical axis represents the impedance value. Figure 9 The solid line represents the real part of the impedance, and the dotted line represents the imaginary part of the impedance.

[0076] like Figure 9 As shown in Figure 1, when the size of the dielectric (for example, the length in the positive direction of the X-axis) changes, the impedance also changes. Therefore, it is desirable to be able to easily adjust the impedance of the antenna.

[0077] In the antenna device 10 of this embodiment, the impedance of the antenna can be adjusted by adjusting the feeding position. Next, an example of impedance adjustment by adjusting the feeding position will be described.

[0078] Figure 10A It is a perspective view showing an example of impedance adjustment of the antenna device 10 - 1 according to the present embodiment. Figure 10B Observed from the positive direction of the X axis Figure 10A FIG. 1 is a diagram showing an example of a radiator 15 - 1 of an antenna device 10 - 1 . Figure 10C Observed from the positive direction of the Z axis Figure 10A FIG. 1 is a diagram showing an example of a radiator 15 - 1 of an antenna device 10 - 1 .

[0079] exist Figure 10A 、 Figure 10B 、 Figure 10C In the antenna device 10-1 shown, the feeding position P2 of the radiator 15-1 is Figures 5 to 8 The feeding position P1 of radiator 15 in antenna device 10 shown in the figure has shifted to the left (in the negative Y-axis direction) compared to the previous position. Furthermore, this shift has caused the distance between through-holes 13A and 13B in the Y-axis direction to change. The amount of shift in the feeding position is referred to as the offset.

[0080] Figure 11 This is a diagram showing an example of impedance change associated with a shift in the power feeding position. Figure 11The horizontal axis represents the offset of the feed position, and the vertical axis represents the impedance value. The unit of the offset on the horizontal axis is [μm]. A value of 0 on the horizontal axis corresponds to the feed position being at the right end of copper foil 12B. The offset on the horizontal axis represents the offset to the left (negative Y-axis direction) from the end of copper foil 12B. Figure 11 The solid line represents the real part of the impedance, and the dotted line represents the imaginary part of the impedance.

[0081] like Figure 11 As shown, even when the antenna device 10 is present inside the dielectric of the multi-layer substrate, the impedance can be easily adjusted by changing the feeding position.

[0082] For example, since the impedance can be easily adjusted, it is possible to easily match the input impedance of the antenna device 10 with the impedance of the circuit configuration that supplies a signal to the antenna device 10 .

[0083] Figure 12A This is a diagram of the first comparative example of single-ended feeding as viewed from the positive direction of the Z axis. Figure 12B Observed from the positive direction of the X axis Figure 12A Diagram of the radiator shown. Figure 12A 、 Figure 12B The first comparative example shown is an example in which the copper foil 12B is omitted from the radiator 15 of the antenna device 10 and the interval between the radiator and the reflector is longer than that of the antenna device 10 .

[0084] like Figure 8 As shown, the antenna device 10 of this embodiment is Figure 12A In contrast, the spacing between the radiator and the reflector along the X-axis is narrower. Figure 12A In the first comparative example shown, the distance between the radiator and the reflector is approximately λ / 4. On the other hand, the distance between the radiator 15 and the reflector 16 of the antenna device 10 can be approximately λ / 10. In this case, λ can be the effective wavelength of the radiated radio wave. In this embodiment, the reduction of the distance between the radiator 15 and the reflector 16 along the X-axis is recorded as a reduction in the height of the antenna device 10. Here, Figure 8 The antenna device 10 shown is Figure 12A A relatively low-profile antenna device.

[0085] Figure 13 This is a diagram showing an example of the directivity gain of the antenna device 10 according to the present embodiment and the first comparative example. Figure 13 The directional gains of the antenna device 10 and the first comparative example on the XY plane are shown in FIG. Figure 13 In FIG, the directivity gain of the antenna device 10 is represented by a solid line, and the directivity gain of the first comparative example is represented by a dotted line. Figure 13 , the direction of 0 degrees is along the positive direction of the X axis.

[0086] like Figure 13 As shown by the directional gain of the antenna device 10 , by lowering the height of the antenna device 10 , the directivity of the antenna can be directed more strongly toward the front direction (X-axis positive direction), and radio waves can be radiated more strongly toward the front direction.

[0087] In addition, if Figure 12A 、 Figure 12B As shown, when single-ended feeding is performed in a loop-shaped radiator without a central copper foil, the distance between the radiator and the reflector must be extended to approximately λ / 4. However, in the antenna device 10 of this embodiment, since power can be fed through the copper foil 12B located in the center of the radiator 15 in the stacking direction, a lower profile can be achieved. Furthermore, the reduced profile allows the size (e.g., volume) of the antenna device 10 to be reduced.

[0088] In addition, Figures 5 to 8 , an antenna device 10 in which the radiators 15 are relatively sparse is shown. Here, the difference between sparseness and density of the conductors will be described.

[0089] Figure 14 : is a perspective view showing an example of an antenna device 90 corresponding to a second comparative example of the antenna device 10 of this embodiment. Figure 14 In the Figures 5 to 8 The same structure is denoted by the same reference numerals and the description thereof may be omitted.

[0090] Figure 14 The antenna device 90 shown is a Figures 5 to 8 The radiator 15 in the antenna device 10 shown is replaced with a radiator 95. The radiator 95 is Figures 5 to 8 The radiator 15 of the antenna device 10 shown has a structure in which the conductors of the radiator 95 are more densely packed.

[0091] As an example, with Figures 5 to 8 Compared to the antenna device 10 shown, Figure 14 In radiator 95 of antenna device 90 , through holes 93A between copper foils 12A, 12B, and 12C are arranged more densely than through holes 13A and through holes 13B in radiator 15 of antenna device 10 .

[0092] right Figures 5 to 8 The antenna device 10 of this embodiment shown in FIG. Figure 14 The electrical characteristics of the antenna device 90 shown as the second comparative example are compared.

[0093] Figure 15This is a diagram showing an example of frequency response of reflection characteristics of the antenna device 10 according to the present embodiment and the second comparative example. Figure 15 The horizontal axis represents frequency, Figure 15 The vertical axis represents the value of S11, an S parameter representing the reflection characteristics.

[0094] like Figure 15 As shown, the reflection characteristics of antenna device 10 show a minimum value at a frequency of approximately 157 GHz. This reflection characteristic indicates that the resonant frequency of antenna device 10 is 157 GHz. On the other hand, the reflection characteristics of antenna device 90 show a minimum value at a frequency of approximately 180 GHz. This reflection characteristic indicates that the resonant frequency of antenna device 90 is 180 GHz.

[0095] Thus, even if antenna devices (e.g., radiators) have the same size, if the conductors are arranged more densely, as in antenna device 90, the resonant frequency shifts to a higher frequency range. For example, when configuring an antenna device that resonates at the same frequency, a structure with relatively sparse conductors, such as antenna device 10, can achieve a smaller size than a structure with relatively dense conductors, such as antenna device 90.

[0096] As described above, the antenna device 10 of this embodiment includes a radiator 15, a reflector 16, and a feeder line 14 (an example of a power feeder). Radiator 15 comprises multiple copper foils (an example of multiple conductor layers) stacked on different layers within a multilayer substrate and extending in the Y-axis direction, and vias connecting the multiple copper foils along the Z-axis direction. Radiator 15 radiates radio waves in a direction centered on the positive X-axis direction, which is perpendicular to the XY plane, which lies along each of the surfaces of the multiple copper foils. The positive X-axis direction is perpendicular to both the Y-axis and Z-axis directions. Reflector 16 is positioned opposite radiator 15 in a direction opposite to the positive X-axis direction. Feeder line 14 is connected to the central copper foil in the Z-axis direction among the multiple copper foils and feeds power to radiator 15. This structure allows radiator 15 to be formed from via 13A and copper foils 12A, 12B, and 12C, enabling a more compact antenna.

[0097] In addition, although the example in which the radiator 15 has three layers of copper foil is shown in this embodiment, the present disclosure is not limited to this. For example, the radiator may also have four or more layers of copper foil. In this case, the feeding position can be set on the copper foil located at the center position in the stacking direction among the multiple copper foils. For example, the feeding position of a radiator having five layers of copper foil can be set on the third layer of copper foil from the top. For example, the antenna device may be set to radiate radio waves with desired polarization characteristics by adjusting the feeding position. As an example, by setting the feeding position on the copper foil located at the center position in the stacking direction among the multiple copper foils, an antenna device that radiates horizontally polarized waves can be provided. Alternatively, by setting the feeding position on the copper foil located at a position other than the center position in the stacking direction among the multiple copper foils, an antenna device that radiates circularly polarized waves can be provided.

[0098] It should be noted that, in this embodiment, although an example is shown in which the radiator 15 has two through-holes, the present disclosure is not limited thereto, and a plurality of copper foils may be connected by three or more through-holes.

[0099] In this embodiment, the term "radio wave" can be replaced with "electromagnetic wave," "signal," "beam," etc. Furthermore, although this embodiment illustrates an example in which the antenna device is a transmitter that radiates radio waves, the antenna device in this embodiment can also be applied to a receiver that receives radio waves.

[0100] <Summary of Implementation Methods>

[0101] An antenna device according to one embodiment of the present disclosure includes: a radiator having a plurality of conductor layers stacked on different layers within a laminate substrate and extending in a first direction, and through holes connecting the plurality of conductor layers and extending in a second direction, and radiating radio waves in a direction centered in a third direction, wherein the second direction is perpendicular to a plane along each of the plurality of conductor layers, and the third direction is perpendicular to the first direction and the second direction; a reflector disposed opposite the radiator in a direction opposite to the third direction; and a feeder connected to a first conductor layer located at the center of the plurality of conductor layers in the second direction, for feeding power to the radiator.

[0102] In this antenna device, the feeder line is connected to the first conductor layer at a position corresponding to the impedance of the antenna device.

[0103] In the antenna device, the reflector is formed of a conductor layer in the multilayer substrate.

[0104] In the antenna device, the reflector is formed of a metal casing.

[0105] In this antenna device, the first position of the first conductor layer connected to the feeder is determined based on the second position of the second conductor layer connected to the through hole and the wavelength of the radio wave, and the second conductor layer is the conductor layer located closest to the end in the second direction among the multiple conductor layers.

[0106] In the antenna device, the length along the conductor between the first position and the second position is approximately half the effective wavelength of the radio wave based on the dielectric constant inside the dielectric of the multilayer substrate.

[0107] While the embodiments have been described above with reference to the accompanying drawings, the present disclosure is not limited to these examples. Those skilled in the art will readily be able to devise various variations or modifications within the scope of the claims. It should be understood that these variations or modifications also fall within the technical scope of the present invention. Furthermore, the various components of the embodiments may be arbitrarily combined without departing from the spirit and scope of the present invention.

[0108] The disclosures of the specification, drawings, and abstract of Japanese patent application No. 2023-032650 filed on March 3, 2023 are incorporated herein by reference in their entirety.

[0109] Industrial Applicability

[0110] One embodiment of the present disclosure is useful for an antenna device.

[0111] Description of Reference Numerals

[0112] 10, 90 antenna device

[0113] 12A, 12B, 12C, 12D copper foil (conductor layer)

[0114] 13A, 13B, 13C, 93A through holes

[0115] 14 Feeders

[0116] 15, 95 Radiator

[0117] 16 reflectors.

Claims

1. An antenna device comprising: a radiator comprising a plurality of conductor layers stacked on different layers within a laminate substrate and extending in a first direction, and a through hole extending in a second direction connecting the plurality of conductor layers, the radiator radiating radio waves in a direction centered in a third direction, the second direction being perpendicular to a plane along each of the plurality of conductor layers, the third direction being perpendicular to the first direction and the second direction; a reflector disposed opposite to the radiator in a direction opposite to the third direction; as well as A feeder line is connected to a first conductor layer located at the center in the second direction among the plurality of conductor layers, and feeds power to the radiator.

2. The antenna device according to claim 1, wherein The feeder line is connected to the first conductor layer at a position corresponding to the impedance of the antenna device.

3. The antenna device according to claim 1, wherein The reflector is formed of a conductor layer in the laminated substrate.

4. The antenna device according to claim 1, wherein The reflector is formed of a metal housing.

5. The antenna device according to claim 1, wherein A first position of the first conductor layer connected to the feeder line is determined based on a second position of the second conductor layer connected to the through hole and a wavelength of the radio wave, wherein the second conductor layer is located closest to the end in the second direction among the plurality of conductor layers. The antenna device according to claim 5 , wherein: The length along the conductor between the first position and the second position is approximately half of the effective wavelength of the radio wave based on the dielectric constant inside the dielectric of the multilayer substrate.

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