Antenna device and communication device equipped with same

Abstract

An antenna device (120) comprises a first substrate (131) and a second substrate (132). The first substrate (131) has a flat-shaped ground electrode (GND1), a flat-shaped radiating element (121), and a peripheral electrode (150) that is electrically connected to the ground electrode (GND1). The second substrate (132) has: a first main surface (132a) that faces the first substrate (131); a second main surface (132b) that is on the side opposite from the first main surface; a ground electrode (GND2) that is disposed on the second main surface (132b); and a ground pad (170) that is disposed on the first main surface (132a). The peripheral electrode (150) and the ground pad (170) are connected via a solder paste (160).

Description

Antenna device and communication device equipped with same

[0001] The present disclosure relates to an antenna device and a communication device equipped with the same.

[0002] International Publication No. 2021 / 059661 (Patent Document 1) discloses a configuration in which a peripheral electrode connected to a ground electrode is arranged on the side of a substrate on which a flat ground electrode and a radiating element (patch antenna) are arranged opposite each other.

[0003] International Publication No. 2021 / 059661

[0004] In the configuration disclosed in International Publication No. 2021 / 059661 (Patent Document 1), radio waves can be emitted from the radiating element in the normal direction of the substrate, but radio waves cannot be emitted in a direction intersecting the normal direction of the substrate.

[0005] The present disclosure has been made to solve the above-mentioned problems, and an object of the present disclosure is to provide an antenna device capable of radiating radio waves in a direction intersecting the normal direction of the substrate.

[0006] The antenna device according to the present disclosure includes a first substrate and a second substrate having a first main surface facing the first substrate and a second main surface opposite the first main surface. The first substrate has a flat-plate-shaped first ground electrode and a radiating element arranged opposite each other in a direction intersecting a normal direction of the second substrate, and a peripheral electrode arranged on an opposing surface facing the second substrate and electrically connected to the first ground electrode. The second substrate has a flat-plate-shaped second ground electrode arranged on the second main surface or between the second main surface and the first main surface and extending along the second main surface, and a ground pad arranged on the first main surface and electrically connected to the second ground electrode. The peripheral electrode and the ground pad are connected via a conductive connecting member.

[0007] According to the present disclosure, it is possible to provide an antenna device capable of radiating radio waves in a direction intersecting the normal direction of a substrate (second substrate).

[0008] 5(C). FIG. 5(D). An example of a block diagram of a communication device to which the antenna device is applied. FIG. 5(E). FIG. 5(F). FIG. 5(G). FIG. 5(H). FIG. 5(I). FIG. 5(I). FIG. 5(I). FIG. 5(I). FIG. 5(I). FIG. 5(I).

[0009] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0010] 1 is an example of a block diagram of a communication device 10 to which an antenna device 120 according to this embodiment is applied. The communication device 10 is, for example, a mobile terminal such as a mobile phone, a smartphone, or a tablet, or a personal computer with a communication function. An example of the frequency band of radio waves used in the antenna device 120 according to this embodiment is millimeter-wave radio waves with center frequencies of 28 GHz, 39 GHz, and 60 GHz, but radio waves in other frequency bands are also applicable.

[0011] 1 , a communication device 10 includes an antenna module 100 and a BBIC 200 that constitutes a baseband signal processing circuit. The antenna module 100 includes an RFIC 110, which is an example of a power supply device, and an antenna device 120. The communication device 10 upconverts an intermediate frequency signal transmitted from the BBIC 200 to the antenna module 100 into a high frequency signal and radiates the high frequency signal from the antenna device 120, and also downconverts a high frequency signal received by the antenna device 120 into an intermediate frequency signal and processes the signal in the BBIC 200.

[0012] The antenna device 120 includes a dielectric substrate 130 on which a plurality of radiating elements 121 are arranged. The dielectric substrate 130 includes a first substrate 131 and a second substrate 132, and the plurality of radiating elements 121 are arranged on a mounting surface 131 a of the first substrate 131.

[0013] 1 shows an example of an array configuration in which four radiating elements 121 are arranged in a line, but the number and arrangement of the radiating elements 121 are not limited to this. A single radiating element 121 may be arranged on the mounting surface 131a of the first substrate 131, or five or more radiating elements 121 may be arranged. Also, an array configuration in which the radiating elements 121 are arranged two-dimensionally may be used.

[0014] The first substrate 131 and the second substrate 132 constituting the dielectric substrate 130 may be, for example, a low-temperature co-fired ceramics (LTCC) multilayer substrate, a multilayer resin substrate formed by stacking multiple resin layers made of resins such as epoxy and polyimide, a multilayer resin substrate formed by stacking multiple resin layers made of liquid crystal polymer (LCP) with a lower dielectric constant, a multilayer resin substrate formed by stacking multiple resin layers made of fluorine-based resin, a multilayer resin substrate formed by stacking multiple resin layers made of PET (Polyethylene Terephthalate), or a ceramic multilayer substrate other than LTCC. The first substrate 131 and the second substrate 132 do not necessarily have a multilayer structure and may be single-layer substrates. Furthermore, the first substrate 131 and the second substrate 132 may be formed of the same dielectric or different dielectrics.

[0015] The radiating element 121 is a patch antenna having a flat plate shape. In this embodiment, the radiating element 121 is a microstrip antenna having a substantially square shape.

[0016] In the antenna module 100 according to this embodiment, a high frequency signal is supplied to each radiating element 121 from the corresponding power supply wiring 140. The antenna module 100 is a so-called single-band single-polarized type antenna module.

[0017] The RFIC 110 includes switches 111A to 111D, 113A to 113D, and 117, power amplifiers 112AT to 112DT, low-noise amplifiers 112AR to 112DR, attenuators 114A to 114D, phase shifters 115A to 115D, a signal combiner / divider 116, a mixer 118, and an amplifier circuit 119.

[0018] When transmitting a high frequency signal, the switches 111A to 111D and 113A to 113D are switched to the side of the power amplifiers 112AT to 112DT, and the switch 117 is connected to the transmitting amplifier of the amplifier circuit 119. When receiving a high frequency signal, the switches 111A to 111D and 113A to 113D are switched to the side of the low noise amplifiers 112AR to 112DR, and the switch 117 is connected to the receiving amplifier of the amplifier circuit 119.

[0019] The intermediate frequency signal transmitted from the BBIC 200 is amplified by the amplifier circuit 119 and up-converted by the mixer 118. The up-converted high frequency signal, that is the transmission signal, is split into four by the signal combiner / divider 116, passes through the corresponding signal paths, and is fed to each different radiating element 121. By individually adjusting the phase shift of the phase shifters 115A to 115D arranged on each signal path, it is possible to adjust the directivity of the radio waves output from the radiating element 121. Furthermore, the attenuators 114A to 114D adjust the strength of the transmission signal.

[0020] The received signals, which are high-frequency signals received by each radiating element 121, are transmitted to the RFIC 110 and combined in the signal combiner / divider 116 via four different signal paths. The combined received signals are down-converted to intermediate frequency signals in the mixer 118, further amplified in the amplifier circuit 119, and transmitted to the BBIC 200.

[0021] The RFIC 110 is formed, for example, as a one-chip integrated circuit component. Alternatively, for each device corresponding to each radiating element (switch, power amplifier, low-noise amplifier, attenuator, phase shifter), a single-chip integrated circuit component may be formed for each corresponding radiating element. Furthermore, the RFIC 110 may be mounted on the second substrate 132 of the antenna device 120.

[0022] (Structure of Antenna Device 120) Next, the configuration of the antenna device 120 will be described in detail using Fig. 2. Fig. 2 is a diagram partially showing the periphery of one radiating element 121 in the antenna device 120. In Fig. 2, a plan view of the antenna device 120 (Fig. 2(A)) is shown in the upper part, a side perspective view of the antenna device 120 (Fig. 2(B)) is shown in the middle part, and a plan view of the first substrate 131 as viewed from the negative direction of the Z axis (Fig. 2(C)) is shown in the lower part.

[0023] As described above, the dielectric substrate 130 includes the first substrate 131 and the second substrate 132 , and the radiating element 121 is disposed on the mounting surface 131 a of the first substrate 131 .

[0024] The first substrate 131 has a mounting surface 131a on which the radiating element 121 is arranged, and an opposing surface 131b that faces the second substrate 132. The mounting surface 131a and the opposing surface 131b are substantially perpendicular to each other.

[0025] The second substrate 132 has a first main surface 132a facing the first substrate 131 and a second main surface 132b opposite to the first main surface 132a. The first main surface 132a of the second substrate 132 and the mounting surface 131a of the first substrate 131 are substantially orthogonal to each other. In other words, the normal direction of the second substrate 132 and the normal direction of the radiating element 121 are substantially orthogonal to each other.

[0026] In the following description, the normal direction to the second substrate 132 is defined as the Z-axis direction, the normal direction to the radiating element 121 is defined as the X-axis direction, and the direction perpendicular to these directions is defined as the Y-axis direction. In addition, the positive direction of the Z-axis in each drawing may be referred to as the upper side, and the negative direction may be referred to as the lower side.

[0027] In addition to the radiating element 121, the first substrate 131 has a flat ground electrode GND1 and a peripheral electrode 150. The ground electrode GND1 is disposed facing the radiating element 121 at a position a predetermined distance away from the radiating element 121 in the X-axis direction. Note that, although the radiating element 121 is disposed in a manner that it is exposed on the mounting surface 131a of the first substrate 131 in FIG. 2 , the radiating element 121 may also be disposed inside the first substrate 131 (between the mounting surface 131a and the ground electrode GND1). In this embodiment, the first substrate 131 is a laminate whose stacking direction is the normal direction (X-axis direction) of the radiating element 121.

[0028] The peripheral electrode 150 is disposed on the opposing surface 131b of the first substrate 131 at a position between the ground electrode GND1 and the radiating element 121, and is electrically connected to the ground electrode GND1. When the first substrate 131 is viewed from the X-axis direction, a distance Z1 from the center of the surface of the radiating element 121 to an end of the peripheral electrode 150 is smaller than a dimension Z2 of the radiating element 121 in the Z-axis direction.

[0029] The peripheral electrode 150 is disposed so as to be exposed to the opposing surface 131b of the first substrate 131. This allows the peripheral electrode 150 to function as a ground pad for the first substrate 131.

[0030] The second substrate 132 has a flat-plate-shaped ground electrode GND2 and a ground pad 170. The ground electrode GND2 is disposed on the second main surface 132b of the second substrate 132, over the entire surface of the second main surface 132b. The ground electrode GND2 may also be disposed in a middle layer of the second substrate 132 (a layer between the second main surface 132b and the first main surface 132a). In this embodiment, the second substrate 132 is a laminated body whose stacking direction is the normal direction (Z-axis direction) of the first main surface 132a.

[0031] The ground pad 170 is disposed on the first main surface 132a of the second substrate 132 and is connected to the ground electrode GND2 through a via 180. More specifically, the ground pad 170 is disposed on the first main surface 132a of the second substrate 132 at a position facing the peripheral electrode 150. The peripheral electrode 150 and the ground pad 170 are connected to each other via solder paste 160. Note that the peripheral electrode 150 and the ground pad 170 need only be electrically connected via a conductive connecting member, and are not necessarily limited to being connected by solder. For example, the peripheral electrode 150 and the ground pad 170 may be connected using a multi-polar connector instead of a solder connection.

[0032] As shown in the lower part of Fig. 2 (Fig. 2C), when the peripheral electrode 150 is viewed from the negative direction of the Z axis, the peripheral electrode 150 is a single electrode as a whole, and has approximately rectangular gaps 151 where no electrode is formed within an area surrounded by an outer edge 152 of the peripheral electrode 150. In particular, the peripheral electrode 150 according to this embodiment has a lattice shape, and portions where an electrode is formed and gaps 151 where no electrode is formed are arranged alternately.

[0033] The power supply wiring 140 is disposed across the first substrate 131 and the second substrate 132. Specifically, the power supply wiring 140 includes a first signal pad 141, a second signal pad 142, a power supply line 143, and solder paste 190.

[0034] The first signal pad 141 is disposed on the opposing surface 131b of the first substrate 131. More specifically, the first signal pad 141 is disposed in a region on the opposing surface 131b of the first substrate 131, on the opposite side of the ground electrode GND1 from the peripheral electrode 150.

[0035] The second signal pad 142 is disposed on the first main surface 132a of the second substrate 132 and is connected to the first signal pad 141 of the first substrate 131 via solder paste 190. The feed line 143 extends inside the first substrate 131 and connects the first signal pad 141 and the feed point SP1 of the radiating element 121.

[0036] A high-frequency signal is supplied to the feed point SP1 of the radiating element 121 from the RFIC 110 (see FIG. 1) via the feed wiring 140. The feed point SP1 is offset in the negative direction of the Y axis from the center of the radiating element 121. As a result, radio waves polarized in the Y axis direction are radiated from the radiating element 121 in the X axis direction.

[0037] The peripheral electrode 150 is connected to the ground electrode GND1, and is also connected to the ground pad 170 via solder paste 160 while facing the ground pad 170 of the second substrate 132. The ground pad 170 is connected to the ground electrode GND2 via a via 180. Therefore, the potential of the peripheral electrode 150 becomes the ground potential.

[0038] For example, if the area of ​​the ground electrode GND1 is limited due to a demand for miniaturization, part of the electric field between the radiating element 121 and the ground electrode GND1 may be generated so as to wrap around to the back side of the ground electrode GND 1. The generation of such an electric field may make it more difficult for radio waves to be emitted from the radiating element 121 than when the area of ​​the ground electrode GND1 is sufficiently large, and the antenna characteristics may be reduced.

[0039] However, in the antenna device 120 according to this embodiment, the peripheral electrode 150 is disposed at a position between the radiating element 121 and the ground electrode GND1 on the opposing surface 131b of the first substrate 131. By disposing the peripheral electrode 150 in this manner, electric field lines are preferentially generated between the radiating element 121 and the peripheral electrode 150, thereby suppressing the generation of an electric field that wraps around to the back side of the ground electrode GND1. Therefore, even if the area of ​​the ground electrode GND1 is limited due to a demand for miniaturization, it is possible to suppress degradation of the antenna characteristics.

[0040] Furthermore, in the antenna device 120 according to this embodiment, the normal direction (X-axis direction) of the radiating element 121 is substantially orthogonal to the normal direction (Z-axis direction) of the second substrate 132. Therefore, radio waves can be radiated from the radiating element 121 in a direction (X-axis direction) substantially orthogonal to the normal direction (Z-axis direction) of the second substrate 132.

[0041] Furthermore, in the antenna device 120 according to this embodiment, the peripheral electrode 150 of the first substrate 131 is connected to the ground pad 170 of the second substrate 132 via the solder paste 160. As a result, not only the peripheral electrode 150 but also the solder paste 160 and the ground pad 170 adjacent to the peripheral electrode 150 in the Z-axis direction are at ground potential, and electric field lines are preferentially generated between the entirety of these portions and the radiating element 121. Therefore, compared to when the peripheral electrode 150 exists alone, the dimension in the Z-axis direction of the portion functioning as a peripheral electrode can be substantially increased. As a result, the electric field coupling between the radiating element 121 and the peripheral electrode 150 can be further strengthened, thereby improving the antenna gain.

[0042] Furthermore, in the antenna device 120 according to this embodiment, when the peripheral electrode 150 is viewed from the Z-axis direction, the peripheral electrode 150 is a single electrode as a whole, and has a lattice shape in which portions where an electrode is formed and gaps 151 where no electrode is formed are alternately arranged. By forming the peripheral electrode 150 in a lattice shape in this way, it is possible to prevent the volume of the peripheral electrode 150 from becoming larger than when the peripheral electrode 150 is formed in a simple flat plate shape. As a result, the cost of the antenna device 120 can be reduced.

[0043] Furthermore, by forming the peripheral electrode 150 in a lattice shape, it is possible to easily adjust the electric field coupling between the radiating element 121 and the peripheral electrode 150 while ensuring the mounting strength of the first substrate 131 to the second substrate 132. For example, if the electric field coupling between the radiating element 121 and the peripheral electrode 150 is too strong, the antenna gain may deteriorate, so it is desirable to weaken the electric field coupling between the radiating element 121 and the peripheral electrode 150. One method for weakening the electric field coupling between the radiating element 121 and the peripheral electrode 150 is to increase the distance in the X-axis direction between the radiating element 121 and the peripheral electrode 150. However, increasing the distance in the X-axis direction between the radiating element 121 and the peripheral electrode 150 would cause the peripheral electrode 150 to be biased toward the ground electrode GND1 on the opposing surface 131b of the first substrate 131, which could reduce the mounting strength of the first substrate 131 to the second substrate 132. In contrast, in the antenna device 120 according to this embodiment, the peripheral electrode 150 has a lattice shape, which prevents the peripheral electrode 150 from being biased toward the ground electrode GND1 on the opposing surface 131b of the first substrate 131, thereby ensuring the mounting strength of the first substrate 131 to the second substrate 132, while reducing the volume of the peripheral electrode 150 and weakening the electric field coupling between the radiating element 121 and the peripheral electrode 150.

[0044] Furthermore, when the first signal pad 141 and the peripheral electrode 150 are molded using paste, forming the peripheral electrode 150 in a lattice shape can easily prevent imbalance between the paste thickness (dimension in the Z-axis direction) of the first signal pad 141 and the paste thickness (dimension in the Z-axis direction) of the peripheral electrode 150. That is, although the first signal pad 141 and the peripheral electrode 150 are present in the same layer in the Z-axis direction, if there is a large difference in area between the first signal pad 141 and the peripheral electrode 150 when viewed in the Z-axis direction, there is a concern that the paste of the first signal pad 141 will be thick while the paste of the peripheral electrode 150 will be thin. In contrast, in the antenna device 120 according to this embodiment, the peripheral electrode 150 has a lattice shape, so that the area of ​​the portion where the electrodes are continuous in the peripheral electrode 150 can be made closer to the area of ​​the first signal pad 141. As a result, compared to when the peripheral electrode 150 is made into a simple flat plate shape, it is easier to prevent the thickness of the paste on the first signal pad 141 and the thickness of the paste on the peripheral electrode 150 from becoming unbalanced.

[0045] Furthermore, in the antenna device 120 according to this embodiment, the first signal pad 141 is disposed in a region on the opposing surface 131b of the first substrate 131 opposite the peripheral electrode 150 across the ground electrode GND1. This facilitates impedance matching of the feed wiring 140. That is, if the first signal pad 141 were disposed in a region on the opposing surface 131b between the ground electrode GND1 and the radiating element 121 (i.e., the same region as the peripheral electrode 150 when viewed from the ground electrode GND1), it would be difficult to maintain a constant distance between the first signal pad 141, through which a high-frequency signal passes, and the peripheral electrode 150, which is at ground potential, making it difficult to achieve impedance matching of the feed wiring 140. In contrast, in the antenna device 120 according to this embodiment, the ground electrode GND1 is disposed between the first signal pad 141 and the peripheral electrode 150, and therefore, impedance matching of the feed wiring 140 can be achieved by maintaining a constant distance between the first signal pad 141 and the ground electrode GND1. This facilitates impedance matching of the power supply wiring 140 .

[0046] Furthermore, in the antenna device 120 according to this embodiment, the first substrate 131 is a laminate whose lamination direction is the normal direction (X-axis direction) of the radiating element 121. Therefore, the radiating element 121 can be formed using a normal electrode pattern instead of vias. This makes it possible to suppress variations in the characteristics of the radio waves radiated from the radiating element 121 compared to when the radiating element 121 is formed using vias.

[0047] The "communication device 10" and the "antenna device 120" according to the present embodiment may correspond to the "communication device" and the "antenna device" of the present disclosure.

[0048] The "first substrate 131," "opposing surface 131b," "ground electrode GND1," and "radiating element 121" according to this embodiment may correspond to the "first substrate," "opposing surface," "first ground electrode," and "radiating element" of the present disclosure, respectively.

[0049] The "peripheral electrode 150" and the "gap 151" according to this embodiment may correspond to the "peripheral electrode" and the "gap" of the present disclosure, respectively.

[0050] The "solder paste 160" according to this embodiment can correspond to the "conductive connecting member" of the present disclosure.

[0051] The "power supply wiring 140," "first signal pad 141," and "second signal pad 142" according to this embodiment may correspond to the "first power supply wiring," "first signal pad," and "second signal pad" of the present disclosure, respectively.

[0052] <Modification 1> In the above-described embodiment, the first substrate 131 is a laminate whose lamination direction is the normal direction (X-axis direction) of the radiating element 121. However, the first substrate 131 may be a laminate whose lamination direction is the normal direction (Z-axis direction) of the second substrate 132. By doing so, the peripheral electrode 150 can be formed using a normal electrode pattern instead of vias. This makes it possible to suppress variation in the characteristics of the peripheral electrode 150 compared to when the peripheral electrode 150 is formed using vias.

[0053] <Modification 2> Although the antenna device 120 according to the above-described embodiment is a so-called single-band, single-polarized type antenna, the antenna device 120 may be an antenna compatible with dual polarized waves or dual bands.

[0054] Fig. 3 is a diagram partially showing the periphery of one radiating element 121 in an antenna device 120A according to Modification 2. The antenna device 120A is a so-called dual-polarized antenna. In Fig. 3, a plan view of the antenna device 120A (Fig. 3(A)) is shown in the upper part, a side perspective view of the antenna device 120A (Fig. 3(B)) is shown in the middle part, and a plan view of a first substrate 131 of the antenna device 120A (Fig. 3(C)) is shown in the lower part.

[0055] The antenna device 120A according to the second modification is obtained by adding a power feed line 140A to the above-described antenna device 120. That is, the antenna device 120A according to the second modification has two power feed lines 140 and 140A.

[0056] As described above, the feed wiring 140 is disposed across the first substrate 131 and the second substrate 132, and is configured to include a first signal pad 141, a second signal pad 142, a feed line 143, and solder paste 190. The feed wiring 140 connects the RFIC 110 and the feed point SP1 of the radiating element 121. Note that, as described above, the feed point SP1 is offset in the negative direction of the Y axis from the center of the radiating element 121. As a result, when a high-frequency signal from the feed wiring 140 is supplied to the feed point SP1 of the radiating element 121, a radio wave polarized in the Y axis direction is radiated from the radiating element 121 in the X axis direction.

[0057] The power feed wiring 140A has a configuration similar to that of the power feed wiring 140. Specifically, the power feed wiring 140A is disposed across the first substrate 131 and the second substrate 132, and is configured to include a third signal pad 141A, a fourth signal pad 142A, a power feed line 143A, and solder paste 190A. The third signal pad 141A is disposed in an area on the opposing surface 131b of the first substrate 131, opposite the peripheral electrode 150, with the ground electrode GND1 in between. The power feed wiring 140A connects the RFIC 110 and a power feed point SP2 of the radiating element 121. Note that the power feed point SP2 is offset from the center of the radiating element 121 in the positive direction of the Z axis. As a result, when a high frequency signal is supplied from the power supply wiring 140A to the power supply point SP2 of the radiating element 121, a radio wave polarized in the Z-axis direction is radiated from the radiating element 121 in the X-axis direction.

[0058] With this configuration, the antenna device 120A can be an antenna that supports dual polarized waves.

[0059] Furthermore, the first signal pad 141 for the power supply wiring 140 and the third signal pad 141A for the power supply wiring 140A are arranged side by side in the Y-axis direction on the opposing surface 131b of the first substrate 131.

[0060] Furthermore, when viewed from the Z-axis direction (the normal direction of the second substrate), a grounding member 153 connected to the peripheral electrode 150 is disposed in the region between the first signal pad 141 and the third signal pad 141A, thereby ensuring isolation between the first signal pad 141 and the third signal pad 141A.

[0061] 2 is a dual-polarized antenna, the antenna device may also be an antenna compatible with dual bands. In that case, for example, a radiating element of a different size from radiating element 121 may be added between radiating element 121 and ground electrode GND1 on first substrate 131, and feed wiring 140A may be connected to the feed point of the added radiating element.

[0062] The "power supply wiring 140A," "third signal pad 141A," and "fourth signal pad 142A" according to this modification example 2 may correspond to the "second power supply wiring," "third signal pad," and "fourth signal pad" of the present disclosure, respectively.

[0063] <Variation 3> The peripheral electrode 150 according to the above-described embodiment has a lattice shape in which portions where an electrode is formed and gap portions 151 where no electrode is formed are arranged alternately, but the peripheral electrode 150 is not necessarily limited to a lattice shape.

[0064] 4 shows a plan view of the first substrate 131 of the antenna device 120B according to the third modification, viewed from the negative direction of the Z axis. When the peripheral electrode 150B provided in the antenna device 120B is viewed from the negative direction of the Z axis, the peripheral electrode 150B is a single electrode as a whole, and has one relatively large gap 151B within an area surrounded by an outer edge 152 of the peripheral electrode 150. Even when the peripheral electrode 150B has such a shape, it is possible to prevent the peripheral electrode 150B from being biased toward the ground electrode GND1 on the opposing surface 131b of the first substrate 131, thereby ensuring the mounting strength of the first substrate 131 to the second substrate 132, while reducing the volume of the peripheral electrode 150B and weakening the electric field coupling between the radiating element 121 and the peripheral electrode 150B.

[0065] The "peripheral electrode 150B" and the "gap 151B" according to the third modification may correspond to the "peripheral electrode" and the "gap" of the present disclosure, respectively.

[0066] <Modification 4> The peripheral electrode 150 and the first signal pad 141 according to the above-described embodiment may be realized by a columnar conductor having a semicircular cross section.

[0067] Fig. 5 is a diagram partially showing the periphery of one radiating element 121 in an antenna device 120C according to Modification 4. In Fig. 5, a plan view (Fig. 5(A)) of the antenna device 120C is shown in the upper part, a side perspective view (Fig. 5(B)) of the antenna device 120C is shown in the middle part, and a plan view (Fig. 5(C)) of a first substrate 131 of the antenna device 120C is shown in the lower part.

[0068] Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 5(C), and Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 5(C).

[0069] The antenna device 120C according to the fourth modification is obtained by changing the first substrate 131 of the above-described antenna device 120 to a first substrate 131C. The first substrate 131C is obtained by changing the peripheral electrode 150 and the first signal pad 141 of the above-described first substrate 131 to a peripheral electrode 150C and a first signal pad 141C.

[0070] The peripheral electrode 150C has a plurality of conductors 154 (three in FIG. 5 ) each extending in the X-axis direction, a conductor 155 connecting end faces of the plurality of conductors 154 in the negative X-axis direction, and a conductor 156 connecting end faces of the plurality of vias 154 in the positive X-axis direction. The plurality of conductors 154 are columnar conductors with semicircular cross sections (see FIG. 6 ). Each conductor 154 can be formed, for example, by splitting a cylindrical via in half. In other words, each conductor 154 can be realized by splitting a cylindrical via in half to form a semicylindrical structure (hereinafter also referred to as a "half-via structure").

[0071] The first signal pad 141C is also a columnar conductor with a semicircular cross section (see FIG. 7) like the conductor 154. That is, like the conductor 154, the first signal pad 141C can also be realized with a half-via structure.

[0072] As described above, the peripheral electrode 150C and the first signal pad 141C may be realized by a half-split via structure.

[0073] <Modification 5> FIG. 8 is a diagram (side perspective view) partially showing the periphery of one radiating element 121 in an antenna device 120D according to Modification 5. In FIG.

[0074] The antenna device 120D according to the fifth modification is obtained by changing the first substrate 131 of the above-described antenna device 120 to a first substrate 131D. The first substrate 131D is obtained by adding a ground electrode GND3 to the above-described first substrate 131.

[0075] The ground electrode GND3 is arranged on a surface 131c of the first substrate 131D opposite to the opposing surface 131b. The ground electrode GND3 is formed in a planar shape along the surface 131c in an area between the ground electrode GND1 and the radiating element 121 on the surface 131c. The end of the ground electrode GND3 in the negative direction of the X-axis is connected to the ground electrode GND1. The end of the ground electrode GND3 in the positive direction of the X-axis is not connected to the radiating element 121.

[0076] By adding such a ground electrode GND3, the width (resonant length, size in the Z-axis direction in FIG. 8) of the radiating element 121 can be further reduced.

[0077] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims.

[0078] It will be understood by those skilled in the art that the above-described embodiments and their modifications are specific examples of the following aspects.

[0079] (Item 1) An antenna device according to the present disclosure includes a first substrate and a second substrate having a first main surface facing the first substrate and a second main surface opposite the first main surface. The first substrate has a flat-plate-shaped first ground electrode and a radiating element arranged opposite each other in a direction intersecting a normal direction of the second substrate, and a peripheral electrode arranged on an opposing surface facing the second substrate and electrically connected to the first ground electrode. The second substrate has a flat-plate-shaped second ground electrode arranged on the second main surface or between the second main surface and the first main surface and extending along the second main surface, and a ground pad arranged on the first main surface and electrically connected to the second ground electrode. The peripheral electrode and the ground pad are connected via a conductive connecting member.

[0080] (2) In the antenna device described in 1, when the first substrate is viewed from the normal direction of the radiating element, the distance from the center of the radiating element to the end of the peripheral electrode is smaller than the dimension of the radiating element in the normal direction of the second substrate.

[0081] (Item 3) In the antenna device described in Items 1 or 2, the ground pad is disposed on the first main surface at a position facing the peripheral electrode, and the peripheral electrode and the ground pad are connected to each other via a connecting member while facing each other.

[0082] (4) In the antenna device described in any one of paragraphs 1 to 3, when the peripheral electrode is viewed from the normal direction of the opposing surface, the peripheral electrode is a single electrode as a whole, and has a gap portion where no electrode is formed within the area surrounded by the outer edge of the peripheral electrode.

[0083] (Item 5) In the antenna device described in item 4, when the peripheral electrode is viewed from the normal direction of the opposing surface, the peripheral electrode has a lattice shape in which areas where electrodes are formed and gaps where no electrodes are formed are arranged alternately.

[0084] (Item 6) The antenna device according to any one of Items 1 to 5 further includes a first feed wiring arranged across the first substrate and the second substrate and supplying a high-frequency signal to the radiating element. The first feed wiring includes a first signal pad arranged on the opposing surface of the first substrate and a second signal pad arranged on the first main surface of the second substrate and connected to the first signal pad. The first signal pad is arranged in an area on the opposing surface of the first substrate opposite the peripheral electrode with the first ground electrode in between.

[0085] (Item 7) The antenna device according to item 6 further includes a second feed wiring arranged across the first and second substrates and supplying a high-frequency signal to the radiating element. The second feed wiring further includes a third signal pad arranged on the opposing surface of the first substrate and a fourth signal pad arranged on the first main surface of the second substrate and connected to the third signal pad. The third signal pad is arranged in an area on the opposing surface of the first substrate opposite the peripheral electrode across the first ground electrode.

[0086] (Item 8) The antenna device according to item 7 further comprises a member that is disposed in a region between the first signal pad and the third signal pad on the first substrate and is connected to the peripheral electrode.

[0087] (Item 9) In the antenna device according to any one of Items 1 to 8, the first substrate is a laminate whose lamination direction is the normal direction of the radiating element.

[0088] (10) In the antenna device according to any one of the first to eighth aspects, the first substrate is a laminate whose lamination direction is the extension direction of the radiating element.

[0089] (Item 11) In the antenna device according to any one of Items 1 to 10, a plurality of combinations of the first substrate and the ground pad are arranged along the first main surface of the second substrate.

[0090] (12th Item) A communication device according to the present disclosure is equipped with the antenna device according to any one of the first to 11th items.

[0091] 10 Communication device, 100 Antenna module, 111A to 113D, 117 Switch, 112AR to 112DR Low noise amplifier, 112AT to 112DT Power amplifier, 114A to 114D Attenuator, 115A to 115D Phase shifter, 116 Distributor, 118 Mixer, 119 Amplification circuit, 120, 120A to 120D Antenna device, 121 Radiating element, 130 Dielectric substrate, 131, 131C, 131D First substrate, 131a Mounting surface, 131b Opposing surface, 131c Surface, 132 Second substrate, 132a First main surface, 132b Second main surface, 140, 140A Power supply wiring, 141, 141C First signal pad, 141A Third signal pad, 142 Second signal pad, 142A Fourth signal pad, 143, 143A Power supply line, 150, 150B, 150C Peripheral electrode, 151, 151B Gap portion, 152 Outer edge, 153 Ground member, 154 to 156 Conductor, 160, 190 Solder paste, 170 Ground pad, 180 Via, GND1, GND2, GND3 Ground electrode, SP1, SP2 Power supply point.

Claims

1. An antenna device comprising: a first substrate; and a second substrate having a first main surface facing the first substrate and a second main surface opposite the first main surface, wherein the first substrate has: a flat first ground electrode and a radiating element arranged opposite to each other in a direction intersecting a normal direction of the second substrate; and a peripheral electrode arranged on an opposing surface facing the second substrate and electrically connected to the first ground electrode, wherein the second substrate has: a flat second ground electrode arranged on the second main surface or between the second main surface and the first main surface and extending along the second main surface, and a ground pad arranged on the first main surface and electrically connected to the second ground electrode, wherein the peripheral electrode and the ground pad are connected via a conductive connecting member.

2. An antenna device as described in claim 1, wherein when the first substrate is viewed from the normal direction of the radiating element, the distance from the center of the radiating element to the end of the peripheral electrode is smaller than the dimension of the radiating element in the normal direction of the second substrate.

3. An antenna device as described in claim 1 or 2, wherein the ground pad is arranged at a position opposite the peripheral electrode on the first main surface, and the peripheral electrode and the ground pad are connected via the connecting member while facing each other.

4. An antenna device as described in any one of claims 1 to 3, wherein when the peripheral electrode is viewed from the normal direction of the opposing surface, the peripheral electrode is a single electrode as a whole, and has a gap portion within an area surrounded by the outer edge of the peripheral electrode where no electrode is formed.

5. An antenna device as described in claim 4, wherein when the peripheral electrode is viewed from the normal direction of the opposing surface, the peripheral electrode has a lattice shape in which portions where electrodes are formed and gaps where no electrodes are formed are arranged alternately.

6. An antenna device as described in any one of claims 1 to 5, further comprising a first power supply wiring arranged across the first substrate and the second substrate for supplying a high frequency signal to the radiating element, the first power supply wiring including: a first signal pad arranged on the opposing surface of the first substrate; and a second signal pad arranged on the first main surface of the second substrate and connected to the first signal pad, the first signal pad being arranged in a region on the opposing surface of the first substrate opposite the peripheral electrode across the first ground electrode.

7. The antenna device according to claim 6, further comprising a second power supply wiring arranged across the first substrate and the second substrate for supplying a high frequency signal to the radiating element, the second power supply wiring further including: a third signal pad arranged on the opposing surface of the first substrate; and a fourth signal pad arranged on the first main surface of the second substrate and connected to the third signal pad, the third signal pad being arranged in a region on the opposing surface of the first substrate opposite the peripheral electrode across the first ground electrode.

8. The antenna device according to claim 7, further comprising a member disposed in a region between the first signal pad and the third signal pad when viewed from the normal direction of the second substrate, and connected to the peripheral electrode.

9. The antenna device according to any one of claims 1 to 8, wherein the first substrate is a laminate whose lamination direction is the normal direction of the radiating element.

10. An antenna device according to any one of claims 1 to 8, wherein the first substrate is a laminate whose lamination direction is the extension direction of the radiating element.

11. The antenna device according to any one of claims 1 to 10, wherein a plurality of combinations of the first substrate and the ground pad are arranged along the first main surface of the second substrate.

12. A communication device equipped with an antenna device according to any one of claims 1 to 11.

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