Antenna module and communication device mounted with same

Abstract

An antenna module (100) is provided with a dielectric substrate (130), a ground electrode (GND) disposed on the dielectric substrate (130), plate-shaped radiating elements (121, 122), and a peripheral electrode (150). The radiating element (121) is disposed so as to face the ground electrode (GND). The radiating element (122) is disposed between the radiating element (121) and the ground electrode (GND). The peripheral electrode (150) is disposed in a layer between the ground electrode (GND) and the radiating element (122) in the dielectric substrate (130), and is electrically connected to the ground electrode (GND). The radiating element (122) radiates radio waves in a frequency band lower than the frequency band of the radio waves radiated by the radiating element (121). The peripheral electrode (150) includes a plurality of plate electrodes (151-156) stacked in a first direction in which the radiating element (121) and the ground electrode (GND) face each other. The plate electrode (156) is disposed in a layer between the plate electrode (151) and the ground electrode (GND). The size of the plate electrode (156) is smaller than that of the plate electrode (151).

Description

Technical Field

[0001] The present disclosure relates to an antenna module and a communication device equipped with the antenna module, and more specifically, to a technology for improving antenna characteristics. Background Art

[0002] The following structure is disclosed in the specification of International Publication No. 2021 / 059661 (Patent Document 1): In a patch antenna having a flat plate shape, a peripheral electrode composed of a plurality of flat plate electrodes is arranged in a layer between a radiating element and a ground electrode. The peripheral electrode is connected to the ground electrode, and the peripheral electrode can suppress the electric field lines formed by the radiating element from winding around the back side of the antenna module by electromagnetic coupling with the radiating element. Thus, even when the area of ​​the ground electrode cannot be fully ensured, the degradation of the antenna characteristics can be suppressed.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2021 / 059661 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The peripheral electrode described above disclosed in International Publication No. 2021 / 059661 (Patent Document 1) is used for the following purpose: to improve the antenna characteristics of the radiating element on the low-frequency side in a so-called dual-band patch antenna formed by stacking radiating elements of different sizes (i.e., different frequency bands).

[0008] The inventors of the present disclosure have conducted intensive studies and have found that by improving the structure of the peripheral electrode used to improve the antenna characteristics of the radiating element on the low-frequency side as described above, the antenna characteristics of the radiating element on the high-frequency side can also be improved.

[0009] An object of the present disclosure is to improve antenna characteristics while achieving miniaturization in an antenna module capable of radiating radio waves in two different frequency bands.

[0010] Solutions for solving problems

[0011] The antenna module involved in the present disclosure comprises a dielectric substrate, a ground electrode arranged on the dielectric substrate, a first radiating element and a second radiating element in a flat plate shape, and a first peripheral electrode. The first radiating element is arranged to face the ground electrode. The second radiating element is arranged between the first radiating element and the ground electrode in the dielectric substrate. The first peripheral electrode is arranged in a layer between the ground electrode and the second radiating element in the dielectric substrate and is electrically connected to the ground electrode. The first radiating element is configured to radiate radio waves in a first frequency band. The second radiating element is configured to radiate radio waves in a second frequency band lower than the first frequency band. The first peripheral electrode includes a plurality of flat plate electrodes stacked in a first direction, and the first direction is a direction in which the first radiating element faces the ground electrode. The plurality of flat plate electrodes include a first electrode and a second electrode arranged in a layer between the first electrode and the ground electrode. The size of the second electrode is smaller than the size of the first electrode.

[0012] Effects of the Invention

[0013] In the antenna module involved in the present disclosure, a plurality of planar electrodes constituting the peripheral electrode include a first electrode and a second electrode having different lengths, and the second electrode having a shorter length is arranged closer to the ground electrode than the first electrode. With such a structure, the peripheral electrode acts as a dielectric resonator to generate an attenuation pole near the frequency band of the radiating element on the high-frequency side, thereby being able to expand the bandwidth of the radiating element on the high-frequency side. That is, the antenna characteristics of the radiating element on the high-frequency side can be improved by using the peripheral electrode provided to suppress the degradation of the antenna characteristics of the radiating element on the low-frequency side accompanying miniaturization. Therefore, in an antenna module capable of radiating radio waves of two different frequency bands, it is possible to improve the antenna characteristics while achieving miniaturization. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is a block diagram of a communication device to which the antenna module according to Embodiment 1 is applied.

[0015] Figure 2 yes Figure 1 A top view of the antenna module and a side perspective view when viewed from the Y-axis direction.

[0016] Figure 3 Observed from the X-axis direction Figure 2 A side perspective view of the antenna module.

[0017] Figure 4 It is a diagram for explaining the gain characteristics of the antenna modules according to the first embodiment and the comparative example.

[0018] Figure 5 It is a diagram for explaining the influence of the length of the peripheral electrode on the reflection loss.

[0019] Figure 6This is a diagram for explaining the principle of improving antenna characteristics in the antenna module according to the first embodiment.

[0020] Figure 7 It is a diagram showing the structure of the peripheral electrode according to Modification Example 1.

[0021] Figure 8 It is a diagram showing the structure of the peripheral electrode of Modification Example 2.

[0022] Fig. 9 It is a diagram showing the structure of the peripheral electrode of Modification Example 3.

[0023] Fig.10 It is a diagram showing the structure of the peripheral electrode of Modification Example 4.

[0024] Fig.11 This is a diagram showing the structure of the peripheral electrode of Modification Example 5.

[0025] Fig.12 This is a diagram for explaining the influence of differences in the structure of peripheral electrodes on horizontal polarization in a dual-polarization antenna module.

[0026] Fig.13 This is a top view of the antenna module according to the second embodiment.

[0027] Fig.14 Observed from the X-axis direction Fig.13 A side perspective view of the antenna module.

[0028] Fig.15 This is a top view of the antenna module according to the third embodiment.

[0029] Fig.16 This is a perspective view of an antenna module according to the fourth embodiment.

[0030] Fig.17 1 and 2 are a top view and a side perspective view of an antenna module according to Embodiment 5.

[0031] Fig.18 This is a diagram showing the structure of the peripheral electrode in the fifth embodiment.

[0032] Fig.19 This is a diagram for explaining the gain characteristics of the antenna module according to the fifth embodiment.

[0033] Fig. 20 This is a diagram showing the structure of the peripheral electrode of Modification Example 6.

[0034] Fig.21 It is a diagram for explaining the gain characteristics of the antenna module using the peripheral electrode of Modification Example 6.

[0035] Fig. 22This is a diagram showing the structure of the peripheral electrode of Modification Example 7.

[0036] Fig.23 This is a diagram showing the structure of the peripheral electrode of Modification Example 8. DETAILED DESCRIPTION

[0037] Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, the same reference numerals are attached to the same or corresponding parts in the drawings, and their description will not be repeated.

[0038] [Implementation Method 1]

[0039] (Basic structure of communication device)

[0040] Figure 1 1 is a block diagram of a communication device 10 to which the antenna module 100 according to the present embodiment is applied. The communication device 10 is, for example, a portable terminal such as a mobile phone, a smart phone or a tablet, a personal computer with a communication function, etc. An example of a frequency band of radio waves used in the antenna module 100 according to the present embodiment is a radio wave in a millimeter wave band with a center frequency of 28 GHz, 39 GHz, and 60 GHz, etc., but radio waves in frequency bands other than the above can also be applied.

[0041] Reference Figure 1 The communication device 10 includes an antenna module 100 and a BBIC 200 constituting a baseband signal processing circuit. The antenna module 100 includes an RFIC 110 as an example of a feeding circuit and an antenna device 120. The communication device 10 up-converts a signal transmitted from the BBIC 200 to the antenna module 100 into a high-frequency signal and radiates the signal from the antenna device 120, and down-converts a high-frequency signal received by the antenna device 120 and processes the signal by the BBIC 200.

[0042] The antenna module 100 is a so-called dual-band antenna module capable of radiating radio waves of two different frequency bands. The antenna device 120 includes a plurality of radiating elements 121 and 122 arranged on a dielectric substrate 130. The radiating element 121 is a radiating element capable of radiating radio waves on a relatively high frequency side. The radiating element 122 is a radiating element capable of radiating radio waves on a relatively low frequency side.

[0043] exist Figure 1In order to facilitate the description, the following case is taken as an example for description: the antenna device 120 is a one-dimensional array in which four groups of radiating elements 121 and 122 are arranged in a row on a rectangular dielectric substrate 130. In addition, the number of each radiating element is not limited to 4. In addition, as described later, the antenna device 120 may be a structure in which each of the radiating elements 121 and 122 is provided with one, or a structure in which multiple groups of radiating elements 121 and 122 are arranged in a two-dimensional array.

[0044] The radiation elements 121 and 122 are patch antennas having a circular, elliptical or polygonal flat plate shape. In this embodiment, the radiation elements 121 and 122 are microstrip antennas having a substantially square shape.

[0045] The RFIC 110 includes switches 111A to 111H, 113A to 113H, 117A, 117B, power amplifiers 112AT to 112HT, low noise amplifiers 112AR to 112HR, attenuators 114A to 114H, phase shifters 115A to 115H, signal synthesizers / distributors 116A, 116B, mixers 118A, 118B, and amplifier circuits 119A and 119B. The switches 111A to 111D, 113A to 113D, 117A, power amplifiers 112AT to 112DT, low noise amplifiers 112AR to 112DR, attenuators 114A to 114D, phase shifters 115A to 115D, signal synthesizers / distributors 116A, mixers 118A, and amplifier circuits 119A are circuits for high frequency signals radiated from the radiating element 121. In addition, the structure of switches 111E~111H, 113E~113H, 117B, power amplifiers 112ET~112HT, low noise amplifiers 112ER~112HR, attenuators 114E~114H, phase shifters 115E~115H, signal synthesizer / distributor 116B, mixer 118B and amplifier circuit 119B is a circuit for high-frequency signals radiated from the radiating element 122.

[0046] When transmitting a high-frequency signal, switches 111A to 111H and 113A to 113H are switched to the power amplifiers 112AT to 112HT, and switches 117A and 117B are connected to the transmitting-side amplifiers of amplifier circuits 119A and 119B. When receiving a high-frequency signal, switches 111A to 111H and 113A to 113H are switched to the low-noise amplifiers 112AR to 112HR, and switches 117A and 117B are connected to the receiving-side amplifiers of amplifier circuits 119A and 119B.

[0047] The signal transmitted from BBIC 200 is amplified by amplifier circuits 119A and 119B and then up-converted by mixers 118A and 118B. The up-converted transmission signal, which is a high-frequency signal, is divided into four by signal synthesizers / distributors 116A and 116B and fed to different radiating elements 121 and 122 through corresponding signal paths. By independently adjusting the phase shifting degree of phase shifters 115A to 115H arranged in each signal path, the directivity of the radio wave output from the radiating element of each substrate can be adjusted.

[0048] The received signals as high frequency signals received by the radiating elements 121 and 122 are transmitted to the RFIC 110, and are synthesized in the signal synthesizers / distributors 116A and 116B after passing through four different signal paths. The synthesized received signals are down-converted by the mixers 118A and 118B, and further amplified by the amplifier circuits 119A and 119B, and then transmitted to the BBIC 200.

[0049] The RFIC 110 is formed, for example, as a single-chip integrated circuit component including the above-mentioned circuit structure. Alternatively, the devices (switches, power amplifiers, low-noise amplifiers, attenuators, phase shifters) corresponding to the radiation elements 121 and 122 in the RFIC 110 may be formed as a single-chip integrated circuit component for each corresponding radiation element.

[0050] (Structure of antenna module)

[0051] Next, use Figure 2 and Figure 3 The structure of the antenna module 100 in the first embodiment will be described in detail. Figure 2 , a top view of the antenna module 100 is shown in the upper layer ( Figure 2 , and a side perspective view of the antenna module 100 when viewed from the negative direction of the Y axis in the figure is shown in the lower layer ( Figure 2 (B)). In addition, Figure 3 is a side perspective view of the antenna module 100 when viewed from the positive direction of the X-axis. Figure 2 and Figure 3 In order to facilitate the description, the case where there are only one radiation element 121 and one radiation element 122 is taken as an example.

[0052] Reference Figure 2 and Figure 3In addition to the dielectric substrate 130, the radiation elements 121, 122 and the RFIC 110, the antenna module 100 also includes feed wirings 141, 142, a peripheral electrode 150 and a ground electrode GND. In addition, in the following description, the normal direction of the dielectric substrate 130 (the radiation direction of the radio wave) is set as the Z-axis direction. In addition, the direction along the long side of the rectangular dielectric substrate 130 in the plane perpendicular to the Z-axis direction is defined as the X-axis, and the direction along the short side is defined as the Y-axis. In addition, the positive direction of the Z-axis in each figure is sometimes referred to as the upper side, and the negative direction is referred to as the lower side.

[0053] The dielectric substrate 130 is, for example, a low temperature co-fired ceramic (LTCC) multilayer substrate, a multilayer resin substrate formed by stacking a plurality of resin layers composed of epoxy, polyimide or other resins, a multilayer resin substrate formed by stacking a plurality of resin layers composed of liquid crystal polymer (LCP) having a relatively low dielectric constant, a multilayer resin substrate formed by stacking a plurality of resin layers composed of fluorine-based resins, a multilayer resin substrate formed by stacking a plurality of resin layers composed of PET (Polyethylene Terephthalate), or a ceramic multilayer substrate other than LTCC. In addition, the dielectric substrate 130 does not necessarily have to be a multilayer structure, and may be a single-layer substrate.

[0054] The dielectric substrate 130 has a rectangular shape when viewed from the normal direction (Z-axis direction). The dimension of the side of the dielectric substrate 130 along the Y-axis is shorter than the dimension of the side along the X-axis. The radiation element 121 is arranged in a layer (a layer on the upper side) close to the upper surface 131 (the surface in the positive direction of the Z-axis) of the dielectric substrate 130. The radiation element 121 may be arranged in a manner exposed on the surface of the dielectric substrate 130, or may be arranged in a manner such that the radiation element 121 is exposed on the surface of the dielectric substrate 130. Figure 2 (B) and Figure 3 It is arranged inside the dielectric substrate 130 as in the example of FIG.

[0055] The radiating element 122 is arranged in the dielectric layer on the lower surface 132 side of the radiating element 121 so as to face the radiating element 121. In addition, the ground electrode GND is arranged at a position close to the lower surface 132 of the dielectric substrate 130 so as to cover the entire surface of the dielectric substrate 130. When viewed from above in the normal direction (Z-axis direction) of the dielectric substrate 130, the radiating elements 121 and 122 and the ground electrode GND overlap. That is, the radiating element 122 is arranged between the radiating element 121 and the ground electrode GND.

[0056] The size of the radiation element 121 is smaller than that of the radiation element 122, and the resonance frequency of the radiation element 121 is higher than that of the radiation element 122. Therefore, the frequency band of the radio wave radiated from the radiation element 121 is higher than the frequency band of the radio wave radiated from the radiation element 122. That is, the antenna module 100 is a dual-band antenna module having a stacked structure that can radiate radio waves of two different frequency bands.

[0057] The radiating elements 121 and 122 are supplied with high-frequency signals from the RFIC 110 via the feed wirings 141 and 142, respectively. The feed wiring 141 passes through the ground electrode GND and the radiating element 122 from the RFIC 110, and is connected to the feed point SP1 of the radiating element 121. In addition, the feed wiring 142 passes through the ground electrode GND from the RFIC 110, and is connected to the feed point SP2 of the radiating element 122. The feed point SP1 is offset in the negative direction of the Y axis with respect to the center of the radiating element 121, and the feed point SP2 is offset in the positive direction of the Y axis with respect to the center of the radiating element 122. As a result, radio waves with the Y axis direction as the polarization direction are radiated from each of the radiating elements 121 and 122.

[0058] The RFIC 110 is mounted on the lower surface 132 of the dielectric substrate 130 via the solder bumps 160. Alternatively, the RFIC 110 may be connected to the dielectric substrate 130 using a multi-pole connector instead of soldering.

[0059] In the antenna module 100, peripheral electrodes 150 are formed at both ends of the dielectric substrate 130 in the Y-axis direction (i.e., the polarization direction). The peripheral electrodes 150 have a strip shape when viewed from the normal direction (Z-axis direction) of the dielectric substrate 130, and the ends of the peripheral electrodes 150 in the Y-axis direction of the dielectric substrate 130 extend along the X-axis direction. Figure 2 In the embodiment, the peripheral electrode 150 has a rectangular shape. In order to ensure the symmetry of the radiated radio waves, the peripheral electrode 150 is arranged in the center of the side along the X-axis direction of the radiating element 122. The peripheral electrode 150 extends in a direction intersecting the polarization direction (Y-axis direction) of the radiating elements 121 and 122.

[0060] The peripheral electrode 150 is arranged at a position that does not overlap with the high-frequency side radiation element 121 when viewed from the normal direction of the dielectric substrate 130. On the other hand, at least a portion of the peripheral electrode 150 overlaps with the low-frequency side radiation element 122. In addition, the peripheral electrode 150 and the radiation element 122 may not necessarily overlap, but by arranging them at a position where they partially overlap, the dimension of the dielectric substrate 130 in the Y-axis direction can be made shorter.

[0061] The peripheral electrode 150 includes a plurality of plate electrodes 151 to 155 arranged in the stacking direction (Z-axis direction) of the dielectric substrate 130 and at least one through hole 170 electrically connecting the plate electrodes. The through hole 170 is connected to the ground electrode GND. Therefore, the potential of the peripheral electrode 150 is the ground potential.

[0062] When the area of ​​the ground electrode GND is limited due to the need for miniaturization such as miniaturization of the antenna module 100 in the Y-axis direction, a part of the electric field between the radiating element 122 on the low-frequency side and the ground electrode GND may be generated in a manner that goes around the back side of the ground electrode GND. Compared with the case where the area of ​​the ground electrode GND is sufficiently large, due to the generation of such an electric field, it is difficult to radiate radio waves from the radiating element 122, and the antenna characteristics may be degraded.

[0063] However, by configuring the peripheral electrode 150, electric lines of force are preferentially generated between the radiation element 122 and the peripheral electrode 150, so that the generation of an electric field that goes around the back side of the ground electrode GND can be suppressed. Therefore, even when the area of ​​the ground electrode GND is limited for the purpose of miniaturization, the degradation of the antenna characteristics of the radiation element 122 can be suppressed.

[0064] In the antenna module 100 of the first embodiment, Figure 2 As shown in the lower layer of FIG. 1 , the sizes of the flat electrodes 151 to 155 constituting the peripheral electrode 150 along the X-axis are different from each other. More specifically, the size of the flat electrode 151 closest to the upper surface 131 is the longest, and the size gradually decreases as it approaches the ground electrode GND. In other words, in FIG. Figure 2 When the dielectric substrate 130 is viewed from the Y-axis direction as if it were a lower layer of the peripheral electrode 150, the peripheral electrode 150 has an inverted triangle shape as a whole.

[0065] The maximum dimension of the peripheral electrode 150 along the X-axis, that is, the dimension of the planar electrode 151, is smaller than the dimension of the side of the radiating element 122 and is substantially the same as the dimension of the side of the radiating element 121 on the high-frequency side. More specifically, when the wavelength in the substrate of the high-frequency signal radiated from the radiating element 121 in consideration of the dielectric constant of the dielectric substrate 130 is set to λ g When the size of the flat electrode 151 is set to about λ g / 2. In addition, the size of the flat electrode 151 may not be exactly equal to λ g / 2, as long as λ g When the radiation element is not rectangular but circular, elliptical or other polygonal, the peripheral electrode 150 is set to have a size substantially the same as the maximum outer diameter of the radiation element 121 in the X-axis direction.

[0066] By forming the peripheral electrode 150 in such a shape, the peripheral electrode 150 functions as a dielectric resonator. More specifically, two λ g In addition, by adjusting the size of the peripheral electrode 150 to a size corresponding to the radiating element 121 as described above, a pole can be generated near the frequency band of the radiating element 121. Therefore, by appropriately adjusting the size of the peripheral electrode 150, the antenna characteristics of the radiating element 121 can be improved.

[0067] (Antenna Characteristics)

[0068] Next, the antenna characteristics of the antenna module 100 according to the first embodiment will be described using a peripheral electrode of a comparative example.

[0069] Figure 4 FIG. 1 is a diagram for explaining gain characteristics of antenna modules according to Embodiment 1 and a comparative example. Figure 4 In the figure, the left column shows the case of Embodiment 1, and the right column shows the case of Comparative Example. Figure 4 The upper layer shows a schematic stereogram of the peripheral electrodes, and the lower layer shows the antenna gain.

[0070] The peripheral electrode 150X of the comparative example is composed of a plurality of planar electrodes of the same length, and is connected to the ground electrode GND through a plurality of through holes. In addition, similarly to the above-mentioned International Publication No. 2021 / 059661 (Patent Document 1), the length of the planar electrode in the peripheral electrode 150X along the Y axis is set to be longer than the side length of the radiation element 122.

[0071] like Figure 4 As shown in the lower layer of FIG. 1 , in the case of the peripheral electrode 150X of the comparative example, as shown by the line LN11, the antenna gain is less than 5 dBi in the entire bandwidth (38 GHz to 44 GHz) of the target bandwidth of the radiating element 121. On the other hand, in the case of the peripheral electrode 150 of the first embodiment, as shown by the line LN10, an antenna gain of 5 dBi or more is achieved in the entire bandwidth of the target bandwidth.

[0072] Figure 5 Graph showing the reflection loss when the maximum length of the plate electrode in the peripheral electrodes is changed. Figure 5 In the figure, the solid line LN20 represents the peripheral electrode 150 of the first embodiment, and the dotted line LN23 represents the peripheral electrode 150X of the comparative example. In addition, the dashed line LN21 represents the first example in which the length of the plate electrode is shorter than that of the peripheral electrode 150 and the shape is the same as that of the peripheral electrode 150, and the double-dashed line LN22 represents the second example in which the length of the plate electrode is further shortened.

[0073] like Figure 5 As shown, in the case of Embodiment 1, the first example, and the second example, a pole is newly added on the low-frequency side of the target frequency band compared to the case of the comparative example. This pole is considered to be generated by the peripheral electrode functioning as a dielectric resonator as described above, and as the planar electrode becomes shorter, the frequency at which the pole is generated moves to the high-frequency side. Figure 5 In the example of , the maximum length of the planar electrode is adjusted to generate a pole near 35 GHz, thereby reducing the reflection loss in a wider range.

[0074] Furthermore, the radiating element 121 on the high frequency side basically regards the radiating element 122 on the low frequency side as a virtual ground electrode, and electromagnetic coupling is performed between the radiating element 121 and the radiating element 122 , whereby radio waves are radiated from the radiating element 121 .

[0075] The peripheral electrode is arranged closer to the radiation element 122 than the ground electrode GND, and thus is easily capacitively coupled to the radiation element 122. Therefore, part of the current flowing through the radiation element 122 due to electromagnetic coupling with the radiation element 121 can flow to the ground electrode GND after passing through the peripheral electrode ( Figure 6 .

[0076] However, when the length of the flat electrode becomes narrower as it approaches the ground electrode as in the peripheral electrode 150 of the first embodiment, Figure 6 As shown by the arrow AR1, the current passing through the peripheral electrode 150 and the current flowing through the ground electrode GND cancel each other out, resulting in a decrease in the current flowing through the ground electrode GND. As a result, the coupling between the radiating element 121 and the radiating element 122 is strengthened, so it is considered that the antenna gain is improved.

[0077] As described above, when the ground electrode is limited for miniaturization, the antenna characteristics (bandwidth, antenna gain) of the radiating element on the high frequency side can be improved by focusing on the size and shape of the peripheral electrode provided to improve the antenna characteristics of the radiating element on the low frequency side. Therefore, in the dual-band antenna module, the antenna characteristics can be improved while miniaturizing the entire antenna module.

[0078] (Variation Example of Peripheral Electrode)

[0079] use Figure 7 to Figure 11 Modification examples of the peripheral electrodes will be described.

[0080] <Modification 1>

[0081] Figure 71 is a perspective view showing the structure of the peripheral electrode 150A of Modification 1. The peripheral electrode 150A is composed of a plurality of planar electrodes of the same length as in the above-mentioned comparative example. However, the length of the planar electrode is set to be equal to the size (λ) of the side of the radiation element 121. g / 2) are substantially the same length, and the bottommost planar electrode is connected to the ground electrode GND by a through hole. With such a structure, the peripheral electrode 150A also functions as a dielectric resonator, and at least a portion of the current between the bottommost planar electrode and the ground electrode GND is offset. Therefore, in the structure of the peripheral electrode 150A, it is also possible to improve the antenna characteristics while miniaturizing the entire antenna module.

[0082] <Modification 2>

[0083] Figure 8 1 is a perspective view showing the structure of the peripheral electrode 150B of Modification 2. The peripheral electrode 150B is generally an intermediate structure between the peripheral electrode 150 of Embodiment 1 and the peripheral electrode 150A of Modification 1. More specifically, the maximum length of the plate electrode in the peripheral electrode 150B is set to approximately λ g / 2, the length of the flat electrode gradually shortens as it approaches the ground electrode GND. In addition, the bottom flat electrode is connected to the ground electrode GND using a through hole. Figure 8 , an example in which the length of the flat plate electrode is set to two stages is shown, but the length of the flat plate electrode may be set to three or more stages.

[0084] In such a structure as well, the peripheral electrode 150B functions as a dielectric resonator, and at least a part of the current between the lowermost plate electrode and the ground electrode GND is canceled out. Therefore, the antenna module as a whole can be miniaturized while improving antenna characteristics.

[0085] <Variation 3>

[0086] Fig. 9 1 is a perspective view showing the structure of a peripheral electrode 150C according to Modification 3. The peripheral electrode 150C has the following structure: g / 2 length of the flat electrode and is set to be greater than λ g The two types of flat plate electrodes are alternately arranged in the Z-axis direction. In addition, the bottom flat plate electrode is connected to the ground electrode GND using a through hole. In addition, the two types of flat plate electrodes can be arranged alternately one by one, or can be arranged alternately in multiples such as every two or every three.

[0087] In such a structure as well, the peripheral electrode 150C functions as a dielectric resonator, and at least a part of the current between the lowermost plate electrode and the ground electrode GND is canceled out. Therefore, the antenna module as a whole can be miniaturized while improving antenna characteristics.

[0088] <Variation 4>

[0089] Fig.10 1 is a perspective view showing the structure of a peripheral electrode 150D according to Modification 4. In the peripheral electrode 150D, the uppermost plate electrode is set to be approximately g The length of the flat electrode is / 2, and the flat electrode gradually becomes shorter from the top flat electrode toward the ground electrode GND until the center, and the flat electrode gradually becomes longer from the center to the bottom. That is, it becomes a so-called "spool-shaped" shape in which the length of the flat electrode near the center in the Z-axis direction is short. In addition, the bottom flat electrode is connected to the ground electrode GND using one through hole.

[0090] In such a structure as well, the peripheral electrode 150D functions as a dielectric resonator, and at least a part of the current between the lowermost plate electrode and the ground electrode GND is canceled out. Therefore, the antenna module as a whole can be miniaturized while improving antenna characteristics.

[0091] <Variation 5>

[0092] Fig.11 1 is a perspective view showing the structure of a peripheral electrode 150E according to Modification 5. In the peripheral electrode 150E, similarly to the peripheral electrode 150 according to Embodiment 1, a plurality of flat electrodes 151 to 156 are arranged in an inverted triangle shape, wherein the topmost flat electrode is set to be approximately λ g / 2 in length. However, in the peripheral electrode 150E, Fig.11 There is no through hole between the plate electrode 152 and the plate electrode 153, but the capacitive coupling is provided. In this case, there is no part directly connected to the ground electrode GND. Fig.11 Although the potential of the plate electrodes 151 and 152 is higher than that of the ground electrode GND by the amount of capacitive coupling, the plate electrodes 151 and 152 function as peripheral electrodes and have substantially the same effect as the peripheral electrode 150 of the first embodiment.

[0093] In this way, even in a structure in which capacitive coupling is achieved between any of the plurality of plate electrodes constituting the peripheral electrode, it is possible to improve antenna characteristics while miniaturizing the entire antenna module.

[0094] (Effect on horizontal polarization)

[0095] As described above, in the antenna module 100 according to the first embodiment, a radio wave having a polarization direction in the Y-axis direction is radiated from the radiating element 121 , and the peripheral electrode 150 is arranged orthogonal to the polarization direction.

[0096] On the other hand, when the radiation element 121 is a so-called dual-polarization antenna module that can also radiate radio waves with the X-axis direction as the polarization direction, the extension direction of the peripheral electrode 150 is parallel to the polarization direction, so the peripheral electrode 150 operating as a resonator may affect the antenna characteristics related to the radio waves in the polarization direction. In addition, for convenience, the polarization in the Y-axis direction is referred to as "vertical polarization", and the polarization in the X-axis direction is referred to as "horizontal polarization".

[0097] Fig.12 FIG. 1 is a diagram for explaining the influence of the difference in the structure of the peripheral electrodes in the dual-polarization antenna module on the horizontal polarization. Fig.12 , the antenna gains of the vertical polarization and the horizontal polarization of the radiation element 121 are shown when the peripheral electrode 150 of the above-mentioned embodiment 1, the peripheral electrode 150A of the modification 1, the peripheral electrode 150B of the modification 2, and the peripheral electrode 150X of the comparative example are used.

[0098] Reference Fig.12 , regarding vertical polarization, if using Figure 4 As described in the examples 1, 1 and 2, the antenna gain in the target frequency band (solid lines LN30, LN30A, LN30B) of the peripheral electrodes of Embodiment 1, Modification 1 and Modification 2 is greater than the antenna gain (solid line LN30X) of the peripheral electrodes of the comparative example. On the other hand, in horizontal polarization, the antenna gain (dashed lines LN31, LN31A, LN31B) of the peripheral electrodes of Embodiment 1, Modification 1 and Modification 2 is slightly smaller as a whole than the antenna gain (dashed line LN31X) of the peripheral electrodes of the comparative example. Furthermore, the antenna gain of the peripheral electrodes of Modification 1 and Modification 2 produces a local low-gain region in the target frequency band.

[0099] The peripheral electrode extends in the X-axis direction and is arranged to be parallel to the direction of horizontal polarization. Therefore, when radiating horizontally polarized radio waves, the peripheral electrode acts as a dipole antenna, and the component corresponding to the resonant frequency of the peripheral electrode in the provided high-frequency signal is propagated to the peripheral electrode due to resonance. As a result, the gain of the corresponding resonant frequency portion decreases. In addition, in the case of the peripheral electrode 150X of the comparative example, the peripheral electrode functions only as a ground electrode protruding in the Z-axis direction, and does not function as a dipole antenna. Therefore, the radiating element 121 does not generate such a low-gain area in the target frequency band.

[0100] like Fig.12 As shown, in the peripheral electrode 150A of the modification example 1 in which all the plate electrodes are of the same length, a low gain region (dashed line LN31A) is generated near 41 GHz within the target frequency band. In the case of the peripheral electrode 150B of the modification example 2 in which the length is shortened in stages, a part of the plate electrodes is shortened compared to the peripheral electrode 150A, thereby increasing the resonance frequency of the peripheral electrode 150B and generating a low gain region near 44 GHz (dashed line LN31B). Moreover, in the peripheral electrode 150 of the embodiment 1 having an inverted triangle shape, the resonance frequency is further increased compared to the peripheral electrode 150B of the modification example 2, so the low gain region is near 45 GHz outside the target frequency band (dashed line LN31).

[0101] Thus, in the case of a dual-polarization antenna module, it is necessary to improve the antenna characteristics with respect to vertical polarization while also considering the influence of the antenna characteristics on horizontal polarization.

[0102] In addition, Fig.12 In the example of FIG. 1 , in the inverted triangle-shaped peripheral electrode 150, the local low-gain region is improved, but the frequency of the low-gain region may also change depending on the size (width) in the Y-axis direction, the size (thickness) in the Z-axis direction and / or the shape of the plate electrode constituting the peripheral electrode. Therefore, regarding the structure of the peripheral electrode, the inverted triangle shape is not necessarily the most suitable, and the structure of the peripheral electrode is appropriately determined according to the state of the low-gain region.

[0103] The "radiating element 121" and the "radiating element 122" in Embodiment 1 correspond to the "first radiating element" and the "second radiating element" in the present disclosure, respectively. Each of the "peripheral electrodes 150 to 150E" in Embodiment 1 is an example of the "first peripheral electrode" in the present disclosure. The "Z-axis direction", "X-axis direction" and "Y-axis direction" in Embodiment 1 correspond to the "first direction", "second direction" and "third direction" in the present disclosure, respectively.

[0104] [Implementation Method 2]

[0105] In the second embodiment, a configuration will be described in which, in addition to the configuration of the first embodiment, a peripheral electrode for the radiating element 121 on the high-frequency side is additionally arranged on the radiating element 122 on the low-frequency side.

[0106] Fig.13 1 is a top view of an antenna module 100A according to Embodiment 2. Fig.14 This is a side perspective view of the antenna module 100A as viewed from the X-axis direction. Note that descriptions of elements in the antenna module 100A that are the same as those of the antenna module 100 of the first embodiment will not be repeated.

[0107] Reference Fig.13 and Fig.14 In the antenna device 120A of the antenna module 100A, a peripheral electrode 180 is arranged at each end of the radiating element 122 in the positive direction and the negative direction in the Y-axis direction. The peripheral electrode 180 includes at least one planar electrode extending in the X-axis direction, and the peripheral electrode 180 is electrically connected to the radiating element 122 using a through hole. In addition, when viewed from the normal direction of the dielectric substrate 130, the peripheral electrode 180 does not overlap with the radiating element 121, but is arranged between the end of the radiating element 121 in the Y-axis direction and the end of the radiating element 122 in the Y-axis direction.

[0108] As described above, the radiating element 121 uses the radiating element 122 as a virtual ground electrode and performs electromagnetic coupling with the radiating element 122, thereby radiating radio waves. Therefore, when the size of the radiating element 122 is limited or when the difference between the resonant frequency of the radiating element 121 and the resonant frequency of the radiating element 122 is small, the area of ​​the radiating element 122 that functions as a ground electrode may be insufficient. In this case, by configuring the peripheral electrode 180 on the radiating element 122 in the same manner as the peripheral electrode 150 for the radiating element 122, it is possible to suppress a part of the electric field generated between the radiating element 121 and the radiating element 122 from bypassing the back side of the radiating element 122, thereby improving the antenna characteristics related to the radiating element 121.

[0109] In addition, the “peripheral electrode 180 ” in Embodiment 2 corresponds to the “second peripheral electrode” in the present disclosure.

[0110] [Implementation method 3]

[0111] In the third embodiment, a configuration is described in which, when each of the radiating elements 121 and 122 is a so-called dual-polarization antenna module capable of radiating two radio waves having mutually different polarization directions, peripheral electrodes are arranged for each polarization direction.

[0112] Fig.15 1 is a top view of an antenna module 100B according to Embodiment 3. In the antenna device 120B of the antenna module 100B, the radiation elements 121 and 122 can radiate radio waves with the X-axis direction as the polarization direction (horizontal polarization) and radio waves with the Y-axis direction as the polarization direction (vertical polarization). Therefore, the radiation element 121 is provided with a feeding point SP1A for horizontal polarization and a feeding point SP1B for vertical polarization. In addition, the radiation element 122 is also provided with a feeding point SP2A for horizontal polarization and a feeding point SP2B for vertical polarization.

[0113] In the antenna module 100B, similarly to the first embodiment, the peripheral electrode 150 is arranged along the X-axis direction at the end portion of the ground electrode GND in the Y-axis direction.

[0114] In the antenna module 100B, peripheral electrodes 157 are arranged along the Y-axis direction at both ends of the radiating element 122 in the X-axis direction. Fig.15 Although not shown in the figure, the peripheral electrode 157 has the same structure as the peripheral electrode 150, and has a structure in which a plurality of plate electrodes extending in the Y-axis direction are stacked in the Z-axis direction. The plurality of plate electrodes are electrically connected to the ground electrode GND by through holes, and when the dielectric substrate 130 is viewed from the X-axis direction, the peripheral electrode 157 has an inverted triangle shape as a whole.

[0115] In this way, in the dual-polarization dual-band antenna module, by providing peripheral electrodes corresponding to the respective polarization waves, it is possible to improve the antenna characteristics related to the respective polarization waves of the radiation element 121 .

[0116] In addition, the “peripheral electrode 157 ” in Embodiment 3 corresponds to the “fourth peripheral electrode” in the present disclosure.

[0117] [Implementation Method 4]

[0118] Embodiments 1 to 3 describe a configuration in which one set of radiating elements 121 and 122 stacked in the normal direction of dielectric substrate 130 is disposed on dielectric substrate 130. Embodiment 4 describes an array antenna in which a plurality of sets of radiating elements 121 and 122 are disposed on dielectric substrate 130.

[0119] Fig.16 1 is a perspective view of an antenna module 100C according to Embodiment 4. The antenna device 120C of the antenna module 100C has a structure in which five groups of radiating elements 121 and 122 are arranged in a one-dimensional array in a row along the X-axis direction on a dielectric substrate 130. A circuit substrate 105 including an RFIC 110 and other circuits is arranged on the lower surface 132 side of the dielectric substrate 130.

[0120] Each set of radiating elements 121 and 122 has the same structure as that of Embodiment 2, and a peripheral electrode 150 is disposed at an end of the ground electrode GND in the Y-axis direction. In addition, a peripheral electrode 180 is disposed at an end of the radiating element 122 in the Y-axis direction.

[0121] The antenna module 100C is a dual-polarization antenna module in which each radiating element can radiate radio waves with the X-axis direction as the polarization direction (horizontal polarization) and radio waves with the Y-axis direction as the polarization direction (vertical polarization). Therefore, a feeding point SP1A for horizontal polarization and a feeding point SP1B for vertical polarization are arranged on the radiating element 121. Fig.16 Although it is hidden by the radiating element 121 and cannot be seen, a feeding point for horizontal polarization and a feeding point for vertical polarization are also arranged in the radiating element 122.

[0122] In the antenna module 100C, the passive elements 190 and 195 extending in the Y-axis direction are arranged so as to be separated from each radiating element in the X-axis direction. More specifically, the passive element 190 is arranged in the positive and negative directions of the X-axis with respect to the radiating element 121. In addition, the passive element 195 is also arranged in the positive and negative directions of the X-axis for the radiating element 122. In addition, one passive element 195 is shared between adjacent radiating elements 122.

[0123] The passive element 190 is arranged in the same layer as the radiating element 121 in the dielectric substrate 130. The size of the passive element 190 in the Y-axis direction is set to be substantially the same as the size of the side of the radiating element 121. Similarly, the passive element 195 is arranged in the same layer as the radiating element 122 in the dielectric substrate 130. The size of the passive element 195 in the Y-axis direction is set to be substantially the same as the size of the side of the radiating element 122. By arranging such passive elements 190 and 195, the frequency band of each radiating element can be expanded.

[0124] In the case of a dual-band array antenna as described above, when the size of the ground electrode relative to the radiating element is limited to miniaturize, by arranging the peripheral electrodes to be orthogonal to the polarization direction, it is possible to suppress the degradation of the antenna characteristics related to the radiating element on the low-frequency side. In addition, by focusing on the size and shape of the peripheral electrodes, the antenna characteristics of the radiating element on the high-frequency side can also be improved.

[0125] In addition, in Embodiment 4, one of the adjacent high-frequency-side radiating elements 121 corresponds to the “first radiating element” of the present disclosure, and the other radiating element 121 corresponds to the “third radiating element” of the present disclosure. In Embodiment 4, one of the adjacent low-frequency-side radiating elements 122 corresponds to the “second radiating element” of the present disclosure, and the other radiating element 122 corresponds to the “fourth radiating element” of the present disclosure. The “passive element 190” and the “passive element 195” in Embodiment 4 correspond to the “first passive element” and the “second passive element” in the present disclosure. In Embodiment 4, the peripheral electrode 150 configured for the first radiating element corresponds to the “first peripheral electrode” of the present disclosure, and the peripheral electrode 150 configured for the third radiating element corresponds to the “third peripheral electrode” of the present disclosure.

[0126] [Implementation method 5]

[0127] Embodiments 1 to 4 describe structures for radiating radio waves with polarization directions along the sides of a rectangular dielectric substrate. Embodiment 5 describes a structure in which the features of the peripheral electrode of the present disclosure are applied to an antenna module for radiating radio waves with polarization directions inclined relative to the sides of a dielectric substrate.

[0128] Fig.17 1 is a top view and a side perspective view of an antenna module 100D according to Embodiment 5. The antenna device 120D of the antenna module 100D and Fig.15 The antenna module 100B shown is also a dual-polarization antenna module capable of radiating radio waves in two different polarization directions. In the antenna module 100D, a peripheral electrode 150F is provided instead of Fig.15 The peripheral electrodes 150 and 157 are arranged in the dielectric substrate 130. In addition, the feed wirings 141A, 141B, 142A, and 142B for transmitting high-frequency signals to the feed points SP1A, SP1B, SP2A, and SP2B, respectively, are arranged in the dielectric substrate 130. Fig.17 in Figure 2 or Fig.15 Description of the repeated element.

[0129] Reference Fig.17 In the antenna module 100D, the sides of the substantially square radiating elements 121 and 122 are arranged to be inclined relative to the sides (i.e., the X-axis and the Y-axis) of the dielectric substrate 130. More specifically, the sides of the radiating elements 121 and 122 are arranged to be inclined at 45° relative to the sides of the dielectric substrate 130. In addition, the inclination angle is not limited to 45°, and any angle may be greater than 0° and less than 90°.

[0130] In the radiation element 121, a feeding point SP1A is arranged at a position offset in the negative direction of the X axis and the negative direction of the Y axis with respect to the center of the element, and a feeding point SP1B is arranged at a position offset in the positive direction of the X axis and the negative direction of the Y axis with respect to the center of the element. In addition, in the radiation element 122, a feeding point SP2A is arranged at a position offset in the positive direction of the X axis and the positive direction of the Y axis with respect to the center of the element, and a feeding point SP2B is arranged at a position offset in the negative direction of the X axis and the positive direction of the Y axis with respect to the center of the element.

[0131] Therefore, by supplying high-frequency signals to the feeding points SP1A and SP2A, radio waves having a polarization direction of 45° from the X-axis to the Y-axis (arrow AR3) are radiated from the radiating elements 121 and 122, respectively. Also, by supplying high-frequency signals to the feeding points SP1B and SP2B, radio waves having a polarization direction of -45° from the X-axis to the Y-axis (arrow AR4) are radiated from the radiating elements 121 and 122, respectively. In other words, the polarization direction of the radio waves radiated from each radiating element is inclined with respect to each side of the dielectric substrate 130.

[0132] The peripheral electrode 150F is arranged to face each side of the radiation elements 121 and 122. The peripheral electrode 150F is composed of a plurality of plate electrodes. When viewed from the normal direction of the dielectric substrate 130, each plate electrode of the peripheral electrode 150F is arranged in a triangle shape in such a manner that the hypotenuse of the triangle faces the radiation element. In addition, the extension direction (fifth direction) of the hypotenuse of each plate electrode is orthogonal to the polarization direction (sixth direction) of each radiation element.

[0133] exist Fig.17 In the example of , the peripheral electrode 150F is composed of 6 flat electrodes 151F to 156F. The flat electrodes 151F to 156F are stacked from the upper surface 131 of the dielectric substrate 130 toward the lower surface 132. The flat electrodes 151F to 156F have shapes similar to each other, and the closer to the lower surface 132, the smaller the size. For example, the length of the hypotenuse of the flat electrode 151F is longer than the length of the hypotenuse of the flat electrode 152F. Similarly, the length of the hypotenuse of the flat electrode 152F is longer than the length of the hypotenuse of the flat electrode 153F. The flat electrodes 151F to 156F are connected to each other using multiple through holes 170, and are also connected to the ground electrode GND.

[0134] Furthermore, the length of the oblique side of the plate electrode 151F is set to be substantially the same as the length of the side of the radiation element 121 that faces the plate electrode 151F.

[0135] Fig.18 150F is a diagram showing the structure of the peripheral electrode 150F. Fig.18The upper layer (A) is a stereoscopic view of the peripheral electrode 150F when viewed from the upper surface 131, and the lower layer (B) is a stereoscopic view of the peripheral electrode 150F when viewed from the lower surface 132. The peripheral electrode 150F is configured such that, when the dielectric substrate 130 is viewed from the normal direction, the vertices of the plate electrodes facing the oblique sides overlap each other.

[0136] By configuring the peripheral electrode 150F in this manner, the peripheral electrode 150F can function as a dielectric resonator similarly to the peripheral electrode 150 of Embodiment 1. Furthermore, by adjusting the size of the oblique side of the planar electrode 151F to a size corresponding to the radiating element 121, a pole can be generated near the frequency band of the radiating element 121. Therefore, the antenna characteristics of the radiating element 121 can be improved.

[0137] Next, use Fig.19 The antenna characteristics of the antenna module 100D will be described. Fig.19 is a diagram for explaining the gain characteristics of the antenna module 100D according to the fifth embodiment. Fig.19 In FIG. 1 , the left column shows the case of the peripheral electrode 150F, and the right column shows the case of the peripheral electrode 150Y of the comparative example in which all the flat plate electrodes have the same size. Fig.19 , the upper layer shows a schematic structure diagram of the peripheral electrodes, and the lower layer shows the antenna gain of each radiating element 121, 122. In the graph of gain characteristics, lines LN40 and LN40Y represent the case of the radiating element 122 on the low frequency side, and lines LN41 and LN41Y represent the case of the radiating element 121 on the high frequency side.

[0138] like Fig.19 As shown, regarding the gain characteristics of the radiation element 121, the peak gain and bandwidth in the case of the fifth embodiment are greatly improved compared with the case of the comparative example. In addition, regarding the gain characteristics of the radiation element 122, although the bandwidth is slightly narrowed, the peak gain in the case of the fifth embodiment is larger than the peak gain in the comparative example.

[0139] As described above, even in an antenna module that radiates radio waves with a polarization direction in a direction inclined relative to each side of a dielectric substrate, the antenna characteristics of the radiating element on the high frequency side can be improved by providing a peripheral electrode extending in a direction orthogonal to the polarization direction and making the size of a plurality of planar electrodes constituting the peripheral electrode smaller as it approaches the ground electrode. Therefore, in a dual-band antenna module, the antenna characteristics can be improved while miniaturizing the entire antenna module.

[0140] <Variation 6>

[0141] Fig. 20 It is a perspective view showing the structure of a peripheral electrode 150G according to Modification Example 6. Fig. 20 The upper layer (A) is a stereoscopic view of the peripheral electrode 150G when viewed from the upper surface 131 side, and the lower layer (B) is a stereoscopic view of the peripheral electrode 150G when viewed from the lower surface 132 side. The peripheral electrode 150G has the following structure similar to the peripheral electrode 150F of the fifth embodiment: a plurality of triangular plate electrodes 151G to 156G having shapes similar to each other are connected through the through hole 170.

[0142] The planar electrodes 151G to 156G are stacked from the upper surface 131 to the lower surface 132 of the dielectric substrate 130, and the size of the electrodes decreases as they approach the lower surface 132. In addition, the peripheral electrode 150G is arranged such that when the dielectric substrate 130 is viewed from the normal direction, the oblique sides of the planar electrodes 151G to 156G facing the radiation element overlap with each other.

[0143] Fig.21 1 is a diagram for explaining the gain characteristics of an antenna module using the peripheral electrode 150G of Modification Example 6. Fig.21 In the embodiment described in 5 Fig.19 Similarly, the schematic structure diagram of the peripheral electrode is shown in the upper layer, and the antenna gain of each radiating element 121 and 122 is shown in the lower layer. In addition, the case of the peripheral electrode 150G is shown in the left column, and the case of the peripheral electrode 150Y in which all the plate electrodes have the same size is shown in the right column as a comparative example. In the graph of gain characteristics, lines LN50 and LN50Y represent the case of the radiating element 122 on the low frequency side, and lines LN51 and LN51Y represent the case of the radiating element 121 on the high frequency side.

[0144] like Fig.21 As shown, in the case of the peripheral electrode 150G, the peak gain and bandwidth of the gain characteristics of the radiation element 121 are greatly improved in the case of the modification example 6 compared with the comparative example. In addition, regarding the gain characteristics of the radiation element 122, the peak gain in the case of the modification example 6 is larger than the peak gain in the comparative example.

[0145] As described above, by using a peripheral electrode having a structure like that of Modification Example 6, the antenna characteristics of the radiating element on the high-frequency side can be improved. In a dual-band antenna module, the antenna characteristics can be improved while achieving miniaturization of the entire antenna module.

[0146] <Variation 7>

[0147] In Modification 7, another example of the arrangement of the plurality of plate electrodes constituting the peripheral electrode will be described. Fig. 22 1 is a perspective view showing the structure of a peripheral electrode 150H according to Modification 7. Fig. 22, a perspective view of the peripheral electrode 150H as viewed from the lower surface 132 side is shown.

[0148] The peripheral electrode 150H has the following structure similar to the peripheral electrode 150F of the fifth embodiment: a plurality of plate electrodes 151H to 156H having triangular shapes similar to each other are connected through the through hole 170. The plate electrodes 151H to 156H are stacked from the upper surface 131 to the lower surface 132 of the dielectric substrate 130, and the size of the electrode is smaller as it approaches the lower surface 132. In addition, the peripheral electrode 150H is arranged so that when the dielectric substrate 130 is viewed from the normal direction, the centers of gravity of the plate electrodes 151H to 156H overlap each other.

[0149] Even in the case of such an arrangement of the planar electrodes 151H to 156H, the peripheral electrode 150H can function as a dielectric resonator, and thus the antenna characteristics of the radiating element 121 can be improved.

[0150] <Variation 8>

[0151] In the fifth embodiment and the sixth and seventh modifications, the example in which the plurality of plate electrodes constituting the peripheral electrode are triangular in shape has been described. However, the shapes of the plate electrodes may be other shapes as long as they are similar to each other.

[0152] Fig.23 1 is a perspective view showing the structure of the peripheral electrode 150I according to Modification 8. Fig.23 , a stereoscopic view of the peripheral electrode 150I as viewed from the lower surface 132 side is shown.

[0153] In the eighth modification, the plate electrodes 151I to 156I constituting the peripheral electrode 150I are arranged so that, when the dielectric substrate 130 is viewed from the normal direction, the plate electrodes 151I to 156I have a sector shape similar to each other, and the arcs of the plate electrodes 151I to 156I face the radiation element 121. The plate electrodes 151I to 156I are stacked from the upper surface 131 to the lower surface 132 of the dielectric substrate 130, and the size of the electrode decreases as it approaches the lower surface 132. In addition, in the peripheral electrode 150I, the centers of the sectors of the plate electrodes 151I to 156I overlap each other when the dielectric substrate 130 is viewed from the normal direction.

[0154] Even in the case of such arrangement of the planar electrodes 151I to 156I having a fan-shaped shape, the peripheral electrode 150I can function as a dielectric resonator, and thus the antenna characteristics of the radiating element 121 can be improved.

[0155] [Way]

[0156] (Item 1) The antenna module includes a dielectric substrate, a ground electrode disposed on the dielectric substrate, a first radiating element and a second radiating element, and a first peripheral electrode. The first radiating element is disposed opposite to the ground electrode. The second radiating element is disposed between the first radiating element and the ground electrode. The first peripheral electrode is disposed in a layer between the ground electrode and the second radiating element in the dielectric substrate and is electrically connected to the ground electrode. The first radiating element and the second radiating element are in a flat plate shape. The first radiating element is configured to radiate radio waves in a first frequency band. The second radiating element is configured to radiate radio waves in a second frequency band lower than the first frequency band. The first peripheral electrode includes a plurality of flat plate electrodes stacked in a first direction, the first direction being a direction in which the first radiating element and the ground electrode face each other. The plurality of flat plate electrodes include a first electrode and a second electrode disposed in a layer between the first electrode and the ground electrode. The size of the second electrode is smaller than the size of the first electrode.

[0157] (Item 2) The antenna module according to Item 1, wherein the plurality of planar electrodes further include a third electrode disposed in a layer between the second electrode and the ground electrode, and the size of the third electrode is smaller than that of the second electrode.

[0158] (Item 3) The antenna module according to Item 1, wherein the plurality of planar electrodes are strip-shaped electrodes extending in the second direction, and a length of the second electrode in the second direction is shorter than a length of the first electrode in the second direction.

[0159] (Item 4) The antenna module according to Item 3, wherein lengths of the plurality of plate electrodes in the second direction become shorter as they approach the ground electrode.

[0160] (Item 5) The antenna module according to Item 3 or Item 4, wherein the first radiation element is configured to be able to radiate radio waves having a polarization direction in a third direction orthogonal to the second direction.

[0161] (Item 6) The antenna module according to Item 5, wherein the first peripheral electrode is arranged corresponding to each end portion of the first radiation element in the third direction.

[0162] (Item 7) The antenna module according to Item 5 or Item 6, wherein a dimension of the dielectric substrate in the third direction is shorter than a dimension of the dielectric substrate in the second direction.

[0163] (Item 8) The antenna module according to any one of Items 1 to 7, wherein the first peripheral electrode further includes a through hole for connecting the plurality of planar electrodes to the ground electrode and a through hole for connecting the plurality of planar electrodes to each other.

[0164] (Item 9) The antenna module according to any one of Items 1 to 7, wherein the plurality of planar electrodes include electrodes that are capacitively coupled to each other.

[0165] (Item 10) The antenna module according to any one of Items 3 to 7, wherein, among the plurality of planar electrodes, a length of the electrode having the longest length in the second direction is within ±25% of a dimension of the first radiation element in the second direction.

[0166] (Item 11) The antenna module according to any one of Items 1 to 10, wherein the first peripheral electrode does not overlap with the first radiation element when viewed in plan from the first direction.

[0167] (Item 12) The antenna module according to Item 11, wherein at least a portion of the first peripheral electrode overlaps with the second radiation element when viewed from above in the first direction.

[0168] (Item 13) The antenna module according to any one of Items 3 to 7, wherein the first radiation element is configured to be able to radiate radio waves having the second direction as a polarization direction.

[0169] (Item 14) The antenna module according to any one of Items 3 to 7 further includes a second peripheral electrode, the second peripheral electrode being disposed on the second radiation element and extending in the second direction, the second peripheral electrode being electrically connected to the second radiation element.

[0170] (Item 15) The antenna module according to any one of items 3 to 7 comprises a third radiating element, a fourth radiating element, and a third peripheral electrode. The third radiating element is arranged adjacent to the first radiating element and is configured to radiate a first frequency band. The fourth radiating element is arranged between the third radiating element and the ground electrode and is configured to radiate a second frequency band. The third peripheral electrode is arranged in a layer between the ground electrode and the fourth radiating element in the dielectric substrate and is electrically connected to the ground electrode. The third peripheral electrode includes a fourth electrode and a fifth electrode stacked in the first direction and extending in the second direction. The fifth electrode is arranged in a layer between the fourth electrode and the ground electrode. The length of the fifth electrode in the second direction is shorter than the length of the fourth electrode in the second direction.

[0171] (Item 16) The antenna module according to Item 15 further includes a first parasitic element, and the first parasitic element is arranged between the first radiation element and the third radiation element.

[0172] (Item 17) The antenna module according to Item 15 or Item 16 further includes a second parasitic element, which is arranged between the second radiation element and the fourth radiation element.

[0173] (Item 18) The antenna module according to Item 13 further includes a fourth peripheral electrode, which is arranged in a layer between the ground electrode and the second radiation element in the dielectric substrate and is electrically connected to the ground electrode. The fourth peripheral electrode includes a sixth electrode and a seventh electrode stacked in the first direction and extending in a fourth direction intersecting the second direction. The seventh electrode is arranged in a layer between the sixth electrode and the ground electrode. The length of the seventh electrode in the fourth direction is shorter than the length of the sixth electrode in the fourth direction.

[0174] (Item 19) The antenna module according to Item 1, wherein the plurality of planar electrodes have shapes similar to each other.

[0175] (Item 20) The antenna module according to Item 19, wherein the plurality of planar electrodes are arranged in a triangle shape with the hypotenuse facing the first radiation element, and the hypotenuse of the second electrode is shorter than the hypotenuse of the first electrode.

[0176] (Item 21) The antenna module according to Item 20, wherein the plurality of planar electrodes are arranged so that vertices of the plurality of planar electrodes facing the oblique sides overlap each other when the dielectric substrate is viewed from a normal direction.

[0177] (Item 22) The antenna module according to Item 20, wherein the plurality of planar electrodes are arranged so that oblique sides of the plurality of planar electrodes overlap with each other when the dielectric substrate is viewed from a normal direction.

[0178] (Item 23) The antenna module according to Item 20, wherein the plurality of planar electrodes are arranged so that the center of gravity positions of the plurality of planar electrodes overlap each other when the dielectric substrate is viewed from a normal direction.

[0179] (Item 24) The antenna module according to any one of Items 20 to 23, wherein when the extending direction of the oblique sides of the plurality of planar electrodes is set to a fifth direction, the first radiation element is configured to be able to radiate radio waves having a polarization direction in a sixth direction orthogonal to the fifth direction.

[0180] (Item 25) The antenna module according to Item 19, wherein, when the dielectric substrate is viewed from the normal direction, the plurality of planar electrodes are arranged in a sector shape so that an arc of the sector faces the first radiation element. The plurality of planar electrodes are arranged so that, when the dielectric substrate is viewed from the normal direction, the centers of the sectors of the plurality of planar electrodes overlap each other.

[0181] (Item 26) The antenna module according to any one of Items 19 to 25, wherein the dielectric substrate has a substantially rectangular shape, and an angle formed by a polarization direction of the first radiating element and each side of the dielectric substrate is greater than 0° and less than 90°.

[0182] (Item 27) The antenna module according to any one of Items 1 to 26 further includes a feed circuit configured to supply a high-frequency signal to each radiating element.

[0183] (Item 28) A communication device including the antenna module according to any one of Items 1 to 27.

[0184] The embodiments disclosed this time should be considered as illustrative in all aspects and not restrictive. The scope of the present invention is indicated by the claims rather than the description of the above embodiments, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0185] Description of Reference Numerals

[0186] 10: communication device; 100, 100A~100D: antenna module; 105: circuit substrate; 110: RFIC; 111A~111H, 113A~113H, 117A, 117B: switch; 112AR~112HR: low noise amplifier; 112AT~112HT: power amplifier; 114A~114H: attenuator; 115A~115H: phase shifter; 116A, 116B: signal synthesizer / distributor; 118A, 118B: mixer; 119A, 119B: amplifier circuit; 120, 120A~120D: antenna Device; 121, 122: radiating element; 130: dielectric substrate; 141, 142: feeding wiring; 150, 150A~150I, 150X, 150Y, 157, 180: peripheral electrodes; 151~156, 151F~156F, 151G~156G, 151H~156H, 151I~156I: flat electrode; 160: solder bump; 170: through hole; 190, 195: passive component; 200: BBIC; GND: ground electrode; SP1, SP1A, SP1B, SP2, SP2A, SP2B: feeding point.

Claims

1. An antenna module, comprising: Dielectric substrate; a ground electrode disposed on the dielectric substrate; A first radiation element, which is arranged facing the ground electrode; a second radiation element disposed between the first radiation element and the ground electrode; as well as a first peripheral electrode disposed in a layer between the ground electrode and the second radiation element in the dielectric substrate and electrically connected to the ground electrode, Wherein, the first radiation element and the second radiation element are in the shape of a flat plate, The first radiating element is configured to radiate radio waves in a first frequency band. The second radiating element is configured to radiate radio waves in a second frequency band lower than the first frequency band. The first peripheral electrode includes a plurality of flat plate electrodes stacked in a first direction, wherein the first direction is a direction in which the first radiation element faces the ground electrode. The plurality of plate electrodes include: a first electrode; and The second electrode is disposed in a layer between the first electrode and the ground electrode, and the size of the second electrode is smaller than that of the first electrode.

2. The antenna module according to claim 1, wherein: The plurality of plate electrodes further include a third electrode, wherein the third electrode is disposed in a layer between the second electrode and the ground electrode. The third electrode has a size smaller than that of the second electrode.

3. The antenna module according to claim 1, wherein: The plurality of flat plate electrodes are strip-shaped electrodes extending in the second direction, A length of the second electrode in the second direction is shorter than a length of the first electrode in the second direction.

4. The antenna module according to claim 3, wherein: The lengths of the plurality of plate electrodes in the second direction become shorter as they approach the ground electrode.

5. The antenna module according to claim 3 or 4, wherein: The first radiating element is configured to be capable of radiating a radio wave having a third direction orthogonal to the second direction as a polarization direction.

6. The antenna module according to claim 5, wherein: The first peripheral electrode is arranged corresponding to each end portion of the first radiation element in the third direction.

7. The antenna module according to claim 5 or 6, wherein: A dimension of the dielectric substrate in the third direction is shorter than a dimension of the dielectric substrate in the second direction.

8. The antenna module according to any one of claims 1 to 7, wherein: The first peripheral electrode further includes through holes for connecting the plurality of plate electrodes to the ground electrode and through holes for connecting the plurality of plate electrodes to each other.

9. The antenna module according to any one of claims 1 to 7, wherein: The plurality of plate electrodes include electrodes that are capacitively coupled to each other.

10. The antenna module according to any one of claims 3 to 7, wherein: Among the plurality of planar electrodes, a length of an electrode having the longest length in the second direction is within ±25% of a dimension of the first radiation element in the second direction.

11. The antenna module according to any one of claims 1 to 10, wherein: When viewed from above in the first direction, the first peripheral electrode does not overlap with the first radiation element.

12. The antenna module according to claim 11, wherein: When viewed in plan from the first direction, at least a portion of the first peripheral electrode overlaps with the second radiation element.

13. The antenna module according to any one of claims 3 to 7, wherein: The first radiating element is configured to be further capable of radiating radio waves having the second direction as a polarization direction.

14. The antenna module according to any one of claims 3 to 7, wherein: It also includes a second peripheral electrode, which is disposed on the second radiation element and extends in the second direction. The second peripheral electrode is electrically connected to the second radiation element.

15. The antenna module according to any one of claims 3 to 7, wherein: have: a third radiating element, disposed adjacent to the first radiating element and configured to radiate the first frequency band; a fourth radiation element disposed between the third radiation element and the ground electrode and configured to radiate the second frequency band; as well as a third peripheral electrode disposed in a layer between the ground electrode and the fourth radiation element in the dielectric substrate and electrically connected to the ground electrode, The third peripheral electrode includes a fourth electrode and a fifth electrode stacked in the first direction and extending in the second direction, The fifth electrode is disposed in a layer between the fourth electrode and the ground electrode. A length of the fifth electrode in the second direction is shorter than a length of the fourth electrode in the second direction.

16. The antenna module according to claim 15, wherein: A first passive element is further provided, and the first passive element is arranged between the first radiating element and the third radiating element.

17. The antenna module according to claim 15 or 16, wherein: A second passive element is further provided, and the second passive element is arranged between the second radiating element and the fourth radiating element.

18. The antenna module according to claim 1, wherein: The plurality of plate electrodes have shapes similar to each other.

19. The antenna module according to any one of claims 1 to 18, wherein: A feeding circuit is further provided, and the feeding circuit is configured to supply a high-frequency signal to each radiating element.

20. A communication device comprising the antenna module according to any one of claims 1 to 19.

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