Antenna module and communication device equipped with the antenna module

Abstract

The antenna module (100) includes flat radiation elements (121, 122) and a feeding wiring (141A) that transmits a high-frequency signal to the radiation element (121). The radiation element (122) is disposed at a position different from that of the radiation element (121) in the normal direction of the radiation element (121) and has a resonance frequency different from that of the radiation element (121). The feeding wiring (141A) penetrates the radiation element (122) from the RFIC (110) and transmits the high-frequency signal to the radiation element (121). The feeding wiring (141A) includes a shift region extending in a direction orthogonal to the normal direction of the radiation element (121) at a position different from that of the radiation element (122) on the path from the RFIC (110) to the radiation element (121). When viewed from the normal direction of the radiation element (121), an opening (150) is formed in a portion of the radiation element (122) that overlaps the shift region.

Description

Technical Field

[0001] The present disclosure relates to an antenna module and a communication device equipped with the antenna module. More specifically, the present disclosure relates to a technique for improving the gain characteristics in a stacked dual-band antenna module. Background Art

[0002] In Japanese Patent Application Laid-Open No. 2015-216577 (Patent Document 1), a so-called stacked dual-band antenna module is disclosed in which a second patch is disposed between a first patch (a flat plate-shaped radiating element) and a ground plane, and radio waves of different frequencies can be radiated from the two patches. In an example of the antenna module disclosed in Japanese Patent Application Laid-Open No. 2015-216577 (Patent Document 1) ( Figure 15 ) of Patent Document 1, the feeding wiring connected to the first patch is configured to extend in a direction away from the center of the patch between the first patch and the second patch and then penetrate the second patch.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2015-216577 Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] In the antenna module having the feeding wiring as described above disclosed in Japanese Patent Application Laid-Open No. 2015-216577 (Patent Document 1), capacitive coupling occurs in a portion where the feeding wiring faces the second patch, and sometimes unwanted resonance that does not contribute to radiation is generated. When such unwanted resonance occurs, energy is consumed due to the resonance, and as a result, the gain characteristics of the entire antenna module may decrease.

[0008] The present disclosure has been made to solve such problems, and an object thereof is to suppress a decrease in gain characteristics by suppressing unwanted resonance in a stacked dual-band antenna module.

[0009] Means for Solving the Problems

[0010] An antenna module according to an aspect of the present disclosure includes: a flat first radiation element and a second radiation element, and a first feeding line that transmits a high-frequency signal to the first radiation element. The second radiation element is disposed at a position different from that of the first radiation element in the normal direction of the first radiation element, and has a resonance frequency different from that of the first radiation element. The first feeding line penetrates the second radiation element from a feeding circuit and transmits a high-frequency signal to the first radiation element. The first feeding line includes a shift region extending in a direction orthogonal to the normal direction of the first radiation element at a position different from the second radiation element on the path from the feeding circuit to the first radiation element. When viewed from above in the normal direction of the first radiation element, an opening is formed in a portion of the second radiation element that overlaps with the shift region.

[0011] Effect of the Invention

[0012] In the antenna module according to the present disclosure, two radiation elements (a first radiation element and a second radiation element) are arranged facing each other, and the feeding line that supplies a high-frequency signal to the first radiation element includes a shift region extending in a direction orthogonal to the normal direction of the first radiation element. Moreover, when viewed from above, an opening is formed in a portion of the second radiation element that overlaps with this shift region. By adopting such a structure, it is possible to suppress the capacitive coupling generated between the shift region of the feeding line and the second radiation element, and thus it is possible to suppress the unwanted resonance generated due to this capacitive coupling. Therefore, it is possible to suppress the degradation of the gain characteristic of the antenna module. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a block diagram of a communication device to which the antenna module according to Embodiment 1 is applied.

[0014] Figure 2 It is a top view of the antenna module according to Embodiment 1.

[0015] Figure 3 is Figure 2 Cross-sectional perspective view taken along line III-III of

[0016] Figure 4 It is a top view of the antenna module of Comparative Example 1.

[0017] Figure 5 is Figure 4 Cross-sectional perspective view taken along line V-V of

[0018] Figure 6 It is a diagram for explaining the reflection loss of the antenna modules of Comparative Example 1 and Embodiment 1.

[0019] Figure 7This is a diagram for explaining the gain characteristics of the high-frequency side radiation element in the antenna modules of Comparative Example 1 and Embodiment 1.

[0020] Figure 8 This is a top view of the antenna module according to Embodiment 2.

[0021] Figure 9 This is a top view of the antenna module of Comparative Example 2.

[0022] Figure 10 This is a diagram for explaining the reflection loss of the antenna modules of Comparative Example 2 and Embodiment 2.

[0023] Figure 11 This is a diagram for explaining the gain characteristics of the high-frequency side radiation element in the antenna modules of Comparative Example 2 and Embodiment 2.

[0024] Figure 12 This is a cross-sectional perspective view of the antenna module of Modification 1.

[0025] Figure 13 This is a cross-sectional perspective view of the antenna module of Modification 2.

[0026] Figure 14 This is a cross-sectional perspective view of the antenna module of Modification 3.

[0027] Figure 15 This is a cross-sectional perspective view of the antenna module of Modification 4.

[0028] Figure 16 This is a cross-sectional perspective view of the antenna module of the first example of Modification 5.

[0029] Figure 17 This is a cross-sectional perspective view of the antenna module of the second example of Modification 5. Detailed Embodiments

[0030] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In addition, the same or corresponding parts in the drawings are denoted by the same reference numerals and their description will not be repeated.

[0031] [Embodiment 1]

[0032] (Basic Structure of Communication Device)

[0033] Figure 1FIG. 0 is a block diagram showing an example of a communication device 10 to which the antenna module 100 according to the first embodiment is applied. The communication device 10 is, for example, a portable terminal such as a mobile phone, a smart phone, or a tablet computer, or a personal computer having a communication function. An example of the frequency band of the radio wave used by the antenna module 100 according to the present embodiment is a radio wave in the millimeter wave band centered on 28 GHz, 39 GHz, 60 GHz, etc., but it can also be applied to radio waves in frequency bands other than the above.

[0034] Referring to Figure 1 , the 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 as an example of a feeding circuit and an antenna device 120. The communication device 10 up-converts the signal transmitted from the BBIC 200 to the antenna module 100 into a high-frequency signal and radiates it from the antenna device 120, and down-converts the high-frequency signal received by the antenna device 120 and processes the signal through the BBIC 200.

[0035] In Figure 1 , the antenna device 120 has a structure in which the radiation elements 125 are arranged in a two-dimensional array. Each radiation element 125 includes two feeding elements 121 and 122. The antenna device 120 is a so-called dual-band type antenna device configured to be able to radiate radio waves in different frequency bands from the feeding element 121 and the feeding element 122 of the radiation element 125. Different high-frequency signals are supplied from the RFIC 110 to the feeding elements 121 and 122. As an example, the frequency band of the radio wave radiated from the feeding element 121 is 39 GHz, and the frequency band of the radio wave radiated from the feeding element 122 is 28 GHz.

[0036] In Figure 1 , for ease of explanation, only the structure corresponding to four radiation elements 125 among the plurality of radiation elements 125 constituting the antenna device 120 is shown, and the structure corresponding to other radiation elements 125 having the same structure is omitted. In addition, the antenna device 120 does not have to be a two-dimensional array, and it may be a case where the antenna device 120 is formed by one radiation element 125. Alternatively, the plurality of radiation elements 125 may be arranged in a one-dimensional array in a row. In the present embodiment, the feeding elements 121 and 122 included in the radiation element 125 are patch antennas having a substantially square flat plate shape.

[0037] 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 combiners / dividers 116A, 116B, mixers 118A, 118B, and amplifier circuits 119A, 119B. Among them, the structures of 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 combiner / divider 116A, mixer 118A, and amplifier circuit 119A are circuits for high-frequency signals in the first frequency band radiated from the feeding element 121. In addition, the structures of switches 111E to 111H, 113E to 113H, 117B, power amplifiers 112ET to 112HT, low-noise amplifiers 112ER to 112HR, attenuators 114E to 114H, phase shifters 115E to 115H, signal combiner / divider 116B, mixer 118B, and amplifier circuit 119B are circuits for high-frequency signals in the second frequency band radiated from the feeding element 122.

[0038] When transmitting high-frequency signals, switches 111A to 111H, 113A to 113H are switched to the power amplifier 112AT to 112HT side, and switches 117A, 117B are connected to the transmitting-side amplifiers of amplifier circuits 119A, 119B. When receiving high-frequency signals, switches 111A to 111H, 113A to 113H are switched to the low-noise amplifier 112AR to 112HR side, and switches 117A, 117B are connected to the receiving-side amplifiers of amplifier circuits 119A, 119B.

[0039] The signals transmitted from the BBIC 200 are amplified by amplifier circuits 119A, 119B and up-converted by mixers 118A, 118B. The up-converted transmission signals as high-frequency signals are divided into four waves by signal combiners / dividers 116A, 116B, and are fed to different feeding elements 121, 122 through the corresponding signal paths. By independently adjusting the phase shift degrees of the phase shifters 115A to 115H arranged in each signal path, the directivity of the antenna device 120 can be adjusted.

[0040] The received signals, which are high-frequency signals received by each of the feeding elements 121 and 122, are transmitted to the RFIC 110, and are combined in the signal combiners / splitters 116A and 116B after passing through four different signal paths. The combined received signals are down-converted by the mixers 118A and 118B, and are amplified by the amplifier circuits 119A and 119B and then transmitted to the BBIC 200.

[0041] The RFIC 110 is formed, for example, as a monolithic integrated circuit component including the above circuit structure. Alternatively, for the devices (switches, power amplifiers, low-noise amplifiers, attenuators, phase shifters) in the RFIC 110 corresponding to each of the radiation elements 125, they can be formed as monolithic integrated circuit components for each corresponding radiation element 125.

[0042] In addition, in the case of a dual-polarization type antenna module capable of radiating radio waves in two polarization directions by each feeding element, two feeding wirings are connected from the RFIC 110 to each feeding element. Alternatively, one feeding wiring can be branched by a branch circuit (not shown) to supply high-frequency signals to each feeding point of the feeding element.

[0043] (Structure of the antenna module)

[0044] Next, use Figure 2 and Figure 3 to describe in detail the structure of the antenna module 100 in Embodiment 1. Figure 2 is a top view of the antenna module 100, Figure 3 is Figure 2 a cross-sectional perspective view taken along line III-III of Figure 2 and Figure 3 shown. In the following description, for ease of explanation, an antenna module having one radiation element 125 is taken as an example for description. In addition, as

[0045] shown in Figure 2 and Figure 3 , the thickness direction of the antenna module 100 is set as the Z-axis direction, and a plane perpendicular to the Z-axis direction is defined by the X-axis and the Y-axis. In addition, sometimes the positive direction of the Z-axis in each figure is referred to as the upper surface side, and the negative direction is referred to as the lower surface side.

[0045] Referring to Figure 2 and Figure 3 , in addition to the RFIC 110 and the radiation element 125 (feeding elements 121 and 122), the antenna module 100 further includes a dielectric substrate 130, a ground electrode GND, and feeding wirings 141A, 141B, 142A, and 142B. In addition, in Figure 2 , the RFIC 110, the ground electrode GND, and the dielectric substrate 130 are omitted.

[0046] The dielectric substrate 130 is, for example, a low-temperature co-fired ceramic (LTCC) multilayer substrate, a multilayer resin substrate formed by laminating multiple resin layers made of resins such as epoxy resin and polyimide, a multilayer resin substrate formed by laminating multiple resin layers made of liquid crystal polymer (LCP) having a lower dielectric constant, a multilayer resin substrate formed by laminating multiple resin layers made of fluororesin, a multilayer resin substrate formed by laminating multiple resin layers made of PET (polyethylene terephthalate) material, or a ceramic multilayer substrate other than LTCC. In addition, the dielectric substrate 130 does not have to be a multilayer structure and may be a single-layer substrate. Further, the dielectric substrate 130 may be the housing of the communication device 10.

[0047] When viewed from above in the normal direction (Z-axis direction), the dielectric substrate 130 has a substantially rectangular shape, and the feeding element 121 is arranged on the upper surface 131 (the surface in the positive direction of the Z-axis) side to face the ground electrode GND. The feeding element 121 may be exposed on the surface of the dielectric substrate 130 or may be arranged in the inner layer of the dielectric substrate 130 as in the example of Figure 3 .

[0048] The feeding element 122 is arranged in the layer closer to the ground electrode GND than the feeding element 121 to face the ground electrode GND. In other words, the feeding element 122 is arranged in the layer between the feeding element 121 and the ground electrode GND. When the dielectric substrate 130 is viewed from above, the feeding element 122 overlaps the feeding element 121. The size of the feeding element 121 is smaller than the size of the feeding element 122, and the resonance frequency of the feeding element 121 is higher than the resonance frequency of the feeding element 122. That is, the frequency of the radio wave radiated from the feeding element 121 is higher than the frequency of the radio wave radiated from the feeding element 122. For example, the center frequency of the radio wave radiated from the feeding element 121 is 39 GHz, and the center frequency of the radio wave radiated from the feeding element 122 is 28 GHz.

[0049] On the lower surface 132 of the dielectric substrate 130, the RFIC 110 is mounted by means of solder bumps (not shown). In addition, instead of soldering connection, a multi-pole connector may be used to connect the RFIC 110 to the dielectric substrate 130.

[0050] A high-frequency signal is transmitted from the RFIC 110 to the feeding element 121 via the feeding wirings 141A and 141B. The feeding wiring 141A penetrates through the ground electrode GND and the feeding element 122 from the RFIC 110, and then is connected to the feeding point SP1A from the lower surface side of the feeding element 121. Similarly, the feeding wiring 141B penetrates through the ground electrode GND and the feeding element 122 from the RFIC 110, and then is connected to the feeding point SP1B from the lower surface side of the feeding element 121. That is, the feeding wirings 141A and 141B transmit high-frequency signals to the feeding points SP1A and SP1B of the feeding element 121, respectively.

[0051] The feeding point SP1A is arranged at a position deviated from the center of the feeding element 121 in the positive direction of the Y axis. In addition, the feeding point SP1B is arranged at a position deviated from the center of the feeding element 121 in the negative direction of the X axis. When a high-frequency signal is provided to the feeding point SP1A, an electric wave with the polarization direction in the Y-axis direction is radiated from the feeding element 121. In addition, when a high-frequency signal is provided to the feeding point SP1B, an electric wave with the polarization direction in the X-axis direction is radiated from the feeding element 121.

[0052] In addition, a high-frequency signal is transmitted from the RFIC 110 to the feeding element 122 via the feeding wirings 142A and 142B. The feeding wiring 142A penetrates through the ground electrode GND from the RFIC 110 and is connected to the feeding point SP2A of the feeding element 122. Similarly, the feeding wiring 142B penetrates through the ground electrode GND from the RFIC 110 and is connected to the feeding point SP2B of the feeding element 122. That is, the feeding wirings 142A and 142B transmit high-frequency signals to the feeding points SP2A and SP2B of the feeding element 122, respectively.

[0053] The feeding point SP2A is arranged at a position deviated from the center of the feeding element 122 in the negative direction of the Y axis. In addition, the feeding point SP2B is arranged at a position deviated from the center of the feeding element 122 in the positive direction of the X axis. When a high-frequency signal is provided to the feeding point SP2A, an electric wave with the polarization direction in the Y-axis direction is radiated from the feeding element 122. In addition, when a high-frequency signal is provided to the feeding point SP2B, an electric wave with the polarization direction in the X-axis direction is radiated from the feeding element 121.

[0054] That is, the antenna module 100 is a so-called dual-band and dual-polarization type antenna module that can radiate electric waves of two different frequency bands and can radiate the electric waves of each frequency band in two different polarization directions.

[0055] Each of the feed wirings 141A, 141B, 142A, and 142B is configured to include an electrode pad 146 formed at the boundary of each dielectric layer and a via hole 145 that penetrates the dielectric layer to connect the electrode pads 146 above and below the dielectric layer. In addition, when each feed wiring extends within the same layer, the electrode pads 146 are connected by a wiring pattern (not shown). In the present disclosure, a portion where the feed wiring extends in a direction orthogonal to the normal direction of the feed element 121 is referred to as a "shift region 170".

[0056] Each feed wiring includes: a portion (first wiring) that penetrates the ground electrode GND from the RFIC 110 and extends in the central direction of the radiating element to below the corresponding feed point in the layer between the feed element 122 and the ground electrode GND, and a portion (second wiring) from below the feed point to the feed point. The shift region 170 is formed in the second wiring. Therefore, the second wiring is connected to the feed point in a meandering manner shifted in the X-axis direction or the Y-axis direction. In the example of the antenna module 100 of Embodiment 1, two shift regions are formed in the feed wirings 141A and 141B.

[0057] In the antenna module 100, the shift region 170 is formed in a direction orthogonal to the direction (polarization direction) extending from the RFIC 110 to below the feed point. For example, the shift region of the feed wiring 141A is shifted in the X-axis direction, and the shift region of the feed wiring 142B is shifted in the Y-axis direction. In this way, by forming a shift region in the feed wiring, it is possible to appropriately adjust the impedance mismatch generated at the connection portion between the dielectric layers.

[0058] As described above, the feed wirings 141A and 141B connected to the feed element 121 penetrate the feed element 122. In the antenna module 100 of Embodiment 1, when looking down at the feed element 121, an opening 150 is formed in a portion of the feed element 122 that overlaps with the shift regions 170 of the feed wirings 141A and 141B.

[0059] Next, use Figure 4 and Figure 5 The comparative example 1 shown is used to illustrate the effects produced by the opening 150 formed in the feed element 122. Figure 4 is a top view of the antenna module 100#1 of Comparative Example 1. In addition, Figure 5 is Figure 4 A cross-sectional perspective view taken along line V-V.

[0060] Refer to Figure 4 and Figure 5, the antenna module 100#1 of Comparative Example 1 basically has the same structure as the antenna module 100 of Embodiment 1, except that an opening 150# is formed only in the portion where the feeding wirings 141A and 141B in the feeding element 122 penetrate.

[0061] In the case of the antenna module 100#1 of Comparative Example 1, as Figure 5 shown, a shift region 170 is formed above or below the feeding element 122 in the feeding wirings 141A and 141B that penetrate the opening 150# of the feeding element 122. When looking down at the antenna module 100#1 from the normal direction (Z direction), this shift region 170 overlaps with the feeding element 122. Therefore, when the distance between the feeding element 122 and the shift region 170 is close, capacitive coupling may occur between the electrode pads 146 included in the shift region 170 and the feeding element 122. When capacitive coupling occurs, sometimes an unwanted resonance that does not contribute to radiation from the feeding element is generated. When such an unwanted resonance is generated, energy is consumed due to this resonance, and as a result, sometimes the gain characteristics of the entire antenna module deteriorate.

[0062] On the other hand, in the antenna module 100 of Embodiment 1, when looking down at the feeding element 121, an opening 150 is formed in the portion of the feeding element 122 that overlaps with the shift region 170. That is, the shift region 170 of the feeding wirings 141A and 141B does not face the feeding element 122. Thereby, capacitive coupling between the shift region 170 and the feeding element 122 is suppressed, and thus generation of an unwanted resonance as in Comparative Example 1 can be suppressed. Therefore, deterioration of the gain characteristics caused by the unwanted resonance can be suppressed.

[0063] Figure 6 and Figure 7 are diagrams for explaining the antenna characteristics of the antenna modules of Comparative Example 1 and Embodiment 1. Figure 6 is a diagram for comparing the reflection losses of the antenna modules of Comparative Example 1 and Embodiment 1, Figure 7 is a diagram for comparing the gain characteristics of the feeding element 121 in the antenna modules of Comparative Example 1 and Embodiment 1. In Figure 6 the upper part ( Figure 6 (a) of Figure 6 ) shows the reflection loss of the antenna module 100#1 of Comparative Example 1, and the lower part ( (b) of

[0064] ) shows the reflection loss of the antenna module 100 of Embodiment 1. In addition, in Figure 6 , the solid lines LN10 and LN20 show the reflection loss of the feeding element 121, and the dashed lines LN11 and LN21 show the reflection loss of the feeding element 122. Also, inFigure 7 Among them, the solid line LN30 shows the gain characteristics in the case of Embodiment 1, and the dashed line LN31 shows the gain characteristics in the case of Comparative Example 1.

[0065] In addition, in the antenna module 100 of Embodiment 1, the thickness of each dielectric layer constituting the dielectric substrate 130 is 50 μm. Further, in each feeding wiring, the diameter of the via hole 145 is 100 μm, the diameter of the electrode pad 146 is 240 μm, and the displacement amount (via hole pitch) of the via holes is 240 μm.

[0066] Referring to Figure 6 and Figure 7 , regarding the reflection loss of the feeding element 122 on the low-frequency side, there is no significant difference between Comparative Example 1 and Embodiment 1. However, regarding the reflection loss of the feeding element 121 on the high-frequency side, Comparative Example 1 shows a lower value compared to Embodiment 1. Therefore, at first glance, the antenna module 100#1 of Comparative Example 1 may seem to show better characteristics than the antenna module 100 of Embodiment 1.

[0067] However, in Figure 7 the gain characteristics, regarding the gain in the desired frequency band, the antenna module 100 of Embodiment 1 is higher than the antenna module 100#1 of Comparative Example 1. That is, it can be seen that in the antenna module 100#1 of Comparative Example 1, due to the resonance generated between the feeding wirings 141A and 142A and the feeding element 121, the loss of the feeding element 121 seems to be reduced from the perspective of reflection loss, but this resonance does not contribute to the gain and instead causes a decrease in the gain.

[0068] On the other hand, it can be seen that in the antenna module 100 of Embodiment 1, by forming the opening 150 in the portion of the feeding element 122 facing the feeding wirings 141A and 141B, the unnecessary resonance is suppressed, and as a result, the decrease in the gain is suppressed.

[0069] As described above, in the stacked dual-band antenna module, when looking at the antenna module from above, an opening is formed in the overlapping portion of the meandering feeding wiring that penetrates the feeding element on the lower surface side and reaches the feeding element on the upper surface side and the feeding element on the lower surface side, thereby suppressing the generation of unnecessary resonance between the feeding wiring and the feeding element on the lower surface side, and thus suppressing the decrease in the gain characteristics of the feeding element on the upper surface side.

[0070] In addition, in the feeding wirings 141A and 141B, when there is a shifted region 170 in the region between the feeding element 122 and the ground electrode GND, and when the shifted region 170 is closer to the ground electrode GND than the feeding element 122, the shifted region 170 is more likely to be coupled to the ground electrode GND than the feeding element 122. Thus, it is not easy to generate the unnecessary resonance as described above. Therefore, as Figure 3 shown, when looking down at the antenna module 100, it is sufficient that the opening 150 formed in the feeding element 122 is formed in a region overlapping with the shifted region 170 at a position closer to the feeding element 122 than the position at 1 / 2 of the distance HT between the feeding element 122 and the ground electrode GND.

[0071] In addition, when the size of the opening 150 becomes larger, the electrode portion of the feeding element 122 decreases, so there is a concern about the influence on the radiation characteristics of the feeding element 122. In addition, when the opening 150 is close to other openings, the isolation of the radio waves from each other may deteriorate. Therefore, the size of the opening 150 is preferably 300% or less of the size of the electrode pad and the wiring pattern when looking down at the antenna module 100. In the example of Embodiment 1, the diameter of the electrode pad is 240 μm, and relatively, the diameter of the opening 150 is 340 μm, so the size of the opening 150 is about 142% of the size of the electrode pad.

[0072] [Embodiment 2]

[0073] In Embodiment 1, the following case was described: the extending direction of the shifted region is a direction orthogonal to the direction (polarization direction) from the feeding point toward the center of the feeding element. In Embodiment 2, the following case will be described: the extending direction of the shifted region is parallel to the polarization direction.

[0074] Figure 8 is a top view of the antenna module 100A according to Embodiment 2. In the antenna module 100A, when looking down at the antenna module 100A, the shifted regions 170X in the feeding wirings 161A and 161B for supplying high-frequency signals to the respective feeding elements extend in the direction from the corresponding feeding point toward the center of the radiation element. Moreover, in the feeding element 122, when looking down at the antenna module 100A, openings 155 are formed in the portions overlapping with the shifted regions 170X in the feeding wirings 161A and 161B. Regarding other structures, they are the same as those of the antenna module 100 of Embodiment 1, so detailed description will not be repeated.

[0075] Regarding such an antenna module 100A, Figure 10 and Figure 11 show the same as Figure 9Comparison of the antenna characteristics of the antenna module 100#2 of Comparative Example 2 shown. Further, in the antenna module 100#2 of Comparative Example 2, an opening 155 is formed only in a portion where the feeding wirings 161A and 161B penetrate the feeding element 122#.

[0076] Figure 10 is a diagram for comparing the reflection loss of the antenna modules of Comparative Example 2 and Embodiment 2, Figure 11 is a diagram for comparing the gain characteristics of the feeding element 121 in the antenna modules of Comparative Example 2 and Embodiment 2. In Figure 10 , similar to Figure 6 , the upper part ( Figure 10 (a) of Figure 10 ) shows the reflection loss in the antenna module 100#2 of Comparative Example 2, and the lower part ( Figure 10 (b) of Figure 11 ) shows the reflection loss in the antenna module 100A of Embodiment 2. In

[0077] Further, in the antenna module 100A, the thickness of each dielectric layer constituting the dielectric substrate 130 is 50 μm. Additionally, in each feeding wiring, the diameter of the via hole 145 is 100 μm, the diameter of the electrode pad 146 is 240 μm, and the via hole pitch is 240 μm.

[0078] Referring to Figure 10 and Figure 11 , compared with the case of Embodiment 2, in Comparative Example 2, the reflection loss of the feeding element 122 on the low-frequency side decreases, but the reflection loss of the feeding element 121 on the high-frequency side hardly changes. However, Figure 10 the resonance peak around 38 GHz in (a) of

[0079] Comparative Example 2 becomes an asymmetric shape compared with the resonance peak of Embodiment 2 due to the influence of unwanted resonance. Figure 11 On the other hand, in the gain characteristics of

[0080] As described above, even when the extending directions of the shifted regions of the feeding wirings are different, when the antenna module is viewed from above, an opening is formed in a portion where the shifted region in the meandering feeding wiring that penetrates the feeding element on the lower surface side and reaches the feeding element on the upper surface side overlaps with the feeding element on the lower surface side. Thereby, generation of unnecessary resonance between the feeding wiring and the feeding element on the lower surface side is suppressed, and thus a decrease in the gain characteristic of the feeding element on the upper surface side can be suppressed.

[0081] [Modification Example]

[0082] In the following Modification Examples 1 to 3, other structural examples of the feeding wiring connected to the feeding element 121 will be described. In addition, in Modification Example 4, an example in which the low-frequency side radiation element has no feeding element will be described. Further, in Modification Examples 1 to 4, regarding the feeding element 121, only the feeding wiring for radiating radio waves with the polarization direction along the Y-axis is shown, but the feeding wiring for radiating radio waves with the polarization direction along the X-axis can also have the same structure.

[0083] (Modification Example 1)

[0084] Figure 12 FIG. is a cross-sectional perspective view of the antenna module 100B of Modification Example 1. In the antenna module 100B, the shifted region 170A in the feeding wiring 141A1 for supplying a high-frequency signal to the feeding element 121 is formed in the layer between the feeding element 121 and the feeding element 122. Moreover, when the antenna module 100B is viewed from above, an opening 150 is formed in a portion of the feeding element 122 that overlaps with the shifted region 170A. By adopting such a structure, capacitive coupling between the shifted region 170A of the feeding wiring 141A1 and the feeding element 122 is suppressed, and thus unnecessary resonance generated due to this capacitive coupling is suppressed. Therefore, a decrease in the gain characteristic of the antenna module can be suppressed.

[0085] (Modification Example 2)

[0086] Figure 13 FIG. is a cross-sectional perspective view of the antenna module 100C of Modification Example 2. In the antenna module 100C, the shifted region 170B of the feeding wiring 141A2 for supplying a high-frequency signal to the feeding element 121 is formed in the layer between the feeding element 122 and the ground electrode GND. Moreover, when the antenna module 100C is viewed from above, an opening 150 is formed in a portion of the feeding element 122 that overlaps with the shifted region 170B of the feeding wiring 141A2. By adopting such a structure, capacitive coupling between the shifted region 170B of the feeding wiring 141A2 and the feeding element 122 is suppressed, and thus unnecessary resonance generated due to this capacitive coupling is suppressed. Therefore, a decrease in the gain characteristic of the antenna module can be suppressed.

[0087] (Modification Example 3)

[0088] Figure 14 FIG. is a cross-sectional perspective view of the antenna module 100D of Modification Example 3. In the antenna module 100D, the shift region 170C of the feeding wiring 141A3 for supplying a high-frequency signal to the feeding element 121 is formed in a stepped shape. Further, when the antenna module 100D is viewed from above, an opening 150A is formed in a portion of the feeding element 122 that overlaps with the shift region 170C of the feeding wiring 141A3. With this structure, the capacitive coupling between the shift region 170C of the feeding wiring 141A3 and the feeding element 122 is suppressed, and thus the unwanted resonance caused by this capacitive coupling is suppressed. Therefore, a decrease in the gain characteristic of the antenna module can be suppressed.

[0089] (Modification Example 4)

[0090] Figure 15 FIG. is a cross-sectional perspective view of the antenna module 100E of Modification Example 4. In the antenna module 100E, the feeding wiring 141A for supplying a high-frequency signal to the feeding element 121 is formed in the same shape as the feeding wiring shown in the antenna module 100 of Embodiment 1. However, the feeding wiring is not connected to the low-frequency side radiation element in the layer disposed between the feeding element 121 and the ground electrode GND, that is, there is no feeding element 123. Further, when the antenna module 100E is viewed from above, an opening 150 is formed in a portion of the non-feeding element 123 that overlaps with the shift region 170 of the feeding wiring 141A. Figure 3 In the case of the antenna module 100E, a high-frequency signal corresponding to the resonance frequency of the non-feeding element 123 is supplied to the feeding wiring 141A, whereby electromagnetic coupling occurs between the feeding wiring 141A and the non-feeding element 123 at a portion where the feeding wiring 141A penetrates the non-feeding element 123, and thus the high-frequency signal is supplied to the non-feeding element 123 in a non-contact manner. Thereby, radio waves are radiated from the non-feeding element 123.

[0091] Also in the structure of the antenna module 100E of Modification Example 4, when the antenna module 100E is viewed from above, an opening 150 is formed in a portion of the non-feeding element 123 that overlaps with the shift region 170 of the feeding wiring 141A. Therefore, the capacitive coupling between the shift region 170 of the feeding wiring 141A and the non-feeding element 123 is suppressed when a high-frequency signal corresponding to the resonance frequency of the feeding element 121 is supplied to the feeding wiring 141A. Therefore, the unwanted resonance caused by the capacitive coupling is suppressed, and thus a decrease in the gain characteristic of the antenna module can be suppressed.

[0092]

[0093] ​In addition, regarding the thickness of the dielectric layer and the dimensions of the feeding wiring that constitute the antenna module, they are not limited to those shown in Embodiment 1 and Embodiment 2. In other examples, the thickness of the dielectric layer can be set to 75 μm, the diameter of the through hole 145 can be set to 150 μm, the diameter of the electrode pad 146 can be set to 290 μm, and the through hole pitch can be set to 290 μm. Also, in other examples, the thickness of the dielectric layer can be set to 100 μm, the diameter of the through hole 145 can be set to 200 μm, the diameter of the electrode pad 146 can be set to 340 μm, and the through hole pitch can be set to 340 μm.

[0094] When the thickness of the dielectric layer is set to be thick, the number of dielectric layers for forming the dielectric substrate 130 becomes smaller, and the film stacking process in the manufacturing process becomes smaller, so the manufacturing cost can be reduced. On the other hand, when the thickness of the dielectric layer becomes thick, it is necessary to increase the energy of the laser irradiated to the dielectric layer when forming the through hole, so the through hole diameter becomes larger, and accordingly the electrode pad diameter and the through hole pitch also become larger. Then, the opening formed in the radiation element on the low frequency side becomes larger, so it may affect the characteristics of the radiation element on the low frequency side or the isolation degree of the two polarization waves. Therefore, the thickness of the dielectric layer is appropriately determined according to the manufacturing cost and the desired antenna characteristics.

[0095] (Modification Example 5)

[0096] In the above-described embodiments and modification examples, the structure in which two radiation elements (feeding element 121 and feeding element 122, feeding element 121 and non-feeding element 123) and the ground electrode GND are formed on the same dielectric substrate 130 has been described. However, each radiation element and the ground electrode GND can also be as follows Figure 16 and Figure 17 in the example, are arranged on different dielectric substrates.

[0097] Figure 16 is a cross-sectional perspective view of the antenna module 100F of the first example in Modification Example 5. In the antenna module 100F, Figure 3 the feeding element 121 shown in the antenna module 100 is formed on a dielectric substrate 130A different from the dielectric substrate 130 on which the feeding element 122 and the ground electrode GND are formed. The feeding wirings 141A and 141B for transmitting high-frequency signals to the feeding element 121 are electrically connected through solder bumps 180 between the dielectric substrate 130 and the dielectric substrate 130A. In addition, instead of the solder bumps 180, the feeding wirings can be electrically connected by crimping or an adhesive layer.

[0098] In addition, Figure 17 is a cross-sectional perspective view of the antenna module 100G of the second example in Modification Example 5. In the antenna module 100G, Figure 3The feeding elements 121 and 122 in the antenna module 100 shown are formed on a dielectric substrate 130B different from the dielectric substrate 130 on which the ground electrode GND is formed. The feeding wirings 141A, 141B for transmitting high-frequency signals to the feeding element 121 and the feeding wirings 142A, 142B for transmitting high-frequency signals to the feeding element 122 are electrically connected between the dielectric substrate 130 and the dielectric substrate 130B through solder bumps 180. In addition, instead of the solder bumps 180, the feeding wirings can be electrically connected through crimping or an adhesive layer.

[0099] In addition, Figure 16 and Figure 17 the structure can also be applied to the structures of other embodiments and variations.

[0100] The "feeding element 121" in the above-described embodiments and variations corresponds to the "first radiation element" in the present disclosure. In addition, the "feeding element 122" or the "non-feeding element 123" corresponds to the "second radiation element" in the present disclosure. The "feeding wirings 141, 161" in the embodiments and variations correspond to the "first feeding wiring" in the present disclosure. In addition, the "feeding wirings 142, 162" correspond to the "second feeding wiring" in the present disclosure.

[0101] In addition, in the above-described embodiments and variations, a structure in which the radiation element and the ground electrode are arranged on the same dielectric substrate is described, but it can also be a structure in which the substrate on which the radiation element is arranged and the substrate on which the ground electrode is arranged are formed of different substrates.

[0102] In addition, in the above-described embodiments and variations, a structure in which the feeding element 121 and the feeding element 122, or the feeding element 121 and the non-feeding element 123 face each other is described, but it can also be a structure in which the feeding element 121 and the feeding element 122 or the non-feeding element 123 do not overlap when looking down at the dielectric substrate from the normal direction.

[0103] In addition, the non-feeding element 123 can also function as a capacitor that is capacitively coupled to the feeding element 121. In this case, the non-feeding element 123 functions as a parasitic element, thereby enabling the expansion of the frequency band of the feeding element 121.

[0104] It should be considered that the embodiments disclosed herein are illustrative rather than restrictive in all respects. The scope of the present disclosure is not shown by the description of the above-described embodiments, but is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0105] Description of Reference Numerals

[0106] 10: Communication device; 100, 100A to 100G, 100#1, 100#2: Antenna modules; 110: RFIC; 111A to 111H, 113A to 113H, 117A, 117B: Switches; 112AR to 112HR: Low-noise amplifiers; 112AT to 112HT: Power amplifiers; 114A to 114H: Attenuators; 115A to 115H: Phase shifters; 116A, 116B: Signal combiners / dividers; 118A, 118B: Mixers; 119A, 119B: Amplification circuits; 120: Antenna device; 121, 122: Feeding elements; 123: Non-feeding element; 125: Radiating element; 130, 130A, 130B: Dielectric substrates; 141A, 141B, 142A, 142B, 161A, 161B, 162A, 162B: Feeding wirings; 145: Via hole; 146: Electrode pad; 150, 150A, 150#, 155, 155#: Openings; 170, 170A to 170C, 170X: Shift regions; 180: Solder bumps; 200: BBIC; GND: Ground electrode; SP1A, SP1B, SP2A, SP2B: Feeding points.

Claims

1. An antenna module, comprising: A flat first radiation element; A flat second radiation element, which is arranged at a position different from that of the first radiation element in the normal direction of the first radiation element and has a resonance frequency different from that of the first radiation element; and A first feeding wiring, which penetrates through the second radiation element from a feeding circuit and transmits a high-frequency signal to the first radiation element, Among them, The first feeding wiring includes a displacement region extending in a direction orthogonal to the normal direction of the first radiation element at a position different from that of the second radiation element on the path from the feeding circuit to the first radiation element, When viewed from the normal direction of the first radiation element, an opening is formed in a portion of the second radiation element that overlaps with the displacement region.

2. The antenna module according to claim 1, wherein The second radiation element is arranged to face the first radiation element.

3. The antenna module according to claim 2, wherein It further includes a ground electrode, which is arranged to face the first radiation element and the second radiation element, The second radiation element is arranged between the first radiation element and the ground electrode, When viewed from the normal direction of the first radiation element, the second radiation element forms the opening in a portion that overlaps with the displacement region of a portion closer to the first radiation element side than the position at half of the distance between the second radiation element and the ground electrode.

4. The antenna module according to claim 3, wherein The displacement region is formed between the second radiation element and the ground electrode.

5. The antenna module according to any one of claims 2 to 4, wherein The displacement region is formed between the first radiation element and the second radiation element.

6. The antenna module according to any one of claims 1 to 5, wherein It further includes a second feeding wiring that transmits a high-frequency signal from the feeding circuit to the second radiation element.

7. The antenna module according to any one of claims 1 to 6, wherein The first feeding wiring includes: A first wiring, which is connected to the feeding circuit and extends in a direction orthogonal to the normal direction of the first radiation element; and A second wiring from the first wiring to the first radiation element, The displacement region is formed in the second wiring in a direction orthogonal to the extending direction of the first wiring.

8. The antenna module according to any one of claims 1 to 6, wherein The first feeding wiring includes: A first wiring, which is connected to the feeding circuit and extends in a direction orthogonal to the normal direction of the first radiation element; and A second wiring from the first wiring to the first radiation element, The displacement region is formed in the second wiring in a direction parallel to the extending direction of the first wiring.

9. The antenna module according to any one of claims 1 to 8, wherein It further includes the feeding circuit.

10. A communication device equipped with the antenna module according to any one of claims 1 to 9.

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