Antenna module and communication device equipped with the same

Abstract

An antenna module (100) includes a radiating element including feed elements (1211, 1212) adjacent to each other, feed wirings (141, 142), a ground electrode (GND1), and filter circuits (151, 152). The ground electrode is configured to face the radiating element. The feed wirings transmit high-frequency signals from an RFIC (110) to the radiating element. The filter circuits are connected between the feed wirings and the feed circuits. The ground electrode includes a first portion (181) facing the radiating element and a second portion (182) configured on an upper side layer closer to the radiating element than the first portion. In a case where the antenna module is viewed from a normal direction, i) the second portion is configured between the 2 feed elements, and ii) the filter circuits overlap the second portion and are configured on a lower side layer closer to the radiating element than the second portion.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an antenna module and a communication apparatus equipped with the same, and more particularly, to a technology for improving the characteristics of an antenna module including a circuit such as a filter in the same substrate as an antenna element. BACKGROUND

[0002] Japanese Patent Application Publication No. 2001-094336 (Patent Literature 1) discloses a filter-embedded patch antenna in which a radiating conductor (antenna element) and a filter are disposed in the same substrate of a dielectric material. In the filter-embedded patch antenna disclosed in Japanese Patent Application Publication No. 2001-094336 (Patent Literature 1), the filter is configured to overlap at least a part of the radiating electrode when the patch antenna is viewed from above.

[0003] PRIOR ART DOCUMENTS

[0004] PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2001-094336 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] For example, such an antenna is sometimes applied to a communication terminal such as a portable telephone or a smartphone. In such a communication terminal, miniaturization and thinning of devices are desired.

[0008] As in Japanese Patent Application Publication No. 2001-094336 (Patent Literature 1), a circuit such as a filter is configured in the same substrate as an antenna element (radiating element), thereby enabling the entire antenna module to be miniaturized. However, in the case where further low-profile of the antenna module is pursued, the distance between the radiating element and the circuit overlapping the radiating element becomes further shorter, and it is possible that the antenna characteristics such as narrowbanding are degraded.

[0009] In addition, in the case where such a circuit is formed in a stripline, there is a possibility that the ground electrodes of the circuit become narrower with the low-profile, and the characteristics of the circuit itself are degraded.

[0010] The present disclosure was made to solve such a problem, and aims to realize low-profile of an antenna module including other circuits in the same substrate as a radiating element while suppressing degradation of antenna characteristics.

[0011] MEANS FOR SOLVING THE PROBLEM

[0012] The antenna module according to the present disclosure includes a radiating element, a feed wiring, a first ground electrode, and a first circuit. The radiating element includes a first feed element and a second feed element adjacent to each other. The first ground electrode is configured to face the radiating element. The feed wiring transmits a high-frequency signal from a feed circuit to the radiating element. The first circuit is connected between the feed circuit and the feed wiring. The first ground electrode includes a first portion facing the radiating element and a second portion configured at a layer closer to an upper side of the radiating element than the first portion. In a case where the antenna module is viewed from a normal direction: i) the second portion is configured between the first feed element and the second feed element; and ii) the first circuit overlaps the second portion and is configured at a layer closer to a lower side of the second portion.

[0013] Effects of the Invention

[0014] According to the antenna module according to the present disclosure, a portion of the ground electrode is configured (elevated) at a position on a feed element side between adjacent two feed elements, and a circuit (first circuit) is configured below the elevated portion. Since the first circuit does not overlap the two feed elements when the antenna module is viewed from above, the influence of the first circuit on the antenna characteristics in the case of low-profile is reduced. In addition, even if low-profile is performed, a space in which the first circuit is configured can be ensured, and thus a decrease in characteristics of the first circuit can be suppressed. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a block diagram of a communication device to which the antenna module according to Embodiment 1 is applied.

[0016] Figure 2 is a plan view and a side perspective view of the antenna module of Figure 1

[0017] Figure 3 is a graph for explaining a relationship between a thickness of a dielectric and a Q value.

[0018] Figure 4 is a side perspective view of an antenna module in a comparative example.

[0019] Figure 5 is a graph for explaining a relationship between an elevation height of a ground electrode and an isolation degree.

[0020] Figure 6 is a first graph for explaining a relationship between a polarization direction and an isolation degree.

[0021] Figure 7 is a second graph for explaining a relationship between a polarization direction and an isolation degree.

[0022] Figure 8 ​This diagram illustrates the relationship between the configuration of the raised section and the directivity in the case of a 2×2 array antenna.

[0023] Figure 9 It is a diagram used to illustrate the directivity of radio waves radiated from a single radiating element in the case of a 2×2 array antenna.

[0024] Figure 10 This is a side perspective view of an antenna module, which is a modified example of an antenna module using a dielectric substrate obtained by combining dielectrics with different dielectric constants.

[0025] Figure 11 This is a side perspective view of the antenna module involved in Embodiment 2.

[0026] Figure 12 This is a schematic diagram of the branch circuit between the power supply element and the filter.

[0027] Figure 13 This is a schematic diagram of a detection circuit used to monitor the power supplied to the power supply element.

[0028] Figure 14 This is a block diagram of a communication device using an antenna module according to implementation method 3.

[0029] Figure 15 yes Figure 14 Side perspective view of the antenna module.

[0030] Figure 16 This is a block diagram of a communication device using an antenna module according to implementation method 4.

[0031] Figure 17 yes Figure 16 Top view and side perspective view of the antenna module. Detailed Implementation

[0032] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. Furthermore, the same or equivalent parts in the drawings will be labeled with the same reference numerals, and their descriptions will not be repeated.

[0033] [Implementation Method 1]

[0034] (Basic structure of a communication device)

[0035] Figure 1This is an example of a block diagram of a communication device 10 that uses the antenna module 100 described in Embodiment 1. The communication device 10 is, for example, a portable terminal such as a mobile phone, a smartphone or tablet computer, or a personal computer with communication capabilities. An example of the frequency band of the radio waves used in the antenna module 100 described in this embodiment is a millimeter-wave band with a center frequency of 28 GHz, 39 GHz, or 60 GHz, but radio waves in other frequency bands can also be used.

[0036] 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 feed circuit), an antenna device 120, and a filter device 105. The communication device 10 uses the RFIC 110 to upconvert the signal transmitted from the BBIC 200 to the antenna module 100 into a high-frequency signal, which is then radiated from the antenna device 120 via the filter device 105. Additionally, the communication device 10 transmits the high-frequency signal received from the antenna device 120 to the RFIC 110 via the filter device 105, performs downconversion, and then processes the signal using the BBIC 200.

[0037] exist Figure 1 For ease of explanation, only the structures corresponding to four of the multiple feed elements 121 constituting the antenna device 120 are shown; the structures corresponding to other feed elements 121 having the same structure are omitted. Furthermore, in Figure 1 The image shows an example of an antenna device 120 formed by a plurality of feed elements 121 configured in a two-dimensional array, but it could also be a one-dimensional array in which the plurality of feed elements 121 are configured in a column. In this embodiment, the feed element 121 is a patch antenna in the shape of a planar plate with approximately square dimensions.

[0038] RFIC 110 includes switches 111A-111D, switches 113A-113D, switch 117, power amplifiers 112AT-112DT, low-noise amplifiers 112AR-112DR, attenuators 114A-114D, phase shifters 115A-115D, signal synthesizer / demultiplexer 116, mixer 118, and amplifier circuit 119.

[0039] When transmitting high-frequency signals, switches 111A-111D and 113A-113D are switched to the power amplifier 112AT-112DT side, and switch 117 is connected to the transmitting-side amplifier of amplifier circuit 119. When receiving high-frequency signals, switches 111A-111D and 113A-113D are switched to the low-noise amplifier 112AR-112DR side, and switch 117 is connected to the receiving-side amplifier of amplifier circuit 119.

[0040] The signal transmitted from BBIC 200 is amplified by amplifier circuit 119 and then up-converted by mixer 118. The up-converted high-frequency transmission signal is divided into four signals by signal synthesizer / demultiplexer 116, and fed to different feed elements 121 through four signal paths. At this time, the directivity of antenna device 120 can be adjusted by independently adjusting the phase shift of phase shifters 115A to 115D configured in each signal path.

[0041] The received high-frequency signals received by each feed element 121 are combined by a signal synthesizer / demultiplexer 116 via four different signal paths. The combined received signals are down-converted by a mixer 118 and amplified by an amplifier circuit 119 before being transmitted to the BBIC 200.

[0042] The filtering device 105 includes filters 105A to 105D. Filters 105A to 105D are respectively connected to switches 111A to 111D of RFIC 110. Filters 105A to 105D have the function of attenuating signals in a specific frequency band. Filters 105A to 105D can also be bandpass filters, high-pass filters, low-pass filters, or combinations of these filters. The high-frequency signal from RFIC 110 is supplied to the corresponding feed element 121 after passing through filters 105A to 105D.

[0043] In the case of high-frequency signals in the millimeter-wave band, there is a tendency for noise components to easily enter as the transmission line length increases. Therefore, it is preferable to shorten the distance between the filter device 105 and the feed element 121 as much as possible. That is, by passing the high-frequency signal through the filter device 105 just before it is radiated from the feed element 121, unwanted waves radiated from the feed element can be suppressed. In addition, by passing the high-frequency signal through the filter device 105 immediately after receiving it in the feed element 121, unwanted waves contained in the received signal can be removed.

[0044] In addition, Figure 1 In this disclosure, the filter device 105 and the antenna device 120 are marked separately, but in this disclosure, as described later, the filter device 105 is formed inside the antenna device 120.

[0045] RFIC 110 may be configured as a single-chip integrated circuit component including the circuit structure described above. Alternatively, the devices (switches, power amplifiers, low-noise amplifiers, attenuators, phase shifters) in RFIC 110 corresponding to each power supply element 121 may be configured as single-chip integrated circuit components according to the corresponding power supply element 121.

[0046] (Structure of the antenna module)

[0047] Next, use Figure 2 This section will describe in detail the structure of the antenna module 100 in Embodiment 1. Figure 2 In the middle, a top view of the antenna module 100 is shown on the upper layer. Figure 2 (a) shows a side perspective view on the lower layer. Figure 2 (b)

[0048] exist Figure 2 In this description, we will take the case where the antenna module 100 is an array antenna with two feed elements 1211 and 1212 as radiating elements as an example. In addition to the feed elements 1211 and 1212 and the RFIC 110, the antenna module also includes a dielectric substrate 130, feed wiring 141 and 142, circuits 151 and 152, connection wiring 161 and 162, and ground electrodes GND1 and GND2. Furthermore, in the following description, the normal direction (radiation direction of the radio wave) of the dielectric substrate 130 is defined as the Z-axis direction, and the X-axis and Y-axis are used to define the plane perpendicular to the Z-axis direction. Additionally, the positive direction of the Z-axis in each figure is sometimes referred to as the upper side, and the negative direction as the lower side.

[0049] The dielectric substrate 130 may be, for example, a low-temperature co-fired ceramic (LTCC) multilayer substrate, a multilayer resin substrate formed by stacking multiple resin layers composed of resins such as epoxy resin and polyimide, a multilayer resin substrate formed by stacking multiple resin layers composed of liquid crystal polymer (LCP) with a lower dielectric constant, a multilayer resin substrate formed by stacking multiple resin layers composed of fluorine-based resin, or a ceramic multilayer substrate other than LTCC. Furthermore, the dielectric substrate 130 may not necessarily be a multilayer structure and may also be a single-layer substrate.

[0050] The dielectric substrate 130 has a generally rectangular shape, and power feeding elements 1211 and 1212 are disposed in a layer (the uppermost layer) near its upper surface 131 (the plane in the positive direction of the Z-axis). The power feeding elements 1211 and 1212 can be exposed on the surface of the dielectric substrate 130, or... Figure 2 As in the example, it is disposed inside the dielectric substrate 130. Furthermore, in the various embodiments of this disclosure, for ease of explanation, the case in which only a feed element is used as a radiating element is described as an example, but it is also possible to have a structure in which a feed element and / or parasitic elements are disposed in addition to the feed element.

[0051] Feed elements 1211 and 1212 are patch antennas with a generally square planar shape. Feed elements 1211 and 1212 are arranged adjacent to each other along the X-axis direction of dielectric substrate 130.

[0052] On the dielectric substrate 130, in the layer near the lower surface 132 (the plane in the negative direction of the Z-axis) of the power feeding elements 1211 and 1212 (the lower side layer), a flat plate-shaped ground electrode GND2 is disposed facing the power feeding elements 1211 and 1212. Additionally, a ground electrode GND1 is disposed in the layer between the power feeding elements 1211 and 1212 and the ground electrode GND2.

[0053] An RFIC 110 is mounted on the lower surface 132 of the dielectric substrate 130, with solder bumps 170 in between. Alternatively, the RFIC 110 can be connected to the dielectric substrate 130 using a multi-pole connector instead of solder.

[0054] In the antenna module 100, when viewed from the normal direction of the dielectric substrate 130, a portion of the ground electrode GND1 located between the feed element 1211 and the feed element 1212 is positioned closer to the upper side of the radiating element than other portions. In the following description, the portion of the ground electrode GND1 facing the radiating element is referred to as the first portion 181, and the portion positioned higher than the first portion 181 is referred to as the second portion. Furthermore, the second portion 182 is sometimes referred to as the "raised portion." The first portion 181 and the second portion 182 of the ground electrode GND1 are connected by a passage 183. An opening is formed in the portion of the first portion 181 of the ground electrode GND1 that overlaps with the second portion 182 when viewed from above.

[0055] By configuring the ground electrode GND1 in such a structure that the thickness (lift height) of the dielectric between the second part 182 of the ground electrode GND1 and the ground electrode GND2 is thicker than the thickness of the dielectric between the first part 181 and the ground electrode GND2.

[0056] Circuits 151 and 152 are, for example, with... Figure 1 The circuit corresponding to the filter device 105 shown. Circuits 151 and 152 are disposed between the second portion 182 of ground electrode GND1 and ground electrode GND2. In other words, when viewed from above the antenna module 100, circuits 151 and 152 overlap with the second portion 182 of ground electrode GND1 and are disposed on a layer below the second portion 182.

[0057] A high-frequency signal is supplied from RFIC 110 to the feed point SP1 of the feed element 1211 via connection wiring 161, circuit 151, and feed wiring 141. Feed wiring 141 descends from circuit 151 downwards via path 1411, extends through wiring pattern 1412 in the layer between ground electrode GND1 and ground electrode GND2, and rises to feed point SP1 via path 1413.

[0058] Additionally, a high-frequency signal is supplied from RFIC 110 to the feed point SP2 of the feed element 1212 via connection wiring 162, circuit 152, and feed wiring 142. Feed wiring 142 descends from circuit 152 downwards via path 1421, extends through wiring pattern 1422 in the layer between ground electrode GND1 and ground electrode GND2, and rises to feed point SP2 via path 1423.

[0059] exist Figure 2 In this example, the feed point of each feed element is positioned offset from the center of the feed element in the positive direction of the Y-axis. By setting the feed point in such a position, electromagnetic waves polarized in the Y-axis direction are radiated from each feed element.

[0060] exist Figure 2 In this system, the conductors that make up the radiating elements, electrodes, and pathways are formed of metals such as aluminum (Al), copper (Cu), gold (Au), silver (Ag), and their alloys.

[0061] As described above, when filters are formed as circuits 151 and 152, each filter is sometimes formed as a stripline disposed between the ground electrodes GND1 and GND2. In filters formed by striplines, generally speaking, it is known that... Figure 3 As shown, the dielectric thickness between the grounding electrodes affects the Q value. More specifically, as... Figure 3 As with the LN10 stripline, a thicker dielectric layer results in a higher Q value. Therefore, when forming a stripline filter, to ensure a high Q value, it is desirable to have a relatively thick dielectric layer between the ground electrodes at the portion forming the filter. Figure 2 The H2 in the middle should be as thick as possible.

[0062] On the other hand, in order to improve antenna characteristics, such as reducing antenna loss and widening the bandwidth, it is necessary to increase the thickness of the dielectric between the radiating element and the ground electrode. Figure 2 H1 in the diagram ensures that, to some extent, the effects on antenna and filter characteristics vary depending on how the grounding electrode is configured when a filter is formed within the antenna assembly.

[0063] Figure 4It is a side perspective view of the antenna modules 100A and 100B in the comparative example. In the antenna modules 100A and 100B, each ground electrode has a flat plate shape, and the overall size (thickness) of the dielectric substrate 130 is the same as Figure 2 the overall size of the dielectric substrate of the antenna module 100 shown.

[0064] The antenna module 100A ( Figure 4 (a) thereof) is an example in the case where filter characteristics are prioritized, and the distance between the ground electrodes GND1 and GND2 is set to be the same as Figure 2 H2. In this case, the distance between the feeding elements 1211 and 1212 and the ground electrode GND1 becomes H1' (<H1), so there is a concern that it is difficult to ensure antenna characteristics.

[0065] On the other hand, the antenna module 100B ( Figure 4 (b) thereof) is an example in the case where antenna characteristics are prioritized, and the distance between the feeding elements 1211 and 1212 and the ground electrode GND1 is set to be the same as Figure 2 H1. In this case, the distance between the ground electrodes GND1 and GND2 becomes H2' (<H2), so there is a concern that it is difficult to sufficiently ensure the Q value of the filter.

[0066] In addition, although not shown, in the case where the distance between the feeding elements 1211 and 1212 and the ground electrode GND1 is simply set to H1 and the distance between the ground electrodes GND1 and GND2 is set to H2, although antenna characteristics and filter characteristics can be ensured, the overall thickness of the dielectric substrate 130 becomes thick. Therefore, it becomes a factor that hinders the thinning of the antenna device, and there may be a situation where the desired device size cannot be achieved.

[0067] In the antenna module 100 according to the first embodiment, as Figure 2 described in, the portion (second portion 182) of the ground electrode GND1 between the feeding elements 1211 and 1212 is raised, and a filter (circuits 151 and 152) is arranged at a position on the lower side of this portion, thereby being able to ensure the distance H1 between the feeding elements 1211 and 1212 and the ground electrode GND1 and ensure the distance H2 between the ground electrodes of the portion forming the filter. Thus, it is possible to suppress the degradation of both antenna characteristics and filter characteristics while maintaining the miniaturization and thinning of the entire device.

[0068] In addition, considering the symmetry of the antenna characteristics, it is desirable to arrange the raised portion (second portion 182) of the ground electrode GND1 at a position equidistant from the two feeding elements 1211 and 1212. In addition, it is desirable that the size of the side of the raised portion facing each feeding element (Figure 2 The dimension in the Y-axis direction is larger than the dimension of one side of the feed elements 1211 and 1212. Figure 2 In this case, the dimension of the raised portion in the Y-axis direction is shorter than the dimension of the dielectric substrate 130 in the Y-axis direction, but it is also possible that the raised portion is formed over the entire area of ​​the dielectric substrate 130 in the Y-axis direction.

[0069] In Embodiment 1, "feeding element 1211" and "feeding element 1212" correspond to the "first feeding element" and "second feeding element" of this disclosure, respectively. In addition, "circuit 151, 152" correspond to the "first circuit" of this disclosure.

[0070] Furthermore, in Embodiment 1, the case where the "first circuit" is a "filter" was described as an example, but the "first circuit" can also be a circuit other than a filter. For example, matching circuits such as stubs, connection circuits such as wiring, and integrated circuits that integrate a large number of circuits can also be used.

[0071] (Regarding antenna characteristics)

[0072] use Figures 5 to 10 This explanation will cover the impact of the structure of Embodiment 1 on various antenna characteristics. Furthermore, the following description will use the case of using radio waves with a center frequency of 28 GHz as an example.

[0073] <Isolation Properties>

[0074] use Figure 5 This explains the relationship between the elevation height of the raised portion (second part 182) of the grounding electrode GND1 and the isolation between the two feed elements 1211 and 1212. Figure 5 In the diagram, the horizontal axis represents frequency, and the vertical axis represents the isolation between the feeding components. Figure 5 In the diagram, the dashed line LN21 represents the isolation level without any elevation (elevation height of 0mm), the dotted-dashed line LN22 represents the isolation level with an elevation height of 0.2mm, the double-dotted-dashed line LN23 represents the isolation level with an elevation height of 0.4mm, and the solid line LN20 represents the isolation level with an elevation height of 0.8mm. For example... Figure 5 As shown, in the frequency band around 28 GHz, where the object is located, the greater the elevation, the more the isolation between the feed components is improved.

[0075] As the elevation height increases, the distance between the raised section and each feed element 1211, 1212 decreases. Since the raised section is positioned between feed elements 1211 and 1212, the higher the elevation height, the easier it is for the electric field lines leaking from feed element 1211 to feed element 1212 to be captured by the raised section of the grounding electrode GND1. Therefore, the higher the elevation height, the greater the improvement in isolation between feed elements.

[0076] Furthermore, when the raised section is positioned above the feed element, there are concerns about its impact on the electromagnetic waves radiated from the feed element. Therefore, it is desirable to position the raised section on the layer where the feed element is located or on the layer below it.

[0077] Next, use Figure 6 and Figure 7 This is used to illustrate the relationship between the polarization direction of the electromagnetic waves radiated from each feeding element and the isolation. Figure 6 It means and Figure 2 Similarly, the diagram shows the isolation when two feed elements are adjacent in a direction perpendicular to the polarization direction (Y-axis direction) (X-axis direction). In other words, it shows the isolation when the extension direction of the raised portion is in the same direction as the polarization direction. On the other hand, Figure 7 It is a diagram showing the isolation of two feeding elements when they are adjacent in the same direction as the polarization direction (X-axis direction). In other words, it is a diagram showing the isolation when the extension direction of the raised part is orthogonal to the polarization direction.

[0078] exist Figure 6 and Figure 7 In the middle, at the upper level ( Figure 6 of (a), Figure 7 (a) shows a schematic diagram of the antenna module representing the polarization direction, in the lower layer ( Figure 6 (b) Figure 7 (b) shows the isolation characteristics. Figure 6 and Figure 7 In the diagram, the dashed lines (LN31, LN41) represent the isolation level without elevation, while the solid lines (LN30, LN40) represent the isolation level with elevation.

[0079] When comparing Figure 6 (b) and Figure 7 In case (b), the feeding elements are adjacent in a direction perpendicular to the polarization direction. Figure 6 The improvement in isolation is greater. This is because the raised section prevents the current component perpendicular to the polarization direction from propagating on the surface of the ground electrode GND1 and flowing into the adjacent feed element.

[0080] <Directivity>

[0081] Figure 8 This diagram illustrates the relationship between the configuration of the raised section and directivity in the case of a 2×2 two-dimensional array antenna. In the upper layer... Figure 8 (a) shows a schematic diagram of the antenna configuration without a raised section and the antenna's directivity. In the middle layer... Figure 8 (b) shows a schematic diagram of the antenna configuration and directivity when raised sections 1821 and 1822 are arranged between adjacent feed elements (between feed element 1211 and feed element 1212, and between feed element 1213 and feed element 1214) in a direction perpendicular to the polarization direction. Figure 8 (c) shows that, in addition to Figure 8 In addition to case (b), the diagram shows the antenna configuration and directivity when raised sections 1823 and 1824 are also arranged between adjacent feed elements along the polarization direction (between feed element 1211 and feed element 1213, and between feed element 1212 and feed element 1214). Furthermore, the directivity diagram is a diagram using contour lines to represent the gain of the radiated radio waves.

[0082] Reference Figure 8 In the absence of a raised section ( Figure 8 In the case of (a)), the directionality becomes approximately circular. Conversely, raised portions 1821 and 1822 are formed only between the feed elements on the side where the improvement in isolation is greater. Figure 8 In case (b), the directionality becomes an elongated ellipse in the Y-axis direction extending from the raised portions 1821 and 1822. The symmetry of the ground electrode GND1 in the X-axis direction is disrupted by the raised portion, thereby disrupting the symmetry of the directionality of each feed element, resulting in a state where the overall symmetry of the array is slightly disrupted.

[0083] In addition to the raised sections formed between adjacent feed elements along the X-axis, raised sections 1823 and 1824 are also formed between adjacent feed elements along the Y-axis. Figure 8 In case (c), the symmetry of the ground electrode GND1 in the X-axis and Y-axis directions is improved, thus improving the directional symmetry of each feed element. Therefore, compared with Figure 8 Compared to case (b), the symmetry is improved and becomes a directionality that is close to a perfect circle.

[0084] Thus, in the case of a two-dimensional antenna array, by arranging raised portions in both the polarization direction and the direction perpendicular to the polarization direction, it is possible to achieve improved directivity and antenna efficiency with enhanced symmetry.

[0085] Figure 9This is a diagram showing the directivity of radio waves radiated from a single radiating element in a 2×2 array antenna. (Upper layer) Figure 9 (a) indicates the case where there is no raised section with a grounding electrode between the feeding elements, and the lower layer Figure 9 (b) indicates the case where a raised portion is provided between adjacent feed elements along the polarization direction (Y-axis direction) and in a direction perpendicular to the polarization direction (X-axis direction). Furthermore, in Figure 9 In the raised portion 1825 of (b), the raised portion extending along the X-axis direction and the raised portion extending along the Y-axis direction are connected to each other to form a cross shape.

[0086] exist Figure 9 The diagram illustrates the directivity when only high-frequency signals are supplied to feed element 1211 without supplying high-frequency signals to other feed elements. Figure 9 In the diagram, the directional pattern is also represented by contour lines to indicate the gain of the radiated radio waves.

[0087] Reference Figure 9 Without the installation of a raised section Figure 9 In (a), the gain of the radiated electromagnetic wave produces two peaks (AR1, AR2). Peak AR1 is generated near the feed element 1213 adjacent to the polarization direction, and peak AR2 is generated near the feed element 1212 adjacent to the polarization direction.

[0088] On the other hand, in areas where raised sections are provided Figure 9 In (b), the gain of peak AR2 near feed element 1212 decreases, and peak AR1, originally located near feed element 1213, also changes to a position closer to feed element 1211 (AR3). That is, due to the configuration of the raised part, the position of the peak gain changes to the vicinity of feed element 1211, which radiates radio waves. It is believed that this is because the raised part 1825 improves the isolation between adjacent feed elements, thereby reducing the high-frequency signal leakage to feed elements 1212 and 1213 along with the power supply to feed element 1211, thereby suppressing the gain of radio waves radiated from feed elements 1212 and 1213.

[0089] The other three feed elements also exhibit the same directivity when radiating radio waves individually. When radio waves are radiated simultaneously from all four feed elements, the overall distribution becomes as follows: Figure 8 The directionality shown.

[0090] In addition, Figure 8 and Figure 9In this disclosure, power supply elements 1211 and 1212 correspond to the "first power supply element" or the "second power supply element". When power supply element 1211 is the "first power supply element", power supply element 1213 corresponds to the "third power supply element" of this disclosure, and when power supply element 1212 is the "first power supply element", power supply element 1214 corresponds to the "third power supply element" of this disclosure.

[0091] (Modified Example)

[0092] In the antenna module of Embodiment 1, a structure in which the dielectric substrate is formed of a dielectric with a single dielectric constant was described. In a modified example, an example in which multiple dielectrics with different dielectric constants are used to form the dielectric substrate was described.

[0093] When a filter is configured within an antenna device, as described above, both antenna characteristics and filter characteristics need to be considered. Here, when considering the relationship between these characteristics and the dielectric constant of the dielectric substrate, it is preferable to have a low dielectric constant in order to broadband the antenna; on the other hand, regarding filter characteristics, it is preferable to have a high dielectric constant in order to increase the Q value.

[0094] In this way, antenna characteristics and filter characteristics may be in a trade-off relationship with respect to dielectric constant. Therefore, when a dielectric substrate is formed using a dielectric with a single dielectric constant, it may not always be a dielectric constant that is suitable for both characteristics.

[0095] Therefore, in a modified example, the following structure is adopted: a dielectric substrate is formed by combining a dielectric with a dielectric constant suitable for an antenna with a dielectric constant suitable for a filter, thereby improving both antenna characteristics and filter characteristics.

[0096] Figure 10 This is a side perspective view of the antenna modules 100D to 100F involved in the modified examples. Figure 10 In the antenna modules 100D to 100F, the dielectric substrate 130A is formed by combining a dielectric 135 having a dielectric constant suitable for an antenna with a dielectric 136 having a dielectric constant suitable for a filter. For example, the relative dielectric constant of the dielectric 135 is about 3, and the relative dielectric constant of the dielectric 136 is about 6.

[0097] exist Figure 10In antenna module 100D of (a), the layer of dielectric substrate 130A above the second portion 182 (raised portion) of ground electrode GND1 is formed of dielectric 135, and the layer of dielectric substrate 130A below the layer where the raised portion is formed is formed of dielectric 136. In this case, since the portion where the filter is formed (the layer between the second portion 182 and the ground electrode GND2) is formed of dielectric 136, it becomes a dielectric substrate structure that prioritizes filter characteristics.

[0098] On the other hand, Figure 10 In antenna module 100E of (b), the layer of dielectric substrate 130A above the first portion 181 of ground electrode GND1 is formed of dielectric 135, and the layer of dielectric substrate 130A below the first portion 181 is formed of dielectric 136. In this case, the portion where the filter is formed contains both dielectric 135 and dielectric 136, but the portion where the antenna is formed (the layer between the feed element and the first portion 181) is formed of dielectric 135 suitable for the antenna. That is, antenna module 100E has a structure of dielectric substrate with antenna characteristics as the priority.

[0099] exist Figure 10 In antenna module 100F of (c), the layer of dielectric substrate 130A above ground electrode GND1 is formed of dielectric 135, and the layer of dielectric substrate 130A below ground electrode GND1 is formed of dielectric 136. That is, in the layer between the feed elements 1211, 1212 and the first portion 181 of ground electrode GND1, the portion located below the second portion 182 is formed of dielectric 136, and the other portions are formed of dielectric 135.

[0100] exist Figure 10 In the structure of dielectric substrate 130A in (c), since the portion where the antenna is formed is formed by dielectric 135 suitable for the antenna, and the portion where the filter is formed is formed by dielectric 136 suitable for the filter, both antenna characteristics and filter characteristics can be optimized.

[0101] In addition, Figure 10 (a) and Figure 10 In (b), the layers of the same type are formed of the same dielectric material. Therefore, priority must be given to either antenna characteristics or filter characteristics. However, since the manufacturing process is relatively easy, it is not necessary to prioritize either antenna characteristics or filter characteristics. Figure 10 Compared to case (c), this can reduce manufacturing costs. On the other hand, in Figure 10In case (c), the layers within the same layer need to be formed from different dielectrics, thus complicating the manufacturing process. The appropriate choice of which of these structures to use should be made by considering the desired antenna and filter characteristics as well as manufacturing costs.

[0102] As in the comparative examples above, a dielectric substrate is formed by combining a dielectric suitable for an antenna and a dielectric suitable for a filter, thereby further improving the antenna characteristics and / or filter characteristics.

[0103] [Implementation Method 2]

[0104] In Embodiment 2, the following structure is described: additional circuits such as branch circuits for distributing the high-frequency signal after passing through the filter to multiple feed elements or detection circuits for monitoring the power supplied to each feed element are provided on the path between the filter and the feed element.

[0105] Figure 11 This is a side perspective view of the antenna module 100G according to Embodiment 2. In the antenna module 100G, it becomes... Figure 2 The side perspective view of antenna module 100 shown in (b) includes the structures of circuits 191 and 192. In antenna module 100G, the structures of circuits 191 and 192 are not repeated. Figure 2 Description of the repeating elements of antenna module 100.

[0106] Reference Figure 11 Circuits 191 and 192 are, for example, as follows Figure 12 The branch circuit 190 is shown. In this case, the high-frequency signal from RFIC 110, after passing through filter 150 (circuits 151, 152), is branched by branch circuit 190 (circuits 191, 192) and then supplied to multiple feed elements 121 via feed wiring 140A (feed wiring 141A, 142A). Figure 12 In the example, the high-frequency signal is branched by the branch circuit 190 and distributed to two feed elements 121, but it is also possible to distribute the high-frequency signal to three or more feed elements.

[0107] like Figure 11 As shown, branch circuits 190 (circuits 191, 192) are configured in the layer between the first portion 181 of ground electrode GND1 and ground electrode GND2. By configuring it in this way, the impact of the added circuitry on the filter characteristics can be reduced.

[0108] Figure 13This diagram illustrates an example of a detection circuit 195 used to monitor the power supplied to each feed element. The detection circuit (coupler) 195 is a line configured parallel to the feed wiring 140 that connects the filter 150 to the feed element 121. Electromagnetically coupled to the feed wiring 140 via this line, a signal corresponding to the current (electricity) flowing through the feed wiring 140 is detected. The detected signal is fed back to RFIC 110 or BBIC 200, and the output power of the radiated electromagnetic waves is adjusted by regulating the amplification circuitry included in RFIC 110.

[0109] The detection circuit 195 needs to be configured along the path from the filter 150 to the feed element 121; therefore, the detection circuit 195 is configured in the layer between the first portion 181 of the ground electrode GND1 and the ground electrode GND2. This reduces the impact of the added circuitry on the filter characteristics.

[0110] [Implementation Method 3]

[0111] In Implementation 3, the following situation is described: the radiating element is a dual-band radiating element, and the filter disposed in the antenna device is a duplexer.

[0112] Figure 14 This is a block diagram of a communication device 10X that uses the antenna module 100X described in Embodiment 3.

[0113] Reference Figure 14 The communication device 10X includes an antenna module 100X and a BBIC 200. The antenna module 100X includes an RFIC 110X, an antenna device 120X, and a filter device 106.

[0114] Antenna device 120X includes a fed element 121 and an unfed element 122 as radiating elements. Antenna device 120X is a so-called dual-band antenna device capable of radiating radio waves in two different frequency bands.

[0115] Figure 15 yes Figure 14 The antenna module 100X is shown in a side perspective view. The antenna module 100X includes feed elements 1211 and 1212 and unfeeded elements 1221 and 1222 as radiating elements. In the dielectric substrate 130, the unfeeded element 1221 is disposed in the layer between the feed element 1211 and the ground electrode GND1. A feed wiring 141 passes through the unfeeded element 1221 and is connected to the feed point SP1 of the feed element 1211. Similarly, in the dielectric substrate 130, the unfeeded element 1222 is disposed in the layer between the feed element 1212 and the ground electrode GND1. The feed wiring 142 passes through the unfeeded element 1222 and is connected to the feed point SP2 of the feed element 1212.

[0116] The dimensions of the unfeeded elements 1221 and 1222 are larger than those of the feed elements 1211 and 1212. Therefore, the resonant frequencies of the unfeeded elements 1221 and 1222 are lower than those of the feed elements 1211 and 1212. By supplying high-frequency signals corresponding to the resonant frequencies of the unfeeded elements 1221 and 1222 to the feed wiring 141 and 142 respectively, it is possible to radiate radio waves with frequencies lower than those of the feed elements 1211 and 1212 from the unfeeded elements 1221 and 1222.

[0117] The RFIC 110X is configured to supply high-frequency signals across two frequency bands. The RFIC 110X includes switches 111A-111H, switches 113A-113H, switch 117A, switch 117B, power amplifiers 112AT-112HT, low-noise amplifiers 112AR-112HR, attenuators 114A-114H, phase shifters 115A-115H, signal synthesizers / demultiplexers 116A, signal synthesizers / demultiplexers 116B, mixers 118A, mixer 118B, and amplifier circuits 119A and 119B. The circuits 111A-111D, 113A-113D, 117A, power amplifiers 112AT-112DT, low-noise amplifiers 112AR-112DR, attenuators 114A-114D, phase shifters 115A-115D, signal synthesizer / demultiplexer 116A, mixer 118A, and amplifier circuit 119A are designed for high-frequency signals in the low-frequency band. The circuits 111E-111H, 113E-113H, 117B, power amplifiers 112ET-112HT, low-noise amplifiers 112ER-112HR, attenuators 114E-114H, phase shifters 115E-115H, signal synthesizer / demultiplexer 116B, mixer 118B, and amplifier circuit 119B are designed for high-frequency signals in the high-frequency band.

[0118] When transmitting high-frequency signals, switches 111A-111H and 113A-113H are switched to the power amplifier 112AT-112HT side, and switch 117A is connected to the transmitting amplifier of amplifier circuit 119A, and switch 117B is connected to the transmitting amplifier of amplifier circuit 119B. When receiving high-frequency signals, switches 111A-111H and 113A-113H are switched to the low-noise amplifier 112AR-112HR side, and switch 117A is connected to the receiving amplifier of amplifier circuit 119A, and switch 117B is connected to the receiving amplifier of amplifier circuit 119B.

[0119] The filtering device 106 includes duplexers 106A to 106D. Each duplexer includes a low-pass filter (filters 106A1, 106B1, 106C1, 106D1) that allows high-frequency signals in the low-frequency band to pass through, and a high-pass filter (filters 106A2, 106B2, 106C2, 106D2) that allows high-frequency signals in the high-frequency band to pass through. Filters 106A1, 106B1, 106C1, and 106D1 are connected to switches 111A to 111D in RFIC 110X, respectively. Additionally, filters 106A2, 106B2, 106C2, and 106D2 are connected to switches 111E to 111H in RFIC 110X, respectively. Duplexers 106A to 106D are connected to corresponding power supply elements 121.

[0120] 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 high-frequency signal is then divided into four signals by signal synthesizers / demultiplexers 116A and 116B, and fed to different power supply elements 121 through corresponding signal paths.

[0121] The transmitted signals from switches 111A to 111D of RFIC 110X are radiated from the corresponding unfed element 122 after passing through filters 106A1 to 106D1, respectively. The transmitted signals from switches 111E to 111H of RFIC 110X are radiated from the corresponding fed element 121 after passing through filters 106A2 to 106D2, respectively.

[0122] The directivity of the antenna device 120X can be adjusted by independently adjusting the phase shift of the phase shifters 115A to 115H configured in each signal path.

[0123] The received high-frequency signals, received by the various radiating elements (feed element 121 and unfeed element 122), are transmitted to the RFIC 110X via the filter device 106. They are then combined by signal synthesizers / demultiplexers 116A and 116B via four different signal paths. The combined received signals are down-converted by mixers 118A and 118B and amplified by amplifier circuits 119A and 119B before being transmitted to the BBIC 200.

[0124] In such a dual-band antenna module, it is also possible to achieve, for example... Figure 15As shown, the duplexers (circuits 151, 152) are positioned between the second part 182 (raised part) of the ground electrode GND1 and the ground electrode GND2 to ensure the distance between the radiating element and the ground electrode GND1, and to ensure the distance between the ground electrodes in the parts where the duplexers are formed. This allows for improvements in both antenna and filter characteristics while maintaining the overall miniaturization and thinness of the device.

[0125] [Implementation Method 4]

[0126] In the above embodiments, a structure in which a filter is formed on the feed wiring from the RFIC to the radiating element is described.

[0127] In embodiment 4, a structure in which a filter is formed on the path before the signal branch in the RFIC is described.

[0128] Figure 16 This is a block diagram of a communication device 10Y that uses the antenna module 100Y described in Embodiment 4. (Refer to...) Figure 16 The communication device 10Y includes an antenna module 100Y and a BBIC 200. The antenna module 100Y includes an RFIC 110Y, an antenna device 120, and a filter device 105Y.

[0129] exist Figure 1 In the antenna module 100 of Embodiment 1 shown, the high-frequency signal from RFIC 110 is transmitted to antenna device 120 via filter 105. In antenna module 100Y, RFIC 110Y and antenna device 120 are directly connected by feed wiring, and filter 105Y is connected between signal synthesizer / demultiplexer 116 and switch 117 in RFIC 110Y. Furthermore, filter 105Y is disposed outside RFIC 110Y, specifically, as will be described later. Figure 17 As described in the text, it is formed inside the antenna device 120.

[0130] Figure 17 Show Figure 16 The detailed structure of the 100Y antenna module. In Figure 17 In the middle, at the upper level Figure 17 Image (a) shows a top view of antenna module 100Y. Additionally, in the lower layer... Figure 17 (b) shows a side perspective view taken from lines XVII-XVII in the top view. Furthermore, in Figure 17 In the top view of (a), the dielectric is omitted for ease of explanation.

[0131] Reference Figure 17 ,like Figure 17As shown in the top view of (a), the antenna module 100Y is an antenna array obtained by arranging four feed elements 1211 to 1214 in a 2×2 two-dimensional configuration. In the antenna module 100Y, a raised section 1826 is provided between adjacent feed elements in the polarization direction (Y-axis direction) and in the direction perpendicular to the polarization direction (X-axis direction). In the raised section 1826, the raised section extending in the X-axis direction and the raised section extending in the Y-axis direction are connected to each other to form a cross shape.

[0132] like Figure 17 As shown in (b), in antenna module 100Y, ground electrodes GND1 and GND2 are formed facing the feed element. In ground electrode GND1, which is formed between the feed element and ground electrode GND2, a second portion 182 corresponding to the aforementioned raised portion 1826 is formed. Furthermore, a portion of this second portion 182 in the layer between ground electrode GND1 and ground electrode GND2 is formed with a shape corresponding to... Figure 16 The circuit 151Y corresponding to the filter device 105Y shown.

[0133] Circuit 151Y is connected to RFIC 110Y via connecting wires 161 and 162. In addition, power supply components 1211 to 1214 are directly connected to RFIC 110Y via power supply wires 141 to 144 respectively.

[0134] By configuring the filtering device on a path shared by four feed elements, as in antenna module 100Y, the number of filters formed within the antenna device can be reduced, thus enabling further miniaturization and thinning of the overall device.

[0135] In addition, Figure 16 In the antenna module 100Y shown, a structure is illustrated in which a filter device 105Y is provided instead of a filter device 105, but it is also possible to have both a filter device 105 and a filter device 105Y. In addition, "circuit 151Y" in embodiment 4 corresponds to "second circuit" in this disclosure.

[0136] It should be considered that the embodiments disclosed herein are exemplary and not restrictive in all respects. The scope of this disclosure is set forth not by the description of the embodiments above but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0137] Explanation of reference numerals in the attached figures

[0138] 10, 10X, 10Y: Communication devices; 100, 100A, 100B, 100D~100G, 100X, 100Y: Antenna modules; 105, 105Y, 106: Filtering devices; 105A~105D, 106A1~106D1, 106A2~106D2, 150: Filters; 106A~106D: Duplexers; 110, 110X, 110Y: RFIC; 111A~111H 113A~113H, 117, 117A, 117B: Switches; 112AR~112HR: Low-noise amplifiers; 112AT~112HT: Power amplifiers; 114A~114H: Attenuators; 115A~115H: Phase shifters; 116, 116A, 116B: Signal synthesizers / demultiplexers; 118, 118A, 118B: Mixers; 119, 119A, 119B: Amplifier circuits; 120, 1 20X: Antenna assembly; 121, 1211, 1212, 1213, 1214: Feeding components; 122, 1221, 1222: No feeding components; 130, 130A: Dielectric substrate; 131: Top surface; 132: Bottom surface; 135, 136: Dielectric; 140, 140A, 141, 141A, 142, 142A, 143, 144: Feed wiring; 1411, 1413, 1421, 14 23, 183: Path; 1412, 1422: Wiring pattern; 151, 151Y, 152, 191, 192: Circuit; 161, 162: Connection wiring; 170: Solder bump; 181: First part; 182, 1821-1826: Second part (raised part); 190: Branch circuit; 195: Detection circuit; 200: BBIC; GND1, GND2: Ground electrode; SP1, SP2: Feed point.

Claims

1. An antenna module, comprising: A radiating element, comprising a first feed element and a second feed element that are adjacent to each other; A first grounding electrode is configured to face the radiating element; The power supply wiring transmits high-frequency signals from the power supply circuit to the radiating element; as well as A first circuit, connected between the power supply circuit and the power supply wiring, includes at least a filter circuit. The first grounding electrode comprises a first portion and a second portion, wherein the first portion faces the radiating element, and the second portion is disposed in a layer closer to the upper side of the radiating element than the first portion. The antenna module is formed on a dielectric substrate, the first circuit is disposed in a layer inside the dielectric substrate, and the second portion is disposed in a layer inside the dielectric substrate. When viewing the antenna module from above in the normal direction... The second part is disposed between the first feed element and the second feed element. The first circuit overlaps with the second portion and is disposed on a layer below the second portion. There is no grounding electrode at the location where the first part of the layer overlaps with the second part.

2. The antenna module according to claim 1, characterized in that, An opening is formed in the portion of the first part that overlaps with the second part when the antenna module is viewed from above.

3. The antenna module according to claim 1, characterized in that, It also includes a second grounding electrode, which is positioned below the first grounding electrode. The first circuit is configured between the second portion and the second ground electrode.

4. The antenna module according to any one of claims 1 to 3, characterized in that, The first feeding element and the second feeding element are adjacent to each other in a direction perpendicular to the polarization direction of the electromagnetic wave radiated from the radiating element.

5. The antenna module according to claim 4, characterized in that, The radiating element further includes a third feeding element, which is adjacent to the first feeding element in the polarization direction of the electromagnetic wave radiated from the radiating element. The second portion is also formed between the first feeding element and the third feeding element.

6. The antenna module according to claim 5, characterized in that, The second portion formed between the first feed element and the second feed element is connected to the second portion formed between the first feed element and the third feed element.

7. The antenna module according to any one of claims 1 to 3, characterized in that, The second part is disposed in the same layer as the radiating element or in the layer between the radiating element and the first part.

8. The antenna module according to any one of claims 1 to 3, characterized in that, The first circuit further includes at least one of a matching circuit, a connection circuit, and an integrated circuit.

9. The antenna module according to any one of claims 1 to 3, characterized in that, It also includes a branch circuit, which is used to distribute the high-frequency signal after passing through the first circuit to multiple feeding elements. The branch circuit is configured on a layer below the first portion.

10. The antenna module according to any one of claims 1 to 3, characterized in that, It also includes a detection circuit for monitoring the high-frequency power supplied to each feed element of the radiating element. The detection circuit is configured in a layer below the first portion.

11. The antenna module according to any one of claims 1 to 3, characterized in that, The layer on the dielectric substrate above the first ground electrode is formed of a first dielectric, and the layer on the dielectric substrate below the first ground electrode is formed of a second dielectric, wherein the dielectric constant of the second dielectric is different from that of the first dielectric.

12. The antenna module according to any one of claims 1 to 3, characterized in that, The layer on the upper side of the dielectric substrate above the first portion is formed of a first dielectric, and the layer on the lower side of the dielectric substrate below the first portion is formed of a second dielectric, wherein the dielectric constant of the second dielectric is different from that of the first dielectric.

13. The antenna module according to any one of claims 1 to 3, characterized in that, The layer on the upper side of the dielectric substrate above the second portion is formed of a first dielectric, and the layer on the lower side of the dielectric substrate below the second portion is formed of a second dielectric, wherein the dielectric constant of the second dielectric is different from that of the first dielectric.

14. An antenna module comprising: A radiating element, comprising a first feed element and a second feed element that are adjacent to each other; A grounding electrode, configured to face the radiating element; and The second circuit, connected to a feed circuit that supplies high-frequency signals to the radiating element, includes at least a filter circuit. in, The grounding electrode includes a first portion and a second portion, the first portion facing the radiating element, and the second portion being disposed in a layer closer to the upper side of the radiating element than the first portion. The antenna module is formed on a dielectric substrate, the second circuit is disposed in a layer inside the dielectric substrate, and the second portion is disposed in a layer inside the dielectric substrate. When viewing the antenna module from above in the normal direction... The second part is disposed between the first feed element and the second feed element. The second circuit overlaps with the second portion and is disposed on a layer below the second portion. There is no grounding electrode at the location where the first part of the layer overlaps with the second part.

15. The antenna module according to any one of claims 1 to 3, 14, characterized in that, It also includes the aforementioned power supply circuit.

16. A communication device, equipped with an antenna module according to any one of claims 1 to 15.

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