Antenna module and communication device equipped with the antenna module

Abstract

An antenna module (100) has flat-plate-shaped feed elements (121, 122) and a ground electrode (GND) disposed opposite to them. The feed element (121) radiates electric waves of a first frequency band. The feed element (122) radiates electric waves of a second frequency band higher than the first frequency band. A distance in a first direction from a center of the feed element (121) to an end of the ground electrode (GND) is less than 1 / 2 of a free space wavelength of the electric waves radiated from the feed element (121) when the feed element (121) is viewed from above. A feed point of the feed element (121) is disposed at a position shifted in a second direction different from the first direction with respect to the center of the feed element (121). A feed point of the feed element (122) is disposed at a position shifted in a third direction with respect to the center of the feed element (122).

Description

Technical Field

[0001] This disclosure relates to an antenna module and a communication device equipped with the antenna module, and more specifically, to an antenna configuration in an antenna module with a substrate size constraint. Background Technology

[0002] In recent years, communication terminal devices, such as mobile phones and smartphones, have been configured to transmit and receive multiple radio waves of different frequency bands. These multi-band communication devices are equipped with antenna elements corresponding to the radio waves of each frequency band.

[0003] Japanese Patent Application Publication No. 2003-152431 (Patent Document 1) discloses a multi-frequency planar antenna capable of operating in multiple frequency bands, wherein at least one frequency band uses circularly polarized waves. In the antenna of Japanese Patent Application Publication No. 2003-152431 (Patent Document 1), multiple radiating electrodes are formed concentrically on the same plane, and a 90° hybrid coupler for supplying high-frequency signals to each radiating electrode is formed concentrically with the radiating electrodes. With this structure, a small planar composite antenna with good circularly polarized wave characteristics can be realized.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2003-152431 Summary of the Invention

[0007] The problem the invention aims to solve

[0008] In portable terminals such as mobile phones or smartphones, the demand for further miniaturization and thinning remains high. This necessitates the miniaturization and reduction of internal devices, such as antenna modules. In particular, when a display screen is formed on the entire main surface of a device, as in smartphones, the area within the communication device where an antenna device with antenna elements (radiating elements) can be configured is limited. Furthermore, the size of the antenna device itself may also be constrained.

[0009] When a patch antenna with a planar shape is used as a radiating element, the radiating element functions as an antenna through electromagnetic field coupling generated between the radiating element and a ground electrode arranged opposite to the radiating element. However, if the area of ​​the ground electrode cannot be sufficiently guaranteed due to the size constraints of the antenna device, there is a possibility that the electromagnetic field coupling between the radiating element and the ground electrode becomes insufficient or disordered, thereby failing to achieve the desired antenna characteristics.

[0010] Japanese Patent Application Publication No. 2003-152431 (Patent Document 1) did not consider the problems mentioned above that are associated with size constraints.

[0011] This disclosure was made to solve this problem, and its purpose is to suppress the degradation of antenna characteristics in an antenna module capable of radiating radio waves in two different frequency bands.

[0012] Solution for solving the problem

[0013] An antenna module according to one aspect of this disclosure includes a first radiating element and a second radiating element in the shape of a planar plate, and a ground electrode disposed opposite to them. The first radiating element radiates radio waves in a first frequency band. The second radiating element radiates radio waves in a second frequency band higher than the first frequency band. Viewed from the normal direction of the first radiating element, the distance in a first direction from the center of the first radiating element to the end of the ground electrode is less than 1 / 2 of the free space wavelength of the radio wave radiated from the first radiating element. Radio waves with a single polarization direction are radiated from the first radiating element. The feed point of the first radiating element is disposed at a position offset from the center of the first radiating element in a second direction different from the first direction. The feed point of the second radiating element is disposed at a position offset from the center of the second radiating element in a third direction.

[0014] An antenna module according to other aspects of this disclosure includes a first radiating element and a second radiating element in the shape of a planar plate, and a ground electrode disposed opposite to them. The first radiating element radiates radio waves in a first frequency band. The second radiating element radiates radio waves in a second frequency band higher than the first frequency band. When viewed from the normal direction of the first radiating element, the dimension of the ground electrode in a first direction is shorter than the dimension in a second direction different from the first direction. Radio waves with a single polarization direction are radiated from the first radiating element. The feed point of the first radiating element is disposed at a position offset from the center of the first radiating element in a second direction different from the first direction. The feed point of the second radiating element is disposed at a position offset from the center of the second radiating element in a third direction and at a position offset from the center of the second radiating element in a fourth direction different from the third direction.

[0015] The effects of the invention

[0016] Using the antenna module according to this disclosure, in environments where the size of the ground electrode is constrained, for the first radiating element on the low-frequency side, where the distance to the ground electrode cannot be sufficiently ensured when viewed from above, a feed point is provided in a direction different from the direction of the size constraint (the first direction). For the second radiating element on the high-frequency side, where the size constraint has a smaller impact, feed points are provided in two directions. By adopting this structure, for the radiating element on the low-frequency side, polarized waves with insufficient antenna characteristics are suppressed, and for the radiating element on the high-frequency side, radio waves can be radiated using two polarized waves. Therefore, in a dual-band type antenna module, the degradation of antenna characteristics can be suppressed. Attached Figure Description

[0017] Figure 1 This is a block diagram of a communication device with an antenna module involved in the application implementation.

[0018] Figure 2 This is a top perspective view of the antenna module involved in the implementation method.

[0019] Figure 3 yes Figure 2 Side perspective view of the antenna module.

[0020] Figure 4 This is a top perspective view of the antenna module of variant example 1.

[0021] Figure 5 This is a side perspective view of the antenna module of variant example 2.

[0022] Figure 6 This is a top perspective view of the antenna module of variant example 3.

[0023] Figure 7 This is a top perspective view of the antenna module in variant example 4.

[0024] Figure 8 This is a top perspective view of the antenna module of variant 5.

[0025] Figure 9 This is a three-dimensional view of the antenna module of variant example 6.

[0026] Figure 10 This is a side perspective view of the antenna module of variant 7.

[0027] Figure 11 This is a side perspective view of the antenna module of variant 8. Detailed Implementation

[0028] The embodiments of this disclosure will now be described in detail with reference to the accompanying drawings. Furthermore, identical or equivalent parts in the drawings will be labeled with the same reference numerals, and their descriptions will not be repeated.

[0029] [Implementation Method]

[0030] (Basic structure of a communication device)

[0031] Figure 1 This is a block diagram of an example of a communication device 10 using the antenna module 100 described in this embodiment. The communication device 10 is, for example, a portable terminal such as a mobile phone, smartphone, or tablet, or a personal computer with communication capabilities.

[0032] 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 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 then radiates it from the antenna device 120. Furthermore, it down-converts the high-frequency signal received by the antenna device 120 and processes the signal through the BBIC 200.

[0033] exist Figure 1 The antenna device 120 has a structure in which radiating elements 125 are arranged in a two-dimensional array. Each radiating element 125 includes two feed elements 121 and 122. (As will be discussed later...) Figure 2 As described, feed elements 121 and 122 are arranged to overlap in the normal direction of the feed elements. Antenna device 120 is configured to radiate radio waves of different frequency bands from feed elements 121 and 122 of radiating element 125. That is, antenna device 120 is a stacked dual-band antenna device. Different high-frequency signals are supplied from RFIC 110 to each feed element 121 and 122.

[0034] exist Figure 1 For ease of explanation, only the structures corresponding to four of the plurality of radiating elements 125 constituting the antenna device 120 are shown, omitting the structures corresponding to the other radiating elements 125 having the same structure. Furthermore, the antenna device 120 is not necessarily a two-dimensional array; it may also be formed by a single radiating element 125. Alternatively, it may be a one-dimensional array of multiple radiating elements 125 arranged in a row. In this embodiment, the feed elements 121 and 122 included in the radiating elements 125 are patch antennas with a planar shape.

[0035] RFIC 110 includes switches 111A-111H, 113A-113H, 117A, and 117B; power amplifiers 112AT-112HT; low-noise amplifiers 112AR-112HR; attenuators 114A-114H; phase shifters 115A-115H; signal synthesizers / demultiplexers 116A and 116B; mixers 118A and 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 circuits for high-frequency signals of the first frequency band radiated from the low-frequency side of the feed element 121. Furthermore, the switches 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 circuits for high-frequency signals in the second frequency band radiated from the high-frequency side of the feed element 122.

[0036] When transmitting high-frequency signals, switches 111A-111H and 113A-113H are switched to the power amplifier 112AT-112HT side, and switches 117A and 117B are connected to the transmitting-side amplifiers of amplifier circuits 119A and 119B. When receiving high-frequency signals, switches 111A-111H and 113A-113H are switched to the low-noise amplifier 112AR-112HR side, and switches 117A and 117B are connected to the receiving-side amplifiers of amplifier circuits 119A and 119B.

[0037] 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 transmission signal is divided into four signals by signal synthesizers / demultiplexers 116A and 116B, and fed to different feed elements 121 and 122 through corresponding signal paths. The directivity of the antenna device 120 can be adjusted by independently adjusting the phase shift of phase shifters 115A to 115H configured in each signal path.

[0038] The received signals, which are high-frequency signals, received by the feed elements 121 and 122 are transmitted to RFIC 110. After passing through four different signal paths, they are synthesized by signal synthesizers / demultiplexers 116A and 116B. The synthesized received signals are down-converted by mixers 118A and 118B, amplified by amplifier circuits 119A and 119B, and then transmitted to BBIC 200.

[0039] RFIC 110 may be configured as an integrated circuit component comprising a single chip including the circuit structure described above. Alternatively, the devices (switches, power amplifiers, low-noise amplifiers, attenuators, phase shifters) in RFIC 110 corresponding to each radiating element 125 may be configured as an integrated circuit component comprising a single chip for each radiating element 125.

[0040] (Structure of the antenna module)

[0041] Next, use Figure 2 and Figure 3 The details of the structure of the antenna module 100 in this embodiment will be explained below.

[0042] exist Figure 2 The image shows a top perspective view of the antenna module 100. Figure 3 A side perspective view of the antenna module 100 is shown. In the following description, for ease of explanation, an antenna module having one radiating element 125 will be used as an example. Furthermore, as... Figure 2 and Figure 3 As shown, the thickness direction of the antenna module 100 is defined as the Z-axis direction, and the X-axis and Y-axis define the surface perpendicular to the Z-axis direction. Additionally, the positive direction of the Z-axis in each figure is sometimes referred to as the upper surface side, and the negative direction as the lower surface side.

[0043] Reference Figure 2 and Figure 3 In addition to the RFIC 110 and radiating elements 125 (feeding elements 121, 122), the antenna module 100 also includes a dielectric substrate 130, feed wirings 141A, 141B, 142A, 142B, and a ground electrode GND. In the top perspective view, the RFIC 110, dielectric substrate 130, and each feed wiring are omitted.

[0044] 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 epoxy, polyimide, or other resins, a multilayer resin substrate formed by stacking multiple resin layers composed of liquid crystal polymer (LCP) with a low dielectric constant, a multilayer resin substrate formed by stacking multiple resin layers composed of fluorine-based resins, 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.

[0045] When viewed from the normal direction (Z-axis direction), the dielectric substrate 130 is formed into a rectangular or approximately rectangular shape having a long side parallel to the X-axis and a short side parallel to the Y-axis. A ground electrode GND, also rectangular in shape, is disposed on the lower surface 132 (the plane in the negative Z-axis direction) of the dielectric substrate 130. A power supply element 122 is disposed facing the ground electrode GND on the upper surface 131 (the plane in the positive Z-axis direction) of the dielectric substrate 130. The power supply element 122 can be either exposed on the upper surface 131 of the dielectric substrate 130 or... Figure 3 As in the example, it is disposed in the inner layer of the dielectric substrate 130. The power supply element 121 is disposed facing the ground electrode GND in a layer closer to the ground electrode GND than the power supply element 122. In other words, the power supply element 121 is disposed in the layer between the layer forming the power supply element 122 and the layer forming the ground electrode GND.

[0046] The power supply elements 121 and 122 are formed of a conductor such as copper or aluminum with a flat plate shape. Figure 2 In the example, when viewed from the normal direction of the dielectric substrate 130, the power supply elements 121 and 122 have a square or approximately square shape, and are configured such that each side is parallel to the side of the rectangular dielectric substrate 130 (and the ground electrode GND). Furthermore, the shape of the power supply elements 121 and 122 is not limited to a square, but can also be a polygon, a circle, an ellipse, or a cross shape.

[0047] Furthermore, when viewed from the normal direction of the dielectric substrate 130, the feed element 121 and feed element 122 are arranged in an overlapping manner. The size of the feed element 122 is smaller than that of the feed element 121, and the resonant frequency of the feed element 122 is higher than that of the feed element 121. That is, the frequency band (second frequency band) of the radio wave radiated from the feed element 122 is higher than the frequency band (first frequency band) of the radio wave radiated from the feed element 121. For example, the frequency band of the radio wave radiated from the feed element 122 is the 39 GHz band, and the frequency band of the radio wave radiated from the feed element 121 is the 28 GHz band.

[0048] An RFIC 110 is mounted on the lower surface 132 of the dielectric substrate 130, with solder bumps 150 in between. Alternatively, the RFIC 110 can be connected to the dielectric substrate 130 using a multi-pole connector instead of soldering.

[0049] High-frequency signals are transmitted from RFIC 110 to feed element 121 via feed lines 141A and 141B. Feed lines 141A and 141B extend from RFIC 110 through the ground electrode GND and are connected to feed points SP1A and SP1B respectively from the lower surface side of feed element 121. That is, feed lines 141A and 141B transmit high-frequency signals to feed points SP1A and SP1B of feed element 121 respectively. Alternatively, when viewed from the normal direction of dielectric substrate 130, the positions of feed points SP1A and SP1B of low-frequency side feed element 121 may overlap with those of high-frequency side feed element 122. However, from the viewpoint of isolation between the two radio waves, it is preferable to position feed points SP1A and SP1B in a position that does not overlap with feed element 122.

[0050] Feed point SP1A is positioned offset in the negative X-axis direction relative to the center of feed element 121. Feed point SP1B is positioned offset in the positive X-axis direction relative to the center of feed element 121. Therefore, when a high-frequency signal is transmitted to feed points SP1A and SP1B, electromagnetic waves polarized along the X-axis direction are radiated from feed element 121. A high-frequency signal that is out of phase with the high-frequency signal supplied to feed point SP1A is supplied to feed point SP1B. In other words, the phase difference between the high-frequency signal supplied to feed point SP1A and the high-frequency signal supplied to feed point SP1B is 180°. By independently supplying high-frequency signals with opposite phases to feed points SP1A and SP1B in this way, the power of the electromagnetic waves radiated from feed element 121 can be multiplied.

[0051] High-frequency signals are transmitted from RFIC 110 to feed element 122 via feed lines 142A and 142B. Feed lines 142A and 142B extend from RFIC 110 through the ground electrode GND and feed element 121, and are connected to feed points SP2A and SP2B from the lower surface of feed element 122. That is, feed lines 142A and 142B transmit high-frequency signals to feed points SP2A and SP2B of feed element 122.

[0052] Feed point SP2A is positioned offset from the center of feed element 122 in the negative X-axis direction. Feed point SP2B is positioned offset from the center of feed element 122 in the negative Y-axis direction. Therefore, when a high-frequency signal is transmitted to feed point SP2A, electromagnetic waves polarized along the X-axis direction are radiated from feed element 122. Similarly, when a high-frequency signal is transmitted to feed point SP2B, electromagnetic waves polarized along the Y-axis direction are radiated from feed element 122.

[0053] Furthermore, in antenna module 100, it is described that... Figure 3 As shown, the power supply elements 121 and 122 are powered by direct connection to the power supply wiring, but it can also be the following structure: one or both of the power supply elements 121 and 122 are powered by capacitive coupling with the corresponding power supply wiring.

[0054] like Figure 2 As shown, when viewed from above along the Z-axis, the antenna module 100 has a rectangular shape with the X-axis as its longer side and the Y-axis as its shorter side. In other words, the dimension along the Y-axis (first direction) is shorter than the dimension along the X-axis (second direction). In the antenna module 100, the distance along the Y-axis from the end of the feed element 121 to the end of the dielectric substrate 130 (i.e., the ground electrode GND) is shorter than the distance along the X-axis. For example, when the antenna module is positioned on the side of a thin communication device such as a smartphone, the dimension in the thickness direction of the communication device (e.g., ...) is... Figure 2 The dimensions in the Y-axis direction are limited.

[0055] In the case where a patch antenna with a planar shape is used as a radiating element, such as in antenna module 100, the radiating element functions as an antenna through electromagnetic field coupling generated between the radiating element and a ground electrode arranged opposite to the radiating element. In the case of antenna module 100, the feed element 121 functions as an antenna through electromagnetic field coupling formed between the feed element 121 and the ground electrode GND. On the other hand, regarding feed element 122, the feed element 121 acts as a ground electrode, and the feed element 122 functions as an antenna through electromagnetic field coupling formed between the feed element 122 and the feed element 121.

[0056] When the area of ​​the ground electrode cannot be sufficiently guaranteed due to limitations such as the size of the dielectric substrate, the following possibilities exist: the electromagnetic field coupling between the radiating element and the ground electrode becomes insufficient, or the electromagnetic field coupling becomes disordered, thereby failing to achieve the desired antenna characteristics. Therefore, in situations such as Figure 2 When the dimensions of the dielectric substrate 130 in the Y-axis direction are constrained, as shown in the antenna module 100, it may affect the antenna characteristics related to the radio waves polarized in the Y-axis direction in the feed element 121 on the low-frequency side. More specifically, the shortest distance L2 in the Y-axis direction from the center of the feed element 121 to the end of the ground electrode GND is greater than the free-space wavelength λ of the radio waves radiated from the feed element 121. L0 When the antenna is half the length, the degradation in antenna characteristics can become significant.

[0057] Therefore, at the aforementioned shortest distance L2, compared to the free space wavelength λ... L0 In the case of a 1 / 2 short length, for the feed element 121, feed points SP1A and SP1B are arranged at positions offset in the X-axis direction relative to the center of the feed element 121, so that the feed element 121 radiates only radio waves with the X-axis polarization direction. This eliminates the effect of the decrease in antenna characteristics associated with the size constraints in the Y-axis direction.

[0058] On the other hand, as described above, through electromagnetic field coupling formed between the high-frequency side feed element 122 and the low-frequency side feed element 121, the high-frequency side feed element 122 functions as an antenna, thus the size constraint of the ground electrode GND has little impact on the antenna characteristics. Therefore, feed points SP2A and SP2B are respectively arranged at positions offset in the X-axis direction and in the Y-axis direction relative to the center of the feed element 122. This allows for the radiation of two radio waves with different polarization directions.

[0059] Furthermore, the "feeding element 121" and "feeding element 122" in the embodiments correspond to the "first radiating element" and "second radiating element" of this disclosure, respectively. In addition, in the embodiments, the "Y-axis direction" corresponds to the "first direction" and "third direction" of this disclosure, and the "X-axis direction" corresponds to the "second direction" and "fourth direction" of this disclosure.

[0060] Furthermore, the above description illustrates an example where the direction (first direction) of the shortest distance between the feed element 121 and the ground electrode GND is orthogonal to the polarization direction (second direction) of the electromagnetic wave radiated from the feed element 121. However, the first and second directions are not necessarily orthogonal. Additionally, the two polarization directions (third and fourth directions) of the feed element 122 are also not necessarily orthogonal.

[0061] (Variation Example 1)

[0062] Figure 4 This is a top perspective view of antenna module 100X of Modified Example 1. In antenna module 100X of Modified Example 1, the difference from antenna module 100 is that a single polarization direction of electromagnetic waves is radiated from the feed element 122 on the high-frequency side. More specifically, in feed element 122, only the feed point SP2A is supplied with a high-frequency signal.

[0063] As described above, compared to the feed element 121, the size constraint of the ground electrode GND has a smaller impact on the antenna characteristics of the high-frequency feed element 122, which is less restrictive on the high-frequency feed element 122. It does not need to radiate radio waves in two polarization directions, and can also be as follows: Figure 4 Such a structure radiates radio waves in only a single polarization direction.

[0064] (Variation Example 2)

[0065] Figure 5 This is a side perspective view of antenna module 100A of Modified Example 2. In antenna module 100A of Modified Example 2, the method of supplying the high-frequency signal to the feed point SP1B of the feed element 121 on the low-frequency side differs from that of antenna module 100. More specifically, instead of independently supplying the high-frequency signal from RFIC 110 to feed point SP1B, the high-frequency signal is supplied to feed point SP1B using feed line 141C branching from feed line 141A which supplies the high-frequency signal to feed point SP1A. In this case, the path length of feed line 141C is set to form a phase opposite to the phase of the signal transmitted to feed point SP1A (e.g., half the wavelength of the transmitted signal).

[0066] Furthermore, in the case of antenna module 100A, a high-frequency signal is supplied to the feed element 121 from RFIC 110 via one path, so the power of the radiated radio wave is half that of antenna module 100.

[0067] (Variation Example 3)

[0068] Figure 6 This is a top perspective view of antenna module 100B of Modified Example 3. In antenna module 100B of Modified Example 3, the feed element 122 on the high-frequency side is arranged at an angle relative to the feed element 121. Specifically, the feed element 122 is arranged such that the angles formed by each side of the feed element 122 with the X-axis and Y-axis are 45°. As a result, radio waves with polarization directions of 45° and -45° relative to the X-axis are radiated from the feed element 122.

[0069] As described above, the high-frequency side feed element 122 functions as an antenna through electromagnetic field coupling formed between the feed element 122 and the feed element 121. Therefore, when the distance from the center of the feed element 122 to the end of the feed element 121 in the polarization direction is limited, the aforementioned distance can be extended by tilting the feed element 122 relative to the feed element 121 as in antenna module 100B, thereby suppressing the degradation of the antenna characteristics of the feed element 122.

[0070] Furthermore, in Modification 3, the "Y-axis direction" and "X-axis direction" correspond to the "first direction" and "second direction" of this disclosure, respectively, and the directions at 45° and -45° relative to the X-axis correspond to the "third direction" and "fourth direction" of this disclosure, respectively.

[0071] (Variation Example 4)

[0072] In variation 4, a structure in which two power supply elements are arranged adjacent to each other is described. Figure 7 This is a top perspective view of antenna module 100C in variant example 4. Antenna module 100C is not as shown... Figure 3 Instead of the stacked antenna module shown, two feed elements 121 and 122A are arranged adjacent to each other with a gap between them. More specifically, in Figure 7 In the example, the power supply element 121 and the power supply element 122A are arranged adjacent to each other in the X-axis direction.

[0073] In antenna module 100C, the shortest distance L2 in the Y-axis direction from the center of feed elements 121 and 122A to the end of the ground electrode GND is greater than the free space wavelength λ of the electromagnetic wave radiated from feed element 121. L0 It is half the length of the free-space wavelength λ of the electromagnetic wave radiated from the feed element 122A. H0 Half the length. On the other hand, the shortest distance L4 in the X-axis direction from the center of the feed element 121 to the end of the ground electrode GND is longer than the free space wavelength λ. L0 The shortest distance L5 in the X-axis direction from the center of the feed element 122A to the end of the ground electrode GND is half the length of the free space wavelength λ. H0 Half the length.

[0074] Therefore, the feed point of the feed element 121 is positioned at a location offset from the center of the feed element 121 in the X-axis direction, and the feed point of the feed element 122A is positioned at a location offset from the center of the feed element 122A in the X-axis direction and in the Y-axis direction.

[0075] In an antenna module where two feed elements with different frequency bands are arranged adjacent to each other, when the distance from the center of the radiating element to the end of the ground electrode GND is constrained, the radio wave is radiated in one polarization direction, and when the distance is not constrained, the radio wave is radiated in two polarization directions, thereby suppressing the degradation of antenna characteristics.

[0076] (Variation Example 5)

[0077] In Variation 5, we will describe an array antenna formed by arranging multiple stacked radiating elements.

[0078] Figure 8 This is a top perspective view of antenna module 100D of Modified Example 5. In antenna module 100D, four radiating elements 125-1 to 125-4 are arranged in a row at intervals along the X-axis. Radiating element 125-1 includes a low-frequency side feed element 121-1 and a high-frequency side feed element 122-1. Radiating element 125-2 includes a low-frequency side feed element 121-2 and a high-frequency side feed element 122-2. Radiating element 125-3 includes a low-frequency side feed element 121-3 and a high-frequency side feed element 122-3. Radiating element 125-4 includes a low-frequency side feed element 121-4 and a high-frequency side feed element 122-4.

[0079] The shortest distance L2 from the center of each feed element to its end in the Y-axis direction of the ground electrode GND is greater than the free-space wavelength λ of the electromagnetic waves radiated from the feed elements 122-1 to 122-4 on the high-frequency side. H0 Half the length of the free-space wavelength λ of the electromagnetic waves radiated from the low-frequency feed elements 121-1 to 121-4. L0 It is half the length of the wavelength. Furthermore, for the radiating elements 125-1 and 125-4 located at the ends, the shortest distance L4 from the center of the radiating element to the end in the X-axis direction of the ground electrode GND is shorter than the free-space wavelength λ. L0 Half the length.

[0080] Therefore, for the low-frequency side feed elements 121-1 to 121-4, feed points are arranged at positions offset in the X-axis direction relative to the center of each feed element. On the other hand, for the high-frequency side feed elements 122-1 to 122-4, feed points are arranged at positions offset in the X-axis direction and in the Y-axis direction relative to the center of each feed element.

[0081] In the case of an array antenna, where the distance from the center of the feed element to the end of the ground electrode GND is limited, the radio wave is radiated in one polarization direction. When the distance is not limited, the radio wave is radiated in two polarization directions, thereby suppressing the degradation of antenna characteristics.

[0082] Furthermore, in Modification 5, for example, the "feed element 121-1" and "feed element 122-1" of radiating element 125-1 correspond to the "first radiating element" and "second radiating element" of this disclosure, respectively, and the "feed element 121-2" and "feed element 122-2" of radiating element 125-2 correspond to the "third radiating element" and "fourth radiating element" of this disclosure, respectively. Additionally, in Modification 5, the "Y-axis direction" corresponds to the "first direction" and "third direction" of this disclosure, and the "X-axis direction" corresponds to the "second direction" and "fourth direction" of this disclosure.

[0083] (Variation Example 6)

[0084] In Variation 6, the case of an antenna module with two array antennas is described.

[0085] Figure 9 This is a perspective view of the antenna module 100Y of Variation 6. The antenna module 100Y includes two different dielectric substrates 130B and 130C extending along the Y-axis. Dielectric substrates 130B and 130C each have a generally rectangular shape with the Y-axis as the longer side, and multiple stacked radiating elements on each of the dielectric substrates 130B and 130C are arranged along the Y-axis. Furthermore, an RFIC 110 is disposed on the back side of the dielectric substrate 130B.

[0086] The normal direction of dielectric substrate 130B is the Z-axis direction, and the normal direction of dielectric substrate 130C is the X-axis direction. Dielectric substrates 130B and 130C are connected to each other by a bent connecting member 123. That is, when viewed from above along the Y-axis, antenna module 100Y has a roughly L-shaped form. With this structure, antenna module 100Y can radiate radio waves in two different directions, the X-axis and Z-axis.

[0087] In dielectric substrate 130B, four radiating elements are arranged in a row at intervals along the Y-axis. Each radiating element in dielectric substrate 130B includes a low-frequency side feed element 121B and a high-frequency side feed element 122B. Similarly, in dielectric substrate 130C, four radiating elements are also arranged in a row at intervals along the Y-axis. Each radiating element in dielectric substrate 130C includes a low-frequency side feed element 121C and a high-frequency side feed element 122C.

[0088] Here, the dimension L20 of the short side (Z-axis direction) of the dielectric substrate 130C is shorter than the dimension L10 of the short side (X-axis direction) of the dielectric substrate 130B (L10>L20). Therefore, the size of the ground electrode in the Z-axis direction is limited in the dielectric substrate 130C. Consequently, for the low-frequency side feed element 121C in the dielectric substrate 130C, similar to the case of Modified Example 5, the feed point is arranged at a position offset in the Y-axis direction relative to the center of each feed element. On the other hand, for the high-frequency side feed element 122C, the feed point is arranged at a position offset in the Y-axis direction and a position offset in the Z-axis direction relative to the center of each feed element.

[0089] In the dielectric substrate 130B, where the size of the ground electrode is limited, feed points are positioned offset in the X-axis direction and in the Y-axis direction relative to the center of each feed element 121B and 122B, respectively. Alternatively, also in the dielectric substrate 130B, if the dimension L10 in the short side direction is made short, similarly to the dielectric substrate 130C, the low-frequency side feed element 121B may be polarized only in the Y-axis direction.

[0090] In the case of an antenna module having two array antennas capable of radiating radio waves in different directions, when the distance from the center of the feed element to the end of the ground electrode GND is limited, the radio waves are radiated in one polarization direction, and when the distance is not limited, the radio waves are radiated in two polarization directions, thereby suppressing the degradation of antenna characteristics.

[0091] (Variations 7 and 8)

[0092] exist Figure 3 In the antenna module 100 of the embodiment shown, a structure is illustrated in which the feed elements 121 and 122 are disposed on the same dielectric substrate 130. However, it is also possible for one or both of the feed elements 121 and 122 to be disposed on separate and different dielectric substrates.

[0093] Figure 10 This is a side perspective view of the antenna module 100E of Modified Example 7. In the antenna module 100E, the following structure is adopted: feed elements 121 and 122 are formed on the dielectric substrate 170, and a ground electrode GND is formed on the dielectric substrate 160. The dielectric substrate 170 corresponds to, for example, the housing of the communication device 10, and supplies high-frequency signals from the RFIC 110 disposed on the dielectric substrate 160 to the radiating elements pre-embedded in the housing.

[0094] In the dielectric substrate 170, a power supply element 122 is formed on the upper surface 171 side, and a power supply element 121 is formed facing the power supply element 122 on the lower surface 172 side. The dielectric substrates 160 and 170 are configured such that the lower surface 172 of the dielectric substrate 170 and the upper surface 161 of the dielectric substrate 160 face each other. On the lower surface 162 of the dielectric substrate 160, an RFIC 110 is mounted with solder bumps 150 in between.

[0095] Solder bumps and other connection terminals 180 are formed between dielectric substrate 160 and dielectric substrate 170, and the connection terminals 180 electrically connect dielectric substrate 160 and dielectric substrate 170. Specifically, power supply wirings 141A, 141B, 142A, and 142B are connected to the power supply points of corresponding power supply components via the connection terminals 180.

[0096] in addition, Figure 11 This is a side perspective view of the antenna module 100F of Modified Example 8. In the antenna module 100F, the following structure is formed: the high-frequency side feed element 122 is disposed on the dielectric substrate 170A, and the feed element 121 and the ground electrode GND are formed on the dielectric substrate 160A.

[0097] A connection terminal 180 is formed between dielectric substrate 160A and dielectric substrate 170A, and the connection terminal 180 electrically connects dielectric substrate 160A and dielectric substrate 170A. Specifically, power supply wirings 142A and 142B are connected to the corresponding power supply points of power supply element 122 via connection terminal 180.

[0098] This is also true in antenna modules with one or both feed elements configured on separate, different dielectric substrates, and... Figure 2 Similarly, if it is not possible to sufficiently ensure the distance from the center of the low-frequency side feed element 121 to the end of the ground electrode GND, radiation of radio waves with the polarization direction of the insufficient distance will not be performed. Instead, the feed point will be positioned in a direction (e.g., an orthogonal direction) that ensures the distance to the end of the ground electrode GND, thereby suppressing the degradation of antenna characteristics.

[0099] The embodiments disclosed herein should be considered illustrative rather than limiting in all respects. The scope of the invention is defined by the claims, not by the description of the embodiments above, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0100] Explanation of reference numerals in the attached figures

[0101] 10: Communication device; 100, 100A~100F, 100X, 100Y: Antenna module; 110: RFIC; 111A~111H, 113A~113H, 117A, 117B: Switch; 112AR~112HR: Low noise amplifier; 112AT~112HT: Power amplifier; 114A~114H: Attenuator; 115A~115H: Phase shifter; 116A, 116B: Signal synthesizer / demultiplexer; 118A, 118B: Mixer; 119A, 119B: Amplifier circuit; 120: Antenna device; 121, 121-1~121-4, 121B, 121C, 122, 122-1~122-4, 122A~122C: Power supply components; 125, 125-1~125-4: Radiation components; 130, 130B, 130C, 160, 160A, 170, 170A: Dielectric substrate; 141A~141C, 142A, 142B: Power supply wiring; 150: Solder bump; 180: Connecting terminal; 200: BBIC; GND: Ground electrode; SP1A, SP1B, SP2A, SP2B: Power supply points.

Claims

1. An antenna module, comprising: A first radiating element in the shape of a flat plate, which is capable of radiating radio waves in a first frequency band; A second radiating element in the shape of a flat plate, capable of radiating radio waves in a second frequency band higher than the first frequency band; and A grounding electrode is configured facing the first radiating element and the second radiating element. in, When viewed from the normal direction of the first radiating element, the distance in a first direction from the center of the first radiating element to the end of the grounding electrode is less than 1 / 2 of the free-space wavelength of the electromagnetic wave radiated from the first radiating element. The first radiating element radiates radio waves with a single polarization direction. The feed point of the first radiating element is positioned at a location offset from the center of the first radiating element in a second direction different from the first direction. The feed point of the second radiating element is positioned at a third-direction offset relative to the center of the second radiating element. The feed point of the second radiating element is also disposed at a position offset from the center of the second radiating element in a fourth direction different from the third direction.

2. The antenna module according to claim 1, wherein, The first radiating element radiates electromagnetic waves with the second direction as the polarization direction. The second radiating element radiates radio waves polarized in the third direction and radio waves polarized in the fourth direction.

3. The antenna module according to claim 1 or 2, wherein, The second direction is consistent with one of the third direction and the fourth direction.

4. The antenna module according to claim 1 or 2, wherein, The second direction is inconsistent with both the third and fourth directions.

5. The antenna module according to claim 1 or 2, wherein, The first radiating element is provided with a first feed point and a second feed point. The first feed point is located at a position offset from the center of the first radiating element in the negative direction of the second direction, and the second feed point is located at a position offset from the center of the first radiating element in the positive direction of the second direction. The phase difference between the high-frequency signal supplied to the first feed point and the high-frequency signal supplied to the second feed point is 180°.

6. The antenna module according to claim 1 or 2, wherein, High-frequency signals are supplied to each feed point of the first and second radiating elements through independent feed lines.

7. The antenna module according to claim 1 or 2, wherein, When viewed from the normal direction of the first radiating element, the first radiating element and the second radiating element are arranged adjacent to each other in the second direction.

8. The antenna module according to claim 1 or 2, wherein, When viewed from the normal direction of the first radiating element, the second radiating element overlaps with the first radiating element. The first radiating element is disposed between the second radiating element and the grounding electrode.

9. The antenna module according to claim 1 or 2, wherein, It also has: A third radiating element in the shape of a flat plate, capable of radiating radio waves in the first frequency band; and A fourth radiating element in the shape of a flat plate, capable of radiating radio waves in the second frequency band. The third radiating element is configured to be separated from the first radiating element in the second direction. The fourth radiating element is configured to be separated from the second radiating element in the second direction. The third radiating element radiates electromagnetic waves with a single polarization direction. The feed point of the third radiating element is positioned at a location offset in the second direction relative to the center of the third radiating element. The feed point of the fourth radiating element is configured at a position offset from the center of the fourth radiating element in the third direction and at a position offset from the center of the fourth radiating element in the fourth direction.

10. The antenna module according to claim 1 or 2, wherein, The third direction is orthogonal to the fourth direction.

11. The antenna module according to claim 1 or 2, wherein, It also has a power supply circuit for supplying high-frequency signals to each radiating element.

12. The antenna module according to claim 1 or 2, wherein, The distance from the center of the first radiating element to the end of the grounding electrode in the second direction is longer than half the free-space wavelength of the electromagnetic wave radiated from the first radiating element.

13. The antenna module according to claim 1 or 2, wherein, The distance from the center of the second radiating element to the end of the grounding electrode in the first direction is longer than half the free-space wavelength of the electromagnetic wave radiated from the second radiating element.

14. An antenna module, comprising: A first radiating element in the shape of a flat plate, which is capable of radiating radio waves in a first frequency band; A second radiating element in the shape of a flat plate, capable of radiating radio waves in a second frequency band higher than the first frequency band; and A grounding electrode is configured facing the first radiating element and the second radiating element. in, Viewed from the normal direction of the first radiating element, the dimension of the grounding electrode in the first direction is shorter than its dimension in the second direction, which is different from the first direction. The first radiating element radiates radio waves with a single polarization direction. The feed point of the first radiating element is positioned at a location offset in the second direction relative to the center of the first radiating element. The feed point of the second radiating element is configured at a position offset from the center of the second radiating element in a third direction and at a position offset from the center of the second radiating element in a fourth direction different from the third direction.

15. The antenna module according to claim 14, wherein, The dimension of the grounding electrode in the first direction is shorter than twice the dimension of the first radiating element in the first direction.

16. The antenna module according to claim 14 or 15, wherein, The dimension of the grounding electrode in the second direction is twice as long as the dimension of the first radiating element in the second direction.

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

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