Antenna module and communication device having the same

Abstract

An antenna module (100) is provided with a radiating element (121) in a flat plate shape; a ground electrode (GND) disposed in a manner facing the radiating element (121); feed wirings (141, 142); and stubs (ST1, ST2) functioning as band elimination filters. The feed wiring (141) transmits a high-frequency signal of a first frequency band to a feed point (SP1) of the radiating element. The feed wiring (142) transmits a high-frequency signal of a second frequency band higher than the first frequency band to a feed point (SP2) of the radiating element. The stub (ST1) is connected to the feed wiring (141) and configured to obstruct passage of the high-frequency signal of the second frequency band. The stub (ST2) is connected to the feed wiring (142) and configured to obstruct passage of the high-frequency signal of the first frequency band.

Description

Technical Field

[0001] This disclosure relates to an antenna module and a communication device having the antenna module, and more particularly, to a technique for radiating radio waves in multiple frequency bands using a single radiating element. Background Technology

[0002] International Publication No. 2023 / 100621 (Patent Document 1) discloses a so-called dual-band antenna module that uses two different radiating elements stacked on a dielectric substrate to radiate radio waves in two frequency bands respectively.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: International Publication No. 2023 / 100621 Summary of the Invention

[0006] The problem the invention aims to solve

[0007] In the antenna module disclosed in International Patent Publication No. 2023 / 100621 (Patent Document 1), when viewed from the normal direction over the dielectric substrate, the two radiating elements are arranged in an overlapping manner. In such a structure, it is preferable to arrange the radiating elements with their centers aligned, but if the two radiating elements are misaligned due to manufacturing deviations, it may become a major cause of reduced antenna performance.

[0008] This disclosure was made to solve the problems described above, and its purpose is to provide an antenna module capable of radiating radio waves in multiple frequency bands using a single radiating element.

[0009] Solution for solving the problem

[0010] The antenna module disclosed herein includes: a planar radiating element; a ground electrode arranged facing the radiating element; a first feed wiring and a second feed wiring; and a first band-stop filter and a second band-stop filter. The first feed wiring transmits high-frequency signals of a first frequency band to a first feed point of the radiating element. The second feed wiring transmits high-frequency signals of a second frequency band higher than the first frequency band to a second feed point of the radiating element. The first band-stop filter is connected to the first feed wiring and is configured to block the passage of high-frequency signals of the second frequency band. The second band-stop filter is connected to the second feed wiring and is configured to block the passage of high-frequency signals of the first frequency band.

[0011] The effects of the invention

[0012] In the antenna module disclosed herein, high-frequency signals of different frequency bands are transmitted to a common radiating element via two feed lines (a first feed line and a second feed line). Furthermore, each feed line is equipped with a band-stop filter configured to block the passage of high-frequency signals transmitted by the other feed line. This structure suppresses the degradation of antenna characteristics and allows the use of a single radiating element to radiate radio waves across multiple frequency bands. Attached Figure Description

[0013] Figure 1 This is an overall structural diagram of a communication device equipped with the antenna module described in Embodiment 1.

[0014] Figure 2 This is a top view of the antenna module involved in Implementation Method 1.

[0015] Figure 3 yes Figure 2 Side perspective view of the antenna module.

[0016] Figure 4 It is shown in Figure 2 The diagram shows the antenna characteristics observed from each feed wiring in the antenna module.

[0017] Figure 5 This is a top view of the antenna module of Variation Example 1.

[0018] Figure 6 This is a top view of the antenna module in variant example 2.

[0019] Figure 7 This is a top view of the antenna module of variant example 3.

[0020] Figure 8 This is a top view of the antenna module in variant example 4.

[0021] Figure 9 This is a top view of the antenna module in variant 5.

[0022] Figure 10 This is a top view of the antenna module of variant 6.

[0023] Figure 11 This is a top view of the antenna module of variant 7.

[0024] Figure 12 This is a top view of the antenna module of variant example 8.

[0025] Figure 13 This is a side perspective view of the antenna module of variant 8.

[0026] Figure 14 This is a top view of the antenna module of variant example 9.

[0027] Figure 15 This is a side perspective view of the antenna module of variant example 9.

[0028] Figure 16 This is a top view of the antenna module of variant 10.

[0029] Figure 17 This is a side perspective view of the antenna module of variant 10.

[0030] Figure 18 This is a top view of the antenna module involved in Embodiment 2.

[0031] Figure 19 This is a top view of the antenna module involved in Embodiment 3. 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 1 This is a block diagram 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 computer, or a personal computer with communication capabilities. An example of the frequency band of the radio waves used by the antenna module 100 described in this embodiment is millimeter-wave radio waves with center frequencies of 28 GHz and 39 GHz, but it can also be applied to radio waves in other frequency bands.

[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 and an antenna device 120.

[0037] The communication device 10 upconverts the signal transmitted from BBIC 200 to antenna module 100 into a high-frequency signal and then radiates it from antenna device 120. The high-frequency signal received by antenna device 120 is downconverted and then processed by BBIC 200.

[0038] Antenna device 120 includes a dielectric substrate 130 and a plurality of radiating elements disposed on the dielectric substrate 130. Figure 1The diagram illustrates, as an example, a structure in which four radiating elements 121 are disposed on the dielectric substrate 130; however, the number of radiating elements disposed on the dielectric substrate 130 is not limited to this. A single radiating element 121 or multiple radiating elements may be disposed on the dielectric substrate 130. Furthermore, in... Figure 1 The example shown is that the radiating elements 121 are arranged in a row on the dielectric substrate 130, i.e., arranged in a one-dimensional array, but the radiating elements can also be arranged in a two-dimensional array on the dielectric substrate 130.

[0039] In embodiment 1, the radiating element 121 is a microstrip antenna with a generally square planar shape. Alternatively, the shape of the radiating element 121 can also be a circle, an ellipse, or other polygons.

[0040] Each radiating element 121 is configured with two feed points SP1 and SP2, and a high-frequency signal is independently provided to each feed point from the RFIC 110. As described later, in the antenna module 100 of Embodiment 1, two different frequency bands of high-frequency signals are provided to one radiating element 121. In each radiating element 121, a high-frequency signal of the first frequency band on the low-frequency side is provided to feed point SP1, and a high-frequency signal of the second frequency band on the high-frequency side is provided to feed point SP2. Furthermore, in the example of Embodiment 1, the first frequency band is the 28 GHz band (24.25 GHz to 29.5 GHz), and the second frequency band is the 39 GHz band (37 GHz to 43.5 GHz).

[0041] RFIC 110 includes switches 111A~111H, 113A~113H, 117A, 117B, power amplifiers 112AT~112HT, low-noise amplifiers 112AR~112HR, attenuators 114A~114H, phase shifters 115A~115H, signal synthesizers / distributors 116A, 116B, mixers 118A, 118B, and amplifier circuits 119A, 119B. The switches 111A~111D, 113A~113D, 117A, power amplifiers 112AT~112DT, low-noise amplifiers 112AR~112DR, attenuators 114A~114D, phase shifters 115A~115D, signal synthesizer / distributor 116A, mixer 118A, and amplifier circuit 119A are configured for high-frequency signals in the first frequency band. In addition, 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 / distributor 116B, mixer 118B, and amplifier circuit 119B are circuits used for high-frequency signals in the second frequency band.

[0042] 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.

[0043] The signal from BBIC 200 is amplified in amplifier circuits 119A and 119B, and up-converted in mixers 118A and 118B. The up-converted high-frequency transmission signal is split into four parts in signal synthesizers / distributors 116A and 116B, and fed to the radiating element through the corresponding signal path. By independently adjusting the phase shift of phase shifters 115A to 115H arranged in each signal path, the directivity of the radio wave output from the radiating element of each substrate can be adjusted. In addition, attenuators 114A to 114H adjust the strength of the transmitted signal.

[0044] Terminals P1 to P4 of switches 111A to 111D are connected to the feed point SP1 in the corresponding radiating element 121. Additionally, terminals P5 to P8 of switches 111E to 111H are connected to the feed point SP2 in the corresponding radiating element 121.

[0045] The received signal, which is a high-frequency signal, received by the radiating element 121 is transmitted to the RFIC 110 and is multiplexed in the signal synthesizers / distributors 116A and 116B via four different signal paths. The multiplexed received signal is down-converted in the mixers 118A and 118B, and further amplified in the amplifier circuits 119A and 119B before being transmitted to the BBIC 200.

[0046] 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 radiating element 121 may also be configured as single-chip integrated circuit components for each corresponding radiating element.

[0047] (Structure of the antenna module)

[0048] Next, use Figure 2 and Figure 3 The details of the structure of the antenna module 100 in Embodiment 1 will be explained below. Figure 2 This is a top view of antenna module 100. Figure 3This is a side perspective view of the antenna module 100.

[0049] Reference Figure 2 and Figure 3 In addition to the radiating element 121 and RFIC 110, the antenna module 100 also includes a dielectric substrate 130, a ground electrode GND, and feed wiring 141 and 142. Furthermore, in Figure 2 In the top view and thereafter, the dielectric of the dielectric substrate 130 is omitted.

[0050] The dielectric substrate 130 has a generally cuboid shape including two rectangular main surfaces 131 and 132 facing each other. Furthermore, in the following description, the normal direction of the main surfaces 131 and 132 of the dielectric substrate 130 will be defined as the Z-axis direction. The direction along one side of each main surface 131 and 132 of the dielectric substrate 130 will be defined as the X-axis direction, and the direction along the other side will be defined as the Y-axis direction. Additionally, in the figures, the positive direction of the Z-axis is sometimes referred to as the upper side, and the negative direction as the lower side.

[0051] 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 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 resins, a multilayer resin substrate formed by stacking multiple resin layers composed of PET (polyethylene terephthalate) material, or a ceramic multilayer substrate other than LTCC. Furthermore, the dielectric substrate 130 may not necessarily be a multilayer structure and may be a single-layer substrate.

[0052] When viewed from above in the normal direction (Z-axis direction), the dielectric substrate 130 has a rectangular shape. A radiating element 121 is disposed at a position near the main surface 131 on the upper surface side of the dielectric substrate 130. The radiating element 121 can be disposed such that it is exposed on the surface of the dielectric substrate 130, or as... Figure 3 As in the example, it is arranged in the inner layer of the dielectric substrate 130.

[0053] In the dielectric substrate 130, a ground electrode GND is disposed across the entire surface of the substrate 130, facing the radiating element 121, on the side closer to the main surface 132. Additionally, an RFIC 110 is mounted on the main surface 132 of the dielectric substrate 130 via solder bumps 160. Alternatively, a multi-pole connector can be used to connect the RFIC 110 to the dielectric substrate 130 instead of solder connections.

[0054] Viewed from above the radiating element 121 along the Z-axis, a feed point SP1 is positioned offset from the center of the radiating element 121 in the positive Y-axis direction, and a feed point SP2 is positioned offset from the center of the radiating element 121 in the negative Y-axis direction. A high-frequency signal is supplied from the RFIC 110 to the feed point SP1 via feed wiring 141. Additionally, a high-frequency signal is supplied from the RFIC 110 to the feed point SP2 via feed wiring 142. By supplying high-frequency signals to both feed points SP1 and SP2, radio waves polarized along the Y-axis are radiated in the positive Z-axis direction.

[0055] As in Figure 1 As explained, a high-frequency signal in the first frequency band relative to the low-frequency side is provided to feed point SP1, and a high-frequency signal in the second frequency band relative to the high-frequency side is provided to feed point SP2. That is, antenna module 100 is a so-called dual-band antenna module capable of radiating two different frequencies of radio waves using a single radiating element. Furthermore, antenna module 100 can radiate radio waves of two frequencies alternately or simultaneously.

[0056] exist Figure 2 In this example, feed line 141 extends from a position relative to the radiating element 121 in the positive X-axis direction toward the radiating element 121 in the negative X-axis direction, and rises below feed point SP1 to connect with feed point SP1. Conversely, feed line 142 extends from a position relative to the radiating element 121 in the negative X-axis direction toward the radiating element 121 in the positive X-axis direction, and rises below feed point SP2 to connect with feed point SP2. Thus, feed lines 141 and 142 are configured to extend in opposite directions relative to the radiating element 121, thereby suppressing coupling between feed lines 141 and 142. This ensures isolation between the feed lines.

[0057] The linear stub lines ST1 and ST2 are respectively provided on the feeding wirings 141 and 142. The stub lines ST1 and ST2 are open stub lines each having one end connected to the corresponding feeding wiring and the other end set as an open end. The stub lines ST1 and ST2 function as band-stop filters for blocking the transmission of signals in the frequency bands on the other side. Therefore, the line lengths of the stub lines ST1 and ST2 are set to be 1 / 4 wavelength of the center frequency of the high-frequency signals provided to the feeding wiring on the other side.

[0058] More specifically, if the wavelength of the high-frequency signals in the second frequency band provided to the feeding wiring 142 is set as λ2 (second wavelength), the line length L1 of the stub line ST1 is set to L1 = λ2 / 4. Similarly, if the wavelength of the high-frequency signals in the first frequency band provided to the feeding wiring 141 is set as λ1 (first wavelength), the line length L2 of the stub line ST2 is set to L2 = λ1 / 4. In addition, the shapes of the stub lines ST1 and ST2 can be a straight line shape as shown in Figure 2 the figure, or a curved shape such as an L-shaped.

[0059] Generally, the size in the polarization direction of the radiation element 121 is set to be 1 / 2 of the wavelength corresponding to the center frequency of the high-frequency signals to be radiated. As described above, the antenna module 100 uses the common radiation element 121 to radiate radio waves in two frequency bands. Therefore, it is preferably set that the resonant frequency of the radiation element 121 is between the frequencies of the two radio waves. In other words, it is preferably set that: the wavelength corresponding to the resonant frequency of the radiation element 121 is longer than the wavelength of the radio wave on the high-frequency side and shorter than the wavelength of the radio wave on the low-frequency side.

[0060] Specifically, in the case of the substantially square radiation element 121, the length Lp of one side of the radiation element 121 (i.e., the length along the polarization direction) is set to satisfy L1 < Lp / 2 < L2. In addition, if this relationship is expressed using the wavelength of the radio wave to be radiated, λ2 / 2 < Lp < λ1 / 2.

[0061] In addition, actually, even when the frequencies of both radio waves are higher or both are lower than the resonant frequency of the radiation element 121, it is possible to radiate radio waves in two frequency bands from one radiation element. However, in this case, the antenna characteristics for the radio wave with a larger difference from the resonant frequency of the radiation element 121 may be lower than those for the other radio wave. Therefore, it is preferably set that the resonant frequency of the radiation element 121 is the frequency between the two frequency bands to be radiated.

[0062] Moreover, matching elements for adjusting the impedance between the radiation element 121 can also be provided on the feeding wirings 141 and 142. In Figure 2In the example, a short stub 151, functioning as a matching element, is provided in feed line 141, and a short stub 152, also functioning as a matching element, is provided in feed line 142. Furthermore, the impedance to the radiating element 121 can vary depending on the connection positions of the short stubs ST1 and ST2 in feed lines 141 and 142. Therefore, if the desired impedance can be achieved through the connection positions of the short stubs ST1 and ST2, there is a possibility that the matching short stubs 151 and 152 may not be provided.

[0063] In this antenna module 100 with this structure, when a high-frequency signal on the low-frequency side is provided through the feed wiring 141, leakage of the high-frequency signal to the feed wiring 142 can be prevented by using a stub ST2 that functions as a band-stop filter. Similarly, when a high-frequency signal on the high-frequency side is provided through the feed wiring 142, leakage of the signal to the feed wiring 141 can be prevented by using a stub ST1. Thus, while ensuring isolation between the feed wirings 141 and 142, a common radiating element can be used to radiate radio waves in two frequency bands.

[0064] Figure 4 It is shown in Figure 2 The diagram shows the antenna characteristics observed from each feed wiring 141, 142 within the antenna module. Figure 4 In the diagram, the horizontal axis represents frequency, and the vertical axis represents insertion loss (solid lines LN10, LN20) and reflection loss (dashed lines LN11, LN21). Figure 4 The left image shows the antenna characteristics as observed from the feed wiring 141. Figure 4 The right figure shows the antenna characteristics as observed from the feed wiring 142.

[0065] Regarding the power supply wiring 141 for transmitting high-frequency signals on the low-frequency side, as follows: Figure 4 As shown in the left figure, an attenuation pole is generated near 39 GHz, ensuring an attenuation of more than 10 dB in the high-frequency band BP2. This prevents high-frequency signals supplied to the feed wiring 142 from passing through the feed wiring 141. On the other hand, in the low-frequency band BP1, the insertion loss is less than 3 dB, enabling the high-frequency signal concerning the radio wave to be radiated to be transmitted to the radiating element 121 with low loss.

[0066] Similarly, regarding the feeder wiring 142 for transmitting high-frequency signals on the high-frequency side, as... Figure 4As shown in the right figure, an attenuation pole is generated near 25 GHz, ensuring an attenuation of more than 10 dB in the low-frequency band BP1. This prevents high-frequency signals supplied to the feed wiring 141 from passing through the feed wiring 142. On the other hand, in the high-frequency band BP2, the insertion loss is less than 3 dB, enabling the high-frequency signal concerning the radio wave to be radiated to be transmitted to the radiating element 121 with low loss.

[0067] Previously, dual-band antenna modules were known to have the following structure: two radiating elements, each independently positioned for each frequency band, are stacked along the normal direction of the dielectric substrate. However, in such a structure, the antenna performance is sometimes degraded due to misalignment of the two radiating elements caused by manufacturing deviations.

[0068] However, by providing two different frequency bands of high-frequency signals to the common radiating element, as in the antenna module 100 of Embodiment 1, a dual-band antenna module can be realized that suppresses the degradation of antenna characteristics associated with misalignment of the radiating element. Furthermore, by providing band-stop filters for each feed line that block the passage of signals in the frequency band supplied to the feed line on the other side, it is possible to ensure isolation between feed lines 141 and 142 while also suppressing the degradation of antenna characteristics associated with signal leakage.

[0069] In Embodiment 1, "feed wiring 141" and "feed wiring 142" correspond to "first feed wiring" and "second feed wiring" in this disclosure, respectively. In Embodiment 1, "stub line ST1" and "stub line ST2" correspond to "first band-stop filter" and "second band-stop filter" in this disclosure, respectively. In Embodiment 1, "frequency band BP1" and "frequency band BP2" correspond to "first frequency band" and "second frequency band" in this disclosure, respectively. In Embodiment 1, "stub line 151" and "stub line 152" correspond to "matching element" in this disclosure, respectively.

[0070] (Variation Example 1)

[0071] In Modification 1 and Modification 2 described later, different methods of band-stop filters will be explained.

[0072] Figure 5 This is a top view of antenna module 100A in variant example 1. Antenna module 100A has the following structure: Figure 2 In antenna module 100, stubs ST1 and ST2 are replaced with stubs ST1A and ST2A, respectively. The other structures in antenna module 100A are the same as those in antenna module 100, and the descriptions of elements that are repeated in antenna module 100 are not repeated.

[0073] Reference Figure 5Short-circuit wires ST1A and ST2A are short-circuit wires with one end connected to the ground electrode GND. That is, one end of short-circuit wire ST1A is connected to the feed line 141, and the other end is connected to the ground electrode GND. Similarly, one end of short-circuit wire ST2A is connected to the feed line 142, and the other end is connected to the ground electrode GND.

[0074] Stubs ST1A and ST2A function as band-stop filters, similar to stubs ST1 and ST2 in antenna module 100. Therefore, the length of each stub ST1A and ST2A is set to half the wavelength corresponding to the frequency to be blocked.

[0075] More specifically, if the wavelength of the high-frequency signal in the second frequency band supplied to the feeder wiring 142 is set to λ2, then the line length L1A of the stub ST1A is set to L1A = λ2 / 2. Similarly, if the wavelength of the high-frequency signal in the first frequency band supplied to the feeder wiring 141 is set to λ1, then the line length L2A of the stub ST2A is set to L2A = λ1 / 2. Furthermore, if the length of one side of the radiating element 121 is set to Lp, then L1A is set to... <Lp<L2A。

[0076] In this way, by using short-circuited stubs as band-stop filters, it is possible to suppress the degradation of antenna characteristics while ensuring the isolation between feed lines 141 and 142, and to realize a dual-band antenna module that uses a shared radiating element.

[0077] However, in the case of a short-circuit stub, the length of the stub becomes longer compared to the case of an open-circuit stub in Embodiment 1. Therefore, when overall miniaturization of the equipment is required, utilizing the open-circuit stub of Embodiment 1 is advantageous.

[0078] In Variation 1, “stub ST1A” and “stub ST2A” correspond to “first band-stop filter” and “second band-stop filter” in this disclosure, respectively.

[0079] (Variation Example 2)

[0080] Figure 6 This is a top view of antenna module 100B in variant example 2. Antenna module 100B has the following structure: Figure 2 In antenna module 100, the stubs ST1 and ST2 are replaced with filters FLT1 and FLT2, respectively. The other structures in antenna module 100B are the same as those in antenna module 100, and the descriptions of elements that are repeated in antenna module 100 are not repeated.

[0081] Reference Figure 6Filters FLT1 and FLT2 are LC resonators formed by connecting an inductor and a capacitor in series. One end of the inductor in filter FLT1 is connected to the feed line 141, and the other end is connected to the ground electrode GND via a capacitor. Similarly, one end of the inductor in filter FLT2 is connected to the feed line 142, and the other end is connected to the ground electrode GND via a capacitor.

[0082] The inductance of the inductor and the capacitance of the capacitor in filter FLT1 are set such that the resonant frequency of filter FLT1 is the center frequency of the high-frequency signal supplied to feed wiring 142. Similarly, the inductance of the inductor and the capacitance of the capacitor in filter FLT2 are set such that the resonant frequency of filter FLT2 is the center frequency of the high-frequency signal supplied to feed wiring 141.

[0083] By setting the resonant frequencies of the LC resonators of filters FLT1 and FLT2 in this way, filters FLT1 and FLT2 function as band-stop filters for high-frequency signals provided by the feed lines on the other side.

[0084] When the frequency band of the radio wave being radiated is relatively low, using a short stub as in Embodiment 1 and Modification 1 results in a long line length, hindering the miniaturization of the dielectric substrate, or significantly affecting the electric field lines generated between the radiating element and the ground electrode, potentially becoming a major cause of degraded antenna performance. In such cases, these problems can be addressed by using an LC filter disposed outside the dielectric substrate as a band-stop filter.

[0085] In Variation 2, “filter FLT1” and “filter FLT2” correspond to “first band-stop filter” and “second band-stop filter” in this disclosure, respectively.

[0086] (Variation Example 3)

[0087] Other configurations of the power supply wiring will be described in Modification 3 and Modifications 4 and 5 described later.

[0088] Figure 7 This is a top view of the antenna module 100C of Modified Example 3. In the antenna module 100 of Embodiment 1, the feed lines 141 and 142 are configured such that, when viewed from the normal direction of the dielectric substrate 130, they extend from the feed point in opposite directions to each other in a direction orthogonal to the polarization direction (Y-axis direction) of the electromagnetic wave radiated from the radiating element 121. In the antenna module 100C, the feed lines 141 and 142 are configured such that, in the same direction as the polarization direction (i.e., the Y-axis direction), they extend from the feed point in opposite directions to each other.

[0089] In this power supply wiring configuration, the separation distance between power supply wiring 141 and power supply wiring 142 can be ensured, thus suppressing mutual coupling between power supply wirings.

[0090] (Variation Example 4)

[0091] Figure 8 This is a top view of antenna module 100D of Variation 3. In antenna module 100 of Embodiment 1 and antenna module 100C of Variation 3, the two feed lines 141 and 142 are arranged along the same direction. In antenna module 100D, the two feed lines 141 and 142 are arranged along directions that intersect each other.

[0092] More specifically, in antenna module 100D, feed wiring 141 is configured along the polarization direction (i.e., the Y-axis direction) starting from feed point SP1, and feed wiring 142 is configured along a direction orthogonal to the polarization direction (i.e., the X-axis direction) starting from feed point SP2. Furthermore, the extension directions of feed wiring 141 and feed wiring 142 only need to intersect each other, but do not necessarily need to be orthogonal.

[0093] In this way, by configuring the power supply wiring from each power supply point along intersecting directions, it is possible to suppress the mutual coupling between power supply wiring.

[0094] In addition, it can also be with Figure 8 Conversely, the feed wiring 141 is arranged along a direction orthogonal to the polarization direction, and the feed wiring 142 is arranged along the polarization direction.

[0095] (Variation Example 5)

[0096] Figure 9 This is a top view of antenna module 100E in Variation 5. In antenna module 100E, feed wiring 141 and feed wiring 142 are configured to extend in the same direction from feed points SP1 and SP2. Specifically, in Figure 9 In the example, the power supply wiring 141 and 142 are arranged parallel to each other along the negative direction of the X-axis from the power supply points SP1 and SP2.

[0097] In addition, in the antenna module 100E, when viewed from the normal direction of the dielectric substrate 130, a plurality of through-holes V1 extending along the normal direction are disposed between the feed wiring 141 and the feed wiring 142. The plurality of through-holes V1 are arranged along the X-axis direction in the same manner as the feed wirings 141 and 142, and are connected to the ground electrode GND. Thus, the plurality of through-holes V1 function as shielding elements. Therefore, even if, for example, design constraints necessitate that the feed wirings be arranged parallel to each other in the same direction from the radiating element, mutual coupling between the feed wirings 141 and 142 can be suppressed.

[0098] (Variation Example 6)

[0099] In Variation 6, another method of matching element for impedance matching between the radiating element is described.

[0100] Figure 10 This is a top view of the antenna module 100F of Modified Example 6. In the antenna module 100F, planar electrodes 151A and 152A, which are respectively connected to the feed wiring 141 and 142, are provided to replace the stubs 151 and 152 that function as matching elements in the antenna module 100 of Embodiment 1.

[0101] The planar electrodes 151A and 152A are respectively configured to face the ground electrode GND, forming a capacitor between them. By changing the area of ​​each planar electrode, the capacitance value can be adjusted to achieve impedance matching between the corresponding feed wiring and the radiating element 121.

[0102] Furthermore, similar to the stubs 151 and 152 in the antenna module 100, the planar electrodes 151A and 152A are not necessary structures. If the desired impedance can be achieved by adjusting the connection positions of the stubs ST1 and ST2, the planar electrodes 151A and 152A may not be required.

[0103] In Modification 6, “flat plate electrode 151A” and “flat plate electrode 152A” respectively correspond to “matching elements” in this disclosure.

[0104] (Variation Example 7)

[0105] In Modification 7, a structure for adjusting impedance by the position of the feed point in the radiating element 121 is described.

[0106] Figure 11 This is a top view of antenna module 100G in variant example 7. In antenna module 100G, the distance from the center CP of radiating element 121 to the feed point SP1 on the low-frequency side is different from the distance from the center CP to the feed point SP2 on the high-frequency side. Figure 11 In the example, compared to feed point SP2, feed point SP1 is farther from the center CP and is thus positioned closer to the end of radiating element 121. In the polarization direction, the electric field is stronger closer to the end of radiating element 121; therefore, the closer the feed point is to the end of radiating element 121, the greater the impedance.

[0107] Therefore, it can also replace the connection points of the short stubs ST1 and ST2 in the power supply wiring, the matching elements such as short stubs 151 and 152, or, based on them, adjust to the desired impedance by the position of the power supply points SP1 and SP2 in the radiating element 121.

[0108] (Variation Example 8)

[0109] In Modification 8 and Modifications 9 and 10 described later, the method of feeding the radiating element through capacitive coupling will be explained.

[0110] Figure 12 This is a top view of the antenna module 100J in variant example 8. Additionally, Figure 13 This is a side perspective view of the antenna module 100J as viewed from the X-axis direction. The antenna module 100J has the following structure: planar electrodes 171 and 172 are added to the antenna module 100 of Embodiment 1.

[0111] Reference Figure 12 and Figure 13 When viewed from above the dielectric substrate 130 along the Z-axis, the planar electrodes 171 and 172 have a circular shape and overlap with the feed points SP1 and SP2 in the radiating element 121, respectively. Figure 13 As shown, the planar electrodes 171 and 172 are arranged at intervals in the dielectric layer near the lower side of the radiating element 121, facing the feed points SP1 and SP2 respectively. Furthermore, a feed wiring 141 is connected to the planar electrode 171, and a feed wiring 142 is connected to the planar electrode 172.

[0112] When a high-frequency signal is supplied to the power supply wiring 141, 142, the high-frequency signal is transmitted to the power supply points SP1 and SP2 respectively through the capacitive coupling between the plate electrodes 171, 172 and the radiating element 121.

[0113] In this feeding method, by setting band-stop filters for each feeding line to block the signal of the frequency band provided to the feeding line on the other side, it is possible to ensure the isolation between feeding lines 141 and 142 while suppressing the reduction of antenna characteristics associated with signal leakage.

[0114] (Variation Example 9)

[0115] Figure 14 This is a top view of the antenna module 100K in variant example 9. Additionally, Figure 15 This is a side perspective view of the antenna module 100K as viewed from the X-axis direction. The antenna module 100K has the following structure: the planar electrodes 171 and 172 in the antenna module 100J described in Variation 8 are replaced with planar electrodes 171A and 172A.

[0116] Reference Figure 14 and Figure 15 When viewed from above the dielectric substrate 130 along the Z-axis, the planar electrodes 171A and 172A have a generally rectangular shape with the side along the polarization direction as the longer side. Figure 14 In the example, the sides of the planar electrodes 171A and 172A along the Y-axis are the longer sides. Planar electrode 171A extends in the positive direction of the Y-axis from the position opposite to the feed point SP1. Planar electrode 172A extends in the negative direction of the Y-axis from the position opposite to the feed point SP2.

[0117] like Figure 15 As shown, planar electrodes 171A and 172A are disposed at intervals in the dielectric layer near the lower side of the radiating element 121, facing the feed points SP1 and SP2 of the radiating element 121, respectively. In planar electrode 171A, feed wiring 141 is connected to a position that does not overlap with feed point SP1 when viewed from above the dielectric substrate 130. Similarly, in planar electrode 172A, feed wiring 142 is connected to a position that does not overlap with feed point SP2 when viewed from above the dielectric substrate 130.

[0118] When high-frequency signals are supplied to the power supply wiring 141 and 142, the high-frequency signals are transmitted to the power supply points SP1 and SP2 respectively through the capacitive coupling between the plate electrodes 171A and 172A and the radiating element 121.

[0119] Thus, in the planar electrodes 171A and 172A, by setting an offset along the polarization direction between the position of the corresponding feed wiring and the feed position in the radiating element 121, the impedance between the feed wiring and the radiating element can be adjusted.

[0120] Furthermore, in the antenna module 100K, by setting band-stop filters for each feed line to block the transmission of signals in the frequency band provided to the feed line on the other side, it is possible to ensure the isolation between feed lines 141 and 142 while suppressing the degradation of antenna characteristics associated with signal leakage.

[0121] (Variation Example 10)

[0122] Figure 16 This is a top view of the antenna module 100L in variant example 10. Additionally, Figure 17 This is a side perspective view of the antenna module 100L as viewed from the X-axis direction. The antenna module 100L has the following structure: the planar electrodes 171 and 172 in the antenna module 100J described in Variation 8 are replaced with planar electrodes 171B and 172B.

[0123] Reference Figure 16and Figure 17 When viewed from above the dielectric substrate 130 along the Z-axis, the planar electrodes 171B and 172B have a generally rectangular shape with the side along the polarization direction as the longer side. Figure 16 In the example, the sides of the planar electrodes 171B and 172B along the Y-axis are the long sides.

[0124] Plate electrodes 171B and 172B are disposed at a distance from the radiating element 121 on the same dielectric layer as the radiating element 121. More specifically, plate electrode 171B is disposed facing the center of the edge of the radiating element 121 in the positive Y-axis direction. Furthermore, plate electrode 172B is disposed facing the center of the edge of the radiating element 121 in the negative Y-axis direction.

[0125] Furthermore, a feed line 141 is connected to the plate electrode 171B, and a feed line 142 is connected to the plate electrode 172B. In this case, in the radiating element 121, the portion facing the plate electrode 171B becomes the feed point SP1, and the portion facing the plate electrode 172B becomes the feed point SP2.

[0126] By providing a high-frequency signal to the feed line 141, the high-frequency signal is transmitted to the feed point SP1 of the radiating element 121 via capacitive coupling through the planar electrode 171B. Similarly, by providing a high-frequency signal to the feed line 142, the high-frequency signal is transmitted to the feed point SP2 of the radiating element 121 via the planar electrode 172B via capacitive coupling.

[0127] In this way, by feeding through capacitive coupling via the planar electrodes 171B and 172B disposed on the same dielectric layer as the radiating element 121, the radiating element 121 and the planar electrodes 171B and 172B for feeding can be disposed on the same dielectric layer, thereby reducing the number of dielectric layers on the dielectric substrate 130.

[0128] Furthermore, in the antenna module 100L, by setting band-stop filters for each feed line to block the passage of signals in the frequency band provided to the feed line on the other side, it is possible to ensure the isolation between the feed lines 141 and 142 while suppressing the degradation of antenna characteristics associated with signal leakage.

[0129] [Implementation Method 2]

[0130] In Embodiment 2, the structure of a so-called dual-polarized antenna module that applies the features of this application to radiate radio waves of each frequency band in two different polarization directions will be described.

[0131] Figure 18This is a top view of the antenna module 100H according to Embodiment 2. In addition to the structure of the antenna module 100 of Embodiment 1, the antenna module 100H also includes feed wiring 143 and 144 for transmitting high-frequency signals to the feed points SP3 and SP4 of the radiating element 121. In the antenna module 100H, elements that are repeated in the description of the antenna module 100 will not be repeated.

[0132] Reference Figure 18 Feed point SP3 is positioned offset from the center of radiating element 121 in the negative X-axis direction, and feed point SP4 is positioned offset from the center of radiating element 121 in the positive X-axis direction. By providing high-frequency signals to feed points SP3 and SP4, radio waves polarized in the X-axis direction are radiated in the positive Z-axis direction.

[0133] A feed line 143 for transmitting high-frequency signals of the first frequency band on the low-frequency side is connected to the feed point SP3. The feed line 143 is configured to extend from the feed point SP3 in the positive direction of the Y-axis when viewed from the normal direction of the radiating element 121. Furthermore, a stub ST3 is provided in the feed line 143 to function as a band-stop filter that blocks the passage of high-frequency signals of the second frequency band. The stub ST3 is an open-circuit stub, and if the wavelength of the high-frequency signal of the second frequency band is set to λ2, the line length of the stub ST3 is set to λ2 / 4. Alternatively, a stub 153 for adjusting the impedance between the feed line 143 and the radiating element 121 can also be provided.

[0134] A feed line 144 for transmitting high-frequency signals of the second frequency band on the high-frequency side is connected at the feed point SP4. The feed line 144 is configured to extend from the feed point SP4 in the negative direction of the Y-axis when viewed from the normal direction of the radiating element 121. Furthermore, a stub ST4 is provided in the feed line 144 to function as a band-stop filter that blocks the passage of high-frequency signals of the first frequency band. The stub ST4 is an open-circuit stub, and if the wavelength of the high-frequency signal of the first frequency band is set to λ1, the line length of the stub ST4 is set to λ1 / 4. Alternatively, a stub 154 for adjusting the impedance between the feed line 144 and the radiating element 121 can also be provided.

[0135] In this way, by providing the high-frequency signal of the first frequency band to the feed points SP1 and SP3, and providing the high-frequency signal of the second frequency band to the feed points SP2 and SP4, it is possible to radiate electromagnetic waves with polarization directions of the X-axis and Y-axis for each frequency band from the radiating element 121.

[0136] Furthermore, short stubs ST1 and ST3, which block the passage of signals in the second frequency band, are respectively arranged in feed lines 141 and 143, and short stubs ST2 and ST4, which block the passage of signals in the first frequency band, are respectively arranged in feed lines 142 and 144. Thus, while ensuring isolation between feed lines, radio waves from both frequency bands can be radiated in both polarization directions using a shared radiating element. Moreover, in antenna module 100H, radio waves from both frequency bands can be radiated simultaneously in both polarization directions.

[0137] Furthermore, regarding the power supply wiring 143 and 144, the features of the above-described modifications 1 to 7 can be appropriately applied within a range that does not produce contradictions.

[0138] In Embodiment 2, “feed wiring 143” and “feed wiring 144” correspond to “third feed wiring” and “fourth feed wiring” in this disclosure, respectively. In Embodiment 2, “stub ST3” and “stub ST4” correspond to “third band-stop filter” and “fourth band-stop filter” in this disclosure, respectively.

[0139] [Implementation Method 3]

[0140] In Embodiment 3, a structure that provides high-frequency signals of two frequency bands to a feed point of a radiating element via a duplexer will be described.

[0141] Figure 19 This is a top view of the antenna module 100I according to Embodiment 3. In the radiating element 121 of the antenna module 100I, a feed point SPA is disposed at a position offset from the center of the radiating element 121 in the positive direction of the X-axis, and a feed point SPB is disposed at a position offset from the center of the radiating element 121 in the negative direction of the Y-axis. Furthermore, a feed wiring 145A is connected to the feed point SPA, and a feed wiring 145B is connected to the feed point SPB.

[0142] Viewed from the normal direction of the radiating element 121, the feed wiring 145A extends from the feed point SPA in the positive direction of the X-axis, branches in two directions at the branch node NA, and connects to terminals TL1 and TH1. A high-frequency signal of the first frequency band on the low-frequency side is provided to terminal TL1. A high-frequency signal of the second frequency band on the high-frequency side is provided to terminal TH1.

[0143] A stub STH1 is connected on the line between terminal TL1 and branch node NA. This stub STH1 functions as a band-stop filter to block the passage of high-frequency signals in the second frequency band. Additionally, a stub STL1 is connected on the line between terminal TH1 and branch node NA. This stub STL1 functions as a band-stop filter to block the passage of high-frequency signals in the first frequency band. In other words, stubs STH1 and STL1 constitute a duplexer.

[0144] The stub STH1 prevents high-frequency signals from the second frequency band from leaking to terminal TL1. Similarly, the stub STL1 prevents high-frequency signals from the first frequency band from leaking to terminal TH1. Furthermore, by providing high-frequency signals of the first frequency band to terminal TL1 and high-frequency signals of the second frequency band to terminal TH1, radio waves of two frequency bands polarized in the X-axis direction can be radiated from the radiating element 121.

[0145] In other words, the above structure can also be interpreted as connecting the power supply wiring 141 and 142 in Embodiment 1 to the same power supply point.

[0146] Viewed from the normal direction of the radiating element 121, the feed wiring 145B extends from the feed point SPB in the negative direction of the Y-axis, branches in two directions at the branch node NB, and connects to terminals TL2 and TH2. A high-frequency signal of the first frequency band on the low-frequency side is provided to terminal TL2. A high-frequency signal of the second frequency band on the high-frequency side is provided to terminal TH2.

[0147] A stub STH2 is connected on the line between terminal TL2 and branch node NB. This stub STH2 functions as a band-stop filter to block the passage of high-frequency signals in the second frequency band. Additionally, a stub STL2 is connected on the line between terminal TH2 and branch node NB. This stub STL2 functions as a band-stop filter to block the passage of high-frequency signals in the first frequency band. In other words, stubs STH2 and STL2 constitute a duplexer.

[0148] The short stub STH2 prevents leakage of high-frequency signals from the second frequency band to terminal TL2. Similarly, the short stub STL2 prevents leakage of high-frequency signals from the first frequency band to terminal TH2. Furthermore, by providing high-frequency signals from the first frequency band to terminal TL2 and high-frequency signals from the second frequency band to terminal TH2, radio waves of two frequency bands polarized along the Y-axis can be radiated from the radiating element 121.

[0149] With the structure described above, the antenna module 100I can radiate radio waves of two frequency bands along two polarization directions using a common radiating element. Furthermore, by providing stubs STL1, STL2, STH1, and STH2 that function as band-stop filters, leakage of high-frequency signals supplied to each feed line can be suppressed.

[0150] In addition, although Figure 19 Although not shown in the diagram, matching elements for adjusting the impedance between each feed line and the radiating element 121 may also be provided on the feed lines 145A and 145B.

[0151] The embodiments disclosed herein should be considered illustrative rather than restrictive in all respects. The scope of the invention is set forth not by the description of the above embodiments, but by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0152] Explanation of reference numerals in the attached figures

[0153] 10: Communication device; 100, 100A~100L: 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 / distributor; 118A, 118B: Mixer; 119A, 119B: Amplifier circuit; 120: Antenna device; 121: Radiating element; 130: Dielectric substrate; 131, 132: Main surface; 14 1~1424, 145A, 145B: Power supply wiring; 151~154, ST1~ST4, ST1A, ST2A, STL1, STL2, STH1, STH2: Short cut wires; 151A, 152A, 171, 172, 171A, 172A, 171B, 172B: Flat electrode; 160: Solder bump; 200: BBIC; CP: Center; FLT1, FLT2: Filter; GND: Ground electrode; NA, NB: Branch node; P1~P8, TH1, TH2, TL1, TL2: Terminal; SP1~SP4, SPA, SPB: Power supply point; V1: Through hole.

Claims

1. An antenna module, comprising: A flat-plate radiating element; A grounding electrode, which is arranged facing the radiating element; The first feed wiring transmits the high-frequency signal of the first frequency band to the first feed point of the radiating element; The second feed wiring transmits high-frequency signals of the second frequency band, which is higher than the first frequency band, to the second feed point of the radiating element; A first band-stop filter, connected to the first feed wiring, is configured to block the passage of high-frequency signals in the second frequency band; and A second band-stop filter is connected to the second feed wiring and is configured to block the passage of high-frequency signals in the first frequency band.

2. The antenna module according to claim 1, wherein, The first band-stop filter and the second band-stop filter are both short stubs with one end connected to the corresponding feed wiring. The line length of the first band-stop filter is shorter than that of the second band-stop filter.

3. The antenna module according to claim 2, wherein, The first band-stop filter and the second band-stop filter are both open-circuit stubs with open ends. The first feed point is positioned offset from the center of the radiating element in a first direction. The second feed point is positioned offset from the center of the radiating element in the second direction. Half the length of the radiating element along the first direction is longer than the line length of the first band-stop filter. Half the length of the radiating element along the second direction is shorter than the line length of the second band-stop filter.

4. The antenna module according to claim 2, wherein, The first band-stop filter and the second band-stop filter are both short-circuited stubs whose other ends are connected to the ground electrode. The first feed point is positioned offset from the center of the radiating element in a first direction. The second feed point is positioned offset from the center of the radiating element in the second direction. The length of the radiating element along the first direction is longer than the line length of the first band-stop filter. The length of the radiating element along the second direction is shorter than the line length of the second band-stop filter.

5. The antenna module according to claim 3 or 4, wherein, The second direction is the opposite direction to the first direction relative to the center of the radiating element.

6. The antenna module according to claim 3 or 4, wherein, The second direction is the direction that intersects the first direction at the center of the radiating element.

7. The antenna module according to any one of claims 3 to 6, wherein, It also includes a dielectric substrate, on which the radiating element and the grounding electrode are disposed. If the wavelength of the signal corresponding to the first frequency band within the dielectric substrate is set as the first wavelength, and the wavelength of the signal corresponding to the second frequency band within the dielectric substrate is set as the second wavelength, then... The length of the radiating element along the first direction is shorter than half the first wavelength. The length of the radiating element along the second direction is longer than half the second wavelength.

8. The antenna module according to any one of claims 2 to 7, wherein, The distance from the center of the radiating element to the first feed point is different from the distance from the center of the radiating element to the second feed point.

9. The antenna module according to claim 1, wherein, The first band-stop filter and the second band-stop filter are both LC filters.

10. The antenna module according to any one of claims 1 to 9, wherein, When viewed from the normal direction of the radiating element, the extension direction of the first feed wire from the first feed point is different from the extension direction of the second feed wire from the second feed point.

11. The antenna module according to any one of claims 1 to 10, wherein, It also includes a matching element disposed on at least one of the first power supply wiring and the second power supply wiring.

12. The antenna module according to claim 11, wherein, The matching element is a short wire with one end connected to the corresponding power supply wiring.

13. The antenna module according to claim 11, wherein, The matching element is a flat plate electrode that is connected to the corresponding feed wiring and is configured to face the ground electrode.

14. The antenna module according to any one of claims 1 to 13, wherein, It also includes a feed circuit configured to output high-frequency signals to the first feed wiring and the second feed wiring. The power supply circuit outputs high-frequency signals independently to the first power supply wiring and the second power supply wiring, respectively.

15. The antenna module according to claim 1, wherein, It also has: The third feed wiring transmits the high-frequency signal of the first frequency band to the third feed point of the radiating element; The fourth feed wiring transmits the high-frequency signal of the second frequency band to the fourth feed point of the radiating element; A third band-stop filter is connected to the third feed wiring and is configured to block the passage of high-frequency signals in the second frequency band; as well as A fourth band-stop filter, connected to the fourth feed wiring, is configured to block the passage of high-frequency signals in the first frequency band. The first feed point is positioned offset from the center of the radiating element in a first direction. The second feed point is positioned offset in a second direction relative to the center of the radiating element, opposite to the first direction. The third feed point is positioned at a location offset in a third direction from the center of the radiating element, intersecting the first direction. The fourth feed point is positioned offset in a fourth direction relative to the center of the radiating element, opposite to the third direction.

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

Images