Antenna module and communication device equipped with same

Abstract

An antenna module (100) is provided with a dielectric substrate (130), a flat plate-shaped radiating element (121), a ground electrode (GND) facing a main surface of the radiating element (121), and a flat plate electrode (151). The flat plate electrode (151) is electrically connected to the ground electrode (GND). The radiating element (121) includes a rectangular body portion (1211), and a protruding portion (1212) in a first direction from a side along a second direction of the body portion (1211). A high-frequency signal is supplied to a power supply point (SP1) offset in the first direction from the center of the radiating element (121). An end portion of the radiating element (121) in the first direction has a region (RG1) having the protruding portion (1212) and a region (RG2) not having the protruding portion (1212). When viewed in a plan view from a normal direction of the dielectric substrate (130), the flat plate electrode (151) is disposed at a position in the first direction from the region (RG2) and in the second direction from the protruding portion (1212).

Description

Antenna Module and Communication Device Equipped with the Same

[0001] The present disclosure relates to an antenna module and a communication device equipped with the same, and more specifically, to a technique for improving the directivity of an antenna.

[0002] International Publication No. 2022 / 185874 (Patent Document 1) discloses an antenna module having a peripheral electrode rising from a ground electrode in the direction of a radiation element in the polarization direction of a flat plate-shaped radiation element (patch antenna). In such an antenna module, an electric line of force is preferentially generated between the radiation element and the peripheral electrode, and a fringing electric field is generated. Thereby, the generation of an electric field that wraps around to the back side of the ground electrode is suppressed, so that the gain characteristics of the antenna can be improved.

[0003] International Publication No. 2022 / 185874

[0004] Since a flat plate-shaped patch antenna has directivity in the normal direction of the radiation element, generally, it is often used in applications where communication with a specific direction is required.

[0005] On the other hand, even within the range of the specific direction, in order to ensure communication quality, it is desirable to enable communication over as wide a range as possible. Therefore, in addition to having high gain characteristics with respect to a specific direction, the development of an antenna module with a wider coverage having a broader directivity is required.

[0006] The present disclosure has been made to solve such problems, and its object is to expand the coverage in an antenna module including a flat plate-shaped radiation element.

[0007] The antenna module according to this disclosure comprises a dielectric substrate, a planar radiating element disposed on the dielectric substrate, a ground electrode, and a planar first peripheral electrode. The ground electrode is disposed on the dielectric substrate opposite to the main surface of the radiating element. The first peripheral electrode is disposed on the radiating element side of the ground electrode and is electrically connected to the ground electrode. The radiating element includes a rectangular body portion having sides in a first direction and a second direction perpendicular to the first direction, and a first projection portion protruding in the first direction from a part of the side of the body portion along the second direction. In the radiating element, a high-frequency signal is supplied to a first feed point located at a position offset in the first direction from the center of the radiating element. The end of the radiating element in the first direction has a first region having the first projection portion and a second region without the first projection portion. When viewed in plan from the normal direction of the dielectric substrate, the first peripheral electrode is located in the first direction from the second region and in the second direction from the first projection portion.

[0008] In the antenna module according to this disclosure, in addition to the fringing electric field generated from the second region of the radiating element in the polarization direction (first direction) relative to the first peripheral electrode, a fringing electric field is also generated from the protruding portion in a direction perpendicular to the polarization direction relative to the first peripheral electrode (second direction). This fringing electric field in the second direction can expand the directivity of radio waves in a direction perpendicular to the radiation direction from the radiating element. Therefore, the coverage of the antenna module can be expanded.

[0009] This is a block diagram of a communication device to which an antenna module according to Embodiment 1 is applied. This is a plan view of the antenna module of Figure 1. This is a cross-sectional view of the antenna module of Figure 2 along line III-III. This is a partial perspective view showing the internal structure of the antenna module of Figure 1. This is a diagram for explaining the gain characteristics of the antenna module of Embodiment 1. This is a partial perspective view showing the internal structure of the antenna module of Modification 1. This is a partial perspective view showing the internal structure of the antenna module of Modification 2. This is a partial perspective view showing the internal structure of the antenna module of Modification 3. This is a partial perspective view showing the internal structure of the antenna module of Modification 4. This is a partial plan view of the antenna module of Modification 5. This is a plan view of the antenna module of Modification 6. This is a partial plan view of the antenna module according to Embodiment 2.

[0010] The embodiments of this disclosure will be described in detail below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and their descriptions will not be repeated.

[0011] [Embodiment 1] (Basic Configuration of Communication Device) Figure 1 is a block diagram of a communication device 10 to which the antenna module 100 according to this embodiment is applied. The communication device 10 is, for example, a mobile terminal such as a mobile phone, smartphone or tablet, or a personal computer equipped with communication functions. An example of the frequency band of radio waves used in the antenna module 100 according to this embodiment is, for example, millimeter-wave radio waves with center frequencies of 28 GHz, 39 GHz and 60 GHz, but it is also applicable to radio waves in frequency bands other than those mentioned above.

[0012] Referring to Figure 1, the communication device 10 comprises an antenna module 100 and a BBIC 200 which constitutes a baseband signal processing circuit. The antenna module 100 comprises an RFIC 110 which is an example of a power supply circuit and an antenna device 120. The communication device 10 upconverts the signal transmitted from the BBIC 200 to the antenna module 100 into a high-frequency signal and radiates it from the antenna device 120, and downconverts the high-frequency signal received by the antenna device 120 and processes the signal with the BBIC 200.

[0013] In Figure 1, for the sake of clarity, only the configurations corresponding to four of the multiple radiating elements 121 that constitute the antenna device 120 are shown, and the configurations corresponding to other radiating elements 121 with similar configurations are omitted. In Figure 1, an example is shown in which the antenna device 120 is formed by multiple radiating elements 121 arranged in a two-dimensional array, but the number of radiating elements 121 does not necessarily have to be multiple, and the antenna device 120 may be formed by a single radiating element 121. Alternatively, the multiple radiating elements 121 may be arranged in a one-dimensional array in a line. In Embodiment 1, the radiating element 121 is described as a patch antenna having a substantially square flat plate shape, but the shape of the radiating element 121 may be circular, elliptical, or other polygons such as hexagons.

[0014] The RFIC 110 comprises switches 111A to 111D, 113A to 113D, and 117, power amplifiers 112AT to 112DT, low-noise amplifiers 112AR to 112DR, attenuators 114A to 114D, phase shifters 115A to 115D, signal combiner / demultiplexer 116, mixer 118, and amplification circuit 119.

[0015] When transmitting a high-frequency signal, switches 111A to 111D and 113A to 113D are switched to the power amplifier 112AT to 112DT side, and switch 117 is connected to the transmitting amplifier of the amplification circuit 119. When receiving a high-frequency signal, switches 111A to 111D and 113A to 113D are switched to the low-noise amplifier 112AR to 112DR side, and switch 117 is connected to the receiving amplifier of the amplification circuit 119.

[0016] The signal transmitted from the BBIC200 is amplified by the amplification circuit 119 and upconverted by the mixer 118. The upconverted high-frequency signal, the transmitted signal, is split into four parts by the signal combiner / demultiplexer 116 and passes through four signal paths to supply power to different radiating elements 121. At this time, the directivity of the antenna device 120 can be adjusted by individually adjusting the phase shift of the phase shifters 115A to 115D located in each signal path. The attenuators 114A to 114D adjust the strength of the transmitted signal.

[0017] The received signals, which are high-frequency signals received by each radiating element 121, pass through four different signal paths and are combined by the signal combiner / demultiplexer 116. The combined received signals are down-converted by the mixer 118, amplified by the amplification circuit 119, and transmitted to the BBIC 200.

[0018] The RFIC 110 is formed, for example, as a single-chip integrated circuit component including the above circuit configuration. Alternatively, the devices corresponding to each radiating element 121 in the RFIC 110 (switch, power amplifier, low-noise amplifier, attenuator, phase shifter) may be formed as a single-chip integrated circuit component for each corresponding radiating element 121.

[0019] (Antenna Module Structure) Next, the details of the configuration of the antenna module 100 in Embodiment 1 will be described using Figures 2 to 4. Figure 2 is a plan view of the antenna module 100. Figure 3 is a cross-sectional view taken along line III-III in Figure 2. Figure 4 is a partial perspective view showing the internal structure of the antenna module in Figure 1. Note that in Figures 2 and 4, the dielectric material in the dielectric substrate 130 is omitted for the sake of clarity. Furthermore, in Figures 2 to 4, the case in which one radiating element 121 is arranged on the dielectric substrate 130 will be described as an example.

[0020] Referring to Figures 2 to 4, the antenna module 100 includes, in addition to the RFIC 110, the radiating element 121, and the dielectric substrate 130, a peripheral electrode 150 and a ground electrode GND.

[0021] The dielectric substrate 130 is a substrate having a main surface that is approximately rectangular in shape. In the following description, the direction normal to the main surface of the dielectric substrate 130 will be defined as the Z-axis direction. The direction along one side of the main surface 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. In addition, in each figure, the positive Z-axis direction may be referred to as the upward side, and the negative Z-axis direction as the downward side.

[0022] The dielectric substrate 130 is, for example, a low-temperature co-fired ceramics (LTCC) multilayer substrate, a multilayer resin substrate formed by laminating multiple resin layers made of epoxy, polyimide, or other resins, a multilayer resin substrate formed by laminating multiple resin layers made of liquid crystal polymer (LCP) having a lower dielectric constant, a multilayer resin substrate formed by laminating multiple resin layers made of fluororesin, a multilayer resin substrate formed by laminating multiple resin layers made of PET (polyethylene terephthalate), or a ceramic multilayer substrate other than LTCC. Note that the dielectric substrate 130 does not necessarily have to be a multilayer structure and may be a single-layer substrate.

[0023] A radiating element 121 is arranged in an internal dielectric layer adjacent to the main surface 131 in the positive Z-axis direction of the dielectric substrate 130. The radiating element 121 may also be arranged so as to be exposed to the main surface 131. An RFIC 110 is mounted on the main surface 132 of the dielectric substrate 130 in the negative Z-axis direction by solder bumps 160.

[0024] In the dielectric substrate 130, a ground electrode GND is arranged across the entire surface of one dielectric layer between the radiating element 121 and the main surface 132, facing the main surface of the radiating element 121. This ground electrode GND and the radiating element 121 constitute a microstrip antenna.

[0025] The radiating element 121 includes a roughly square main body 1211 and protruding portions 1212 that project from the sides of the main body 1211 along the X-axis in the positive and negative directions of the Y-axis. In the antenna module 100 of Embodiment 1, the protruding portions 1212 are located in a region RG1 (first region) near the center of the side of the main body 1211 along the X-axis. As a result, as shown in Figure 2, when viewed from the Z-axis direction in a plan view, the radiating element 121 has a main surface that is roughly rectangular in shape with the four corners cut out.

[0026] If λ is the wavelength corresponding to the center frequency of the frequency band of the radio waves to be radiated from the antenna module 100, then the dimensions of the main body 1211 in the X-axis and Y-axis directions are set to λ / 2. The feed point SP1 is located at a position offset in the positive Y-axis direction from the center CP of the radiating element 121. When a high-frequency signal is transmitted from the RFIC 110 to the feed point SP1 by a feed wiring (not shown), the radiating element 121 radiates radio waves in the Z-axis direction with the Y-axis direction as the polarization direction.

[0027] Furthermore, the dimensions of the main body 1211 are not necessarily limited to λ / 2, and may be smaller than λ / 2. For example, by shortening the distance between the radiating element 121 and the ground electrode GND, the capacitance component between the radiating element 121 and the ground electrode GND is increased, and the resonant frequency of the radiating element 121 is reduced, thereby making the size of the radiating element 121 smaller than λ / 2.

[0028] Alternatively, by forming a slit in the radiating element 121 to increase the inductance component in the equivalent circuit of the patch antenna and lowering the resonant frequency of the radiating element 121, the size of the radiating element 121 can be reduced to less than λ / 2.

[0029] The peripheral electrode 150 includes flat plate electrodes 151 and 152 and a plurality of vias 153. The flat plate electrodes 151 and 152 are substantially rectangular electrodes extending in the X-axis direction, and their main surfaces are positioned to face the ground electrode GND.

[0030] As shown in Figures 2 and 4, when viewed from above in the Z-axis direction, the flat electrode 151 is positioned opposite the four corner regions RG2 (second region) of the dielectric substrate 130 where the main body portion 1211 is absent. In other words, the protrusion 1212 of the radiating element 121 is located between the two flat electrodes 151. In the antenna module 100, the flat electrode 151 is located in the same dielectric layer as the radiating element 121 in the dielectric substrate 130.

[0031] The length of the flat electrode 152 along the X-axis is set to be approximately the same as the length of the main body 1211 of the radiating element 121. The flat electrode 152 is positioned below the protruding portion 1212 in the dielectric layer between the radiating element 121 and the ground electrode GND. The flat electrode 152 is connected to the ground electrode GND by a plurality of vias 153. In addition, the flat electrode 152 is connected to one of the two flat electrodes 151 by some of the vias 153.

[0032] Therefore, the peripheral electrode 150 essentially has the same potential as the ground electrode GND. In other words, the peripheral electrode 150 corresponds to a configuration in which the ground electrode GND is partially close to the radiating element 121.

[0033] Generally, in a flat-plate patch antenna, the electric field is maximum at the polarization-direction end of the radiating element, and a fringing electric field is generated from that end toward the ground electrode, causing it to function as an antenna and radiate radio waves. In the configuration of the antenna module 100 shown in Figure 2, a fringing electric field is generated from the Y-axis end toward the ground electrode GND.

[0034] In this case, if the ground electrode is sufficiently larger than the radiating element, the electric field lines generated by the fringing electric field are transmitted to the ground electrode at its surface. However, if the area of ​​the ground electrode in the polarization direction is limited for miniaturization or other reasons, some of the electric field lines generated at the edge of the radiating element wrap around to the back side of the ground electrode and are transmitted to the back side of the ground electrode. Due to the generation of such an electric field, compared to when the area of ​​the ground electrode is sufficiently large, it becomes more difficult for radio waves to be emitted from the radiating element, which can reduce the antenna characteristics.

[0035] In such cases, by positioning a peripheral electrode connected to the ground electrode closer to the radiating element than the ground electrode, near the edge of the radiating element where fringing electric fields occur, electric field lines are preferentially generated between the radiating element and the peripheral electrode. This suppresses the generation of electric fields that wrap around to the back side of the ground electrode, thus suppressing a decrease in antenna characteristics even when the area of ​​the ground electrode is limited.

[0036] Furthermore, in the antenna module 100 of Embodiment 1, a protrusion 1212 is provided at the polarization direction end of the radiating element 121, and the portion of RG2 without the protrusion 1212, and the X-axis direction end (side) of the protrusion 1212, face the flat plate electrode 151 of the peripheral electrode 150.

[0037] With this configuration, in region RG2, a fringing electric field is generated along the Y-axis direction, as indicated by arrow AR1, from the Y-axis end of the main body portion 1211 toward the flat plate electrode 151, and a fringing electric field is generated along the X-axis direction, as indicated by arrow AR2, from the side surface of the protruding portion 1212 toward the flat plate electrode 151.

[0038] In this way, the protrusion 1212 generates a fringing electric field in a direction perpendicular to the polarization direction (Y-axis direction) (X-axis direction). This makes it possible to increase the intensity of radio waves in the direction intersecting the polarization direction while maintaining the intensity of radio waves radiated in the polarization direction. Therefore, the radiation range (i.e., coverage) of radio waves in the direction intersecting the polarization direction can be expanded, and an antenna module with broader directivity can be provided.

[0039] (Antenna Characteristics) Figure 5 is a diagram illustrating the gain characteristics of the antenna module 100 of Embodiment 1. Figure 5 shows the peak gain of radio waves in the ZX plane passing through the center of the radiating element 121. In Figure 5, the positive direction of the Z axis is the direction of radio wave radiation.

[0040] In FIG. 5, the solid line LN10 indicates the gain characteristics of the antenna module 100 of Embodiment 1, and the dashed line LN11 indicates the gain characteristics of the antenna module of the comparative example without the peripheral electrode 150. As shown in FIG. 5, the peak gain in the radiation direction (Z-axis direction, θ = 0°) is almost the same for both the antenna module 100 of Embodiment 1 and the comparative example. However, as the angle θ from the Z-axis approaches ±90°, the peak gain of the antenna module 100 becomes larger than the peak gain of the comparative example. That is, while maintaining the peak gain in the radiation direction (Z-axis direction), the radiation range in the X-axis direction, that is, the coverage, is expanded.

[0041] As described above, in a patch antenna having a flat plate-shaped radiation element, by providing a protrusion partially on the side in the polarization direction of the radiation element and arranging a peripheral electrode in a region without the protrusion, it is possible to expand the coverage while maintaining the peak gain in the radiation direction and realize a broad directivity.

[0042] The "flat plate electrode 151" in Embodiment 1 corresponds to the "first peripheral electrode" in the present disclosure. The "protrusion 1212" in Embodiment 1 corresponds to the "first protrusion" in the present disclosure. The "feeding point SP1" in Embodiment 1 corresponds to the "first feeding point" in the present disclosure.

[0043] [Modification Example] Next, variations in the configuration of the peripheral electrode 150 will be described using FIGS. 6 to 11.

[0044] (Modification Example 1) Modification Example 1 is a first example in which the position of the flat plate electrode 151 in the Z-axis direction in the peripheral electrode 150 is changed. FIG. 6 is a partial perspective view showing the internal structure of the antenna module 100A of Modification Example 1.

[0045] In the antenna module 100A, the flat electrode 151 in the peripheral electrode 150 is disposed at a position closer to the main surface 131 of the dielectric substrate 130 than the radiating element 121. In other words, in the normal direction (Z-axis direction) of the dielectric substrate 130, the flat electrode 151 is disposed at a position where the distance between the ground electrode GND and the flat electrode 151 is larger than the distance between the ground electrode GND and the plurality of radiating elements 121.

[0046] Even in such a configuration, since a fringing electric field in the X-axis direction is generated from the protruding portion 1212 of the radiating element 121 toward the flat electrode 151, in the antenna module 100A as well, similar to the antenna module 100 of the first embodiment, the coverage can be expanded while maintaining the peak gain in the radiation direction.

[0047] (Modification 2) Modification 2 is a second example in which the position of the flat electrode 151 in the Z-axis direction in the peripheral electrode 150 is changed. FIG. 7 is a partial perspective view showing the internal structure of the antenna module 100B of Modification 2.

[0048] In the antenna module 100B, contrary to the antenna module 100A of Modification 1, the flat electrode 151 in the peripheral electrode 150 is disposed at a position closer to the main surface 132 of the dielectric substrate 130 than the radiating element 121. In other words, in the normal direction of the dielectric substrate 130, the flat electrode 151 is disposed at a position where the distance between the ground electrode GND and the flat electrode 151 is smaller than the distance between the ground electrode GND and the plurality of radiating elements 121.

[0049] Even in such a configuration, since a fringing electric field in the X-axis direction is generated from the protruding portion 1212 of the radiating element 121 toward the flat electrode 151, in the antenna module 100B as well, similar to the antenna module 100 of the first embodiment, the coverage can be expanded while maintaining the peak gain in the radiation direction.

[0050] (Modification 3) Modification 3 describes a configuration in which the shape of the flat electrode 151 in the antenna module 100B shown in Figure 7 is changed. Figure 8 is a partial perspective view showing the internal structure of the antenna module 100C of Modification 3.

[0051] In antenna module 100C, similar to antenna module 100B in modified example 2, the flat plate electrode 151C of the peripheral electrode 150 is positioned closer to the main surface 132 of the dielectric substrate 130 than the radiating element 121. Furthermore, in antenna module 100C, the dimension of the flat plate electrode 151C in the X-axis direction is set to be longer than that of the flat plate electrode 151, and when viewed from the normal direction of the dielectric substrate 130, a part of the flat plate electrode 151C overlaps with the protruding portion 1212 of the radiating element 121.

[0052] Even in this configuration, a fringing electric field in the X-axis direction is generated from the protruding portion 1212 of the radiating element 121 toward the flat plate electrode 151C. Therefore, in the antenna module 100C, as with the antenna module 100 of Embodiment 1, the coverage can be expanded while maintaining the peak gain in the radiation direction.

[0053] Furthermore, when viewed from a plan view in the direction normal to the dielectric substrate 130, a portion of the flat electrode 151C overlaps with the radiating element 121. This allows for a reduction in the size of the radiating element by strengthening the coupling with the ground electrode GND while maintaining the coverage expansion effect due to the fringing electric field in the X-axis direction. Consequently, the overall antenna module can be miniaturized.

[0054] (Modification 4) Modification 4 describes a configuration in which the shape of the flat plate electrode 152 in the peripheral electrode 150 is changed. Figure 9 is a partial perspective view showing the internal structure of the antenna module 100D of Modification 4.

[0055] In the antenna module 100D, the flat plate electrode 152 in the antenna module 100 of Embodiment 1 is replaced with a flat plate electrode 152D. The flat plate electrode 152D is an enlarged version of the flat plate electrode 152 in the antenna module 100 in terms of its Y-axis dimension, with the Y-axis dimension W2 of the flat plate electrode 152D being larger than the Y-axis dimension W1 of the flat plate electrode 151 (W1 < W2).

[0056] In this configuration, similar to the antenna module 100 of Embodiment 1, a fringing electric field in the Y-axis direction is generated from the main body 1211 of the radiating element 121 with respect to the flat electrode 151, and a fringing electric field in the X-axis direction is generated from the protruding portion 1212. Furthermore, the proportion of the fringing electric field generated in the Y-axis direction from the protruding portion 1212 that reaches the flat electrode 152D increases (arrow AR 5). As a result, the intensity of the electric field in the polarization direction increases compared to the antenna module 100, and thus the peak gain in the radiation direction can be improved.

[0057] As described above, by configuring the antenna module 100D, coverage can be expanded and the peak gain in the radiation direction can be improved.

[0058] In Modification 4, the "flat electrode 152D" corresponds to the "second peripheral electrode" in this disclosure.

[0059] (Modification 5) Modification 5 describes a first example of a configuration in which the flat plate electrode 151 is changed in accordance with the change in the shape of the protruding portion of the radiating element 121.

[0060] Figure 10 is a partial plan view of the antenna module 100E of Modification 5. In the antenna modules of Embodiment 1 and Modifications 1 to 4, the protrusion 1212 was located near the center of the side along the X-axis of the main body 1211 of the radiating element 121. In the antenna module 100E of Modification 5, two protrusions 1212A and 1212B are located on the side along the X-axis of the main body 1211.

[0061] More specifically, the central portion of the protrusion 1212 in the antenna module 100 of Embodiment 1 is removed and divided into protrusion 1212A and protrusion 1212B. Accordingly, the flat plate electrode 151 of the peripheral electrode 150 is also arranged in the portion between protrusion 1212A and protrusion 1212B.

[0062] In other words, along the X-axis of the radiating element 121, two regions RG1 with protrusions and three regions RG2 without protrusions are formed, and the shape is symmetrical with respect to a virtual line CL parallel to the Y-axis passing through the power supply point SP1.

[0063] With this configuration, a fringing electric field (arrow AR1) in the Y-axis direction is generated from the edge of the main body 1211 along the X-axis for each flat plate electrode 151, and a fringing electric field (arrow AR2) in the X-axis direction is generated from the adjacent protrusions 1212A and 1212B. Fringing electric fields are generated from the protrusions 1212A and 1212B in both the positive and negative directions of the X-axis.

[0064] Thus, even in a configuration where multiple protrusions are arranged on the edge of the polarization direction of the main body of the radiating element, a fringing electric field is generated in a direction perpendicular to the polarization direction. This expands the directivity of radio waves in a direction perpendicular to the radiation direction from the radiating element, thereby increasing the coverage of the antenna module.

[0065] In particular, by arranging multiple protrusions, the fringing electric field in the direction perpendicular to the polarization direction increases compared to the case of a single protrusion, such as the antenna module 100 of Embodiment 1, thus enabling a wider coverage compared to the antenna module 100. Note that the number of protrusions arranged on each side of the radiating element is not limited to two, but may be three or more.

[0066] In Modification 5, the "protrusion 1212A" and "protrusion 1212B" correspond to the "first part" and "second part" in this disclosure, respectively.

[0067] (Modification 6) Modification 6 describes a second example of a configuration in which the flat plate electrode 151 is changed in accordance with the change in the shape of the protruding portion of the radiating element 121.

[0068] Figure 11 is a plan view of the antenna module 100F of Modification 6. In the antenna module 100F, similar to the antenna module 100E of Modification 5, two protrusions are arranged on the side along the X axis of the main body 1211 of the radiating element 121, but the protrusions on each side are not symmetrically arranged.

[0069] More specifically, on the positive Y-axis side of the main body 1211, a projection 1212A is positioned tangent to the negative X-axis side, and a projection 1212B is positioned between the projection 1212A and the positive X-axis side.

[0070] On the negative Y-axis side of the main body 1211, a projection 1212C is positioned tangent to the positive X-axis side, and a projection 1212D is positioned between the projection 1212C and the negative X-axis side.

[0071] In this configuration, the main body portion 1211 on which the protrusions are located has two regions RG1 where the protrusions are located and two regions RG2 without protrusions. The flat plate electrode 151 is positioned in the two regions RG2 without protrusions.

[0072] In this case, although the arrangement of the protrusions is asymmetrical, which may cause some bias in directivity, a fringing electric field is generated from each protrusion toward the flat plate electrode 151 in the X-axis direction perpendicular to the polarization direction (arrow AR2). Therefore, compared to the case without protrusions, the directivity of radio waves in the direction perpendicular to the radiation direction from the radiating element can be expanded. Consequently, the coverage of the antenna module can be expanded.

[0073] In Modification 6, each of the "protrusion 1212A" and "protrusion 1212C" corresponds to the "first part" in this disclosure. In Modification 6, each of the "protrusion 1212B" and "protrusion 1212D" corresponds to the "second part" in this disclosure.

[0074] [Embodiment 2] In the antenna modules of Embodiment 1 and its various modifications described above, a configuration was described in which radio waves are radiated from the radiating element in one polarization direction. In Embodiment 2, a configuration is described in which the features of this disclosure are applied to a so-called dual-polarization type antenna module that is capable of radiating radio waves from the radiating element in two different polarization directions.

[0075] Figure 12 is a partial plan view of the antenna module 100G according to Embodiment 2. In the antenna module 100G, in addition to the feed point SP1 located at a position offset in the positive Y-axis direction from the center CP of the radiating element 121, a feed point SP2 is located at a position offset in the negative X-axis direction from the center CP. By supplying a high-frequency signal corresponding to the resonant frequency of the radiating element 121 to the feed point SP2, the radiating element 121 emits radio waves with the X-axis direction as the polarization direction in the positive Z-axis direction.

[0076] In the radiating element 121 of the antenna module 100G, a protrusion 1212 is positioned near the center on each side of the main body 1211 along the X-axis. Additionally, a protrusion 1213 is positioned near the center on each side of the main body 1211 along the Y-axis.

[0077] Furthermore, on each side, a flat plate electrode 151G of the peripheral electrode 150 is positioned in the region RG2 without protrusions. When viewed from the normal direction of the dielectric substrate 130, the flat plate electrode 151G has a substantially L-shape and faces the region RG2 on each side, as well as the sides of the protrusions 1212 and 1213.

[0078] With this configuration, for radio waves polarized in the Y-axis direction, a fringing electric field along the Y-axis (as shown by arrow AR1) and a fringing electric field along the X-axis (as shown by arrow AR2) are generated. Similarly, for radio waves polarized in the X-axis direction, a fringing electric field along the Y-axis (as shown by arrow AR3) and a fringing electric field along the X-axis (as shown by arrow AR4) are generated.

[0079] Therefore, a fringing electric field is generated in a direction perpendicular to the polarization direction for each polarization direction of radio waves, which expands the directivity of radio waves in a direction perpendicular to the radiation direction. Consequently, the coverage of the antenna module can be expanded.

[0080] In Embodiment 2, the "flat electrode 151G" corresponds to the "first peripheral electrode" in this disclosure. In Embodiment 2, the "protrusion 1213" corresponds to the "second protrusion" in this disclosure. In Embodiment 2, the "power supply point SP2" corresponds to the "second power supply point" in this disclosure.

[0081] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the description of the embodiments above, and all modifications within the meaning and scope of the claims are intended to be included.

[0082] 10 Communication equipment, 100, 100A-100G Antenna module, 110 RFIC, 111A-111D, 113A-113D, 117 Switch, 112AR-112DR Low-noise amplifier, 112AT-112DT Power amplifier, 114A-114D Attenuator, 115A-115D Phase shifter, 116 Signal combiner / demultiplexer, 118 Mixer, 119 Amplifier circuit, 120 Antenna device, 121 Radiating element, 130 Dielectric substrate, 131, 132 Main surface, 150 Peripheral electrode, 151, 151C, 151G, 152, 152D Flat electrode, 153 Via, 160 Solder bump, 1211 Main body, 1212, 1212A to 1212D, 1213 Projection, 200 BBIC, CL virtual line, CP center, GND ground electrode, RG1, RG2 area, SP1, SP2 power supply point.

Claims

1. An antenna module comprising: a dielectric substrate; a flat plate-shaped radiating element disposed on the dielectric substrate; a ground electrode disposed on the dielectric substrate opposite to the main surface of the radiating element; and a flat plate-shaped first peripheral electrode disposed on the radiating element side of the ground electrode and electrically connected to the ground electrode, wherein the radiating element includes a rectangular body portion having sides in a first direction and a second direction perpendicular to the first direction, and a first protrusion protruding in the first direction from a part of the side of the body portion along the second direction, a high-frequency signal is supplied to a first feed point of the radiating element located at a position offset in the first direction from the center of the radiating element, the end of the radiating element in the first direction having a first region having the first protrusion and a second region without the first protrusion, and when viewed in plan from the normal direction of the dielectric substrate, the first peripheral electrode is located in the first direction from the second region and in the second direction from the first protrusion.

2. The antenna module according to claim 1, wherein the distance between the ground electrode and the first peripheral electrode in the direction normal to the dielectric substrate is the same as the distance between the ground electrode and the radiating element.

3. The antenna module according to claim 1, wherein, in the direction normal to the dielectric substrate, the distance between the ground electrode and the first peripheral electrode is greater than the distance between the ground electrode and the radiating element.

4. The antenna module according to claim 1, wherein, in the direction normal to the dielectric substrate, the distance between the ground electrode and the first peripheral electrode is smaller than the distance between the ground electrode and the radiating element.

5. The antenna module according to claim 4, wherein, when viewed in plan from the normal direction of the dielectric substrate, a portion of the first peripheral electrode overlaps with the radiating element.

6. The antenna module according to any one of claims 1 to 5, further comprising a second peripheral electrode disposed between the first peripheral electrode and the ground electrode in the direction normal to the dielectric substrate and electrically connected to the ground electrode, wherein, when viewed in plan from the direction normal to the dielectric substrate, the portion of the second peripheral electrode facing the first protrusion protrudes further in the first direction than the first protrusion.

7. The antenna module according to any one of claims 1 to 6, wherein the first projection is located in the center of the side of the main body along the second direction, and the first peripheral electrodes are located on both sides of the first projection in the second direction.

8. The antenna module according to any one of claims 1 to 6, wherein the first projection includes a first portion and a second portion located at two different locations on a side of the main body along the second direction, and the first peripheral electrode is located between the first portion and the second portion.

9. The antenna module according to claim 8, wherein the first and second parts are positioned symmetrically with respect to a virtual line passing through the center of the radiating element and along the first direction.

10. The antenna module according to claim 1, wherein the radiating element further includes a second projection that protrudes in a second direction from a part of the edge of the main body along the first direction, a high-frequency signal is supplied to the radiating element at a second feeding point located at a position offset in a second direction from the center of the radiating element, the end of the radiating element in the second direction has a third region having the second projection and a fourth region without the second projection, and when viewed in plan from the normal direction of the dielectric substrate, the first peripheral electrode is located in the second direction from the fourth region and in the first direction from the second projection.

11. The antenna module according to any one of claims 1 to 10, further comprising a power supply circuit configured to supply a high-frequency signal to the radiating element.

12. A communication device equipped with an antenna module according to any one of claims 1 to 11.

Images