Antenna substrate, antenna module provided with same, and communication device

Abstract

An antenna substrate (20) is provided with: a flat plate-shaped radiation element (121) disposed parallel to a main surface (30a) of a flat plate-shaped dielectric body (30); and an external connection terminal (21) disposed so as to be partially exposed to a side surface (30b) of the dielectric body (30). When the normal direction of the radiation element (121) is defined as a Z-axis direction, and the two directions orthogonal to the Z-axis direction and orthogonal to each other are defined as an X-axis direction and a Y-axis direction, the external connection terminal (21) has an electrode portion (21a) that does not overlap the radiation element (121) when viewed from the Z-axis direction and that overlaps the radiation element (121) when viewed from the X-axis direction and when viewed from the Y-axis direction.

Description

Antenna substrate, and antenna module and communication device including same

[0001] The present disclosure relates to an antenna substrate, and an antenna module and a communication device including the same.

[0002] Japanese Patent Laid-Open Publication No. 2004-274259 (Patent Document 1) discloses an antenna substrate including a flat patch (radiating element) disposed on the upper surface of a flat dielectric body and an external connection terminal disposed and exposed on a side surface of the dielectric body, where the external connection terminal is disposed in a position that does not overlap with the patch when viewed from the normal direction to the main surface of the dielectric body.

[0003] Japanese Patent Application Laid-Open No. 2004-274259

[0004] As communication devices such as smartphones have become more sophisticated in recent years, the space available for mounting antenna boards in these devices has become more limited. This has led to demands for smaller antenna boards and for expanded coverage (the range over which radio waves can be transmitted and received) of the antenna boards.

[0005] The present disclosure has been made to solve the above-mentioned problems, and its purpose is to expand the coverage while miniaturizing an antenna substrate that has a flat radiating element (patch) arranged on the main surface of a dielectric and a terminal (external connection terminal) arranged exposed on the side surface of the dielectric.

[0006] The antenna substrate according to the present disclosure includes a flat-plate radiating element arranged parallel to a main surface of a flat-plate dielectric, and a first terminal arranged with at least a portion exposed on a side surface of the dielectric. When a first direction is a direction normal to the radiating element and two directions orthogonal to the first direction and orthogonal to each other are defined as a second direction and a third direction, the first terminal has a portion that does not overlap with the radiating element when viewed from the first direction, but overlaps with the radiating element when viewed from both the second direction and the third direction.

[0007] An antenna module of the present disclosure includes the above-described antenna substrate.A communication device of the present disclosure includes the above-described antenna module.

[0008] According to the present disclosure, it is possible to reduce the size of an antenna substrate having a flat radiating element arranged on the main surface of a dielectric and a terminal arranged exposed on the side surface of the dielectric while expanding its coverage.

[0009] 1 is an example of a block diagram of a communication device including an antenna substrate; FIG. 1 is a perspective view of an antenna device; FIG. 2 is a perspective view of an antenna substrate; FIG. 1 shows antenna characteristics; FIG. 2 shows antenna characteristics; FIG. 3 shows antenna characteristics; FIG. 4 shows antenna characteristics in the case of direct feeding and in the case of capacitive feeding; FIG. 5 shows an example of the configuration of an antenna substrate; FIG. 6 shows an example of the configuration of an antenna substrate; FIG. 7 shows an example of the configuration of an antenna substrate; FIG. 8 shows an example of the configuration of an antenna substrate; FIG. 9 shows an example of the configuration of an antenna substrate; FIG. 1 is a partial perspective view of an antenna module. FIG. 2 is a partial perspective view (part 2) of the antenna module.

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference numerals, and description thereof will not be repeated.

[0011] 1 is an example of a block diagram of a communication device 1 including an antenna substrate 20 according to this embodiment. The communication device 1 is, for example, a mobile terminal such as a mobile phone, smartphone, or tablet, or a personal computer with a communication function. An example of the frequency band of radio waves used in the antenna substrate 20 according to this embodiment is millimeter-wave radio waves with center frequencies of 28 GHz, 39 GHz, and 60 GHz, but radio waves in other frequency bands are also applicable.

[0012] 1, the communication device 1 includes an antenna module 100 and a BBIC 200 that configures a baseband signal processing circuit. The antenna module 100 includes an RFIC 110, which is an example of a power supply device, and an antenna device 120.

[0013] The communication device 1 upconverts a signal transmitted from the BBIC 200 to the antenna module 100 into a high-frequency signal in the RFIC 110 and radiates the signal from the antenna device 120. The communication device 1 also transmits a high-frequency signal received by the antenna device 120 to the RFIC 110, downconverts the signal, and processes it in the BBIC 200.

[0014] The antenna module 100 is a so-called dual-polarized antenna module capable of radiating two radio waves having different polarization directions. The antenna device 120 has multiple antenna substrates 20, each including multiple radiating elements 121. Each of the radiating elements 121 is a flat patch antenna. For ease of explanation, FIG. 1 shows only the configurations corresponding to four of the multiple radiating elements 121 included in the antenna device 120, and omits the configurations corresponding to the other radiating elements 121 having similar configurations.

[0015] Each of the radiating elements 121 is provided with a first feed point SP1 to which a high frequency signal for a first polarization is supplied from the RFIC 110, and a second feed point SP2 to which a high frequency signal for a second polarization is supplied from the RFIC 110. The antenna module 100 is not limited to being a dual-polarized type antenna module, and may be a single-polarized type antenna module.

[0016] The RFIC 110 includes switches 111A to 111H, 113A to 113H, 117A, and 117B, power amplifiers 112AT to 112HT, low-noise amplifiers 112AR to 112HR, attenuators 114A to 114H, phase shifters 115A to 115H, signal combiners / demultiplexers 116A and 116B, mixers 118A and 118B, and amplifier circuits 119A and 119B. Of these, the configuration of switches 111A to 111D, 113A to 113D, and 117A, power amplifiers 112AT to 112DT, low-noise amplifiers 112AR to 112DR, attenuators 114A to 114D, phase shifters 115A to 115D, signal combiner / demultiplexer 116A, mixer 118A, and amplifier circuit 119A constitutes a circuit for high-frequency signals of the first polarization. Also, the configuration of switches 111E to 111H, 113E to 113H, and 117B, power amplifiers 112ET to 112HT, low-noise amplifiers 112ER to 112HR, attenuators 114E to 114H, phase shifters 115E to 115H, signal combiner / demultiplexer 116B, mixer 118B, and amplifier circuit 119B constitutes a circuit for high-frequency signals of the second polarization.

[0017] When transmitting a high frequency signal, the switches 111A to 111H and 113A to 113H are switched to the power amplifiers 112AT to 112HT, and the switches 117A and 117B are connected to the transmission amplifiers of the amplifier circuits 119A and 119B. When receiving a high frequency signal, the switches 111A to 111H and 113A to 113H are switched to the low noise amplifiers 112AR to 112HR, and the switches 117A and 117B are connected to the reception amplifiers of the amplifier circuits 119A and 119B.

[0018] The signal transmitted from the BBIC 200 is amplified by amplifier circuits 119A and 119B and up-converted by mixers 118A and 118B. The up-converted high-frequency signal, that is, the transmission signal, is branched into four by signal combiner / branchers 116A and 116B, passes through corresponding signal paths, and is fed to different radiating elements 121, respectively.

[0019] The received signals, which are high-frequency signals received by each radiating element 121, are transmitted to the RFIC 110 and then combined in the signal combiners / demultiplexers 116A and 116B via four different signal paths. The combined received signals are down-converted in the mixers 118A and 118B, amplified in the amplifier circuits 119A and 119B, and transmitted to the BBIC 200.

[0020] The RFIC 110 is formed as, for example, a one-chip integrated circuit component including the above circuit configuration. Alternatively, the devices (switches, power amplifiers, low-noise amplifiers, attenuators, phase shifters) corresponding to the respective radiating elements 121 in the RFIC 110 may be formed as one-chip integrated circuit components for each corresponding radiating element 121.

[0021] 2 is a perspective view of the antenna device 120. The antenna device 120 includes a base substrate 10 having dielectric properties and a plurality of antenna substrates 20.

[0022] The base substrate 10 has a substantially rectangular parallelepiped shape and includes a flat ground electrode GND extending along a main surface 10a.

[0023] The plurality of antenna substrates 20 are mounted side by side on the main surface 10a of the base substrate 10. Each of the plurality of antenna substrates 20 includes a flat dielectric 30, a radiating element 121, and four external connection terminals 21 to 24. Each of the external connection terminals 21 to 24 is arranged with a portion exposed on a side surface 30b of the dielectric 30.

[0024] Hereinafter, the normal direction of the radiating element 121 (i.e., the normal direction of the main surface 30a of the dielectric 30) will be referred to as the "Z-axis direction," and the two directions that are perpendicular to the Z-axis direction and perpendicular to each other will be referred to as the "X-axis direction" and the "Y-axis direction." Note that in this embodiment, an example is shown in which the short-side direction and long-side direction of the main surface 10a of the base substrate 10 are the X-axis direction and the Y-axis direction, respectively.

[0025] In addition, in the following, the positive direction of the Z axis in each figure (the direction from the base substrate 10 toward the antenna substrate 20) may be referred to as "up," and the negative direction of the Z axis (the direction from the antenna substrate 20 toward the base substrate 10) may be referred to as "down."

[0026] The multiple antenna substrates 20 are arranged in an array in the Y-axis direction at predetermined intervals on the main surface (upper surface) 30a of the dielectric 30. This improves the antenna gain compared to when a single radiating element 121 is arranged.

[0027] 3 is a perspective view of the antenna substrate 20. As described above, the radiating element 121 is provided with a first feed point SP1 to which a high-frequency signal for the first polarized wave is supplied, and a second feed point SP2 to which a high-frequency signal for the second polarized wave is supplied.

[0028] A line P1 connecting the first feed point SP1 and the center of the radiating element 121 and a line P2 connecting the second feed point SP2 and the center of the radiating element 121 are perpendicular to each other. In this embodiment, the first feed point SP1 is disposed at a position offset from the center of the radiating element 121 in the negative direction of the X axis, so the line P1 extends in the X axis direction. The second feed point SP2 is disposed at a position offset from the center of the radiating element 121 in the negative direction of the Y axis, so the line P2 extends in the Y axis direction. When a high-frequency signal for the first polarization is supplied to the first feed point SP1, a first radio wave whose polarization direction is along the line P1 (in this embodiment, the X axis direction) is radiated from the radiating element 121. When a high-frequency signal for the second polarization is supplied to the second feed point SP2, a second radio wave whose polarization direction is along the line P2 (in this embodiment, the Y axis direction) is radiated from the radiating element 121.

[0029] When viewed from the Z-axis direction, radiating element 121 has a shape having side 11, side 12 opposing side 11, and sides 13 and 14 that are perpendicular to side 11 and extend parallel to each other. Each of sides 11 to 14 of radiating element 121 is cut out so as not to come into contact with external connection terminals 21 to 24. Specifically, side 11 and side 13 are connected by curved portion 15, side 12 and side 13 are connected by curved portion 16, side 12 and side 14 are connected by curved portion 17, and side 11 and side 14 are connected by curved portion 18.

[0030] The external connection terminals 21 to 24 each have an electrode portion 21 a to 24 a disposed on the main surface 30 a of the dielectric 30. The electrode portion 21 a is disposed in a region between an intersection 150 of a line overlapping with the side 11 and a line overlapping with the side 13 and the curved portion 15, a predetermined distance away from the curved portion 15. The electrode portion 22 a is disposed in a region between an intersection 160 of a line overlapping with the side 12 and a line overlapping with the side 13 and the curved portion 16, a predetermined distance away from the curved portion 16. The electrode portion 23 a is disposed in a region between an intersection 180 of a line overlapping with the side 11 and a line overlapping with the side 14 and the curved portion 18, a predetermined distance away from the curved portion 18. The electrode portion 24 a is disposed in a region between an intersection 170 of a line overlapping with the side 12 and a line overlapping with the side 14 and the curved portion 17, a predetermined distance away from the curved portion 17.

[0031] In this way, the electrode portions 21a to 24a of the external connection terminals 21 to 24 do not overlap with the radiating element 121 when viewed from the Z-axis direction, and overlap with the radiating element 121 when viewed from both the X-axis direction and the Y-axis direction. This arrangement reduces the distance between the external connection terminals 21 to 24 and the radiating element 121, thereby enabling the antenna substrate 20 to be miniaturized. Furthermore, the electric field between the external connection terminals 21 to 24 and the radiating element 121 is increased, making it easier to form capacitance. This allows the antenna substrate 20 to be miniaturized while expanding the antenna coverage, compared to when the external connection terminals 21 to 24 are positioned farther away from the radiating element 121 than in the present disclosure (specifically, positions where the external connection terminals 21 to 24 overlap with the radiating element 121 only when viewed from one of two directions perpendicular to the Z-axis direction and do not overlap with the radiating element 121 when viewed from the other direction). This point will be described in more detail later.

[0032] In this embodiment, the external connection terminals 21 and 22 are arranged in line symmetry with respect to the line P2. The external connection terminals 23 and 24 are arranged in line symmetry with respect to the line P2. The external connection terminals 21 and 23 are arranged in line symmetry with respect to the line P1. The external connection terminals 22 and 24 are arranged in line symmetry with respect to the line P1. Furthermore, the external connection terminals 21 to 24 according to this embodiment are arranged in rotational symmetry with respect to the line Z0 extending from the center of the radiating element 121 in the Z-axis direction. This arrangement can improve the symmetry of the electric field. This can prevent the directivity of the radio waves from deviating from the Z-axis direction.

[0033] When the antenna substrate 20 is viewed from the Z-axis direction, the distance between each of the external connection terminals 21 to 24 and the end of the radiating element 121 is less than half the size of the radiating element 121 in the polarization direction of the radiating element 121. For example, as shown in FIG. 3, the distance between the end of the external connection terminal 22 (electrode portion 22a) and the end of the radiating element 121 (curved portion 16) is defined as D １ and the size of the radiating element 121 in the Y-axis direction is S １ When D １ <S １ In addition, if the wavelength within the substrate of the high frequency signal supplied to the radiating element 121 is λ, the distance between the end of each of the external connection terminals 21 to 24 and the end of the radiating element 121 is less than λ / 4. １ <λ / 4. By setting the distances to these values, the capacitive coupling between each of the external connection terminals 21 to 24 and the radiating element 121 can be strengthened.

[0034] 3 shows an example in which the sizes of radiating element 121 in the X-axis direction and Y-axis direction match those of dielectric 30, but the size of radiating element 121 is not limited to this. In other words, the size of radiating element 121 is not particularly limited as long as at least a portion of each of external connection terminals 21 to 24 overlaps with radiating element 121 when viewed from both the X-axis direction and the Y-axis direction. For example, as shown in FIG. 4, the sizes of radiating element 121 in the X-axis direction and Y-axis direction may be made smaller than the sizes of dielectric 30 in the X-axis direction and Y-axis direction.

[0035] (Antenna Characteristics) In the antenna substrate 20 according to this embodiment, not only the radiating element 121 but also the electrode portion 21a of the external connection terminal 21 is arranged on the main surface 30a of the dielectric 30. The electrode portion 21a does not overlap with the radiating element 121 when viewed from the Z-axis direction, and overlaps with the radiating element 121 when viewed from both the X-axis direction and the Y-axis direction.

[0036] That is, although the electrode portion 21a of the external connection terminal 21 is separated from the radiating element 121, it is arranged in the same layer as the radiating element 121 and in a position close to the radiating element 121. Therefore, a capacitance can be formed between the electrode portion 21a of the external connection terminal 21 and the end (curved portion 15) of the radiating element 121. A portion of the external connection terminal 21 is exposed on the side surface 30b of the dielectric 30, and has a portion that extends between the radiating element 121 and the ground electrode GND in the Z-axis direction. By arranging the external connection terminal 21 in this manner, the capacitance between the radiating element 121 and the ground electrode GND can be adjusted.

[0037] Like the electrode portion 21a of the external connection terminal 21, the electrode portions 22a to 24a of the external connection terminals 22 to 24 do not overlap with the radiating element 121 when viewed from the Z-axis direction, and overlap with the radiating element 121 when viewed from both the X-axis direction and the Y-axis direction. Therefore, like the external connection terminal 21, the arrangement of the external connection terminals 22 to 24 also makes it possible to adjust the capacitance between the radiating element 121 and the ground electrode GND.

[0038] The lower end portions of the external connection terminals 21 to 24 may or may not be directly connected to the ground electrode GND of the base substrate 10. Furthermore, the number of external connection terminals is not necessarily limited to four, as long as it is one or more. In either case, the capacitance between the radiating element 121 and the ground electrode GND can be adjusted. By adjusting the capacitance in this way, the coverage of the antenna substrate 20 can be expanded.

[0039] FIG. 5 is a diagram (part 1) showing antenna characteristics when an antenna configuration according to the present disclosure is used. The right side of FIG. 5 shows a graph of the configuration of the present disclosure and the antenna gain, while the left side of FIG. 5 shows a graph of the configuration of a comparative example and the antenna gain. The configuration according to the present disclosure in FIG. 5 is a configuration in which three of the four external connection terminals 21 to 24 on the antenna substrate 20 are removed, leaving only one, and this one external connection terminal is not directly connected to the ground electrode GND. The configuration of the comparative example is a configuration in which all four external connection terminals 21 to 24 are removed from the antenna substrate 20.

[0040] 5, in the comparative example in which all external connection terminals are removed, the half-power band width (the point 3 dB below the peak gain) is 77.1 degrees. In contrast, in the case in which one external connection terminal of the present disclosure is provided, the half-power band width is 79.5 degrees, which is wider than the comparative example. Thus, even when only one external connection terminal of the present disclosure is provided, the coverage can be expanded compared to when the external connection terminal of the present disclosure is not provided.

[0041] Fig. 6 is a diagram (part 2) showing antenna characteristics when the antenna configuration of the present disclosure is used. The right side of Fig. 6 shows a configuration of the antenna substrate 20 on which four external connection terminals 21-24 are arranged and a graph of the antenna gain, while the left side of Fig. 6 shows a configuration in which three of the four external connection terminals 21-24 are removed and only one is arranged and a graph of the antenna gain (i.e., the same graph as the graph shown on the right side of Fig. 5). Note that in the configuration of Fig. 6, none of the external connection terminals are directly connected to the ground electrode GND.

[0042] 6, when only one external connection terminal of the present disclosure is arranged, the half-width is 79.5 degrees. In contrast, when four external connection terminals of the present disclosure are arranged, the half-width is 82.5 degrees, which is wider than when only one external connection terminal is arranged. In this way, by arranging four external connection terminals of the present disclosure, it is possible to further expand the coverage compared to when only one external connection terminal of the present disclosure is arranged.

[0043] Fig. 7 is a diagram (part 3) showing antenna characteristics when the antenna configuration of the present disclosure is used. The right side of Fig. 7 shows a contour graph of the antenna gain when the four external connection terminals 21 to 24 are not connected to the ground electrode GND, and the left side of Fig. 7 shows a contour graph of the antenna gain when the four external connection terminals 21 to 24 are connected to the ground electrode GND.

[0044] As shown in Figure 7, when the external connection terminals 21 to 24 are not connected to the ground electrode GND, the peak gain is 6.3 [dBi] and the antenna efficiency is -0.8 [dB]. In contrast, when the external connection terminals 21 to 24 are connected to the ground electrode GND, the peak gain is 6.0 [dBi] and the antenna efficiency is -0.8 [dB]. In other words, when the external connection terminals 21 to 24 are connected to the ground electrode GND, the peak gain is lower than when the external connection terminals 21 to 24 are not connected to the ground electrode GND, but the antenna efficiency is the same. From this result, it can be seen that by connecting the external connection terminals to the ground electrode GND, it is possible to maintain directivity in the Z-axis direction (upward) while maintaining antenna efficiency and expanding coverage in the X- and Y-axis directions (horizontal directions) compared to when the external connection terminals are not connected to the ground electrode GND.

[0045] It is not necessary that all of the external connection terminals 21 to 24 are connected to the ground electrode GND. In other words, even if at least one of the external connection terminals 21 to 24 is connected to the ground electrode GND, it can be expected that the effect of expanding coverage will be more easily achieved compared to a case in which the external connection terminals 21 to 24 are not connected to the ground electrode GND.

[0046] As described above, in the antenna substrate 20 according to this embodiment, the external connection terminals 21 to 24 are provided with electrode portions 21 a to 24 a that do not overlap with the radiating element 121 when viewed from the Z-axis direction, and that overlap with the radiating element 121 when viewed from both the X-axis direction and the Y-axis direction. This makes it possible to increase the coverage while miniaturizing the antenna substrate 20.

[0047] The "radiating element 121" and the "dielectric 30" in this embodiment may correspond to the "radiating element" and the "dielectric" in the present disclosure, respectively.

[0048] The "first feeding point SP1" and the "second feeding point SP2" in this embodiment may correspond to the "first feeding point" and the "second feeding point" of the present disclosure, respectively.

[0049] The "external connection terminal 21" of the present embodiment may correspond to the "first terminal" of the present disclosure. The "external connection terminals 22 to 24" of the present embodiment may correspond to the "second to fourth terminals" of the present disclosure, respectively.

[0050] The "ground electrode GND" in this embodiment may correspond to the "ground electrode" in the present disclosure. The "Z-axis," "X-axis," and "Y-axis" in this embodiment may correspond to the "first direction," "second direction," and "third direction," respectively, in the present disclosure.

[0051] [Modification 1] In the above embodiment, an example has been shown in which the feeder lines L1 and L2 are connected to the radiating element 121 to directly feed power (wired power) from the feeder lines L1 and L2 to the radiating element 121.

[0052] In contrast to this, in the present first modification, the power feed lines L1 and L2 are connected to the external connection terminals 21 and 22, respectively, so that power is capacitively fed (wirelessly fed) from the external connection terminals 21 and 22 to the radiating element 121.

[0053] When a high-frequency signal for the first polarization is supplied to the external connection terminal 21, the polarization direction of the first radio wave radiated from the radiating element 121 is along the line connecting the external connection terminal 21 and the center of the radiating element 121. When a high-frequency signal for the second polarization is supplied to the external connection terminal 22, the polarization direction of the second radio wave radiated from the radiating element 121 is along the line connecting the external connection terminal 22 and the center of the radiating element 121. The line connecting the external connection terminal 21 and the center of the radiating element 121 and the line connecting the external connection terminal 22 and the center of the radiating element 121 are orthogonal to each other. In other words, the polarization direction of the first radio wave and the polarization direction of the second radio wave are orthogonal to each other.

[0054] 8 is a diagram showing the antenna characteristics when direct feeding is performed (the above-described embodiment) and when capacitive feeding is performed (modification 1). In Fig. 8, the top row shows an outline of the configuration, the middle row shows the antenna gain as a contour graph, and the bottom row shows the return loss.

[0055] As shown in the upper part of Figure 8, the size of the radiating element when capacitive feeding is used is smaller than when direct feeding is used. This is the result of adjusting the resonant frequency so that the capacitive feeding and direct feeding are the same. In other words, when capacitive feeding is performed from the external connection terminal to the radiating element, a new capacitance component is generated in the feeding section between the external connection terminal and the radiating element, which changes the overall balance between the capacitance component and the reactance component compared to when direct feeding is used. Due to this effect, if you try to adjust the resonant frequency when capacitive feeding is used to be the same as when direct feeding, the size of the radiating element when capacitive feeding is used will be smaller than when direct feeding is used.

[0056] As shown in Figure 8, in the case of direct feeding, the peak gain is 6.2 [dBi] and the antenna efficiency is -0.8 [dB]. In contrast, in the case of capacitive feeding, the peak gain is reduced to 5.9 [dBi] compared to the case of direct feeding, but the antenna efficiency is improved to -0.7 [dB]. Furthermore, the return loss in the case of capacitive feeding is not significantly different from the return loss in the case of direct feeding. From this difference in characteristics, it can be seen that in the case of capacitive feeding, compared to the case of direct feeding, it is possible to maintain directivity in the Z-axis direction (upward), improve antenna efficiency, and expand coverage in the X- and Y-axis directions (horizontal directions).

[0057] Fig. 9 is a diagram schematically showing the operation modes when capacitive power is fed from the external connection terminal 21 to the radiating element 121. In this case, in addition to a mode in which the radiating element 121 operates as a patch antenna, there is also a mode in which the external connection terminal 21 and the radiating element 121 operate as a single monopole antenna, as shown in Fig. 9. It is presumed that this influence causes the difference in antenna characteristics shown in Fig. 8.

[0058] The "external connection terminal 21" and the "power supply line L1" of this modification 1 may correspond to the "first terminal" and the "first power supply line" of the present disclosure, respectively. The "external connection terminal 22" and the "power supply line L2" of this modification 1 may correspond to the "second terminal" and the "second power supply line" of the present disclosure, respectively.

[0059] [Modification 2] In the above-described embodiment, the single feed line L1 may be branched into two and connected to two adjacent radiating elements 121. Similarly, the single feed line L2 may be branched into two and connected to two adjacent radiating elements 121.

[0060] Fig. 10 is a diagram (part 1) showing an example of an antenna configuration according to Modification 2. Fig. 10 shows an example in which power is fed directly to radiating element 121 from below radiating element 121.

[0061] 10 , the feed line L1 branches into two at a branch L1a and is connected to first feed points SP1 of two adjacent radiating elements 121. When viewed from the Z-axis direction, the branch L1a is disposed between the two adjacent radiating elements 121. With this configuration, the transmission line of the high-frequency signal for the first polarization can be shortened, thereby reducing loss.

[0062] Similarly, the feed line L2 branches into two at branch L2a and is connected to second feed points SP2 of two adjacent radiating elements 121. When viewed from the Z-axis direction, branch L2a is disposed at a position between the two adjacent radiating elements 121. With this configuration, the transmission line of the high-frequency signal for the second polarization can be shortened, thereby reducing loss.

[0063] Fig. 11 is a diagram (part 2) showing an example of the antenna configuration according to Modification 2. Fig. 11 shows an example in which capacitive feeding is performed from external connection terminals 21 and 22 to radiating element 121.

[0064] In Fig. 11, two adjacent radiating elements 121 are referred to as the "first radiating element 121R" and the "second radiating element 121L." In Fig. 11, the external connection terminal 21 of the first radiating element 121R and the external connection terminal 21 of the second radiating element 121L are connected to a single feeder line L1 via a branch portion L1a. When viewed from the Z-axis direction, the branch portion L1a is disposed at a position between the first radiating element 121R and the second radiating element 121L. This makes it possible to shorten the transmission line of the high-frequency signal for the first polarization and keep loss low.

[0065] Similarly, the external connection terminal 22 of the first radiating element 121R and the external connection terminal 22 of the second radiating element 121L are connected to a single feeder line L2 via a branch portion L2a. When viewed from the Z-axis direction, the branch portion L2a is disposed at a position between the first radiating element 121R and the second radiating element 121L. This makes it possible to shorten the transmission line of the high-frequency signal for the second polarization and keep loss low.

[0066] Note that a line P1R connecting the external connection terminal 21 of the first radiating element 121R to the center of the first radiating element 121R is parallel to a line P1L connecting the external connection terminal 21 of the second radiating element 121L to the center of the second radiating element 121L. This makes it possible to match the polarization direction of the first radio wave radiated from the first radiating element 121R with the polarization direction of the first radio wave radiated from the second radiating element 121L.

[0067] Furthermore, if the length of the feeder line between the branch L1a and the external connection terminal 21 of the first radiating element 121R is "L", then the length of the feeder line between the branch L1a and the external connection terminal 21 of the second radiating element 121L is set to "L+λ / 2", where λ is the wavelength (electrical length) of the high-frequency signal within the antenna substrate 20. By arranging the branch L1a in this position, it is possible to match the phase of the first radio wave radiated from the first radiating element 121R and the phase of the first radio wave radiated from the second radiating element 121L.

[0068] Similarly, a line P2R connecting the external connection terminal 22 of the first radiating element 121R to the center of the first radiating element 121R is parallel to a line P2L connecting the external connection terminal 22 of the second radiating element 121L to the center of the second radiating element 121L. Therefore, the polarization direction of the second radio wave radiated from the first radiating element 121R can be made to coincide with the polarization direction of the second radio wave radiated from the second radiating element 121L.

[0069] Furthermore, if the length of the feeder line between the branch L2a and the external connection terminal 22 of the first radiating element 121R is "L", then the length of the feeder line between the branch L2a and the external connection terminal 22 of the second radiating element 121L is set to "L+λ / 2". By arranging the branch L2a in this position, it is possible to match the phase of the second radio wave radiated from the first radiating element 121R and the phase of the second radio wave radiated from the second radiating element 121L.

[0070] The "first radiating element 121R" and the "second radiating element 121L" of this modification example 2 may correspond to the "first radiating element" and the "second radiating element" of the present disclosure, respectively.

[0071] The "feeder line L1" and the "branch portion L1a" of the present modification example 2 may correspond to the "single feeder line" and the "branch portion" of the present disclosure, respectively.

[0072] The "straight line P1R" and "straight line P1L" in this variant example 2 may correspond to the "straight line connecting the center of the first radiating element and the first terminal" and the "straight line connecting the center of the second radiating element and the first terminal" of the present disclosure, respectively.

[0073] [Modification 3] When capacitive power is fed from the external connection terminals 21 and 22 to the radiating element 121, the front and back of the antenna substrate 20 may have the same design.

[0074] 12 is a diagram showing an example of an antenna substrate 20A according to Modification 3. In the antenna substrate 20A according to Modification 3, a radiating element 121 is arranged on the main surface (upper surface) on the front side of the dielectric 30, and a specific electrode 122 is arranged on the main surface (lower surface) on the back side of the dielectric 30. When the antenna substrate 20A is viewed from the Z-axis direction, the specific electrode 122 is arranged at a position overlapping with the radiating element 121. In other words, the specific electrode 122 has the same shape as the radiating element 121. Furthermore, the electrode portions on the upper surface and the electrode portions on the lower surface of the external connection terminals 21 to 24 have the same shape.

[0075] That is, the antenna substrate 20A has the same design whether viewed from one main surface or the other. Therefore, there is no need to specify the front and back of the antenna substrate 20A when mounting the antenna substrate 20A on the base substrate 10. As a result, the mounting work is easier, and the manufacturing cost can be reduced accordingly.

[0076] 12 shows an example in which the specific electrode 122 is connected to the ground electrode GND, but if the specific electrode 122 is connected to the ground electrode GND, it is expected that capacitance will be easily formed between the radiating element 121 and the specific electrode 122, which will result in a deterioration of the frequency bandwidth. In consideration of this, a configuration in which the specific electrode 122 is not connected to the ground electrode GND may be used, as in the antenna substrate 20B shown in FIG. 13. In this way, it is possible to suppress deterioration of the frequency bandwidth while maintaining the same design on both sides of the antenna substrate 20B.

[0077] 14, a parasitic element 123 larger than the size of the radiating element 121 and the size of the specific electrode 122 may be arranged in the center between the radiating element 121 and the specific electrode 122. In this way, the front and back of the antenna substrate 20C can have the same design, while the frequency bandwidth can be adjusted by the parasitic element 123.

[0078] It is also possible to feed power to the parasitic element 123 so that the parasitic element 123 serves as a second radiating element. In this case, radiating elements (patches) 121 and 123 of different sizes can be stacked one above the other to support dual bands.

[0079] The "specific electrode 122" and the "ground electrode GND" in this modification example 3 may correspond to the "specific electrode" and the "ground electrode" of the present disclosure, respectively.

[0080] [Variation 4] In the antenna substrate 20 according to the above embodiment, the shape of the radiating element 121 when viewed in the Z-axis direction is a square with the four corners cut out and curved. However, the shape of the radiating element 121 when viewed in the Z-axis direction is not limited to the shape shown in the above embodiment. Furthermore, the shape of each of the external connection terminals 21 to 24 when viewed in the Z-axis direction is not limited to the shape shown in the above embodiment.

[0081] For example, the shape of the radiating element 121 when viewed from the Z-axis direction may be circular, as in the antenna substrate 20D shown in Fig. 15. The shape of the radiating element 121 when viewed from the Z-axis direction may be square, as in the antenna substrate 20E shown in Fig. 16. The shape of the radiating element 121 when viewed from the Z-axis direction may be substantially cross-shaped, as in the antenna substrate 20E shown in Fig. 17. The shape of the radiating element 121 when viewed from the Z-axis direction may be a square with the four corners cut out to form concave and convex lines, as in the antenna substrate 20G shown in Fig. 18.

[0082] 15 to 18, the external connection terminals 21 to 24 need only be arranged in positions that do not overlap the radiating element 121 when viewed from the Z-axis direction, are perpendicular to the Z-axis direction, and overlap with the radiating element 121 when viewed from either of the two mutually perpendicular directions (the X-axis direction and the Y-axis direction). As long as the external connection terminals 21 to 24 are arranged in such positions, there are no particular limitations on the shapes of the external connection terminals 21 to 24 when viewed from the Z-axis direction.

[0083] [Modification 5] The antenna substrate 20 according to the first embodiment described above may be used as a first antenna substrate, and a second antenna substrate having the same configuration as the first antenna substrate may be stacked on top of the first antenna substrate.

[0084] 19 is a partial perspective view of an antenna module 100H according to Modification 5. The antenna module 100H includes a base substrate 10, a first antenna substrate 20H1, and a second antenna substrate 20H2.

[0085] The first antenna substrate 20H1 is disposed on the base substrate 10. The first antenna substrate 20H1 has a configuration similar to that of the above-described antenna substrate 20. The radiating element 121H1 of the first antenna substrate 20H1 is a dual-polarized type antenna element configured to be able to radiate radio waves polarized in the X-axis direction and radio waves polarized in the Y-axis direction.

[0086] The second antenna substrate 20H2 is disposed on the first antenna substrate 20H1. In the example shown in Fig. 19, the second antenna substrate 20H2 is mounted to the radiating element 121 of the first antenna substrate 20H1 by soldering or another connection method.

[0087] The second antenna substrate 20H2 has the same configuration as the above-described antenna substrate 20, i.e., the same configuration as the first antenna substrate 20H1. However, the size of the second antenna substrate 20H2 is smaller than that of the first antenna substrate 20H1. That is, the size of the radiating element 121H2 of the second antenna substrate 20H2 is smaller than the size of the radiating element 121H2 of the first antenna substrate 20H1.

[0088] Like the radiating element 121H1 of the first antenna substrate 20H1, the radiating element 121H2 of the second antenna substrate 20H2 is configured to be able to radiate radio waves polarized in the X-axis direction and radio waves polarized in the Y-axis direction.

[0089] The radiating element 121H2 of the second antenna substrate 20H2 is fed with power from power feed vias 25 and 26 that each extend in the Z-axis direction, penetrating the first antenna substrate 20H1. Note that, although Fig. 19 shows an example in which the tips of the power feed vias 25 and 26 are connected to the radiating element 121H2 to feed power directly from the power feed vias 25 and 26 to the radiating element 121H2, capacitive feed electrodes may be disposed at the tips of the power feed vias 25 and 26, and power may be capacitively fed from the capacitive feed electrode to the radiating element 121H2 in a non-contact manner.

[0090] With the above configuration, the frequency of the radio waves radiated from the radiating element 121H2 of the second antenna substrate 20H2 can be made higher than the frequency of the radio waves radiated from the radiating element 121H2 of the first antenna substrate 20H1, thereby making the antenna module 100H dual-band.

[0091] Furthermore, because the size of the second antenna substrate 20H2 is smaller than the size of the first antenna substrate 20H1, the antenna module 100H can be made smaller than when two antenna substrates of the same size are stacked. Furthermore, because the proportion of the dielectric material around the radiating element 121H2 of the second antenna substrate 20H2 is reduced, the effective dielectric constant around the radiating element 121H2 is kept low. This allows the frequency bandwidth of the radio waves radiated by the radiating element 121H2 to be expanded.

[0092] 19 shows an example in which two antenna substrates 20H1 and 20H2 are stacked, the number of stacked antenna substrates may be three or more, which makes it possible to support multi-band operation capable of emitting radio waves of three or more different frequencies.

[0093] Furthermore, in the antenna module 100H shown in Figure 19, the polarization directions of the radio waves radiated from the two stacked antenna substrates 20H1 and 20H2 are the same, but the polarization directions of the radio waves radiated from the two stacked antenna substrates may be different from each other.

[0094] FIG. 20 is a partial perspective view of an antenna module 100G according to the fifth modification. The antenna module 100G shown in FIG. 20 is obtained by replacing the second antenna substrate 20H2 of the antenna module 100H shown in FIG. 19 with a second antenna substrate 20G2. The second antenna substrate 20G2 is obtained by rotating the second antenna substrate 20H2 shown in FIG. 19 by 45 degrees counterclockwise when viewed from the positive direction of the Z axis. This allows the polarization direction of the radio waves radiated from the first antenna substrate 20H1 and the second antenna substrate 20G2 to be different from each other. Specifically, the polarization direction of the radio waves radiated from the first antenna substrate 20H1 can be set to the X-axis direction and the Y-axis direction, while the polarization direction of the radio waves radiated from the second antenna substrate 20G2 can be set to a direction tilted at an angle of 45 degrees counterclockwise with respect to the X-axis direction and a direction tilted at an angle of 45 degrees counterclockwise with respect to the Y-axis direction.

[0095] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the description of the above embodiments, and is intended to include all modifications within the meaning and scope of the claims.

[0096] It will be understood by those skilled in the art that the above-described embodiments and their modifications are specific examples of the following aspects.

[0097] (Item 1) An antenna substrate according to the present disclosure includes a flat radiating element arranged parallel to a main surface of a flat dielectric, and a first terminal arranged with at least a portion exposed on a side surface of the dielectric. When a first direction is a direction normal to the radiating element and two directions orthogonal to the first direction and orthogonal to each other are defined as a second direction and a third direction, the first terminal has a portion that does not overlap with the radiating element when viewed from the first direction, but overlaps with the radiating element when viewed from both the second direction and the third direction.

[0098] (Item 2) The antenna substrate according to item 1 further includes, in addition to the first terminal, a second terminal, a third terminal, and a fourth terminal, each of which is arranged with at least a portion exposed on a side surface of the dielectric. Each of the second to fourth terminals has a portion that does not overlap with the radiating element when viewed from the first direction, and overlaps with the radiating element when viewed from both the second and third directions.

[0099] (Item 3) In the antenna substrate described in item 2, the radiating element is disposed opposite the ground electrode, and at least one of the first to fourth terminals is connected to the ground electrode.

[0100] (4) In the antenna substrate according to any one of the first to third aspects, the first terminal is connected to a first feeder line for supplying a high frequency signal to the radiating element.

[0101] (Item 5) In the antenna substrate described in item 4, the second terminal is connected to a second feeder line for supplying a high-frequency signal to the radiating element, and when viewed from a first direction, a line connecting the first terminal and the center of the radiating element is perpendicular to a line connecting the second terminal and the center of the radiating element.

[0102] (Item 6) The antenna substrate according to any one of items 1 to 5, further comprising a plurality of combinations of radiating elements and first terminals. Two adjacent radiating elements are connected to a single feed line via a branch portion. The branch portion is disposed between the two adjacent radiating elements.

[0103] (Clause 7) The antenna substrate according to any one of clauses 1 to 5, further comprising a plurality of combinations of radiating elements and first terminals. When two adjacent radiating elements are a first radiating element and a second radiating element, the first terminal of the first radiating element and the first terminal of the second radiating element are connected to a single feeder line via a branch portion. The branch portion is disposed at a position between the first radiating element and the second radiating element when viewed from a first direction. A straight line connecting the center of the first radiating element and the first terminal is parallel to a straight line connecting the center of the second radiating element and the first terminal.

[0104] (Item 8) The antenna substrate according to any one of items 1 to 7, further comprising a specific electrode disposed at a position overlapping the radiating element when viewed from the first direction.

[0105] (Item 9) In the antenna substrate according to item 8, the radiating element is disposed opposite the ground electrode, and the specific electrode is not connected to the ground electrode.

[0106] (Item 10) The antenna substrate according to item 1 further comprises a second terminal at least a portion of which is exposed on a side surface of the dielectric body, the first terminal and the second terminal being arranged symmetrically with respect to a line parallel to the polarization direction of the radiating element.

[0107] (Item 11) In the antenna substrate described in item 2 or 3, the first to fourth terminals are arranged rotationally symmetrically with respect to an axis of a straight line extending from the center of the radiating element in the first direction.

[0108] (Item 12) In the antenna substrate described in item 11, the radiating element has a shape, when viewed from a first direction, that has a first side, a second side opposite the first side, and third and fourth sides that are perpendicular to the first side and extend parallel to each other. The first terminal has a portion that is located between the radiating element and an intersection of a line that overlaps the first side and a line that overlaps the third side. The second terminal has a portion that is located between the radiating element and an intersection of a line that overlaps the second side and a line that overlaps the third side. The third terminal has a portion that is located between the radiating element and an intersection of a line that overlaps the first side and a line that overlaps the fourth side. The fourth terminal has a portion that is located between the radiating element and an intersection of a line that overlaps the second side and a line that overlaps the fourth side.

[0109] (Item 13) In the antenna substrate according to any one of Items 1 to 3, the radiating element has a first feed point connected to a first feed line for supplying a first high frequency signal to the radiating element, and a second feed point connected to a second feed line for supplying a second high frequency signal to the radiating element, wherein a line connecting the first feed point and the center of the radiating element is perpendicular to a line connecting the second feed point and the center of the radiating element.

[0110] (Item 14) In the antenna substrate described in any one of items 1 to 13, when viewed from the first direction, the distance between the first terminal and the end of the radiating element is less than half the size of the radiating element in the polarization direction of the radiating element.

[0111] (Item 15) In the antenna substrate described in any one of items 1 to 13, when the wavelength of the high-frequency signal supplied to the radiating element within the antenna substrate is λ, the distance between the first terminal and the end of the radiating element when viewed from a first direction is less than λ / 4.

[0112] (Item 16) In the antenna substrate according to any one of Items 1 to 15, the radiating element has a shape with a first side that is linear when viewed from a first direction. The first side is cut out so as not to come into contact with the first terminal.

[0113] (17th Item) An antenna module of the present disclosure includes the antenna substrate according to any one of the first to sixteenth items.

[0114] (Item 18) A communication device of the present disclosure includes the antenna module described in Item 17. (Item 19) An antenna module of the present disclosure includes a first antenna substrate and a second antenna substrate, each having the antenna substrate configuration described in any one of Items 1 to 16, and arranged one on top of the other.

[0115] (Item 20) In the antenna module described in Item 19, the direction of polarization of the radio waves radiated from the first antenna substrate and the direction of polarization of the radio waves radiated from the second antenna substrate are different from each other.

[0116] 1 Communication device, 10 Base substrate, 10a, 30a Main surface, 11 to 14 Side, 15 to 18 Curved portion, 20, 20A to 20G, 20H1, 20H2, 20G2 Antenna substrate, 21 to 24 External connection terminal, 21a to 24a Electrode portion, 30 Dielectric, 30b Side, 100, 100H, 100G Antenna module, 111A to 113H, 117A, 117B Switch, 112AR to 112HR Low noise amplifier, 112AT to 112HT Power amplifier, 114A to 114H Attenuator, 115A to 115H Phase shifter, 116A, 116B Branching filter, 118A, 118B Mixer, 119A, 119B Amplification circuit, 120 Antenna device, 121 Radiating element, 122 specific electrode, 123 parasitic element, GND ground electrode, L1, L2 feed line, L1a, L2a branch portion, SP1 first feed point, SP2 second feed point.

Claims

1. An antenna substrate comprising: a flat radiating element arranged parallel to the main surface of a flat dielectric; and a first terminal arranged with at least a portion exposed on a side surface of the dielectric, wherein when the normal direction of the radiating element is defined as a first direction and two directions that are perpendicular to the first direction and perpendicular to each other are defined as a second direction and a third direction, the first terminal has a portion that does not overlap with the radiating element when viewed from the first direction, and that overlaps with the radiating element when viewed from both the second direction and the third direction.

2. The antenna substrate as described in claim 1, further comprising, in addition to the first terminal, a second terminal, a third terminal and a fourth terminal, each of which is arranged with at least a portion exposed on a side surface of the dielectric, and each of the second to fourth terminals has a portion that does not overlap with the radiating element when viewed from the first direction, and which overlaps with the radiating element when viewed from both the second direction and the third direction.

3. The antenna substrate according to claim 2, wherein the radiating element is disposed opposite a ground electrode, and at least one of the first to fourth terminals is connected to the ground electrode.

4. The antenna substrate according to any one of claims 1 to 3, wherein the first terminal is connected to a first feed line for supplying a high-frequency signal to the radiating element.

5. An antenna substrate as described in claim 4, wherein the second terminal is connected to a second feeder line for supplying a high-frequency signal to the radiating element, and when viewed from the first direction, a straight line connecting the first terminal and the center of the radiating element is perpendicular to a straight line connecting the second terminal and the center of the radiating element.

6. An antenna board according to any one of claims 1 to 5, comprising a plurality of combinations of the radiating element and the first terminal, wherein two adjacent radiating elements are connected to a single feeder line via a branch portion, and the branch portion is disposed at a position between the two adjacent radiating elements.

7. An antenna board as described in any one of claims 1 to 5, comprising a plurality of combinations of the radiating element and the first terminal, wherein when two adjacent radiating elements are a first radiating element and a second radiating element, the first terminal of the first radiating element and the first terminal of the second radiating element are connected to a single feeder line via a branch portion, the branch portion is disposed at a position between the first radiating element and the second radiating element when viewed from the first direction, and a straight line connecting the center of the first radiating element and the first terminal is parallel to a straight line connecting the center of the second radiating element and the first terminal.

8. An antenna substrate according to any one of claims 1 to 7, further comprising a specific electrode arranged at a position overlapping with said radiating element when viewed from said first direction.

9. The antenna substrate according to claim 8, wherein the radiating element is disposed opposite a ground electrode, and the specific electrode is not connected to the ground electrode.

10. The antenna substrate as described in claim 1, further comprising a second terminal arranged with at least a portion exposed on a side surface of the dielectric, the first terminal and the second terminal being arranged symmetrically with respect to a straight line parallel to the polarization direction of the radiating element.

11. The antenna substrate according to claim 2 or 3, wherein the first to fourth terminals are arranged rotationally symmetrically about a straight line extending from the center of the radiating element in the first direction.

12. The antenna substrate described in claim 11, wherein the radiating element has a shape having a first side, a second side opposite to the first side, and a third side and a fourth side perpendicular to the first side and extending parallel to each other, when viewed from the first direction, the first terminal has a portion located between the radiating element and an intersection of a straight line overlapping the first side and a straight line overlapping the third side, the second terminal has a portion located between the radiating element and an intersection of a straight line overlapping the second side and a straight line overlapping the third side, the third terminal has a portion located between the radiating element and an intersection of a straight line overlapping the first side and a straight line overlapping the fourth side, and the fourth terminal has a portion located between the radiating element and an intersection of a straight line overlapping the second side and a straight line overlapping the fourth side.

13. An antenna substrate as described in any one of claims 1 to 3, wherein the radiating element has a first feed point connected to a first feed line for supplying a first high frequency signal to the radiating element, and a second feed point connected to a second feed line for supplying a second high frequency signal to the radiating element, and a straight line connecting the first feed point and the center of the radiating element is perpendicular to a straight line connecting the second feed point and the center of the radiating element.

14. An antenna substrate according to any one of claims 1 to 13, wherein when viewed from the first direction, the distance between the first terminal and the end of the radiating element is less than half the size of the radiating element in the polarization direction of the radiating element.

15. An antenna substrate as described in any one of claims 1 to 13, wherein, when viewed from the first direction, the distance between the first terminal and the end of the radiating element is less than λ / 4, where λ is the wavelength within the antenna substrate of a high-frequency signal supplied to the radiating element.

16. An antenna substrate as described in any one of claims 1 to 15, wherein the radiating element has a shape having a straight first side when viewed from the first direction, and the first side is cut out so as not to come into contact with the first terminal.

17. An antenna module comprising an antenna substrate according to any one of claims 1 to 16.

18. A communication device comprising an antenna module according to claim 17.

19. An antenna module comprising a first antenna substrate and a second antenna substrate, each of which comprises an antenna substrate arrangement as claimed in any one of claims 1 to 16, and which are disposed one above the other.

20. The antenna module according to claim 19, wherein the polarization direction of the radio waves radiated from said first antenna substrate and the polarization direction of the radio waves radiated from said second antenna substrate are different from each other.

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