Array antenna module

Abstract

To provide an array antenna module having a heat dissipation structure capable of dissipating heat generated by an amplifier.SOLUTION: An array antenna module includes: a housing having a plurality of heat radiation plates and a holding part for holding the plurality of heat radiation plates; a plurality of substrates provided between the plurality of heat radiation plates, each substrate having an end side; a plurality of antennas for constructing an array antenna, where at least one antenna is provided in each of the plurality of substrates, the plurality of antennas disposed at positions where a radio wave can be radiated from the plurality of end sides of the plurality of substrates toward the outside of the plurality of substrates; and a plurality of amplifiers mounted on each of the plurality of substrates and connected to the plurality of antennas, each amplifier having a first surface mounted on the substrate and a second surface opposite to the first surface, in which the second surface is connected to the heat radiation plates.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an array antenna module. [Background technology]

[0002] Conventionally, there has been a planar microwave antenna in which a dipole and a feeder line feeding the dipole are printed on both sides of a dielectric substrate, a director spaced from the dipole is printed on at least one of the two sides of the substrate, a reflector is installed on one side of the substrate, and a planar Yagi-Uda antenna is constructed by the director, the reflector, and the dipole, and a tapered balun connected to the feeder line on the other side of the substrate and a ground conductor connected to the tapered balun are printed on the other side of the substrate. A one-dimensional microwave antenna is constructed by arranging a plurality of such planar microwave antennas in parallel on a common substrate. A two-dimensional microwave antenna array is constructed by arranging a plurality of such one-dimensional microwave antennas on top of each other (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-200719 Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional two-dimensional microwave antenna arrays (array antenna modules) do not have a heat dissipation structure. For example, when transmitting radio waves in the millimeter wave band of 100 GHz or higher, such as those used in fifth-generation mobile communication systems (5G) and sixth-generation mobile communication systems (6G), an amplifier is used to amplify the signal to extend the communication distance. However, since the amplifier generates heat, a heat dissipation structure is required.

[0005] Therefore, an object of the present invention is to provide an array antenna module having a heat dissipation structure capable of dissipating heat generated by an amplifier. [Means for solving the problem]

[0006] An array antenna module of an embodiment of the present disclosure includes a housing having a plurality of heat sink layers and a holding portion that holds the plurality of heat sink layers; a plurality of substrates that are arranged between the plurality of heat sink layers, each substrate having an end edge; a plurality of antennas that constitute an array antenna, wherein at least one antenna is provided on each of the plurality of substrates and the antennas are positioned in positions that allow radio waves to be emitted from the end edges of the plurality of substrates toward the outside of the plurality of substrates; and a plurality of amplifiers that are mounted on each of the plurality of substrates and connected to the plurality of antennas, each amplifier having a first surface that is mounted on the substrate and a second surface opposite the first surface, the second surface being connected to the heat sink. [Effects of the Invention]

[0007] It is possible to provide an array antenna module having a heat dissipation structure capable of dissipating heat generated by the amplifier. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram showing an example of a planar configuration of an array antenna module 100 according to an embodiment. [Figure 2] 3 is a diagram showing an example of a planar configuration (planar configuration as viewed from the arrow BB in FIG. 3) in a state where some components of the array antenna module 100 shown in FIG. 1 are omitted. [Figure 3] 2 is a diagram showing an example of the configuration of a cross section taken along the arrow AA in FIG. 1. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment to which the array antenna module of the present disclosure is applied will be described.

[0010] Hereinafter, an embodiment to which the array antenna module of the present disclosure is applied will be described. In the following, the same elements will be denoted by the same reference numerals, and duplicated explanations may be omitted.

[0011] In the following description, an XYZ coordinate system is defined. The direction parallel to the X axis (X direction), the direction parallel to the Y axis (Y direction), and the direction parallel to the Z axis (Z direction) are perpendicular to one another. The X direction is an example of a first axis direction, the Y direction is an example of a second axis direction, and the Z direction is an example of a third axis direction. For ease of explanation, the -Z direction may be referred to as the lower side or bottom, and the +Z direction may be referred to as the upper side or top. Planar view refers to viewing from the XY plane. In the following description, the length, width, thickness, etc. of each part may be exaggerated to make the configuration easier to understand. Terms such as parallel, right angle, orthogonal, horizontal, vertical, and up and down may be misaligned to the extent that they do not impair the effects of the embodiments.

[0012] In the following description, the radio waves transmitted or received by the antenna of the array antenna module of the embodiment are, as an example, 300 GHz radio waves, which are terahertz waves in the frequency band of 100 GHz or higher and may be used in sixth-generation mobile communication systems (6G) and the like. The wavelength of 300 GHz radio waves in free space is approximately 1 mm. However, the radio waves transmitted or received by the antenna of the array antenna module of the embodiment may be in the millimeter wave band of fifth-generation mobile communication systems (5G) and the like, or radio waves in the frequency band of 1 GHz to 30 GHz, including Sub-6.

[0013] <Embodiment> Fig. 1 is a diagram showing an example of the planar configuration of an array antenna module 100 of an embodiment. Fig. 2 is a diagram showing an example of the planar configuration in a state in which some components of the array antenna module 100 shown in Fig. 1 are omitted. Fig. 3 is a diagram showing an example of the configuration of a cross section taken along the line AA in Fig. 1. Fig. 2 shows the planar configuration taken along the line BB in Fig. 3.

[0014] <Configuration of array antenna module 100> The array antenna module 100 includes a housing 110, a plurality of substrates 120, a plurality of antennas 130, a plurality of PAs 140, a plurality of adhesive layers 145, a plurality of waveguides 150, and a plurality of phase shifters 160. The PA 140 is an example of an amplifier.

[0015] 3, the array antenna module 100 has a layered structure in which five housing pieces 110A to 110E of a housing 110 and four substrates 120 are alternately stacked in the Z direction. Four waveguides 150 are provided corresponding to the four substrates 120, one waveguide 150 for each substrate 120. As an example, one phase shifter 160 is provided for each waveguide 150.

[0016] For this reason, the array antenna module 100 having the configuration shown in Fig. 3 includes four waveguides 150 and four phase shifters 160. The four waveguides 150 are arranged side by side in the Z direction on the -Y direction side of the housing 110 in Fig. 3, similar to the four substrates 120 arranged side by side in the Z direction shown in Fig. 3. The positions of the four waveguides 150 in the Z direction are equal to the positions of the four substrates 120 in the Z direction. The four waveguides 150 are arranged in four stages in the Z direction, and are fixed to the housing 110 or the like by a fixture or the like (not shown).

[0017] In Fig. 1, some of the components covered by the housing 110 (part of the wiring 121, part of the multiple antennas 130, and multiple PAs 140) are indicated by dashed lines. The components indicated by dashed lines inside the housing 110 in Fig. 1 are components mounted on the top-layer substrate 120, and are part of the wiring 121, part of the multiple antennas 130, and multiple PAs 140. Fig. 2 shows the top-layer substrate 120, the antennas 130 and PAs 140 mounted on the top-layer substrate 120, a top-stage waveguide 150 connected to the wiring 121 on the top-layer substrate 120, and a phase shifter 160 provided in the top-stage waveguide 150. Fig. 2 also shows an enlarged view of one antenna 130 surrounded by a dashed circle.

[0018] 1 and 2, the components that enter the inside of the waveguide 150 (the −Y direction side end of the protruding portion 120B of the substrate 120 and the −Y direction side end 121A of the wiring 121) are shown transparently by dashed lines.

[0019] <Case 110> 1, the housing 110 is located at the center of the array antenna module 100 in a plan view, and has a rectangular shape with a longitudinal direction along the X direction and a lateral direction along the Y direction in a plan view. The portion of the substrate 120 on the side of the end edge 120A (+Y direction side) (the portion where the antenna 130 is arranged) and the protrusion 120B where the portion of the wiring 121 on the end 121A side is arranged are located outside the housing 110 in a plan view.

[0020] As shown in FIG. 3, the housing 110 has multiple layers of heat sinks 111, multiple walls 112, multiple partition walls 113, and multiple fasteners 115. The walls 112 are an example of a holder. For example, the housing 110 can be separated into five layers of housing pieces 110A to 110E, and the housing pieces 110A to 110E are stacked in this order in the Z direction and secured by multiple fasteners 115. The housing piece 110A is located in the bottom layer, and the housing piece 110E is located in the top layer. The first to fourth housing pieces 110A to 110D each hold four boards 120. That is, the housing 110 holds four boards 120.

[0021] As shown in FIG. 3, the housing 110 has, as an example, five heat sinks 111 and four substrates 120. Hereinafter, the heat sinks 111 will be referred to as the first to fifth layers from the bottom to the top. Furthermore, the substrates 120 will be referred to as the first to fourth layers from the top to the bottom. Hereinafter, a configuration having four substrates 120 will be described as an example, but the substrates 120 may have at least two layers, and stacking two or more layers of substrates using the housing 110 is referred to as multi-layer integration. Furthermore, the waveguides 150 will be referred to as the first to fourth layers from the bottom to the top.

[0022] The housing 110 is made of aluminum, for example, with gold plating formed on the surface. The housing 110 may be made of a metal other than aluminum. One example of such a metal is copper.

[0023] Furthermore, as an example, the housing 110 may be made of any one of silicon carbide (SiC), silicon nitride (SiN), aluminum nitride (AlN), and silicon (Si). Furthermore, the housing 110 may have a layered structure in which a plurality of layers made of any two or more materials selected from silicon carbide (SiC), silicon nitride (SiN), aluminum nitride (AlN), silicon (Si), and metal are stacked.

[0024] Housing piece 110A has a first-layer heat sink 111 and a wall portion 112 extending above the first-layer heat sink 111. Housing pieces 110B to 110D are located in the second to fourth layers and have the same configuration. Housing pieces 110B to 110D each have a second-layer to fourth-layer heat sink 111, a wall portion 112 extending above the second-layer to fourth-layer heat sink 111, and a partition wall 113 extending downward from the bottom surface of the second-layer to fourth-layer heat sink 111. Housing piece 110E has a fifth-layer heat sink 111 and a partition wall 113 extending downward from the bottom surface of the fifth-layer heat sink 111.

[0025] Housing piece 110A is formed integrally with first-layer heat sink 111 and wall portion 112 extending above first-layer heat sink 111. This is the same for housing pieces 110B to 110E.

[0026] Furthermore, housing piece 110A may have a configuration in which heat sink 111 and wall 112 are formed from separate members and joined by adhesive, welding, or the like, or fixed with a fixing member. Housing pieces 110B to 110D may have a configuration in which heat sink 111, wall 112, and partition wall 113 are formed from separate members and joined with a fixing member or the like. Housing piece 110E may have a configuration in which heat sink 111 and partition wall 113 are formed from separate members and joined with a fixing member or the like.

[0027] <Heat sink 111> The heat sink 111 is a plate-like portion extending parallel to the XY plane. The lengths of the heat sink 111 in the X and Y directions in a plan view are equal to the lengths of the housing 110 in the X and Y directions in a plan view. In other words, the heat sink 111 extends over the entire housing 110 in a plan view.

[0028] In FIG. 3, the heat sinks 111 in the first and fifth layers are, for example, thicker than the heat sinks 111 in the second to fourth layers, but the thickness of the heat sinks 111 in the fifth layer may be set to an appropriate thickness depending on the heat generation characteristics of the PA 140, etc.

[0029] Walls 112 are provided at the +Y side end and the -Y side end of the top surfaces of the heat sinks 111 of the first to fourth layers. Walls 112 are not provided at the +X side end and the -X side end of the top surfaces of the heat sinks 111 of the first to fourth layers. Therefore, the housing pieces 110A to 110D are U-shaped when viewed from the XZ plane. In other words, the housing pieces 110A to 110D have a concave shape that is concave downward between the wall 112 on the +Y side and the wall 112 on the -Y side when viewed from the XZ plane. The wall 112 is not provided on the heat sink 111 of the fifth layer.

[0030] The first to fourth substrates 120 are provided on the upper surfaces of the first to fourth heat sinks 111. The substrates 120 are fixed to the heat sinks 111 with a conductive adhesive such as silver paste. That is, the first to fourth substrates 120 are provided in the recesses between the wall 112 on the +Y direction side and the wall 112 on the −Y direction side of the upper surfaces of the housing pieces 110A to 110D.

[0031] <Wall section 112> The walls 112 are provided at the +Y end and the -Y end of the top surfaces of the first to fourth heat sinks 111, and extend parallel to the YZ plane from the -Y end to the +Y end of the heat sinks 111. The walls 112 are provided to hold the five heat sinks 111 in place.

[0032] <Partition Wall 113> The partition walls 113 are thin wall portions that extend downward from the lower surfaces of the second to fifth heat sinks 111 and extend parallel to the YZ plane. The partition walls 113 extend from the end of the heat sink 111 on the -Y direction side to the end on the +Y direction side. The lower end of each partition wall 113 contacts the upper surface of the metal layer 124.

[0033] The partition walls 113 are provided in groups of three at equal intervals in the X direction on the lower surfaces of the second to fifth heat sinks 111. The partition walls 113 separate the PAs 140 adjacent to each other in the X direction and are provided to ensure isolation between the adjacent PAs 140. The thickness of the partition walls 113 in the X direction may be set to a thickness that ensures isolation between the adjacent PAs 140.

[0034] <Fixing fixture 115> Fixing device 115 may be any member capable of fixing housing pieces 110A to 110E together, and may be any member capable of fixing two adjacent housing pieces 110A to 110E in the Z direction together by screw fastening, fitting, or the like.

[0035] <Substrate 120> 2, substrate 120 has a rectangular parallelepiped shape in a plan view, and has edge 120A extending in the X direction at the end on the +Y direction side, and four protrusions 120B protruding in the -Y direction from the end on the -Y direction side of the rectangular parallelepiped portion. Substrate 120 also has four wires 121, five ground layers 122, a ground layer 123, and multiple metal layers 124. As an example, substrate 120 can be a wiring board conforming to standards such as FR-4 (Flame Retardant type 4).

[0036] Although the fourth-layer substrate 120 is shown in Fig. 2, the first to third layer substrates 120 have the same configuration as the fourth-layer substrate 120. Therefore, the configuration of the fourth-layer substrate 120 will be described here. Also, the waveguide 150 shown in Fig. 2 is the fourth-stage waveguide 150. The configuration of the first to third stages of the waveguide 150 is the same as the configuration of the fourth-stage waveguide 150.

[0037] Four antennas 130 and four PAs 140 are provided on the substrate 120. The four antennas 130 are arranged at equal intervals in the X direction along the edge 120A within approximately half of the area on the +Y direction side of the entire substrate 120 in a plan view.

[0038] The positions of the four antennas 130 and the four PAs 140 in the X direction correspond to the positions of the four protruding portions 120B in the X direction. The four protruding portions 120B are provided at equal intervals in the X direction, the four antennas 130 are arranged at equal intervals in the X direction, and the four PAs 140 are arranged at equal intervals in the X direction. The four antennas 130 are connected to the four PAs 140, respectively. The PAs 140 are connected to terminals or the like on the upper surface of the substrate 120 via BGA (Ball Grid Array) 141. The BGA 141 is realized by gold bumps, for example. The PAs 140 are mounted on the substrate 120 by the BGA 141 using a flip-chip bonding method.

[0039] <Wiring 121> The four wirings 121 are provided on the upper surface of the substrate 120, and extend in the Y direction toward the end of the protrusion 120B on the -Y direction side of the four PAs 140. Each wiring 121 may be made of metal, and can be produced by patterning copper foil, for example.

[0040] The +Y direction end of each wiring 121 is connected to PA 140, and the −Y direction end 121A extends up to just before the −Y direction end of convex portion 120B. End 121A and the −Y direction end of convex portion 120B are inserted inside end 152 of waveguide 150 on the +Y direction side.

[0041] End 152 on the +Y direction side of waveguide 150 has a waveguide through which radio waves propagate in the X direction, and an opening is provided on a side surface on the +Y direction side parallel to the XZ plane into which end 121A of wiring 121 and the end on the -Y direction side of protrusion 120B can be inserted. The opening is parallel to the XZ plane.

[0042] End 121A is inserted into the interior through the opening of end 152 on the +Y direction side of waveguide 150. End 152 on the +Y direction side of waveguide 150 and end 121A of wiring 121 are configured to convert between radio waves propagating inside waveguide 150 and electrical signals propagating through wiring 121.

[0043] <Ground Layer 122> The five ground layers 122 are provided in an area of ​​the upper surface of the substrate 120 that overlaps with the housing 110 in a plan view, so as to sandwich the four PAs 140 therebetween in the X direction. In other words, the five ground layers 122 are provided in an area that overlaps with the ground layer 123 in a plan view, so as to sandwich the four PAs 140 therebetween in the X direction. The ground layers 122 are connected to the ground terminals of the PAs 140. The ground layers 122 may be made of metal, and can be produced by patterning copper foil, for example.

[0044] <Ground Layer 123> The ground layer 122 is a rectangular metal layer provided on the underside of the substrate 120 in a portion where the substrate 120 overlaps with the housing 110 in a plan view. A ground terminal of the PA 140 is connected to the ground layer 123. The ground layer 123 may be made of metal, and can be produced by patterning copper foil, for example. The ground layer 123 is formed in an area where the five ground layers 122 and four PAs 140 are arranged in a plan view.

[0045] <Metal layer 124> The metal layer 124 is provided on the upper surface of the substrate 120 in a portion where the partition wall 113 is located in a plan view. The metal layer 124 has a width in the X direction that is equal to or greater than the width of the partition wall 113 in the X direction, and a length in the Y direction that is equal to the length of the partition wall 113 in the Y direction. The lower end of the partition wall 113 is in contact with the upper surface of the metal layer 124.

[0046] The metal layer 124 may be made of metal, and as an example, can be produced by patterning copper foil. In this way, the lower ends of the partition walls 113 contact the upper surface of the metal layer 124, thereby further strengthening the isolation between adjacent PAs 140. Note that if sufficient isolation between adjacent PAs 140 can be ensured without providing the metal layer 124, the substrate 120 does not need to have the metal layer 124.

[0047] <Antenna 130> Four antennas 130 are provided on the substrate 120. The antennas 130 are T-shaped in plan view. The four antennas 130 are arranged at equal intervals in the X direction on the +Y direction side of the four PAs 140 in plan view. The four antennas 130 are arranged along the edge 120A. The four antennas 130 are arranged in positions that allow them to radiate radio waves from the four edge sides 120A toward the outside of the four substrates 120 (toward the +Y direction).

[0048] 1, the end of antenna 130 on the -Y direction side that is connected to PA 140 overlaps with housing 110, and the portions of each antenna 130 other than the end on the -Y direction side that is connected to PA 140 do not overlap with housing 110 in a plan view and are located outside housing 110. This is to prevent housing 110 from blocking radiation from antenna 130.

[0049] "Placing antenna 130 in a position where it can radiate radio waves from four edge sides 120A toward the outside (+Y direction side) of four substrates 120" means that the portion of each antenna 130 where radiation mainly occurs (the tip of the T shape) is located near edge 120A and does not overlap with housing 110 in a plan view. "Placing antenna 130 where radiation mainly occurs (the tip of the T shape) is located near edge 120A" means that the length in the Y direction of the portion of substrate 120 that is closer to edge 120A than antenna 130 is made short enough so as not to affect the radiation of antenna 130.

[0050] Furthermore, when the antenna 130 radiates radio waves from the four edges 120A toward the outside (+Y direction) of the four substrates 120, this does not necessarily mean that the radio waves radiated from the antenna 130 propagate in a direction other than the +Y direction. When the antenna 130 radiates radio waves from the four edges 120A toward the outside (+Y direction) of the four substrates 120, this means that the radio waves may be radiated beyond the edges 120A, and may be radiated in a direction angled with respect to the +Y direction (diagonal with respect to the +Y direction) within the XY plane or the YZ plane.

[0051] Since there are four substrates 120, the entire array antenna module 100 has a total of 16 antennas 130 arranged in an array of 4 (X direction) x 4 (Y direction), with four in the X direction and four in the Y direction.

[0052] Generally, the pitch between adjacent antennas in an array antenna is set to less than half the wavelength of radio waves in free space at the operating frequency in order to suppress unwanted radiation such as interference waves. However, the operating frequency of the antenna 130 is, for example, 300 GHz, and the wavelength λ of radio waves in free space is approximately 1 mm. With such a short wavelength λ, it is not easy to process the antenna 130 or to miniaturize the PA 140.

[0053] From this perspective, the pitch P1 in the X direction of the antennas 130 shown in Fig. 1 is set to less than the wavelength λ (one wavelength). This is to suppress unwanted radiation such as interference waves. Note that Fig. 3 does not show the antennas 130, but does show the pitch P1. The pitch P1 is the distance between the centers in the X direction of antennas 130 adjacent to each other in the X direction.

[0054] Furthermore, since the antennas 130 are arranged overlapping each other in the Z direction, the pitch P2 (see FIG. 3) of the antennas 130 in the Z direction shown in FIG. 3 is set to less than the wavelength λ (one wavelength), similar to the pitch P1. This is to suppress unwanted radiation such as interference waves between antennas 130 adjacent to each other in the Z direction.

[0055] The pitch P2 is the distance between the centers in the Z direction of adjacent antennas 130 sandwiching the heat sink 111, the substrate 120, the PA 140, and the adhesive layer 145 in the Z direction. The pitch P2 is equal to the distance between the upper surfaces of adjacent substrates 120 sandwiching the heat sink 111, the PA 140, and the adhesive layer 145 in the Z direction. The pitch P2 can be adjusted by adjusting the total height of the heat sink 111 and the wall portion 112.

[0056] As shown in an enlarged view of the leftmost antenna 130 in Fig. 2, the antenna 130 has two antenna elements 131 and 132. The antenna element 131 is formed on the lower surface of the substrate 120 and is L-shaped in plan view. The antenna element 132 is formed on the upper surface of the substrate 120 and is inverted L-shaped in plan view. The antenna elements 131 and 132 are arranged overlapping each other to form a T-shape in plan view.

[0057] The antenna elements 131 and 132 are connected by a connection portion 133 constructed by a via or the like that penetrates the substrate 120 in the Z direction. FIG. 2 shows the connection portion 133 schematically. The antenna elements 131 and 132 are arranged one on top of the other to form a T-shape in a plan view, and the connection portion 133 is connected to the PA 140. The connection portion 133 of the antenna 130 is a feeding point to which a signal amplified by the PA 140 is fed. Such an antenna 130 is, for example, a dipole antenna, but is not limited to a dipole antenna as long as it can radiate radio waves from the end edge 120A toward the outside of the four substrates 120 (toward the +Y direction).

[0058] The antenna 130 may be a Yagi-Uda antenna, a Substrate-Integrated-Waveguide (SIW) antenna, a Vivaldi antenna, a tapered slot antenna, or the like.

[0059] 2, there are actually four substrates 120 provided with four antennas 130, as shown in FIG. 3, for example, and one waveguide 150 is provided for each of the four antennas 130 on each substrate 120, and each waveguide 150 is provided with a phase shifter 160. Therefore, by adjusting the phases of the radio waves radiated from the 16 antennas 130 arranged in an array of 4 (X direction) x 4 (Y direction) using the four phase shifters 160 arranged in the Z direction, it is possible to control the angles of the beams formed by the radio waves radiated from the 16 antennas 130 within the YZ plane.

[0060] Furthermore, for example, one phase shifter 160 may be provided at each of the four ends 152 of each waveguide 150. In this case, the array antenna module 100 includes four waveguides 150 and 16 phase shifters 160, making it possible to scan the angles of the beams formed by the radio waves radiated from the 16 antennas 130 within the XY plane and the YZ plane.

[0061] It is sufficient that at least one antenna 130 is provided on each substrate 120. For example, if there are four substrates 120, the array antenna module 100 as a whole may have one antenna 130 in the X direction and four in the Y direction, a total of four antennas 130 arranged in an array of 1 (X direction) × 4 (Y direction). Using four antennas 130 arranged in a 1 (X direction) × 4 (Y direction) configuration makes it possible to scan beams formed by radio waves radiated from the four antennas 130 so as to be angled with respect to the +Y direction within the YZ plane.

[0062] <pa140> PA 140 is mounted on the upper surface of each substrate 120 by being connected to a terminal on the upper surface of each substrate 120 via BGA 141. The lower surface of PA 140 is an example of a first surface mounted on substrate 120, and the upper surface of PA 140 is an example of a second surface.

[0063] 2, four PAs 140 are provided on each substrate 120. Since the array antenna module 100 emits, for example, 300 GHz radio waves among terahertz waves, it is desirable that the PAs 140 have high output power to ensure a long communication distance. From this perspective, the PAs 140 may be, for example, amplifiers that use compound semiconductors such as gallium nitride (GaN) or indium phosphide (InP).

[0064] The PA 140 is bonded to the lower surface of the heat sink 111 located above it by an adhesive layer 145. The adhesive layer 145 is thermally conductive, allowing heat generated by the PA 140 to be dissipated through the adhesive layer 145 to the heat sink 111. Although there is a path on the lower side of the PA 140 that connects the BGA 141 to the heat sink 111 via the substrate 120, this path plays a small role as a heat dissipation path due to the high thermal resistance of the BGA 141, among other reasons. Therefore, the path connecting the upper surface of the PA 140 to the heat sink 111 via the adhesive layer 145 has low thermal resistance and is effective as a heat dissipation structure that efficiently dissipates heat generated by the PA 140, which is becoming increasingly high-output. The heat dissipation structure of the array antenna module 100 is realized by the path connecting the PA 140 to the heat sink 111 via the thermally conductive adhesive layer 145, resulting in high heat dissipation efficiency.

[0065] <Adhesive layer 145> The adhesive layer 145 bonds the upper surface of each PA 140 to the lower surface of the heat sink 111 located above each PA 140. The adhesive layer 145 can be formed by applying a thermally conductive adhesive containing a thermally conductive filler between the upper surface of the PA 140 and the lower surface of the heat sink 111.

[0066] <Waveguide 150> The waveguides 150 are arranged in four stages in the Z direction, corresponding to the four substrates 120 arranged side by side in the Z direction. The four waveguides 150 have the same structure. The waveguide 150 shown in FIG. 2 is a fourth-stage waveguide 150 connected to the wiring 121 of the fourth-layer substrate 120.

[0067] As an example, the waveguide 150 has one end 151 and four end portions 152. The end portion 151 is an end portion to which radio waves are input, and is connected to a transmitter that outputs radio waves for transmission. The waveguide 150 is branched twice from the end portion 151 toward the end portion 152, thereby extending to the four end portions 152. The first branching of the waveguide 150 occurs in one location, and the second branching occurs in two locations. The number of end portions 152 may be adjusted to match the number of antennas 130 mounted on one substrate 120.

[0068] The waveguide 150 can be realized by, for example, a rectangular waveguide made of metal, or a substrate-integrated-waveguide (SIW) mounted on a substrate.

[0069] <Phase shifter 160> As an example, one phase shifter 160 is provided for each of the four waveguides 150. Therefore, the array antenna module 100 includes four waveguides 150 and four phase shifters 160.

[0070] As one example, phase shifter 160 is provided between end 151 of waveguide 150 and the first branch, and as one example, a phase shifter that can advance or delay the phase of the radio waves input from end 151 can be used. Furthermore, as described above, one phase shifter 160 may be provided at each of the four end portions 152 of each waveguide 150, and the angles of the beams formed by the radio waves radiated from the 16 antennas 130 may be scanned within the XY plane and the YZ plane.

[0071] <Effects> The array antenna module 100 includes a housing 110 having a plurality of heat sinks 111 and a wall portion 112 that holds the plurality of heat sinks 111; a plurality of substrates 120 arranged between the plurality of heat sinks 111, each substrate 120 having an end side 120A; a plurality of antennas 130 that form an array antenna, each of the plurality of substrates 120 having at least one antenna 130 and arranged in positions that allow radio waves to be emitted from the plurality of end sides 120A of the plurality of substrates 120 toward the outside of the plurality of substrates 120; and a plurality of PAs 140 mounted on each of the plurality of substrates 120 and connected to the plurality of antennas 130, each PA 140 having a first surface (bottom surface) mounted on the substrate 120 and a second surface opposite the first surface, the second surface (top surface) being connected to the heat sink 111. Therefore, a heat dissipation structure capable of dissipating heat from the second surface (top surface) of PA 140 through heat sink 111 is obtained.

[0072] Therefore, it is possible to provide the array antenna module 100 having a heat dissipation structure capable of dissipating heat generated by the amplifier (PA 140). Furthermore, by arranging a plurality of substrates 120 one on top of the other, multi-layer integration can be realized.

[0073] Furthermore, a plurality of antennas 130 and PAs 140 may be provided on each substrate 120, and the plurality of antennas 130 may be arranged along the edge 120A of each substrate 120. Because the plurality of antennas 130 are arranged linearly (one-dimensionally) along the edge 120A, it is easier to narrow the pitch between adjacent antennas 130 compared to, for example, a two-dimensional arrangement. Therefore, when transmitting terahertz waves, it is possible to narrow the pitch between the plurality of antennas 130 to match an operating frequency of 100 GHz or higher. Therefore, it is possible to provide an array antenna module 100 that can achieve both multi-layer integration by stacking a plurality of substrates 120 and narrowing the pitch of the antennas 130.

[0074] Furthermore, the housing 110 may have partition walls 113 that are provided between the heat sinks 111 in multiple layers and that separate the PAs 140 provided in multiple numbers on each substrate 120. This makes it possible to ensure isolation between adjacent PAs 140.

[0075] Furthermore, the substrate 120 may have a metal layer 124 provided on the surface on the side where the partition wall 113 is located, and the partition wall 113 may be connected to the metal layer 124. This makes it possible to ensure stronger isolation between adjacent PAs 140.

[0076] The device may further include an adhesive layer 145 provided between the second surface and the heat sink 111. The adhesive layer 145 allows the PA 140 to be more reliably fixed to the heat sink 111, and a configuration can be realized in which heat generated by the PA 140 can be easily transferred to the heat sink 111.

[0077] Furthermore, adhesive layer 145 may be formed of an adhesive containing a thermally conductive filler, thereby realizing a configuration in which heat generated by PA 140 can be reliably transferred to heat sink 111.

[0078] The heat sink 111 may be made of any one of silicon carbide (SiC), silicon nitride (SiN), aluminum nitride (AlN), silicon (Si), or metal, or may have a laminated structure in which multiple layers made of multiple materials of silicon carbide (SiC), silicon nitride (SiN), aluminum nitride (AlN), silicon (Si), or metal are stacked. This allows for a heat dissipation structure that can more efficiently dissipate heat generated by the PA 140.

[0079] Furthermore, the pitch of the antennas 130 provided on each substrate 120 may be shorter than one wavelength of radio waves at the operating frequency of the antennas 130. This makes it possible to suppress unnecessary radiation such as interference waves, and also to achieve a narrower pitch for the antennas 130.

[0080] The above describes an array antenna module according to an exemplary embodiment of the present disclosure. However, the present disclosure is not limited to the specifically disclosed embodiment, and various modifications and variations are possible without departing from the scope of the claims. [Explanation of symbols]

[0081] 100 Array Antenna Module 110 Case 110A~110E Housing pieces 111 Heat sink 112 Wall portion (an example of a holding portion) 113 Partition Wall 115 Fixtures 120 boards 120A edge 120B convex part 121 Wiring 122 Ground Layer 123 Ground Layer 130 Antenna 131, 132 Antenna elements 133 Connection 140 PA (example of amplifier) 150 Waveguide 151, 152 End 160 phase shifter

Claims

1. a housing having a plurality of heat sink layers and a holder for holding the plurality of heat sink layers; a plurality of substrates disposed between the plurality of heat sink layers, each substrate having an edge; a plurality of antennas that constitute an array antenna, at least one of the antennas being provided on each of the plurality of substrates, and the antennas being arranged at positions that allow radio waves to be emitted from the plurality of edge sides of the plurality of substrates toward outside the plurality of substrates; a plurality of amplifiers mounted on each of the plurality of substrates and connected to the plurality of antennas, each amplifier having a first surface mounted on the substrate and a second surface opposite to the first surface, the second surface being connected to the heat sink; an array antenna module comprising:

2. a plurality of the antennas and a plurality of the amplifiers are provided on each substrate; 2. The array antenna module according to claim 1, wherein the plurality of antennas are arranged along the edge of each substrate.

3. 3. The array antenna module according to claim 2, wherein the housing has partition walls provided between the plurality of heat sink layers and separating the plurality of amplifiers provided on each substrate.

4. the substrate has a metal layer provided on a surface on which the partition wall is located, The array antenna module according to claim 3 , wherein the partition wall is connected to the metal layer.

5. The array antenna module according to claim 1 , further comprising an adhesive layer provided between the second surface and the heat sink.

6. The array antenna module according to claim 5 , wherein the adhesive layer is formed of an adhesive containing a thermally conductive filler.

7. 2. The array antenna module of claim 1, wherein the heat sink is formed of any one of silicon carbide (SiC), silicon nitride (SiN), aluminum nitride (AlN), silicon (Si), or metal, or has a laminated structure in which multiple layers formed of any two or more materials of silicon carbide (SiC), silicon nitride (SiN), aluminum nitride (AlN), silicon (Si), or metal are stacked.

8. 3. The array antenna module according to claim 2, wherein the pitch of the plurality of antennas provided on each substrate is shorter than one wavelength of radio waves at the operating frequency of the antennas.

Images