Antenna module

Abstract

An antenna module (1) comprises: a base member (70); a printed board (10P) having a first layer (10) which has a first interconnect (11) for conveying a signal of a first frequency and which is disposed on a reference surface (70a) of the base member (70), and a second layer (20) which is disposed on a first surface (10b) of the first layer (10) on the opposite side from the reference surface (70a) and which has a second interconnect (21) for conveying electric power; an antenna-in-package (100) in which an antenna element (120) and an RFIC (110) are packaged and which is disposed on the reference surface (70a) so as to be close to the printed board (10P); a first wire (50) connecting the first layer (10) and the antenna-in-package (100); and a second wire (60) connecting the second layer (20) and the antenna-in-package (100).

Description

Antenna Module

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

[0002] Conventionally, a phased array antenna module has been disclosed that includes: a frequency conversion IC that generates a high-frequency signal using an LO signal; a beamforming IC that imparts a phase difference to the generated high-frequency signal; and a phased array antenna that varies a beam direction according to the phase difference of the high-frequency signal (see, for example, Patent Document 1). In this phased array antenna module, a substrate provided with the phased array antenna and the beamforming IC are connected via bumps of the beamforming IC.

[0003] Japanese Unexamined Patent Application Publication No. 2024-129366

[0004] In recent years, the operating frequency of antenna modules handling high-frequency signals has been increasing, and higher density of antennas and wiring than conventional designs is required. However, when a substrate provided with an antenna and an integrated circuit are connected via bumps as in the phased array antenna module described in Patent Document 1, there is a problem that it is difficult to achieve further higher density of antennas and wiring.

[0005] The present disclosure has been made based on recognition of the above problem, and an object of the present disclosure is to provide an antenna module that allows higher density of antennas and wiring than conventional antenna modules.

[0006] The antenna module according to this disclosure is characterized by comprising: a base member having a planar reference surface; a printed circuit board having a first layer having first wiring for transmitting a signal of a first frequency and arranged on the reference surface; a second layer having second wiring for transmitting power and arranged on the first surface opposite to the reference surface of the first layer, so as to be located opposite to the base member with respect to the first layer; an antenna element; and a radio frequency integrated circuit for communicating a signal of a second frequency with the antenna element, wherein the antenna element and the radio frequency integrated circuit are packaged and arranged on the reference surface so as to be close to the printed circuit board in a reference direction along the reference surface; a first wire for transmitting a signal of a first frequency between the first wiring and the radio frequency integrated circuit by connecting the first layer and the antenna in package; and a second wire for transmitting power between the second wiring and the radio frequency integrated circuit by connecting the second layer and the antenna in package.

[0007] According to this disclosure, antennas and wiring can be made more densely packed than in conventional systems.

[0008] This is a functional block diagram showing the schematic configuration of the antenna module according to Embodiment 1. This is a front view showing the antenna module according to Embodiment 1. This is a plan view showing the base member according to Embodiment 1. This is a plan view showing the antenna module according to Embodiment 1. This is a plan view showing the antenna module according to Embodiment 2 with the second printed circuit board removed. This is a plan view showing the antenna module according to Embodiment 2. This is a front view showing the antenna module according to Embodiment 3. Figures 8A, 8B, and 8C are enlarged front views showing a modified example of the antenna module according to Embodiment 3.

[0009] Hereinafter, embodiments relating to this disclosure will be described in detail with reference to the drawings. Embodiment 1. First, the function of the antenna module 1 according to Embodiment 1 will be described with reference to Figure 1. Figure 1 is a functional block diagram showing the schematic configuration of the antenna module 1 according to Embodiment 1. As shown in Figure 1, the antenna module 1 according to Embodiment 1 comprises a printed circuit board 10P, an antenna-in-package 100, a first wire 50, and a second wire 60.

[0010] The printed circuit board 10P comprises a first printed circuit board 10 and a second printed circuit board 20. The first printed circuit board 10, as the first layer, has a first wiring 11 (see Figure 2) that transmits a signal of a first frequency. For example, the first wiring 11 receives a 75 GHz band signal as the first frequency from a local oscillator (not shown) electrically connected to the printed circuit board 10P, and transmits the input signal to the antenna-in-package 100 via the first wiring 11. Alternatively, for example, the first wiring 11 receives a 75 GHz band signal as the first frequency from the antenna-in-package 100, and transmits the input signal to an external device via the first wiring 11.

[0011] The second printed circuit board 20, as the second layer, has a second wiring 21 (see Figure 2) that transmits power. For example, the second printed circuit board 20 receives bias power from a power supply device (not shown) electrically connected to the printed circuit board 10P, and transmits the input bias power to the antenna-in-package 100 via the second wiring 21. Also, for example, the second printed circuit board 20 receives control signals from an external device (not shown) that is electrically connected to the printed circuit board 10P, and transmits the input control signals to the antenna-in-package 100 via the second wiring 21. For example, the second printed circuit board 20 is formed as a printed circuit board independent of the first printed circuit board. Note that the second wiring 21 may consist of wiring that transmits power and wiring that transmits control signals independently of each other, or it may be configured to transmit power and control signals through a common wiring.

[0012] The first printed circuit board 10 and the second printed circuit board 20 may each be composed of a single-layer printed circuit board, or each may be composed of a multi-layer printed circuit board, or one of the first printed circuit board 10 and the second printed circuit board 20 may be composed of a single-layer printed circuit board and the other may be composed of a multi-layer printed circuit board. For example, by composing the first printed circuit board 10 and the second printed circuit board 20 as single-layer printed circuit boards, it is possible to reduce costs compared to the case where they are composed of multi-layer printed circuit boards. Also, for example, by composing the first printed circuit board 10 and the second printed circuit board 20 as multi-layer printed circuit boards, it is possible to increase the density of wiring compared to the case where they are composed of a single-layer printed circuit board. Furthermore, the first printed circuit board 10 and the second printed circuit board 20 may be formed as independent printed circuit boards, or they may be formed integrally as a single printed circuit board.

[0013] The antenna-in-package 100 includes an antenna element 120 and a radio frequency integrated circuit (RFIC) 110, with the antenna element 120 and the RFIC 110 being packaged together.

[0014] The RFIC 110 communicates with the antenna element 120 using a second frequency signal. For example, the RFIC 110 is composed of a radio frequency integrated circuit that performs radio frequency signal transmission and reception, frequency control, and power consumption control by the antenna element. Specifically, the RFIC 110 has an active circuit (not shown) that performs frequency multiplication, signal amplification, frequency mixing, etc., and performs radio frequency signal transmission and reception, frequency control, and power consumption control by the antenna element. In Embodiment 1, "active circuit" refers to a nonlinear circuit having an active element. For example, a transistor can be used as an active element.

[0015] For example, the RFIC 110 operates using power and control signals from the second printed circuit board 20, converts a first-frequency signal from the first printed circuit board 10 into a second-frequency signal higher than the first frequency, and outputs the second-frequency signal toward the antenna. Specifically, the RFIC 110 operates using power and control signals input from the second printed circuit board 20, multiplies a signal of less than 100 GHz as the first frequency input from the first printed circuit board 10 to a signal of 100 GHz or higher, and outputs the signal of 100 GHz or higher toward the antenna element 120. More specifically, the RFIC 110 operates using power and control signals input from the second printed circuit board 20, multiplies a 75 GHz band signal as the first frequency input from the first printed circuit board 10 to a terahertz band signal, and outputs the subterahertz band signal toward the antenna element 120.

[0016] Furthermore, for example, the RFIC 110 operates using power and control signals from the second printed circuit board 20, converts the second frequency signal from the antenna element 120 into a first frequency signal, and outputs the first frequency signal toward the first printed circuit board 10. Specifically, the RFIC 110 operates using power and control signals from the second printed circuit board 20, multiplies the second frequency signal from the antenna element 120 (100 GHz or higher) to a signal less than 100 GHz, and outputs the signal less than 100 GHz toward the first printed circuit board 10. More specifically, the RFIC 110 operates using power and control signals from the second printed circuit board 20, multiplies the second frequency signal from the antenna element 120 (subterahertz band) to a 75 GHz band signal, and outputs the 75 GHz band signal toward the first printed circuit board 10.

[0017] The antenna element 120 transmits and receives radio waves. For example, the antenna element 120 is composed of an excitation element that is excited based on power control from the RFIC 110.

[0018] The first wire 50 transmits a signal of a first frequency between the first wiring 11 and the RFIC 110 by connecting the first printed circuit board 10 and the antenna-in-package 100. The second wire 60 transmits power between the second wiring 21 and the RFIC 110 by connecting the second printed circuit board 20 and the antenna-in-package 100. For example, the second wire 60 transmits power between the second wiring 21 and the RFIC 110, as well as a control signal between the second wiring 21 and the RFIC 110, by connecting the second printed circuit board 20 and the antenna-in-package 100.

[0019] The first wire 50 and the second wire 60 may each consist of a single wire or multiple wires. Furthermore, if the first wire 50 and the second wire 60 are composed of multiple wires, these multiple wires may be configured to be used for different purposes among the transmission of frequency signals, power, and control signals. For example, the first wire 50 may consist of multiple wires, including a wire that transmits a first frequency signal, a wire that transmits power, and / or a wire that transmits a control signal, or any or more of these wires that transmit the first frequency signal, the wire that transmits power, and the wire that transmits a control signal may be composed of one or more wires. Also, for example, the second wire 60 may consist of a single wire that transmits power and a control signal, or it may consist of one or more wires that transmit power and one or more wires that transmit a control signal. With this configuration, the antenna module 1 according to Embodiment 1 is configured to transmit and receive radio waves in the terahertz band, for example.

[0020] Next, the details of the antenna module 1 will be described with reference to Figures 2 to 4. Figure 2 is a front view showing the antenna module 1 according to Embodiment 1. As shown in Figure 2, the antenna module 1 includes a printed circuit board 10P, an antenna in-package 100, a first wire 50, and a second wire 60, as well as a base member 70 and fasteners 90 for holding the first printed circuit board 10 and the second printed circuit board 20 to the base member 70. In Embodiment 1, the rightward direction shown in Figure 2 is the X direction, the downward direction is the Z direction, and the direction from front to back is the Y direction.

[0021] The base member 70 has a planar reference surface 70a perpendicular to the Z direction. For example, the base member 70 is formed of a metal plate. Figure 3 is a plan view showing the base member 70 according to Embodiment 1. As shown in Figure 3, for example, the base member 70 has a plurality of fastening holes 72 and a recess 71. For example, the plurality of fastening holes 72 are arranged in a position that overlaps with the first printed circuit board 10 when viewed in the Z direction, which is a direction perpendicular to the reference surface 70a, and hold the fastener 90. For example, the fastener 90 is made of male screws, and the fastening holes 72 are made of female screws. When the first printed circuit board 10 and the second printed circuit board 20 are stacked on top of each other, the fastener 90 passes through through holes (not shown) formed in the first printed circuit board 10 and the second printed circuit board 20, and the fastener 90 is held in the fastening holes 72, thereby holding the first printed circuit board 10 and the second printed circuit board 20 to the base member 70. The first printed circuit board 10 and the second printed circuit board 20 are held to the base member 70 by a plurality of fasteners 90 and a plurality of fastening holes 72, thereby correcting their respective warping. For example, the antenna module 1 is assembled by connecting the first wire 50 and the second wire 60 while the first printed circuit board 10 and the second printed circuit board 20 are held to the base member 70 by the fasteners 90. Also, for example, the recess 71 is formed at a position corresponding to the center of the first printed circuit board 10 when viewed in the Z direction. For example, the recess 71 is formed so that a part of the contour of the base member 70 is recessed in a U-shape along the reference surface 70a.

[0022] As shown in Figure 2, the first printed circuit board 10 is positioned on the reference surface 70a. For example, the first printed circuit board 10 is formed to have multiple layers, including an outer layer and an inner layer, and is positioned between the base member 70 and the second printed circuit board 20 such that one side surface 10a is in close contact with the reference surface 70a. Also, for example, the first printed circuit board 10 is formed such that the distance between the first surface 10b, which is the other side surface in the X direction as a reference direction along the reference surface 70a, and the reference surface 70a is the same as the distance between the package surface 100b of the antenna-in-package 100 and the reference surface 70a. In other words, the printed circuit board 10P is formed such that the distance between the first surface 10b and the reference surface 70a in the X direction is the same as the distance between the package surface 100b and the reference surface 70a.

[0023] For example, the printed circuit board 10P is formed such that the difference between the distance between the first surface 10b and the reference surface 70a in the Z direction and the distance between the package surface 100b and the reference surface 70a in the Z direction is 10% or less of the thickness of the first printed circuit board 10 in the Z direction. Preferably, the printed circuit board 10P is formed such that the difference between the distance between the first surface 10b and the reference surface 70a in the Z direction and the distance between the package surface 100b and the reference surface 70a in the Z direction is 1 mm or less. More preferably, the printed circuit board 10P is formed such that the difference between the distance between the first surface 10b and the reference surface 70a in the Z direction and the distance between the package surface 100b and the reference surface 70a in the Z direction is 0.5 mm or less.

[0024] Furthermore, since the thickness of the first printed circuit board 10 and the antenna-in-package 100 in the Z direction is sufficiently larger than the thickness of the wiring formed on the outer surfaces of the first printed circuit board 10 and the antenna-in-package 100, the positions of the first surface 10b and the package surface 100b may include the thickness of these wirings, or they may not.

[0025] Furthermore, for example, in the first printed circuit board 10, a portion of the first wiring 11 is formed on the outer layer of the end 10c on the antenna-in-package 100 side of the first surface 10b, and a portion is formed on the inner layer or the outer layer of the surface 10a on the reference surface 70a side, and these are connected by vertical power supply parts such as vias. With this configuration, the first printed circuit board 10 connects the first wire 50 to the portion of the first wiring 11 formed on the outer layer of the first surface 10b, while avoiding contact between the first wiring 11 and the surface 20a of the second printed circuit board 20 on the reference surface 70a side. Also, for example, a portion of the first wiring 11 formed on the outer layer of the surface 10a on the reference surface 70a side is positioned to correspond to a recess 71 in the base member 70. This avoids contact between the first wiring 11 and the base member 70.

[0026] The second printed circuit board 20 is positioned on the first surface 10b of the first printed circuit board 10, which is the surface opposite to the reference surface 70a of the first printed circuit board 10, so as to be positioned opposite to the base member 70 relative to the first printed circuit board 10. In other words, the second printed circuit board 20 is positioned on the first printed circuit board 10, which is the surface opposite to the reference surface 70a of the first printed circuit board 10, so as to be superimposed on the first printed circuit board 10, in a position opposite to the base member 70 relative to the first printed circuit board 10. For example, the second printed circuit board 20 is positioned such that a portion of the first surface 10b is exposed at the end 10c of the first printed circuit board 10 on the antenna-in-package 100 side.

[0027] Specifically, the second printed circuit board 20 is positioned in the X direction at a location further from the antenna-in-package 100 than the end 10c of the first printed circuit board 10, so that a portion of the first surface 10b is exposed at the end 10c of the first printed circuit board 10 on the antenna-in-package 100 side. In other words, the second printed circuit board 20 is positioned such that the distance in the X direction between the second surface 20b, which is the surface opposite to the surface 20a on the first surface 10b side, and the package surface 100b of the antenna-in-package 100 is greater than the distance in the X direction between the first surface 10b and the package surface 100b, so that a portion of the first surface 10b is exposed at the end 10c of the first printed circuit board 10 on the antenna-in-package 100 side. In other words, the first printed circuit board 10 and the second printed circuit board 20 are arranged in a stepped manner such that the ends 10c and 20c on the antenna-in-package 100 side are offset from each other in the X direction.

[0028] Furthermore, for example, in the second printed circuit board 20, a portion of the second wiring 21 is formed on the outer layer of the end 20c on the antenna-in-package 100 side of the second surface 20b, and a portion is formed on the inner layer or the outer layer of the surface 20a on the first printed circuit board 10 side, and these are connected by vertical power supply parts such as vias. With this configuration, the second wire 60 is connected to the portion of the second wiring 21 formed on the outer layer of the second surface 20b of the second printed circuit board 20. Note that, unlike the first wiring 11, the second wiring 21 is for transmitting power and control signals, so the second wiring 21 may be configured to be connected to the second wire 60 at a location other than near the end 20c on the antenna-in-package 100 side.

[0029] The antenna-in-package 100 is positioned on the reference surface 70a so as to be close to the first printed circuit board 10 in the X direction. For example, the antenna-in-package 100 is formed as a rectangle with sides of several millimeters when viewed from the Z direction. Alternatively, for example, the antenna-in-package 100 is positioned on the reference surface 70a so as to be close to the first printed circuit board 10, such that the distance to the first printed circuit board 10 in the X direction is smaller than the wavelength of the signal transmitted by the first wire 50. Alternatively, for example, the antenna-in-package 100 is positioned on the reference surface 70a so as to be close to the first printed circuit board 10, such that the distance to the first printed circuit board 10 in the X direction is less than 1 mm. In Embodiment 1, "close" includes a state where the distance is 0 and they are in contact.

[0030] Furthermore, for example, the antenna-in-package 100 is positioned on the reference surface 70a via a heat dissipation material 80 between the surface 100a on the side of the reference surface 70a and the reference surface 70a. For example, the heat dissipation material 80 is made of TIM (Thermal Interface Material) such as grease, sheet, or putty, and transfers heat from the antenna-in-package 100 to the base member 70. Also, for example, the antenna-in-package 100 has a plurality of conductor layers and a plurality of insulating layers formed planarly along the reference surface 70a, and at least a portion of it is a rewiring section 160 positioned between the RFIC 110 and the antenna element 120 in the Z direction. Specifically, the antenna-in-package 100 is composed of a fan-out package in which, when viewed from the Z direction, at least a portion of the rewiring section 160 is formed outside the RFIC 110 and is formed to be larger in size than the RFIC 110.

[0031] For example, the rewiring section 160 is formed such that, among the multiple conductor layers, the conductor layer located between the RFIC 110 and the antenna element 120 in the Z direction and closest to the RFIC 110 does not have a ground conductor that overlaps with the active circuit of the RFIC 110 when viewed in the Z direction. Specifically, the rewiring section 160 is formed such that, among the multiple conductor layers, the conductor layer closest to the RFIC 110 in the Z direction does not have a ground conductor that overlaps with one or more of the signal amplification circuit, frequency mixing circuit, and inductor of the RFIC 110 when viewed in the Z direction. Also, for example, the rewiring section 160 is formed such that, among the multiple conductor layers, the conductor layer located between the RFIC 110 and the antenna element 120 in the Z direction and closest to the antenna element 120 does not have a ground conductor that overlaps with the antenna element 120 when viewed in the Z direction.

[0032] For example, the rewiring section 160 has two or more conductor layers in its inner layer. Preferably, the rewiring section 160 has three or more conductor layers in its inner layer. More preferably, the rewiring section 160 has four or more conductor layers in its inner layer. For example, by having three or more conductor layers in its inner layer, the antenna-in-package 100 can be formed such that, among the multiple conductor layers, the conductor layer closest to the antenna element 120 located on the package surface 100b in the Z direction does not have a ground conductor that overlaps with the antenna element 120 when viewed in the Z direction. In this way, the conductor layer furthest from the antenna element 120 in the Z direction can be formed to have a ground conductor, and the conductor layer between the conductor layer closest to the antenna element 120 and the conductor layer furthest from the antenna element 120 can have a ground conductor. With the rewiring section 160 configured in this way, the antenna-in-package 100 can separate the antenna element 120 from the ground conductor and the wiring other than the ground conductor, making it easier to obtain the desired antenna characteristics. Furthermore, by having three or more conductor layers in the inner layer of the rewiring section 160, the antenna-in-package 100 can improve the design flexibility of the conductor layers in the rewiring section 160 compared to the case where the rewiring section has only two or fewer conductor layers in the inner layer, making it easier to achieve high gain in the antenna while increasing density.

[0033] Figure 4 is a plan view showing an antenna module 1 according to Embodiment 1. As shown in Figure 4, for example, the antenna-in-package 100 has a plurality of antenna elements 120, and the RFIC 110 communicates with these plurality of antenna elements 120 with signals of a second frequency. For example, the antenna elements 120 are composed of circular patch antennas. Also, for example, the antenna elements 120 are arranged so as not to overlap with the RFIC 110 when viewed in the Z direction. In other words, the antenna elements 120 are arranged in a fan-out region that does not overlap with the RFIC 110 when viewed in the Z direction. Also, for example, the antenna-in-package 100 has a first power distribution circuit 130 that distributes and supplies power to each of the plurality of antenna elements 120. The first power distribution circuit 130 may be formed as part of the conductor layer of the rewiring section 160, or as part of the internal circuit of the RFIC 110. Furthermore, the antenna element is not limited to a circular patch antenna; it may be a square patch antenna, a planar antenna with slots or notches, a dipole antenna, or any other shape of antenna. The antenna-in-package may also have a dielectric lens in addition to the antenna element. In addition, the antenna-in-package may have a resist applied to areas on the package surface other than where the first wire 50, the second wire 60, and other mounted components are connected. This configuration allows the antenna-in-package to suppress corrosion of the package surface and peeling of the antenna element.

[0034] As shown in Figure 2, the first wire 50 electrically connects the first printed circuit board 10 and the antenna-in-package 100. For example, one end of the first wire 50 is connected to the first surface 10b of the first printed circuit board 10, and the other end is connected to the package surface 100b of the antenna-in-package 100 opposite to the reference surface 70a. Specifically, the first wire 50 is made of bonding wire, formed as part of the first wiring 11, with one end connected to a pad located at the end 10c of the first surface 10b on the antenna-in-package 100 side, and the other end connected to a pad located at the end of the package surface 100b on the first printed circuit board 10 and the second printed circuit board 20 side, respectively.

[0035] The second wire 60 electrically connects the second printed circuit board 20 and the antenna-in-package 100. For example, one end of the second wire 60 is connected to the second surface 20b of the second printed circuit board 20, which is the surface opposite to the surface 20a on the first surface 10b, and the other end is connected to the package surface 100b. Specifically, the second wire 60 is made of bonding wire, formed as part of the second wiring 21, with one end connected to a pad located at the end 20c of the second surface 20b on the antenna-in-package 100 side, and the other end connected to a pad located at the end of the package surface 100b on the first printed circuit board 10 and the second printed circuit board 20 side, which is formed as part of the conductor layer of the antenna-in-package 100. The second wire 60 is connected in this way to form a loop that is longer than the first wire 50.

[0036] As described above, the antenna module 1 according to Embodiment 1 comprises a base member 70 having a planar reference surface 70a, a first printed circuit board 10 having first wiring 11 for transmitting a first frequency signal and positioned on the reference surface 70a, a second printed circuit board 20 positioned on the first surface 10b of the first printed circuit board 10 opposite to the reference surface 70a and positioned opposite to the base member 70 relative to the first printed circuit board 10, and having second wiring 21 for transmitting power, an antenna element 120, and an RFIC 1 for communicating a second frequency signal between the antenna element 120 and the RFIC 1. The antenna-in-package 100 comprises an antenna element 120 and an RFIC 110, which are packaged together and positioned on the reference plane 70a so as to be close to the printed circuit board 10P in the X direction along the reference plane 70a; a first wire 50 that transmits a signal of a first frequency between the first wiring 11 and the RFIC 110 by connecting the first printed circuit board 10 and the antenna-in-package 100; and a second wire 60 that transmits power between the second wiring 21 and the RFIC 110 by connecting the second printed circuit board 20 and the antenna-in-package 100.

[0037] For example, the antenna module 1 according to Embodiment 1 includes a second wiring 21 that transmits power and control signals from an external device, and a second wire 60 that transmits power and control signals between the second wiring 21 and the RFIC 110 by connecting the second printed circuit board 20 and the antenna in-package 100.

[0038] Furthermore, for example, the antenna module 1 according to Embodiment 1 includes a second printed circuit board 20 which is arranged at the end 10c of the first printed circuit board 10 on the antenna-in-package 100 side, exposing a part of the first surface 10b.

[0039] Furthermore, for example, the antenna module 1 according to Embodiment 1 includes a second printed circuit board 20 positioned at a location where the distance between the second surface 20b and the package surface 100b in the X direction is greater than the distance between the first surface 10b and the package surface 100b in the X direction.

[0040] Further, for example, the antenna module 1 according to the first embodiment includes a printed circuit board 10P held on a base member 70 by a fastener 90.

[0041] Further, for example, the antenna module 1 according to the first embodiment includes an RFIC 110 that multiplies the frequency of an input signal such that the second frequency is higher than the first frequency.

[0042] Further, for example, the antenna module 1 according to the first embodiment includes an RFIC 110 that multiplies the frequency of an input signal such that the second frequency is not less than 100 GHz and the first frequency is less than 100 GHz.

[0043] Further, for example, the antenna module 1 according to the first embodiment includes: an antenna-in-package 100 having a plurality of antenna elements 120; and an RFIC 110 that communicates a signal of the second frequency with the plurality of antenna elements 120.

[0044] Further, for example, the antenna module 1 according to the first embodiment includes an antenna-in-package 100 having a first power distribution circuit 130 that distributes and supplies power to each of the plurality of antenna elements 120.

[0045] With this configuration, the antenna module 1 packages the antenna elements 120 and the RFIC 110 into the antenna-in-package 100, so that the density of antennas and wiring can be increased compared to a case where an integrated circuit such as an RFIC and a substrate are connected via bumps. Further, in the antenna module 1, since the first printed circuit board 10 and the second printed circuit board 20 are arranged to overlap each other, the area of the module viewed from the Z direction can be reduced, and the wiring density can be increased compared to conventional structures.

[0046] Furthermore, in the antenna module 1, the antenna-in-package 100 and the first printed circuit board 10 are connected by a first wire 50, and the antenna-in-package 100 and the second printed circuit board 20 are connected by a second wire 60. This makes it possible to reduce the package size compared to, for example, a case where the antenna element, RFIC, the wiring for transmitting high-frequency signals and the wiring for transmitting power are all packaged as an antenna-in-package, thereby making it possible to reduce the productivity and cost of the antenna module.

[0047] Furthermore, in the antenna module 1, the antenna-in-package 100 and the first printed circuit board 10 disposed close to the antenna-in-package 100 are connected by the first wire 50. This makes it possible to reduce the length of the first wire 50 compared to a case where the antenna-in-package and the substrate, which are not disposed close to each other, are connected by a wire, thereby suppressing the influence of the length of the first wire 50 on the connection between the antenna-in-package 100, for which impedance matching is of high importance, and the first printed circuit board 10.

[0048] Furthermore, since the antenna module 1 does not require processes such as flip-chip mounting of integrated circuits during assembly, it can be assembled with simple equipment, making it possible to improve productivity compared to conventional techniques.

[0049] Furthermore, for example, the antenna module 1 according to Embodiment 1 includes a first wire 50, one end of which is connected to the first surface 10b and the other end of which is connected to the package surface 100b of the antenna-in-package 100 opposite to the reference surface 70a; a second wire 60, one end of which is connected to the second surface 20b of the second printed circuit board 20 opposite to the first surface 10b and the other end of which is connected to the package surface 100b; and a printed circuit board 10P formed such that the distance between the first surface 10b and the reference surface 70a in the Z direction perpendicular to the reference surface 70a is the same as the distance between the package surface 100b and the reference surface 70a in the Z direction. With this configuration, the antenna module 1 can suppress the length of the first wire 50 connecting the antenna-in-package 100 and the first printed circuit board 10, and can suppress the influence of the length of the first wire 50 on the connection between the antenna-in-package 100 and the first printed circuit board 10, where impedance matching is of high importance.

[0050] Furthermore, for example, the antenna module 1 according to Embodiment 1 includes an antenna-in-package 100 having a plurality of conductor layers and a plurality of insulating layers formed planarly along a reference plane 70a, and at least a portion of which is a rewiring section 160 arranged between the RFIC 110 and the antenna element 120 in the Z direction.

[0051] For example, the antenna module 1 according to Embodiment 1 includes a rewiring section 160 in which, among a plurality of conductor layers, the conductor layer located between the RFIC 110 and the antenna element 120 in the Z direction and closest to the RFIC 110 has no ground conductor that overlaps with the active circuit of the RFIC 110 when viewed in the Z direction. With this configuration, the antenna module 1 can suppress the influence of the conductor layer of the rewiring section 160 on the impedance of the active circuit of the RFIC.

[0052] Furthermore, for example, the antenna module 1 according to Embodiment 1 includes a rewiring section 160 in which, among the multiple conductor layers, the conductor layer located between the RFIC 110 and the antenna element 120 in the Z direction and closest to the antenna element 120 does not have a ground conductor that overlaps with the antenna element 120 when viewed in the Z direction. With this configuration, the antenna module 1 can separate the antenna element 120 from the ground conductor and the wiring other than the ground conductor, making it easier to obtain the desired antenna characteristics.

[0053] Furthermore, for example, the antenna-in-package 100 according to Embodiment 1 includes an antenna element 120 that is arranged so as not to overlap with the RFIC 110 when viewed in the Z direction. Generally, when packaging an integrated circuit in an antenna-in-package, distortion of the package's outer shape may occur due to necking and molding shrinkage of the mold resin. However, by arranging the antenna element 120 so as not to overlap with the RFIC 110 when viewed in the Z direction, it becomes possible to ensure the flatness of the surface on which the antenna element 120 is arranged, making it easier to obtain the desired antenna characteristics.

[0054] Furthermore, for example, the antenna module 1 according to Embodiment 1 includes a base member 70 having a recess 71 formed at a position corresponding to the center of the first printed circuit board 10 when viewed in the Z direction. With this configuration, even if the antenna module 1 has wiring and mounted components such as resistors or capacitors (not shown) on the surface 10a of the first printed circuit board 10 on the side of the base member 70, it is possible to avoid contact between these wiring and mounted components and the base member 70, thereby enabling higher density wiring and suppression of the thickness in the Z direction on the first printed circuit board 10. Also, with this configuration, the antenna module 1 can, for example, place a connector (not shown) for connecting the first printed circuit board 10 to an external device such as an AD converter on the surface 10a of the first printed circuit board 10 on the side of the base member 70. This makes it possible to place the connector and the cable (not shown) connected to the connector at a position opposite to the antenna element 120 relative to the first printed circuit board 10, thereby suppressing the influence of the connector and cable on the antenna.

[0055] In Embodiment 1, the base member 70 has a recess 71 formed such that a part of its contour is recessed in a U-shape along the reference surface 70a, but it is not limited to this. The recess of the base member only needs to be able to avoid contact with wiring and mounted components when the first printed circuit board has wiring and mounted components on the exterior surface of the base member. For example, the recess may be formed to be recessed in the Z direction to avoid contact with wiring and mounted components arranged on the exterior surface of the first printed circuit board, or it may be formed as a through hole penetrating in the Z direction, or if the first printed circuit board does not have wiring and mounted components on the exterior surface of the base member, the base member may not have a recess.

[0056] Furthermore, in Embodiment 1, the printed circuit board 10P is held to the base member 70 by fasteners 90, but is not limited to this. The printed circuit board may be held to the base member by means other than fasteners. For example, the printed circuit board may be held to the base member by adhesive, or by both fasteners and adhesive. For example, if the first printed circuit board and the second printed circuit board are formed as independent printed circuit boards, the first printed circuit board may be held to the base member by adhesive, and the second printed circuit board may be held to the first printed circuit board by adhesive.

[0057] Furthermore, in Embodiment 1, the first wiring 11 is configured to transmit a signal of a first frequency, and the first wire 50 is configured to transmit a signal of a first frequency between the first wiring 11 and the RFIC 110 by connecting the first printed circuit board 10 and the antenna-in-package 100, but the embodiment is not limited to this. The first wiring only needs to be configured to transmit a signal of at least a first frequency, and the first wire is configured to transmit a signal of at least a first frequency between the first wiring and the RFIC by connecting the first printed circuit board and the antenna-in-package. For example, the first wiring may transmit a signal of a first frequency in addition to at least one of power and a control signal from an external device, and the first wire may be configured to transmit a signal of a first frequency in addition to at least one of power and a control signal from an external device between the first wiring and the RFIC by connecting the first printed circuit board and the antenna-in-package.

[0058] Embodiment 2. Next, the antenna module 1A according to Embodiment 2 will be described with reference to Figures 5 and 6. The antenna module 1A according to Embodiment 2 differs from the antenna module 1 according to Embodiment 1 in that it has a plurality of antenna-in-packages 100, but some of the other components are the same, and components that are the same as in Embodiment 1 will be given the same names and reference numerals as in Embodiment 1 and will not be described.

[0059] Figure 5 is a plan view showing the antenna module 1A according to Embodiment 2 with the second printed circuit board removed, and Figure 6 is a plan view showing the antenna module 1A according to Embodiment 2. As shown in Figures 5 and 6, the antenna module 1A includes a printed circuit board having a first printed circuit board 10A and a second printed circuit board 20A, a plurality of antenna-in-packages 100, a plurality of first wires 50, a plurality of second wires 60, a base member 70A, and fasteners (not shown) for holding the printed circuit board to the base member 70A. For example, the antenna module 1A includes a plurality of antenna-in-packages 100 arranged so that their distance from each other is uniform along a specific direction along a reference plane. With this configuration, the antenna module 1A constitutes an array antenna module with a plurality of antenna-in-packages 100.

[0060] As shown in Figure 5, the first printed circuit board 10A has a first wiring 11A that transmits a signal and power of a first frequency. For example, the first wiring 11A has a second power distribution circuit 12 that distributes and supplies power to each of the multiple antenna-in-packages 100. For example, the first printed circuit board 10A has the second power distribution circuit 12 on the side facing the reference plane (the side facing the base member 70A) or in an inner layer of the first printed circuit board 10A. Note that if the first printed circuit board 10A has the second power distribution circuit 12 on the side facing the reference plane (the side facing the base member 70A), the antenna module 1A may be configured such that contact between the second power distribution circuit 12 and the base member 70A is avoided by a recess formed in the base member 70A.

[0061] Embodiment 3. Next, with reference to Figure 7, the antenna module 1B according to Embodiment 3 will be described. The antenna module 1B according to Embodiment 3 differs from the antenna module 1 according to Embodiment 1 in the configuration of the second wire and some parts of the antenna-in-package, but the other configurations are the same, and the same names and reference numerals as in Embodiment 1 will be used for the same configurations as in Embodiment 1 and their description will be omitted.

[0062] Figure 7 is a front view showing an antenna module 1B according to Embodiment 3. As shown in Figure 7, the antenna module 1B comprises a printed circuit board having a first printed circuit board 10 and a second printed circuit board 20B, an antenna-in-package 100B, a first wire 50, a second wire 60, a base member 70, and a fastener 90.

[0063] As shown in Figure 7, the antenna-in-package 100B includes a holding portion 150 held on the package surface using an adhesive or the like, a film substrate 140 held by the holding portion 150, an antenna element 120 as an excitation element held on the film substrate 140, and a non-excitation element 170 as a non-excitation element positioned at a distance from the antenna element 120. With this configuration, the antenna module 1B according to Embodiment 3 is able to expand the range of frequencies that can be transmitted and received compared to the antenna module 1 according to Embodiment 1.

[0064] Next, with reference to Figure 8, a modified example of the antenna module according to Embodiment 3 will be described. Figures 8A, 8B, and 8C are enlarged front views showing a modified example of the antenna module 1B according to Embodiment 3.

[0065] For example, as shown in Figure 8A, the antenna-in-package 100C according to the first modified example includes an antenna element 120, a rewiring section 160C having four conductive layers in its inner layer, a holding section 150, a film substrate 140, and a powerless element 170.

[0066] Furthermore, as shown in Figure 8B, for example, the antenna-in-package 100D according to the second modified example includes an antenna element 120 and a rewiring section 160C having four conductor layers in its inner layer.

[0067] Furthermore, as shown in Figure 8C, for example, the antenna-in-package 100E according to the third modified example includes an antenna element 120E as an excitation element, a parasitic element 170E as a non-excitation element positioned at a distance from the antenna element 120E, and a rewiring section 160E having four conductor layers in its inner layer. For example, the antenna element 120E is positioned in the conductor layer furthest from the reference plane 70a among the conductor layers of the inner layer, and the parasitic element 170E is positioned on the package surface. Thus, a variety of configurations are possible for the rewiring section and the antenna of the antenna-in-package.

[0068] In any of the embodiments described above, a single antenna-in-package may include multiple RFICs, and an antenna module may be configured as an array antenna module by including multiple antenna-in-packages, each comprising multiple RFICs and multiple antenna elements packaged together.

[0069] Furthermore, in any of the embodiments described above, the second printed circuit board may also include wires 61 (see Figure 7) that connect two different points in the second circuit.

[0070] Furthermore, in any of the embodiments described above, the first printed circuit board, the second printed circuit board, and the antenna-in-package may have resistor chips, capacitors, and other mounted components not shown.

[0071] Furthermore, this disclosure allows for free combination of each embodiment, modification of any component of each embodiment, or omission of any component in each embodiment.

[0072] The antenna module relating to this disclosure can be used as a module for transmitting and receiving radio waves.

[0073] 1 Antenna module, 1A Antenna module, 1B Antenna module, 10 First printed circuit board (first layer), 10A First printed circuit board (first layer), 10P Printed circuit board, 10a side, 10b first side, 10c end, 11 First wiring, 11A First wiring, 12 Second power distribution circuit, 20 Second printed circuit board (second layer), 20A Second printed circuit board (second layer), 20B Second printed circuit board (second layer), 20a side, 20b second side, 20c end, 21 Second wiring, 50 First wire, 60 Second wire, 61 Wire, 70 Base member, 70A Base member, 70a Reference surface, 71 Recess, 72 Fastening hole, 80 Heat dissipation material, 90 Fastener, 100 Antenna-in-package, 100B Antenna-in-package, 100C Antenna-in-package, 100D Antenna-in-package, 100E Antenna-in-package, 100a surface, 100b package surface, 110 Radio frequency integrated circuit (RFIC), 120 Antenna element, 120E Antenna element, 130 First power distribution circuit, 140 Film substrate, 150 Holding part, 160 Rewiring part, 160C Rewiring part, 160E Rewiring part, 170 Passive element, 170E Passive element.

Claims

1. An antenna module comprising: a printed circuit board having a base member having a planar reference surface; a first layer having first wiring for transmitting a signal of a first frequency and disposed on the reference surface; a second layer having second wiring for transmitting power and disposed on the first surface of the first layer opposite to the reference surface, so as to be located opposite to the base member with respect to the first layer; an antenna in-package having an antenna element and a radio frequency integrated circuit for communicating a signal of a second frequency with the antenna element, wherein the antenna element and the radio frequency integrated circuit are packaged and disposed on the reference surface so as to be close to the printed circuit board in a reference direction along the reference surface; a first wire for transmitting a signal of a first frequency between the first wiring and the radio frequency integrated circuit by connecting the first layer and the antenna in-package; and a second wire for transmitting power between the second wiring and the radio frequency integrated circuit by connecting the second layer and the antenna in-package.

2. The antenna module according to claim 1, wherein one end of the first wire is connected to the first surface and the other end is connected to the package surface of the antenna in-package opposite to the reference surface, one end of the second wire is connected to the second surface of the second layer opposite to the first surface and the other end is connected to the package surface, and the printed circuit board is formed such that the distance between the first surface and the reference surface in an orthogonal direction perpendicular to the reference surface is the same as the distance between the package surface and the reference surface in the orthogonal direction.

3. The antenna module according to claim 2, characterized in that the second layer is arranged such that a portion of the first surface is exposed at the end of the first layer on the antenna-in-package side.

4. The antenna module according to claim 3, characterized in that the second layer is positioned such that the distance between the second surface and the package surface in the reference direction is greater than the distance between the first surface and the package surface in the reference direction.

5. The antenna module according to any one of claims 1 to 4, characterized in that the antenna-in-package has a plurality of conductive layers and a plurality of insulating layers each formed planarly along the reference plane, and at least a portion of it has a rewiring section disposed between the radio frequency integrated circuit and the antenna element in an orthogonal direction perpendicular to the reference plane.

6. The antenna module according to claim 5, characterized in that, among the plurality of conductor layers, the conductor layer located between the radio frequency integrated circuit and the antenna element in an orthogonal direction perpendicular to the reference plane and closest to the radio frequency integrated circuit does not have a ground conductor that overlaps with the active circuit of the radio frequency integrated circuit when viewed in the orthogonal direction.

7. The antenna module according to claim 5 or 6, characterized in that, among the plurality of conductor layers, the conductor layer located between the radio frequency integrated circuit and the antenna element and closest to the antenna element in a direction perpendicular to the reference plane does not have a ground conductor that overlaps with the antenna element when viewed in the direction perpendicular to the reference plane.

8. The antenna module according to any one of claims 1 to 7, characterized in that the radio frequency integrated circuit multiplies the frequency of the input signal such that the second frequency is higher than the first frequency.

9. The antenna module according to claim 8, characterized in that the radio frequency integrated circuit multiplies the frequency of the input signal such that the second frequency is 100 GHz or higher and the first frequency is less than 100 GHz.

10. The antenna module according to any one of claims 1 to 9, characterized in that the antenna elements are arranged so as not to overlap with the radio frequency integrated circuit when viewed in a direction perpendicular to the reference plane.

11. The antenna module according to any one of claims 1 to 10, characterized in that the printed circuit board is held to the base member by at least one of a fastener and an adhesive.

12. The antenna module according to any one of claims 1 to 11, characterized in that the second wiring transmits power and control signals from an external device, and the second wire transmits power and control signals between the second wiring and the radio frequency integrated circuit by connecting the second layer and the antenna in-package.

13. The antenna module according to any one of claims 1 to 12, characterized in that the first wiring transmits, in addition to the signal of the first frequency, at least one of power and a control signal from an external device, and the first wire transmits, in addition to the signal of the first frequency, at least one of power and a control signal from an external device between the first wiring and the radio frequency integrated circuit by connecting the first layer and the antenna in package.

14. The antenna module according to any one of claims 1 to 13, characterized in that the base member has a recess formed at a position corresponding to the central part of the first layer when viewed in a direction perpendicular to the reference plane.

15. The antenna module according to any one of claims 1 to 14, characterized in that the antenna-in-package comprises the antenna element as an excitation element and a de-excitation element arranged at a distance from the excitation element.

16. The antenna module according to any one of claims 1 to 15, wherein the antenna-in-package has a plurality of antenna elements, and the radio frequency integrated circuit communicates signals of the second frequency with the plurality of antenna elements.

17. The antenna module according to claim 16, characterized in that the antenna-in-package has a first power distribution circuit that distributes and supplies power to each of the plurality of antenna elements.

18. The antenna module according to claim 16, wherein the antenna-in-package has a plurality of radio frequency integrated circuits, and the plurality of antenna elements and the plurality of radio frequency integrated circuits are packaged together.

19. The antenna module according to any one of claims 1 to 18, comprising a plurality of antenna-in-packages, wherein the first wiring has a second power distribution circuit that distributes and supplies power to each of the plurality of antenna-in-packages.

20. The antenna module according to claim 19, characterized in that the first layer has the second power distribution circuit on the side of the reference plane.

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