JP2010109466A - Radio communication equipment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide radio communication equipment in which a high frequency circuit and an antenna are unified, and which is improved in antenna gain in a desired electromagnetic wave radiation direction. <P>SOLUTION: In an antenna-integrated module 1, a first dielectric substrate 1a includes a tip-opened coplanar waveguide 2 and its ground surface 5, a ground layer 1b has a slot 3, and the ground surface 5 of the top-opened coplanar waveguide 2 is electrically connected to the ground layer 1b at least around the slot 3 by a plurality of through-holes 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wireless communication apparatus having an antenna function for transmitting microwaves or millimeter waves, and more particularly, to a wireless communication apparatus including a slot antenna and a high-frequency circuit that handles high-frequency signals in one module. Is.

  In recent years, wireless transmission of video signals for high-definition television has attracted attention.

  In wireless transmission of the above video signals, in addition to the development of wireless communication devices using microwaves, wireless communication devices using millimeter waves (wireless video) that can transmit large amounts of information by securing a wide transmission frequency band. Development of transmission equipment) is in progress.

  Here, in particular, in wireless transmission by a wireless communication device using millimeter waves, an antenna and a high-frequency circuit that handles a high-frequency signal with a frequency of about 30 GHz to 300 GHz are separately formed and connected by a connector or the like. In this case, the power loss at the connection portion becomes large.

  Therefore, in order to reduce the power loss, as a wireless communication device that wirelessly transmits millimeter waves, a wireless communication device including an antenna and a high-frequency circuit in one module has been recently developed. Patent Document 1 discloses this.

  The slot antenna disclosed in Patent Document 1 includes a first dielectric substrate 101, a high-frequency transmission line 102, a ground layer 103, a slot 104, a second dielectric substrate 105, and a via conductor 107, as shown in FIG. Configured.

  In the slot antenna shown in FIG. 6, a high-frequency signal transmitted from a high-frequency element (high-frequency circuit) (not shown) via the high-frequency transmission line 102 is composed of a combination of the open end 102 a of the high-frequency transmission line 102 and the slot 104. Power is supplied to the slot 104 by electromagnetic coupling. The second dielectric substrate 105 performs impedance matching between the slot 104 and the space, and the slot 104 radiates an electromagnetic wave corresponding to the high-frequency signal to the space.

In Patent Document 1, a radio communication device (wiring board) including an antenna and a high-frequency circuit in one module is realized by mounting the high-frequency element on the slot antenna.
Japanese Patent Laid-Open No. 11-251829 (published on September 17, 1999) Japanese Patent Laying-Open No. 2006-67403 (published on March 9, 2006)

  In the slot antenna disclosed in Patent Document 1 shown in FIG. 6, the high-frequency signal transmitted via the high-frequency transmission line 102 is fed to the slot 104 and radiated as an electromagnetic wave. The length in the longitudinal direction is set such that the high frequency signal having a certain frequency (wavelength) resonates. A slot antenna uses this resonance to radiate a strong electromagnetic wave. At this time, the electric field intensity of the electromagnetic wave becomes maximum near the center in the longitudinal direction of the slot 104 (see FIG. 7).

  Here, since the electromagnetic wave whose intensity is increased by the resonance propagates through the dielectric body and is radiated to the space, in the case of the slot antenna disclosed in Patent Document 1, not only the second dielectric substrate 105 side but also the side. The first dielectric substrate 101 is also radiated (see reference numeral 200 in FIG. 8).

  As a result, in the slot antenna disclosed in Patent Document 1, the intensity of the electromagnetic wave radiated in a desired direction is reduced due to the radiation of the unnecessary electromagnetic wave toward the first dielectric substrate 101 side. As a result, there arises a problem that the antenna gain in the desired electromagnetic radiation direction is reduced.

  The present invention has been made in view of the above problems, and an object of the present invention is to improve an antenna gain in a desired electromagnetic wave radiation direction in a wireless communication device in which a high-frequency circuit and an antenna are integrated. It is to provide a wireless communication device.

  In order to solve the above problem, a wireless communication device according to the present invention is connected to a high-frequency circuit that outputs a high-frequency signal and one end connected to the high-frequency circuit to transmit a high-frequency signal output from the high-frequency circuit. On the other hand, a high-frequency signal transmission line whose other end is open, and a ground plane of the high-frequency signal transmission line, a first dielectric substrate provided on one surface, and the first dielectric substrate And a ground conductor substrate provided with a slot for radiating electromagnetic waves according to the high-frequency signal supplied from the high-frequency signal transmission line, and provided on the ground conductor substrate. A second dielectric substrate for radiating an electromagnetic wave radiated from the slot to the outside, wherein the ground conductor substrate is electrically connected to at least the ground plane of the high-frequency signal transmission line. It is characterized in that.

  According to the above configuration, power is supplied to the slot formed in the ground conductor substrate provided on the other surface of the first dielectric substrate using the high-frequency signal transmission line with the other end open. Can do. Here, the high-frequency signal transmission line can be formed with a ground plane on one surface of the first dielectric substrate on which the high-frequency signal transmission line is to be provided. So-called grand co-planar track).

  And according to said structure, since the radiation | emission of the unnecessary electromagnetic wave from the 1st dielectric substrate side to the exterior is suppressed by the ground plane of a high frequency signal transmission line, it originated in the radiation | emission of this unnecessary electromagnetic wave, A decrease in the intensity of the electromagnetic wave radiated to the second dielectric substrate side (that is, the desired electromagnetic wave radiation direction) can be suppressed.

  As a result, in the wireless communication device according to the present invention, in the wireless communication device in which the high-frequency circuit and the slot having the antenna function are integrated, the antenna gain in the desired electromagnetic wave radiation direction can be improved as compared with the conventional case.

  Here, the multilayer aperture antenna disclosed in Patent Document 2 is fed using a line conductor that can use a coplanar line with one end open to a slot formed on the same grounded conductor layer. And the radiation from the upper ground conductor layer side can be suppressed.

  However, in the multilayer aperture antenna having the above-described configuration disclosed in Patent Document 2, a technique for connecting a line conductor formed inside the antenna and a high-frequency circuit is mentioned in order to reduce power loss. Not.

  Further, as described above, in order to realize a wireless communication device with low power loss, it is necessary to reduce transmission loss in the path between the high-frequency circuit and the slot as much as possible. When the line conductor is formed inside the antenna as in the multilayer aperture antenna having the above-described configuration disclosed in Patent Document 2, some conversion is performed on the high-frequency signal transmitted through the line conductor. It is considered that the converted high-frequency signal needs to be supplied to the slot via the high-frequency signal transmission line formed on the surface. However, in general, a large power loss is likely to occur in the high-frequency signal conversion part of the conductor line and the discontinuous part of the line itself. Therefore, in this case, the power loss becomes large as a wireless communication device. The antenna gain may be greatly reduced.

  On the other hand, in the wireless communication device according to the present invention, by providing a high frequency circuit on one surface of the first dielectric substrate, that is, by providing a high frequency circuit in the wireless communication device, power loss can be reduced, and further, the high frequency circuit By directly connecting the circuit and the high-frequency signal transmission line for feeding power to the slot by a simple connection procedure such as wire bonding, the transmission loss in the path between the high-frequency circuit and the slot is sufficiently reduced, and the antenna The gain can be improved.

  In other words, the radio communication device according to the present invention is provided with the high frequency signal transmission line in one module in which the radio communication device itself having a slot antenna is further provided with a high frequency circuit and a high frequency signal transmission line. It can be interpreted that the configuration can suppress the emission of electromagnetic waves from the surface.

  In the wireless communication apparatus according to the present invention, a ground plane is provided on a part of the second dielectric substrate, and the ground conductor substrate further includes a ground plane of the second dielectric substrate. It is characterized by being electrically connected.

  According to said structure, since the radiation | emission of the electromagnetic wave from the 2nd dielectric substrate side can be suppressed partially, the radiation range of the electromagnetic wave from the 2nd dielectric substrate side can be restrict | limited. As a result, the antenna gain can be further improved in a desired electromagnetic radiation direction in which the restriction is not performed. This configuration is suitable when it is desired to further limit the range of electromagnetic radiation from the second dielectric substrate to the outside.

  In the wireless communication device according to the present invention, the electrical connection is performed by a ground through hole formed so as to penetrate at least the ground conductor substrate and the ground surface of the high-frequency signal transmission line. It is characterized by.

  According to the above configuration, by electrically connecting the ground conductor substrate and the ground plane of the high-frequency signal transmission line through at least the ground through-hole penetrating them, the electrical process can be performed by a simple manufacturing process. Connection can be made.

  The radio communication apparatus according to the present invention is characterized in that one or a plurality of the ground through holes are formed so as to surround a slot provided in the ground conductor substrate.

  According to the above configuration, since the grounding through hole is formed so as to surround the slot, the radiation range of the electromagnetic wave from the second dielectric substrate side can be limited to a narrow range, It is possible to further improve the antenna gain in a desired electromagnetic wave radiation direction without restriction.

  The wireless communication apparatus according to the present invention further includes a mounting board on which the wireless communication apparatus is mounted, and the mounting board radiates the electromagnetic wave to a position facing the slot of the wireless communication apparatus. Therefore, even if the electromagnetic wave radiation through hole for exposing the second dielectric substrate of the wireless communication device is formed, the same effect as described above can be obtained. Note that the position on the mounting board that faces the slot of the wireless communication device is the position of the mounting board that provides the shortest linear distance from the slot. At this time, the electromagnetic wave radiated from the second dielectric substrate is propagated and radiated to the outside through the electromagnetic wave radiation through hole.

Further, in the wireless communication device according to the present invention, the electromagnetic wave radiation through hole has a rectangular cross section parallel to the surface of the mounting substrate, the length of the long side of the rectangle is a, When the wavelength is λ, the following formula (1),
λ / 2 ≦ a ≦ λ (1)
It is characterized by satisfying.

  According to said structure, since the length a of the long side of the electromagnetic wave radiation through-hole which is rectangular satisfies the said Numerical formula (1) with respect to the wavelength (lambda) of electromagnetic waves, only the electromagnetic wave of TE10 mode optimal for radiation | emission is sufficient. Can propagate with low power loss.

Further, in the wireless communication device according to the present invention, when the electromagnetic wave radiation through hole has a rectangular cross section parallel to the surface of the mounting substrate, the length of the short side of the rectangle is b. (2),
0 <b ≦ λ / 2 (2)
It is characterized by satisfying.

  According to said structure, since the length of the short side of the electromagnetic wave radiation through-hole which is a rectangle is about half with respect to the length of the long side of the electromagnetic wave radiation through-hole, The vertical electromagnetic wave is cut off, and thereby the polarization ratio of the electromagnetic wave radiated to the outside can be improved.

  In the wireless communication device according to the present invention, the electromagnetic wave radiation through hole is a through hole for electrically connecting both surfaces of the mounting substrate.

  According to said structure, since the power loss when electromagnetic waves pass an electromagnetic wave radiation | emission through-hole can be reduced, an antenna gain can further be improved. This is because the through hole functions as a waveguide.

  The wireless communication apparatus according to the present invention further includes a lens made of a dielectric, and the focal point of the lens is on the center of the electromagnetic wave radiation through hole on one surface of the mounting substrate and on the other surface of the mounting substrate. It is located on a straight line connecting the center of the electromagnetic wave radiation through hole.

  According to the above configuration, the electromagnetic wave to be radiated to the outside is converted into a plane wave by the lens made of a dielectric and radiated to the outside, so that the antenna gain can be further improved.

  The wireless communication device according to the present invention further includes a horn antenna connected to the mounting board, and the electromagnetic wave radiation through hole and one opening part of the horn antenna at a connection part between the mounting board and the horn antenna. Is characterized by a contract.

  According to the above configuration, since all electromagnetic waves to be radiated to the outside are radiated from the horn antenna, it is possible to form a highly efficient and high gain antenna.

  As described above, a wireless communication device according to the present invention includes a high-frequency circuit that outputs a high-frequency signal, and one end connected to the high-frequency circuit to transmit a high-frequency signal output from the high-frequency circuit, while the other end An open high-frequency signal transmission line and a ground plane of the high-frequency signal transmission line are provided on one surface of the first dielectric substrate and on the other surface of the first dielectric substrate. A ground conductor substrate provided with a slot for radiating an electromagnetic wave corresponding to the high frequency signal supplied from the high frequency signal transmission line, and a slot provided on the ground conductor substrate. A second dielectric substrate for radiating the electromagnetic wave to the outside, and the ground conductor substrate is electrically connected to at least the ground plane of the high-frequency signal transmission line.

  Therefore, in the wireless communication apparatus in which the high-frequency circuit and the antenna are integrated, the antenna gain in the desired electromagnetic wave radiation direction can be improved.

  The best mode for carrying out the present invention will be described with reference to FIGS.

  FIGS. 1A to 1D show an embodiment of the present invention and are diagrams showing a configuration of a wireless communication apparatus.

  Specifically, FIG. 1A is a plan view of the wireless communication device as viewed from the first dielectric substrate side, and FIG. 1B is a plan view of the wireless communication device on the second dielectric substrate side. FIG. 1C is a cross-sectional view taken along line AA ′ in FIG. 1A, and FIG. 1D is a cross-sectional view taken along line BB in FIG. It is arrow sectional drawing in a 'line.

  An antenna-integrated module (wireless communication device) 1 shown in FIGS. 1A to 1D includes a wireless communication device that wirelessly transmits a video signal for high-vision television, an inter-vehicle radar, and a wireless LAN (Local Area Network). ) And the like, and can be applied as a core part of a wireless communication device constituting various communication systems using millimeter wave electromagnetic waves.

  As shown in FIGS. 1A to 1D, the antenna-integrated module 1 includes a first dielectric substrate 1a, a ground layer (ground conductor substrate) 1b, and a second dielectric substrate 1c. Specifically, the antenna-integrated module 1 has a configuration in which a ground layer 1b and a first dielectric substrate 1a are sequentially stacked on a second dielectric substrate 1c.

  The laminated structure of the first dielectric substrate 1a, the ground layer 1b, and the second dielectric substrate 1c (hereinafter referred to as “multilayer substrate”) has a relative dielectric constant of 3.33, for example. A prepreg having a relative dielectric constant of 3.54 and a thickness of 100 μm on one surface of the substrate (ground layer 1b) made of a resin core material having a thickness of 500 μm (first layer). The dielectric substrate 1a and the second dielectric substrate 1c) are attached, and a general copper foil (the other of the first dielectric substrate 1a and the second dielectric substrate 1c) is attached to the other surface. It can be configured by attaching.

  However, the configuration of the multilayer substrate is not limited to the above. That is, for example, instead of the substrate made of the resin core material, a ceramic fired material may be used.

  The antenna-integrated module 1 includes an open-ended coplanar line (high frequency signal transmission line) 2, a slot 3, a through hole (ground through hole) 4, a ground plane (a ground plane of the high frequency signal transmission line) 5, a high frequency integrated circuit ( (High frequency circuit) 6, microstrip line 7, surface mount terminal 8, ground plane (ground plane of the second dielectric substrate) 9, and conductor extraction portion 10.

  The open-ended coplanar line 2 is provided on the surface of the first dielectric substrate 1a (one surface of the first dielectric substrate) opposite to the ground layer 1b and is exposed to the outside. One end of the open-ended coplanar line 2 is connected to the high-frequency integrated circuit 6 by a wire bonding method using a wire 11, and the other end is opened as shown as an open end 2a. The open-ended coplanar line 2 is a line for transmitting a high-frequency signal, which will be described later, output from the high-frequency integrated circuit 6.

  The slot 3 is provided in the ground layer 1b. The slot 3 has a central portion of the slot 3 itself at a lower portion of the open end coplanar line 2 that is separated from the open end 2a by a distance corresponding to about ¼ wavelength of the electromagnetic wave passing through the second dielectric substrate 1c. The open-ended coplanar line 2 is provided so as to intersect (orthogonally in FIG. 1A). Further, the longitudinal direction of the slot 3 (the vertical direction in FIG. 1A) is a length corresponding to about ½ wavelength of the electromagnetic wave passing through the second dielectric substrate 1c.

  The plurality of through holes 4 are formed so as to surround the slot 3, and each of the through holes 4 is a hole formed so as to penetrate the ground surface 5, the ground layer 1 b, and the ground surface 9. is there. The through hole 4 electrically connects the ground plane 5, the ground layer 1 b, and the ground plane 9.

  However, only one through hole 4 may be provided as necessary. For example, by passing through the ground surface 5 and the ground layer 1b, the ground surface 5 and the ground layer 1b are connected. It may be configured to be electrically connected. Furthermore, instead of the through hole 4, a metal wall (not shown) is provided so as to surround the slot 3, and the ground plane 5 and the ground layer 1b (with the ground plane 9) are electrically connected by the metal wall. It may be.

  The ground surface 5 is provided on the surface of the first dielectric substrate 1a opposite to the ground layer 1b, as with the open-ended coplanar line 2, and is exposed to the outside. The ground surface 5 is provided on both sides of the open end coplanar line 2 so as to surround the open end coplanar line 2, and is electrically connected to the open end coplanar line 2. Functions as a ground plane.

  The high-frequency integrated circuit 6 is provided on the surface of the first dielectric substrate 1a opposite to the ground layer 1b, and is exposed to the outside, like the open-ended coplanar line 2 and the ground plane 5. The high-frequency integrated circuit 6 is connected to one end of the open-ended coplanar line 2 and the microstrip line 7 by a wire bonding method using the wire 11. Moreover, the high frequency integrated circuit 6 is provided on the ground plane 5, and the ground plane 5 is used as a ground plane of the high frequency integrated circuit 6 itself.

  The microstrip line 7 is provided on the surface of the first dielectric substrate 1a opposite to the ground layer 1b, like the open-ended coplanar line 2, the ground plane 5, and the high-frequency integrated circuit 6, and externally. Exposed. A plurality of surface mount terminals 8 are provided on the surfaces of the first dielectric substrate 1a and the second dielectric substrate 1c on the opposite side of the ground layer 1b so as to correspond to each other and exposed to the outside. Has been. One end of the microstrip line 7 is connected to the high-frequency integrated circuit 6 by a wire bonding method using the wire 11, and the other end is connected to the mounting substrate 12 (see FIG. 3) via the surface mounting terminal 8. (See (a) and (b)).

  The ground plane 9 is provided on the surface of the second dielectric substrate 1c opposite to the ground layer 1b, and is a ground plane of the second dielectric substrate 1c exposed to the outside.

  The conductor extraction portion 10 is a rectangular (rectangular) conductor portion formed at a position facing the slot 3 in the second dielectric substrate 1c. In addition, the dimension of the conductor extraction part 10 is the dimension prescribed | regulated by waveguide standard WR-15, for example, length (direction substantially parallel to the longitudinal direction of the slot 3) 3.8 mm, side (short side of the slot 3) The direction is substantially 1.9 mm.

  Here, the ground layer 1b is formed on the surface opposite to the surface on which the open end coplanar line 2 and the like are provided (the other surface of the first dielectric substrate) with respect to the first dielectric substrate 1a. It can be interpreted that it is provided.

  Here, the principle of the antenna integrated module 1 radiating electromagnetic waves to the outside will be described.

  The high-frequency integrated circuit 6 generates and outputs a high-frequency signal having a millimeter-wave band frequency of, for example, about 60 GHz, and the output high-frequency signal is transmitted to the open end coplanar line 2 via the wire 11.

  Here, as described above, the slot 3 is located below the open end coplanar line 2 away from the open end 2a by a distance corresponding to about ¼ wavelength of the electromagnetic wave passing through the second dielectric substrate 1c. The central portion intersects the open end coplanar line 2. At this time, electromagnetic coupling occurs between the open end coplanar line 2 to which the high-frequency signal is transmitted and the slot 3. That is, when a current flows through the open-ended coplanar line 2, a current in the opposite direction to the current flowing through the open-ended coplanar line 2 tends to flow through the ground layer 1b. Here, when the slot 3 is provided, an electric field is generated in the slot 3 due to the current flowing through the ground layer 1b. The signal of the open-ended coplanar line 2 is transmitted to the slot 3 by the electric field generated in the slot 3.

  Due to the electromagnetic coupling, the high-frequency signal is supplied (powered) from the open-ended coplanar line 2 to the slot 3.

  Here, since the longitudinal direction of the slot 3 is a length corresponding to about ½ wavelength of the electromagnetic wave passing through the second dielectric substrate 1c, when the high-frequency signal is supplied to the slot 3, the slot 3 Then, resonance of the high frequency signal occurs. Thereby, the high frequency signal is radiated from the slot 3 as an electromagnetic wave. That is, an electromagnetic wave corresponding to the high-frequency signal supplied from the open end coplanar line 2 is radiated from the slot 3.

  Here, regarding the electromagnetic wave radiated from the slot 3 provided in the ground layer 1b, the electromagnetic wave radiated to the first dielectric substrate 1a side is blocked by the ground plane 5, while the second dielectric The electromagnetic wave radiated from the substrate 1c side through the second dielectric substrate 1c is radiated to the space (external) through the conductor extraction portion 10 provided in the second dielectric substrate 1c.

  According to the above configuration, power can be supplied to the slot 3 using the open end coplanar line 2. And since the radiation of unnecessary electromagnetic waves from the first dielectric substrate 1a side to the outside is suppressed by the ground plane 5, the conductor removal of the second dielectric substrate 1c caused by the radiation of the unnecessary electromagnetic waves is suppressed. A decrease in the intensity of the electromagnetic wave radiated from the portion 10 can be suppressed. As a result, the antenna integrated module 1 can improve the antenna gain in the desired electromagnetic wave radiation direction in the module in which the high frequency integrated circuit 6 and the antenna (slot 3) are integrated.

  In the antenna-integrated module 1, by providing the high frequency integrated circuit 6 on the surface of the first dielectric substrate 1a opposite to the ground layer 1b, power loss can be reduced first. Since the open-ended coplanar line 2 for feeding power to the slot 3 can be directly connected by a simple connection structure using a wire bonding method using a wire 11, the high-frequency integrated circuit 6 and the slot It is possible to sufficiently reduce the transmission loss in the path between the two. That is, in the antenna integrated module 1, in the configuration in which the high-frequency integrated circuit 6 and the open end coplanar line 2 are provided on the surface thereof, it is possible to suppress the emission of electromagnetic waves from the surface on which the open end coplanar line 2 is provided. It is.

  When the open end coplanar line 2 is used as the high-frequency signal transmission line according to the present invention, the ground plane for the open end coplanar line 2 requires the ground plane 5 in addition to the ground layer 1b. Here, the open end coplanar line 2 is a so-called grounded coplanar line having an inner ground layer 1b and a ground plane 5 provided on the same plane as the open end coplanar line 2 as a ground plane. In the present embodiment, a slot 3 for electromagnetic wave radiation is formed in the ground layer 1b, while the ground plane 5 is used to suppress electromagnetic wave radiation from the first dielectric substrate 1a side. . Thus, in the present embodiment, the ground plane 5 and the ground layer 1b are used for different purposes.

  On the other hand, for example, when the microstrip line 7 is used as the high-frequency signal transmission line according to the present invention, the ground plane for the microstrip line 7 is provided with only one type of the ground layer 1b. Although it is possible to form the slot 3, it is technically difficult to use it to suppress the emission of electromagnetic waves from the first dielectric substrate 1 a side.

  However, here, the high-frequency signal transmission line according to the present invention is not limited as long as a ground plane can be further formed on the surface on which the high-frequency signal transmission line is provided.

  FIG. 2A shows an electromagnetic wave radiation pattern of the antenna-integrated module 1 when a high-frequency signal is supplied to the slot 3 using the open end coplanar line 2 in the antenna-integrated module 1.

  FIG. 2B shows an electromagnetic wave radiation pattern of the wireless communication device when a high-frequency signal is supplied to the slot using the open-end microstrip line in the wireless communication device according to the related art. Here, the “tip-open microstrip line” is a microstrip line in which one end is connected to a high-frequency circuit and the other end is open, like the tip-open coplanar line 2 of the antenna integrated module 1. That is.

  In the case of the antenna integrated module 1, the antenna gain in the direction of the antenna surface (surface on the second dielectric substrate 1c side) is about 5.58 dBi as shown in FIG. In the case of a wireless communication device according to the prior art using a microstrip line, as shown in FIG. 2 (b), it is about 4.71 dBi.

  On the other hand, the antenna gain in the direction of the circuit surface (the surface on the first dielectric substrate 1a side), which is regarded as unnecessary radiation in the wireless communication device, is as shown in FIG. As shown, it is about −8.15 dBi, whereas in the case of a wireless communication device according to the prior art using an open-ended microstrip line, it is about −2.91 dBi.

  From the above comparison between the radiation pattern shown in FIG. 2 (a) and the radiation pattern shown in FIG. 2 (b), in the antenna integrated module 1 according to the present invention, the wireless communication according to the prior art using the open-end microstrip line is used. It can be seen that the antenna gain in the antenna surface direction is improved as compared with the device, and unnecessary electromagnetic radiation in the circuit surface direction can be suppressed.

  FIG. 3A shows another embodiment of the present invention, and is a diagram showing a configuration of a wireless communication apparatus provided with a mounting board from the mounting board side. FIG. 3B is a cross-sectional view taken along the line CC ′ of FIG.

  As shown in FIGS. 3A and 3B, the antenna-integrated module 1 may be provided on the mounting substrate 12 through, for example, the surface mounting terminals 8 (see FIG. 1B). As the mounting board 12, a printed board made of a resin material such as polyimide, glass epoxy, or polyester can be used.

  The ground plane 9 of the antenna integrated module 1 is mounted on a connection terminal (not shown) on the mounting substrate 12 by soldering. Although not shown, each of the surface mount terminals 8 of the antenna integrated module 1 is preferably mounted on the ground surface 14 on the mounting substrate 12 by soldering. Further, the antenna integrated module 1 is provided with a lid 16 so as to cover the open end coplanar line 2 and the high frequency integrated circuit 6 of the first dielectric substrate 1a.

  A through hole (electromagnetic radiation through hole) 13 having a rectangular cross section parallel to the surface of the mounting substrate 12 is formed in the mounting substrate 12. The through-hole 13 is formed at a position facing the slot 3 of the antenna-integrated module 1, and the second dielectric substrate 1c of the antenna-integrated module 1 is radiated to the outside so as to radiate electromagnetic waves radiated from the slot 3. The conductor extraction portion 10 is exposed. The through hole 13 has a copper plating (not shown) applied to the inner wall 15, and the ground surfaces 14 provided on both surfaces of the mounting substrate 12 are electrically connected by the through hole 13.

  The rectangular dimension which is a cross section parallel to the surface of the mounting substrate 12 in the through hole 13 is a dimension defined by, for example, the waveguide standard WR-15, and is a conductor extraction portion of the antenna integrated module 1. 10 is the same size. That is, the dimensions of the rectangle are such that the length (a) in the vertical direction (substantially parallel to the longitudinal direction of the slot 3) is 3.8 mm, and the length (b) in the horizontal direction (substantially parallel to the lateral direction of the slot 3) is 1. .9 mm. The through hole 13 is formed so that substantially all of the opening portion overlaps the conductor extraction portion 10 of the antenna integrated module 1 in a direction perpendicular to the surface of the mounting substrate 12.

  However, the rectangle in the through hole 13 is not necessarily a complete rectangle, and there is no particular problem even if it is an incomplete rectangle (substantially rectangular shape) in which the round shape of the drill at the time of forming the through hole 13 remains.

  The through hole 13 is formed so that the cross-sectional shape of the opening portion is substantially the same as the cross-sectional shape of the conductor extraction portion 10, and substantially the entire opening portion overlaps the conductor extraction portion 10 of the antenna integrated module 1. ing. At this time, the electromagnetic wave radiated from the slot 3 of the antenna-integrated module 1 through the conductor extraction portion 10 propagates through the through hole 13 without being reflected and is radiated to the outside.

  Since the through-hole 13 functions as a waveguide because the inner wall 15 is plated with copper, the electromagnetic wave radiated from the conductor-extracted portion 10 is directed in the front direction (the vertical direction in FIG. 3B). ) Will propagate only to.

  By the way, the waveguide standard WR-15 stipulates that the frequency of the electromagnetic wave to be transmitted propagates only in the TE10 mode of about 50 GHz to about 75 GHz. Here, since the size of the opening portion of the through hole 13 is substantially the same as the size defined by the waveguide standard WR-15, the electromagnetic wave radiated from the antenna integrated module 1 (60 GHz band high frequency signal) ) Is guided to the front direction as it is through the through-hole 13 without being converted to a higher-order mode, and is emitted to the outside.

The opening shape of the through-hole 13 is not necessarily a size that conforms to a certain waveguide standard, but the vertical length a, which is the long side of the rectangle, is expressed by the following formula (3),
λ / 2 ≦ a ≦ λ (3)
It is preferable to satisfy Where λ is the wavelength of the electromagnetic wave to be radiated to the outside.

  Note that a = λ / 2 is a dimension that cuts off the TE10 mode electromagnetic wave in the rectangular waveguide, and a = λ is the TE20 mode that is the first higher-order mode in the rectangular waveguide. This is the dimension at which the electromagnetic wave is cut off. Further, when a <λ / 2, the TE10 mode electromagnetic wave is cut off, so that the intensity of the emitted electromagnetic wave is greatly attenuated (there is no other mode that can propagate). This is not preferable because a part of the electromagnetic wave in the TE10 mode is converted to the TE20 mode and is radiated, thereby lowering the antenna efficiency.

Further, the horizontal length b, which is the short side of the rectangle, is expressed by the following formula (4),
0 <b ≦ λ / 2 (4)
Is preferably satisfied, and thereby, cross-polarized waves that can be generated in the electromagnetic wave to be radiated can be suppressed. Further, when the horizontal length b is set to a value substantially equal to b = a / 2, when a = λ, b = λ / 2, and the electromagnetic wave perpendicular to the propagation direction is cut off. Therefore, it is preferable.

  In the case of b> λ / 2, for example, when the right and left balance of the structure is broken due to mounting variation or the like, an electromagnetic wave that is perpendicular to the propagation direction of the electromagnetic wave to be emitted is generated separately and polarized The ratio may decrease.

  However, the vertical length a and the horizontal length b are set to dimensions conforming to a certain waveguide standard, so that the mounting substrate 12 is provided via the through-hole 13 as a waveguide. It is possible to connect the antenna-integrated module 1 to a measuring instrument (not shown), and for example, it is possible to shorten the inspection time during mass production.

  FIG. 4 shows still another embodiment of the present invention, and is a cross-sectional view showing a configuration of a wireless communication apparatus provided with a lens and a mounting substrate.

  As shown in FIG. 4, the antenna-integrated module 1 may further include a lens 18 made of a dielectric in addition to the mounting substrate 12 and the lid 16. In addition, the form shown in FIG. 4 is further provided with a mortar-shaped structure 17.

  The structure 17 is made of a metal such as aluminum and is suitably used as a housing of the antenna integrated module 1. The structure 17 has an opening 17 a at a position facing the through hole 13 of the mounting substrate 12, and the opening 17 a passes through the mounting substrate 12 in a direction perpendicular to the surface of the mounting substrate 12. The holes 13 are formed so that their cross-sectional shapes coincide and overlap. And as for the structure 17, the cross-sectional area in the direction parallel to the surface of the mounting board | substrate 12 of the opening part 17a becomes large sequentially as the linear distance to the mounting board | substrate 12 becomes long.

  A lens 18 is provided at the end of the structure 17 opposite to the mounting substrate 12.

  The lens 18 is preferably formed of a material with low power loss, such as polypropylene, polyethylene, polytetrafluoroethylene, or the like.

  First, similarly to the operation described above in the form shown in FIGS. 3A and 3B, the electromagnetic wave radiated from the conductor punched portion 10 is guided in the front direction through the through hole 13 without being reflected. Radiated. The electromagnetic wave radiated from the through hole 13 is propagated while spreading in a direction parallel to the surface of the mounting substrate 12, but this spread is limited by the wall surface of the structure 17. As a result, the electromagnetic wave enters the lens 18 without causing leakage (spillover). That is, the through hole 13 can be regarded as a point wave source of the lens 18.

  Here, the focal point 18 a of the lens 18 is located on a straight line 132 connecting the centers 131 of the through holes 13 on both surfaces of the mounting substrate 12. At this time, the electromagnetic wave incident on the lens 18 is converted into an in-phase plane wave by the lens 18 and radiated to the outside. Thereby, in the form shown in FIG. 4, compared with the form shown to FIG. 1 (a)-(d), an antenna gain can be improved further.

  FIG. 5 shows still another embodiment of the present invention, and is a cross-sectional view showing a configuration of a wireless communication apparatus including a horn antenna and a mounting board.

  As shown in FIG. 5, the antenna integrated module 1 may further include a horn antenna 19 in addition to the mounting substrate 12 and the lid 16.

  The horn antenna 19 is made of a metal such as aluminum, and is preferably fixed to a housing 20 for housing the antenna integrated module 1. The horn antenna 19 has an opening 19 a at a position facing the through hole 13 of the mounting substrate 12, that is, at a connection portion between the mounting substrate 12 and the horn antenna 19, and the opening 19 a In the direction perpendicular to the surface, the through hole 13 of the mounting substrate 12 is formed so as to have the same cross-sectional shape and overlap. That is, the through hole 13 and the opening 19a of the horn antenna 19 are engaged. In the horn antenna 19, the cross-sectional area of the opening 19 a in the direction parallel to the surface of the mounting substrate 12 is gradually increased as the linear distance to the mounting substrate 12 becomes longer.

  In the form shown in FIG. 5, desired directivity can be obtained by appropriately setting the length of the horn antenna 19 and the opening dimension of the tip (end opposite to the mounting substrate 12).

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope shown in the claims. That is, embodiments obtained by combining technical means appropriately modified within the scope of the claims are also included in the technical scope of the present invention.

  The present invention can improve an antenna gain in a desired electromagnetic wave radiation direction in a wireless communication device in which a high-frequency circuit and an antenna are integrated. For this reason, the present invention is applied to a wireless communication device that wirelessly transmits a video signal for high-definition television, and a wireless communication device that constitutes various communication systems using millimeter wave electromagnetic waves, such as an inter-vehicle radar and a wireless LAN. Is possible.

FIG. 1A shows an embodiment of the present invention. FIG. 1A is a plan view of an antenna integrated module viewed from the first dielectric substrate side, and FIG. 1B is an antenna integrated type. It is the top view which looked at the module from the 2nd dielectric substrate side, FIG.1 (c) is arrow sectional drawing in the AA 'line of the same figure (a), FIG.1 (d) is It is arrow sectional drawing in the BB 'line | wire of the same figure (a). FIG. 2A shows an electromagnetic wave radiation pattern of the antenna-integrated module when a high-frequency signal is supplied to the slot using an open-ended coplanar line in the antenna-integrated module. ) Shows an electromagnetic wave radiation pattern of the wireless communication device when a high-frequency signal is supplied to the slot using the open-end microstrip line in the wireless communication device according to the related art. FIG. 3A shows another embodiment of the present invention, and is a diagram showing a configuration of a wireless communication device provided with a mounting board from the mounting board side, and FIG. It is arrow sectional drawing in the CC 'line of the figure (a). FIG. 24 is a cross-sectional view illustrating still another embodiment of the present invention and illustrating a configuration of a wireless communication device including a lens and a mounting substrate. FIG. 25 is a cross-sectional view illustrating still another embodiment of the present invention and illustrating a configuration of a wireless communication device including a horn antenna and a mounting substrate. It is a figure which shows schematic structure of the slot antenna which concerns on a prior art. It is a figure which shows the general relationship between the length of the longitudinal direction of a slot, and the resonance of a high frequency signal. FIG. 4 is a cross-sectional view showing a situation where a problem to be solved by the present invention occurs in the slot antenna.

Explanation of symbols

1. Antenna integrated module (wireless communication device)
1a First dielectric substrate 1b Ground layer (ground conductor substrate)
1c Second dielectric substrate 2 Open end coplanar line (high-frequency signal transmission line)
2a Open termination (the other end of the high-frequency signal transmission line)
3 slots 4 through holes (grounding through holes)
5 Ground plane (ground plane of high-frequency signal transmission line)
6. High frequency integrated circuit (high frequency circuit)
9 Ground plane (ground plane of the second dielectric substrate)
12 Mounting board 13 Through hole (electromagnetic radiation through hole)
18 Lens 18a Focal point of lens 18 19 Horn antenna 19a Horn antenna opening (opening)

Claims (11)

A high-frequency circuit for outputting a high-frequency signal; a high-frequency signal transmission line having one end connected to the high-frequency circuit for transmitting a high-frequency signal output from the high-frequency circuit; A ground plane of the transmission line, a first dielectric substrate provided on one surface;
A grounding conductor substrate provided on the other surface of the first dielectric substrate, and provided with a slot for radiating an electromagnetic wave corresponding to the high-frequency signal supplied from the high-frequency signal transmission line;
A second dielectric substrate for radiating an electromagnetic wave radiated from a slot provided in the ground conductor substrate to the outside,
The radio communication apparatus, wherein the ground conductor substrate is electrically connected to at least a ground plane of the high-frequency signal transmission line. A part of the second dielectric substrate is provided with a ground plane,
2. The wireless communication apparatus according to claim 1, wherein the ground conductor substrate is further electrically connected to a ground plane of the second dielectric substrate.   The electrical connection is performed by a ground through hole formed so as to penetrate at least the ground conductor substrate and the ground plane of the high-frequency signal transmission line. Wireless communication device.   4. The wireless communication apparatus according to claim 3, wherein one or a plurality of the ground through holes are formed so as to surround a slot provided in the ground conductor substrate. A mounting board on which the wireless communication device is mounted;
The mounting substrate is formed with an electromagnetic wave radiation through hole for exposing the second dielectric substrate of the wireless communication device to radiate the electromagnetic wave to the outside at a position facing the slot of the wireless communication device. The wireless communication device according to claim 1, wherein the wireless communication device is a wireless communication device. The electromagnetic radiation through hole has a rectangular cross section parallel to the surface of the mounting substrate,
When the length of the long side of the rectangle is a and the wavelength of the electromagnetic wave is λ, the following formula (1),
λ / 2 ≦ a ≦ λ (1)
The wireless communication apparatus according to claim 5, wherein: The electromagnetic wave radiation through hole has a rectangular cross section parallel to the surface of the mounting substrate, where the length of the short side of the rectangle is b and the wavelength of the electromagnetic wave is λ, the following formula (2 ),
0 <b ≦ λ / 2 (2)
The wireless communication apparatus according to claim 5, wherein: When the length of the short side of the rectangle is b, the following mathematical formula (3),
0 <b ≦ λ / 2 (3)
The wireless communication apparatus according to claim 6, wherein:   The wireless communication apparatus according to claim 5, wherein the electromagnetic wave radiation through hole is a through hole for electrically connecting both surfaces of the mounting substrate. It further includes a lens made of a dielectric,
The focal point of the lens is located on a straight line connecting the center of the electromagnetic wave radiation through hole on one surface of the mounting board and the center of the electromagnetic wave radiation through hole on the other surface of the mounting board. The wireless communication apparatus according to claim 9. Further comprising a horn antenna connected to the mounting board,
The wireless communication device according to claim 9, wherein the electromagnetic wave radiation through hole and one opening portion of the horn antenna are engaged with each other at a connection portion between the mounting substrate and the horn antenna.

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