JP2009055574A - Branched waveguide line, and multi-layer wiring and antenna substrates having the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a miniature waveguide line which has not nearly any electromagnetic-wave leakage and has a small quantity of loss, and multi-layer wiring and antenna substrates having the waveguide line. <P>SOLUTION: The branched waveguide line branches from a first dielectric waveguide line 1 to an upper second dielectric waveguide line 2 and to a lower third waveguide line 3. A second lower main conductor layer 22 and a third upper main conductor layer 31 comprise one conductor layer. The conductor layer is disposed on the lower-side of a first upper main conductor layer 11 and on the upside of a first lower main conductor layer 12. The end surface of the first dielectric waveguide line 1 is opposed to the end surface of the second dielectric waveguide line 2 and to the end surface of the third dielectric waveguide line 3 which are disposed up and down in an overlapping manner. The structure branched upward and downward from the first dielectric waveguide line 1 to the second and third dielectric waveguide lines 2, 3 is constituted. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is mainly used in a microwave band and a millimeter wave band, and a branched waveguide line for branching a high-frequency transmission line in the laminating direction of an insulating substrate in which dielectric layers are laminated, and a multilayer wiring board and antenna having the branched waveguide line It relates to a substrate.

  In recent years, research and development of wireless communication technologies typified by mobile phones and wireless LANs have been actively conducted. In research and development of wireless communication, some have achieved a transmission speed of FTTH (Fiber to The Home) represented by optical communication, 100 Mbps or more. However, the transmission speed of wireless communication devices currently on the market is less than that of optical communication. In many wireless communication devices, microwaves are used as carrier waves. However, microwaves have a low data transmission rate, and are suitable for transferring large volumes of uncompressed video data that suppresses image quality degradation of high-definition video, for example. Absent.

  Therefore, wireless communication using electromagnetic waves having a frequency higher than that of microwaves, for example, quasi-millimeter waves and millimeter waves of 20 GHz or more, has been attracting attention as a means for transmitting large amounts of data, and research and development have been promoted. ing. In particular, in the 60 GHz band, a wide band is allocated for communication in the world, and wireless communication using such 60 GHz band electromagnetic waves has been put into practical use. It is used for such as and is spreading. In addition, a radar system using a millimeter wave band has been installed in a general passenger car as a means to support safe driving of automobiles.

  In order to realize these communication systems and radar systems, research and development of millimeter wave devices and millimeter wave circuits are underway. Typical transmission lines for millimeter wave circuits are microstrip lines, strip lines, coplanar lines, rectangular metal waveguide lines, dielectric waveguide lines, and these high-frequency transmissions formed inside an insulating substrate. A branching waveguide line may be required when routing the line.

  Here, as shown in FIG. 12, as the branching waveguide line for branching the high-frequency signal inside the insulating substrate toward the upper surface side and the lower surface side of the insulating substrate, a microstrip line type or strip line type power supply line is used. 71, a conductive metal foil formed on the inner surface of the through hole or a conductor embedded in the inside, and a feed line 72 formed toward the upper surface of the insulating substrate, and formed toward the lower surface of the insulating substrate. The high-frequency signal propagating through the feed line 71 includes the feed line 73, the patch antenna 74 formed on the upper surface of the insulating base, and the patch antenna 75 formed on the lower surface of the insulating base. 73, which is branched from the patch antenna 74 and radiated from the patch antenna 75 (see Patent Document 1). .

  However, in the branched waveguide line shown in FIG. 12, if the power ratio of the high-frequency signal is changed to branch up and down, electromagnetic waves leak from the end of the feed line 71 and become noise. The intensity of the high frequency signal is attenuated by the amount leaked at the end of the feed line 71.

  Specifically, when adjusting the power of the high-frequency signal branched up and down to an arbitrary ratio, the upper and lower through-hole diameters and through-hole positions are different, but at this time, the high-frequency signal in the strip line When the transmission direction is used as an axis, the structure is asymmetrical in the vertical direction, and the symmetry of the magnetic field strength distribution is lost. Therefore, there is a problem that electromagnetic waves leak and attenuate from the end of the feed line 71. In the structure shown in FIG. 12, even when the high frequency signal is equally distributed up and down, the ceramic green sheet and the ceramic green sheet that are adjacent in the stacking direction when the ceramic green sheet that becomes the dielectric layer after firing are stacked. In many cases, a so-called stacking deviation that does not overlap at a desired wiring position occurs, and this causes leakage of electromagnetic waves in the same manner as when the power of a high-frequency signal is made different and branched up and down.

  On the other hand, a dielectric waveguide line composed of a pair of conductor layers that sandwich the dielectric substrate and a group of through conductors 84 (via hole conductors) that electrically connect the pair of conductor layers (through hole conductor group) ( The first dielectric waveguide line 81) includes two dielectric waveguide lines (second dielectric waveguides) having the same conductor layer as the pair of conductor layers and separated by a through conductor group. A branch structure (branch waveguide line) that branches into a tube line 82 and a third dielectric waveguide line 83) is known (see Patent Document 2).

  When this branching structure (branch waveguide line) is formed inside the insulating base and a high-frequency signal propagated through the structure is desired to be propagated to the upper surface side and the lower surface side of the insulating base, for example, the second A slot is formed in the conductor layer on the upper side of the dielectric waveguide line 82 and propagated to the dielectric waveguide line disposed on the upper side, and the conductor on the lower side of the third dielectric waveguide line 83. A structure is conceivable in which a slot is formed in a layer and propagated to a dielectric waveguide line disposed below the slot.

However, according to this structure, the high-frequency signal is propagated to the dielectric waveguide lines arranged on the upper side and the lower side, which are once branched in the plane direction and coupled with the slots, so that the loss is large In addition, an area in the plane direction is required.
JP 2006-5851 A JP-A-11-186816

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a small-sized branched waveguide line with little leakage of electromagnetic waves and little loss, and a multilayer wiring board and an antenna board having the same. .

  The present invention relates to a branched waveguide line formed on an insulating substrate formed by laminating dielectric layers, the first upper main conductor layer and the first lower main conductor facing each other vertically with the dielectric layer interposed therebetween. A pair of first main conductor layers, and a first sidewall forming via-hole conductor electrically connecting the pair of first main conductor layers with a signal wavelength of less than half of the signal wavelength. A first dielectric waveguide line comprising two rows of via-hole conductor groups for forming first sidewalls arranged at intervals, a second upper main conductor layer and a second lower surface facing each other vertically with a dielectric layer in between A pair of second main conductor layers each including a side main conductor layer, and a second sidewall forming via-hole conductor that electrically connects the pair of second main conductor layers to the signal transmission direction by half the signal wavelength. 2 rows of via-hole conductor groups for forming the second side wall arranged at intervals of less than 1 A second dielectric waveguide line and a pair of third main conductor layers composed of a third upper main conductor layer and a third lower main conductor layer facing each other up and down across the dielectric layer, Two rows of via-hole conductor groups for forming third sidewalls, in which via-hole conductors for forming third sidewalls electrically connecting the pair of third main conductor layers are arranged in the signal transmission direction at intervals of less than one half of the signal wavelength. A third dielectric waveguide line, wherein the second lower main conductor layer and the third upper main conductor layer are composed of one conductor layer, and the conductor layer is the first dielectric layer. 1 lower main conductor layer and lower than the first lower main conductor layer, an end of the first upper main conductor layer and an end of the second upper main conductor layer Direct or boundary wall forming via hole conductors are arranged in a direction perpendicular to the signal transmission direction with an interval of less than half of the signal wavelength. A boundary wall forming via hole conductor group, and an end portion of the first lower main conductor layer and an end portion of the third lower main conductor layer are directly or directly connected to the boundary wall forming via hole. The first dielectric waveguide is electrically connected via a boundary wall forming via-hole conductor group in which conductors are arranged in a direction perpendicular to the signal transmission direction at intervals of less than half of the signal wavelength. The first dielectric waveguide faces the end surface of the second dielectric waveguide line and the end surface of the third dielectric waveguide line that are arranged so that the end surfaces of the line overlap with each other. A branched waveguide line characterized in that an upper and lower branch structure is formed from a line to the second dielectric waveguide line and the third dielectric waveguide line.

  The present invention also includes a substrate body having the above-described branching waveguide line, and a semiconductor element provided on each of the opposing main surfaces of the substrate body, the semiconductor element provided on one main surface, A high frequency signal is propagated between the second dielectric waveguide line and between the semiconductor element provided on the other main surface and the third dielectric waveguide line. A multilayer wiring board characterized in that a high-frequency signal is propagated.

  The present invention also includes a substrate body having the above-described branching waveguide line and a plurality of antenna elements respectively provided on opposing main surfaces of the substrate body, and a plurality of antenna elements provided on one main surface. A high-frequency signal is propagated between the antenna element and the second dielectric waveguide line, and a plurality of antenna elements provided on the other main surface and the third dielectric waveguide. The antenna substrate is characterized in that a high-frequency signal is propagated between the pipe lines.

  According to the branching waveguide line of the present invention, the transmission path of the high-frequency signal is surrounded by the pair of main conductor layers and the side wall forming via-hole conductor group, and therefore can be branched so as not to cause leakage of electromagnetic waves. . In addition, since the structure directly branches in the upper and lower stacking directions, there is little loss and a reduction in size can be realized.

  A multilayer wiring board having such a branched waveguide line is provided with semiconductor elements on the opposing main surfaces (upper surface and lower surface) of the substrate body, and is small in size when it is desired to distribute high-frequency signals vertically. Can be realized.

  Similarly, an antenna substrate having such a branched waveguide line is provided with a plurality of antenna elements on opposite main surfaces (upper surface and lower surface) of the substrate body, and a loss occurs when it is desired to distribute high-frequency signals vertically. Therefore, the size can be reduced. And, according to such a bi-directional antenna substrate, it can be preferably used as a side sensor by being installed in a passenger car.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic perspective view showing an embodiment of a branching waveguide line according to the present invention. In FIG. 1, the main conductor layer is partially omitted so that the internal structure can be seen, and the dielectric layer is also omitted.

  The branching waveguide line of the present invention is formed on an insulating substrate formed by laminating dielectric layers, and is arranged above and below the first dielectric waveguide line 1 to be a first dielectric. It has a branching structure that branches into a second dielectric waveguide line 2 and a third dielectric waveguide line 3 that share the same signal transmission direction as the waveguide line.

  Here, the dielectric waveguide line has a pair of main conductor layers (an upper main conductor layer and a lower main conductor layer) facing each other up and down across the dielectric layer and a signal wavelength of 2 in the transmission direction of the high frequency signal. Comprising two rows of via-hole conductor groups for sidewall formation formed so as to be electrically connected to the upper main conductor layer and the lower main conductor layer, which are arranged at intervals of less than one part. It is obtained by laminating and firing a dielectric green sheet to which a paste for coating is applied, and its thickness can be easily set. The thicker the dielectric waveguide line, the smaller the transmission loss, and the desired transmission characteristics can be obtained by setting the thickness.

  In FIG. 1, a first dielectric waveguide line 1 includes a pair of first main conductor layers (a first upper main conductor layer 11 and a first upper main conductor layer 11) that are vertically opposed to each other with two dielectric layers (not shown) interposed therebetween. A first lower main conductor layer 12) is provided. Also, the first sidewall forming via-hole conductor that electrically connects between the first upper main conductor layer 11 and the first lower main conductor layer 12 is spaced at a distance less than half the signal wavelength in the signal transmission direction. The first side wall forming via-hole conductor groups 41 and 42 are arranged in two rows, and the first side wall forming via-hole conductor groups 41 and 42 are formed with a predetermined interval (width), and the electric side walls are formed. Forming. Further, in order to form the side wall of the first dielectric waveguide line 1 at the boundary between the two-layered dielectric layer and the dielectric layer, like the first side wall forming via-hole conductor groups 41 and 42. The sub-conductor layer 13 is provided, and electromagnetic waves in various directions are shielded by the side wall formed in a fine lattice pattern by the first side-wall forming via-hole conductor groups 41 and 42 and the sub-conductor layer 13. In the figure, the form in which the dielectric layers constituting the first dielectric waveguide line 1 have a two-layer structure is illustrated, but the number of layers is not limited.

  The second dielectric waveguide line 2 has the same configuration as the first dielectric waveguide line 1 and has the same signal transmission direction as that of the first dielectric waveguide line 1. Specifically, a pair of second main conductor layers (a second upper main conductor layer (not shown) and a second lower main conductor layer 22) that are vertically opposed to each other with a dielectric layer (not shown) interposed therebetween are provided. It has. Also, second side wall forming via-hole conductors that electrically connect the second upper main conductor layer and the second lower main conductor layer 22 are arranged in the signal transmission direction at intervals of less than one half of the signal wavelength. The second sidewall forming via hole conductor groups 43 and 44 are provided in two rows. In the figure, the dielectric layer constituting the second dielectric waveguide line 2 has a single layer structure, and the second upper main conductor layer 21 is formed on the same plane as the first upper main conductor layer 11. The configuration shown is shown.

  The third dielectric waveguide line 3 shown in FIG. 1 has the same configuration as that of the first dielectric waveguide line 1 and the second dielectric waveguide line 2 and the first dielectric waveguide line 3 is also used. The signal transmission direction is the same as that of the body waveguide line and the second dielectric waveguide line 2. Specifically, a pair of third main conductor layers (a third upper main conductor layer 31 and a third lower main conductor layer 32) that are vertically opposed to each other with a dielectric layer (not shown) interposed therebetween are provided. . Also, a third sidewall forming via-hole conductor that electrically connects the pair of third main conductor layers 31 and 32 is arranged in the signal transmission direction at an interval of less than half the signal wavelength. Two rows of via-hole conductor groups 45 and 46 are provided. In the figure, the dielectric layer constituting the third dielectric waveguide line 3 has a single layer structure, and the third lower main conductor layer 32 is flush with the first lower main conductor layer 12. The structure formed is shown in FIG.

  As shown in FIG. 1, the second lower main conductor layer 22 and the third upper main conductor layer 31 are composed of one conductor layer, and this conductor layer is lower than the first upper main conductor layer 11. However, it is disposed above the first lower main conductor layer 12. The second dielectric waveguide line 2 and the third dielectric waveguide line 3 are arranged so as to overlap each other, and this one conductor layer (second lower main conductor layer 22, third The upper main conductor layer 31) separates the second dielectric waveguide line 2 from the third dielectric waveguide line 3.

  The end of the first upper main conductor layer 11 and the end of the second upper main conductor layer 21 are directly electrically connected, and the end of the first lower main conductor layer 12 and the third lower side The end portion of the main conductor layer 32 is directly electrically connected.

  Further, the end face of the first dielectric waveguide line 1 faces the end face of the second dielectric waveguide line 2 and the end face of the third dielectric waveguide line 3.

  The branching waveguide line of the present invention has such a vertically branched structure from the first dielectric waveguide line 1 to the second dielectric waveguide line 2 and the third dielectric waveguide line 3. It is comprised so that it may have.

  Common to the first dielectric waveguide line 1, the second dielectric waveguide line 2, and the third dielectric waveguide line 3, a pair of main conductor layers arranged in parallel is disposed between the TE conductor layers. Since the wave (Transverse Electric Wave electric field component is transverse to the incident surface) or TM wave (Transverse Magnetic Wave magnetic field component is transverse to the incident surface) is propagated, the distance between adjacent via-hole conductors is the signal wavelength (inside wavelength) λ Is larger than one half (λ / 2) of the electromagnetic wave, the electromagnetic wave fed to the dielectric waveguide line leaks from between the via-hole conductor and the pseudo-waveguide made here. Does not propagate along. On the other hand, if the interval between adjacent via-hole conductors is less than λ / 2, the electromagnetic wave is propagated in the signal transmission direction of the dielectric waveguide line while being reflected.

  The side wall forming via hole conductor groups 41 and 42, the second side wall forming via hole conductor groups 43 and 44, and the third side wall forming via hole conductor groups 45 and 46 are the same as described above. These are arranged at intervals of less than λ / 2, and this interval is preferably a constant repetition interval in order to achieve good transmission characteristics, but may be any interval less than λ / 2, It can be set appropriately.

  Here, in FIG. 1, each of the second dielectric waveguide line 2 and the third dielectric waveguide line 3 has a structure having one dielectric layer, but the number of layers is not limited. As shown in FIG. 2, each of the dielectric layers has a two-layer structure, and the second upper main conductor layer 21 is not formed on the same plane as the first upper main conductor layer 11. 3 The lower main conductor layer 32 may not be formed on the same plane as the first lower main conductor layer 12.

  In the structure shown in FIG. 2, the end of the first upper main conductor layer 11 and the end of the second upper main conductor layer 21 are not directly connected, and the end of the first upper main conductor layer 11 and the second The boundary wall is formed by the boundary wall forming via hole conductor group 47 in which the boundary wall forming via hole conductors connecting the end portions of the two upper main conductor layers 21 are arranged at intervals of less than λ / 2. Similarly, the end of the first lower main conductor layer 12 and the end of the third lower main conductor layer 32 are not directly connected, and the end of the first lower main conductor layer 12 and the third lower main conductor layer 32 are not directly connected. A boundary wall is formed by the boundary wall forming via hole conductor group 47 in which the boundary wall forming via hole conductors connecting the end portions of the side main conductor layer 32 are arranged at intervals of less than λ / 2.

  Further, as viewed from above, the end of the first upper main conductor layer 11, the end of the first lower main conductor layer 12, and the end of the second lower main conductor layer 22 (third upper main conductor layer 31) Are separated, and the second upper main conductor layer 21 to the third lower main conductor layer 32 have a so-called blow-through structure. The distance between the ends of the first upper main conductor layer 11 and the first lower main conductor layer 12 and the end of the second lower main conductor layer 22 (third upper main conductor layer 31) is the signal wavelength λ. It is preferable that it is 1/4 or more.

  The layer thickness of the first dielectric waveguide line 1 and the layer thicknesses of the second dielectric waveguide line 2 and the third dielectric waveguide line 3 are the same as those shown in FIG. In the branch structure, transmission loss can be reduced as compared with the structure shown in FIG.

  According to the branching waveguide line shown in FIGS. 1 and 2, the high-frequency signal propagating through the first dielectric waveguide line 1 is transmitted between the second dielectric waveguide line 2 and the third dielectric waveguide. It is equally distributed to the wave guide line 3.

  On the other hand, the following structure is mentioned as a form which changed this distribution ratio.

  FIG. 3 shows the configuration of FIG. 1 in the second dielectric waveguide line 2 and in the vicinity of the connection end with the first dielectric waveguide line 1 (second dielectric). Two via hole conductors 5 are provided in the vicinity of the first dielectric waveguide line 1 side entrance of the waveguide line 2, and the line width of the portion where the via hole conductor 5 is provided is reduced to reduce the second width. This is a branched waveguide line in which the propagation of a high-frequency signal to the third dielectric waveguide line 3 is larger than that of the dielectric waveguide line 2. By providing the via-hole conductor 7, the impedance of the second dielectric waveguide line 2 is changed, and the matching is changed. As a result, the distribution ratio between the high-frequency signal transmitted to the second dielectric waveguide line 2 and the high-frequency signal transmitted to the third dielectric waveguide line 3 can be made different.

  4 shows the distance between the second sidewall forming via-hole conductor group 43 and the second sidewall forming via-hole conductor group 44 constituting the second dielectric waveguide line 2 in the configuration of FIG. (Line width) is made larger than the interval (line width) between the third sidewall forming via-hole conductor group 45 and the third sidewall forming via-hole conductor group 46 constituting the third dielectric waveguide line 3. Therefore, the high frequency signal is propagated to the second dielectric waveguide line 2 more than the third dielectric waveguide line 3. By widening the line width, the impedance of the second dielectric waveguide line 2 is changed, and the matching is changed. As a result, the distribution ratio between the high-frequency signal transmitted to the second dielectric waveguide line 2 and the high-frequency signal transmitted to the third dielectric waveguide line 3 can be made different.

  FIG. 5 shows a structure in which the second dielectric waveguide line 2 shown in FIG. 1 is changed from a one-layer structure to a two-layer structure. A branched waveguide branching from the tube line 1 to a second dielectric waveguide line 2 having a two-layered dielectric layer and a third dielectric waveguide line 3 having a one-layered dielectric layer It is a track. In the structure shown in FIG. 5, boundary wall forming via-hole conductors connecting the end portions of the first upper main conductor layer 11 and the end portions of the second upper main conductor layer 21 are arranged at intervals of less than λ / 2. A boundary wall is formed by the boundary wall forming via-hole conductor group 47. Further, when viewed from above, the end of the first upper main conductor layer 11 and the end of the second lower main conductor layer 22 (third upper main conductor layer 31) are separated from each other, and the second upper main conductor layer 21 is separated. From the first lower main conductor layer 12 to the first lower main conductor layer 12 has a so-called blowout structure. The end of the first upper main conductor layer 11 and the second lower main conductor layer 22 (third upper main conductor layer 31) The distance from the end is preferably at least a quarter of the signal wavelength λ.

  According to such a branched waveguide line of the present invention, a dielectric waveguide line for propagating a high-frequency signal in the vertical direction is further arranged on the branched structure (branched waveguide line) shown in FIG. In comparison, the area in the plane direction can be reduced. Further, branching or coupling can be reduced once compared to a structure in which a dielectric waveguide line for propagating a high-frequency signal is further arranged on the branch structure (branch waveguide line) shown in FIG. Therefore, loss can be reduced. Furthermore, according to the branching waveguide line of the present invention, compared to a structure in which a dielectric waveguide line for propagating a high-frequency signal is arranged further up and down in the branching structure (branching waveguide line) shown in FIG. Thus, the thickness can be reduced. That is, in the structure shown in FIG. 13, if the thickness of the dielectric waveguide line is t in order to branch up and down, the thickness t required for branching in the plane direction and the dielectric waveguide line disposed above and below the thickness t. A thickness corresponding to 3t including the thickness t is required, but according to the branching waveguide line of the present invention, the thickness corresponding to 2t including each thickness t of the branched dielectric waveguide line is required. Good.

  The branch waveguide line described so far is suitably used as a multilayer wiring board or antenna board that is formed inside the board body and distributes high-frequency signals toward the main surfaces of the board body facing each other. It is done.

  A multilayer wiring board includes a substrate body having the above-described branching waveguide line, and a semiconductor element provided on each of the opposing main surfaces of the substrate body. A high-frequency signal is propagated between the two dielectric waveguide lines 2 and between the semiconductor element provided on the other main surface and the third dielectric waveguide line 3. The high-frequency signal is propagated through.

  Specifically, for example, a structure as described in Japanese Patent Application Laid-Open No. 2004-104816, in which slots are formed in the second upper main conductor layer 21 and the third lower main conductor layer 32 and the slots are formed in the slots. A structure in which a microstrip line is formed at a position facing each other and a high-frequency signal is propagated to the semiconductor element via the microstrip line can be mentioned.

  Further, for example, a structure as described in Japanese Patent Application Laid-Open No. 2005-51331 is provided, and openings are formed in the second upper main conductor layer 21 and the third lower main conductor layer 32, and through each opening, micros are formed. A transmission via hole is extended from the end of the strip line into the dielectric waveguide, and the second upper main conductor layer 21 and the third lower main conductor are formed at the end of the transmission via hole in the dielectric waveguide. A structure in which a conductor pattern parallel to the layer 32 is formed, and a structure in which a high-frequency signal is propagated to the semiconductor element through the transmission via hole and the microstrip line may be used.

  Further, for example, a structure as described in Japanese Patent Application Laid-Open No. 10-215104, which is formed of via hole conductor groups of the second dielectric waveguide line 2 and the third dielectric waveguide line 3. One end of another transmission line is inserted into the second dielectric waveguide line 2 and the third dielectric waveguide line 3 via the side surface or the end surface, and the semiconductor is connected via the other transmission line. A structure in which a high-frequency signal is propagated to the element may be used.

  Still further, the second upper main conductor layer 21 and the third lower main conductor layer 32 are formed on the surface of the insulating base, and the second dielectric waveguide line 2 and the third dielectric are provided. A structure in which a microstrip line is directly electrically connected to the end of the waveguide line 3 and a high-frequency signal is propagated to the semiconductor element via the microstrip line may be employed.

  On the other hand, as shown in FIG. 6, the antenna substrate includes a substrate body 61 having the above-described branching waveguide line, and a plurality of antenna elements 62 respectively provided on the opposing main surfaces of the substrate body 61. A high frequency signal is propagated between the plurality of antenna elements 62 provided on one main surface and the second dielectric waveguide line 2, and a plurality provided on the other main surface. A high frequency signal is propagated between the antenna element 62 and the third dielectric waveguide line 3.

  Specifically, for example, as shown in FIG. 6, a fourth dielectric waveguide line 63 (feeding dielectric waveguide line) is disposed on the second dielectric waveguide line 2, The second dielectric waveguide line 2 and the fourth dielectric waveguide line 63 are coupled by the slot, and the slot provided on the upper surface of the fourth dielectric waveguide line 63 as the antenna element 62. A dielectric resonator antenna having a dielectric resonator is provided on the antenna or slot, and similarly, a fifth dielectric waveguide line 64 (for feeding) is provided under the third dielectric waveguide line 3. A dielectric waveguide line) is arranged, and the third dielectric waveguide line 3 and the fifth dielectric waveguide line 64 are coupled by a slot, and a fifth dielectric conductor as the antenna element 62 is coupled. A slot antenna provided on the lower surface of the wave guide line 64 or a dielectric resonator on the slot The dielectric resonator antenna is provided structure, a high-frequency signal is propagated include those turned (powered by) such.

  Further, without providing another dielectric waveguide line as described above, the antenna element 62 is provided on the upper side (second upper main conductor layer 21) of the second dielectric waveguide line 2 and the third The antenna element 62 may be provided on the lower side (third lower main conductor layer 32) of the dielectric waveguide line 3 and directly coupled to the antenna element 62.

  However, when a large number of antenna elements 62 must be arranged on the upper and lower surfaces of the substrate body, the structure shown in FIG. 6 through the feeding dielectric waveguide line is preferable in terms of phase matching. Thus, a small antenna substrate with good radiation characteristics can be obtained.

  Then, as shown in FIG. 7, by installing this antenna board 6 on the front side of the car, it functions as a sensor antenna and cannot detect obstacles in the side direction or approaching objects that cannot be detected by the collision prevention radar. Safety can be increased because it can be detected. Further, although not shown, the same effect can be obtained by installing on the rear side.

  In addition, the board | substrate which has the branched waveguide track | line of this invention and the board | substrate which has an antenna element may be formed separately, and the structure formed by joining may be sufficient.

  With respect to the branched waveguide line of the present invention, transmission characteristics were evaluated by electromagnetic field analysis using a finite element method.

(Example 1)
First, transmission characteristics (frequency characteristics) were evaluated for the structure shown in FIG. An input / output port to the first dielectric waveguide line 1 having a dielectric layer having a two-layer structure is referred to as port 1, and the dielectric layer is connected to the second dielectric waveguide line 2 having a one-layer structure. The input / output port is port 2, and the input / output port to the third dielectric waveguide line 3 having a single dielectric layer structure is port 3.

  Specifically, the dielectric constant of the dielectric layer constituting the first dielectric waveguide line 1 is 9.75, and the total thickness of the dielectric layer is 0.30 mm (dielectric having a thickness of 0.15 mm per layer). A structure in which two body layers are stacked), the distance between the via-hole conductor group 41 for side wall formation and the via-hole conductor group 42 for side wall formation that is the line width of the first dielectric waveguide line 1 (between the centers of the via-hole conductors). The distance was 1.1 mm, and the thicknesses of the first upper main conductor layer 11 and the first lower main conductor layer 12 constituting the upper and lower walls of the first dielectric waveguide line 1 were 0.01 mm. .

  The relative dielectric constant of the dielectric layer constituting the second dielectric waveguide line 2 is 9.75, the thickness of the dielectric layer is 0.15 mm, and the line width of the second dielectric waveguide line 2 The distance between the via hole conductor group 43 and the via hole conductor group 44 between the side wall forming via hole conductor group 43 and the side wall forming via hole conductor group 44 (referred to as the distance between the centers of the via hole conductors) is 1.1 mm, and the second upper main conductor layer The thickness of 21 was 0.01 mm, and the thickness of the second lower main conductor layer 22 was 0.005 mm.

  Further, the dielectric constant of the dielectric layer constituting the third dielectric waveguide line 3 is 9.75, the thickness of the dielectric layer is 0.15 mm, and the line width of the third dielectric waveguide line 3 The distance between the side wall forming via hole conductor group 45 and the side wall forming via hole conductor group 46 (referred to as the distance between the centers of the via hole conductors) is 1.1 mm, the thickness of the third upper main conductor layer 31 is 0.005 mm, 3 The thickness of the lower main conductor layer 32 was 0.01 mm.

  The diameter of the via hole conductor for forming the sidewall is 0.12 mm, the via hole pitch in the signal transmission direction (the distance between the centers of the via hole conductors) is 0.3 mm, and the distance in the signal transmission direction of the first laminated waveguide 1 Was 1.5 mm, and the distance in the transmission direction of the second dielectric waveguide line 2 and the third dielectric waveguide line 3 was 1.3 mm.

  The transmission characteristics (frequency characteristics) in this structure are shown in FIG. In FIG. 8, the horizontal axis indicates the frequency (unit: GHz), the vertical axis indicates the S parameter (unit: dB), and each characteristic curve includes S11 (reflection amount), S21 (transmission amount), and S31 among the S parameters. (Transmission amount). Note that loss due to dielectrics and loss due to conductors are not considered.

  According to FIG. 8, S11 (reflection amount) at −76.5 GHz is −35.5 dB, S21 (transmission amount) is −3.02 dB, S31 (transmission amount) is −3.05 dB, and the distribution ratio is port 2: Port 3 = 1: 1 (equal distribution). Then, it can be seen that the distribution can be performed with a good characteristic such that S11 (reflection amount) is -30 dB or less in a wide band extending from 71 to 82 GHz. In addition, since the frequency of the millimeter wave radar is assigned to 76 to 77 GHz, the center is evaluated at 76.5 GHz.

(Example 2)
Next, transmission characteristics (frequency characteristics) were evaluated for the structure shown in FIG. The input / output port to the first dielectric waveguide line 1 is designated as port 1, the input / output port to the second dielectric waveguide line 2 is designated as port 2, and a third dielectric waveguide is provided. The input / output port to the line 3 is designated as port 3.

  Specifically, in the structure shown in FIG. 1, two via-hole conductors 7 are provided in the line of the second dielectric waveguide line 2 so as to narrow the line width. The diameter of the via-hole conductor 7 was 0.12 mm, and the distance between them (the distance between the centers of the via-hole conductors) was 0.9 mm. Other numerical values are the same as those in the first embodiment.

  The transmission characteristics (frequency characteristics) in this structure are shown in FIG. In FIG. 9, the horizontal axis indicates the frequency (unit: GHz), the vertical axis indicates the S parameter (unit: dB), and each characteristic curve includes S11 (reflection amount), S21 (transmission amount), and S31 among the S parameters. (Transmission amount). Note that loss due to dielectrics and loss due to conductors are not considered.

  According to FIG. 9, S11 at 76.5 GHz was −20.0 dB, S21 was −2.28 dB, S31 was −4.00 dB, and the distribution ratio was port 2: port 3 = 1: 0.67. And it turns out that S11 (reflection amount) is -15 dB or less in a wide band ranging from 71 to 82 GHz, and the distribution ratio can be changed.

(Example 3)
Next, transmission characteristics (frequency characteristics) were evaluated for the structure shown in FIG. The input / output port to the first dielectric waveguide line 1 is designated as port 1, the input / output port to the second dielectric waveguide line 2 is designated as port 2, and a third dielectric waveguide is provided. The input / output port to the line 3 is designated as port 3.

  Specifically, in the structure shown in FIG. 1, the line width of the second dielectric waveguide line 2 is widened. The line width of the second dielectric waveguide line 2 (the distance between the centers of the via-hole conductors) was 1.4 mm.

  The transmission characteristics (frequency characteristics) in this structure are shown in FIG. In FIG. 10, the horizontal axis represents frequency (unit: GHz), the vertical axis represents S parameter (unit: dB), and each characteristic curve includes S11 (reflection amount), S21 (transmission amount), and S31 among S parameters. (Transmission amount). Note that loss due to dielectrics and loss due to conductors are not considered.

  According to FIG. 10, S11 at 76.5 GHz was −20.0 dB, S21 was −2.28 dB, S31 was −4.00 dB, and the distribution ratio was port 2: port 3 = 1: 0.67. And it turns out that S11 (reflection amount) is -15 dB or less in a wide band ranging from 71 to 82 GHz, and the distribution ratio can be changed.

  According to FIG. 10, S11 at 76.5 GHz was −20.5 dB, S21 was −3.84 dB, S31 was −2.38 dB, and the distribution ratio was port 2: port 3 = 0.71: 1. And it turns out that S11 (reflection amount) is -15 dB or less in a wide band ranging from 72 to 82 GHz, and the distribution ratio can be changed.

Example 4
Next, transmission characteristics (frequency characteristics) were evaluated for the structure shown in FIG. The input / output port to the first dielectric waveguide line 1 is designated as port 1, the input / output port to the second dielectric waveguide line 2 is designated as port 2, and a third dielectric waveguide is provided. The input / output port to the line 3 is designated as port 3.

  Specifically, the second dielectric waveguide line 2 shown in FIG. 1 is changed from a one-layer structure to a two-layer structure. The total thickness of the dielectric layers of the second dielectric waveguide line 2 was 0.30 mm (a structure in which two dielectric layers each having a thickness of 0.15 mm were stacked). Other numerical values are the same as those in the first embodiment.

  The transmission characteristics (frequency characteristics) in this structure are shown in FIG. In FIG. 11, the horizontal axis indicates the frequency (unit: GHz), the vertical axis indicates the S parameter (unit: dB), and each characteristic curve includes S11 (reflection amount), S21 (transmission amount), and S31 among the S parameters. (Transmission amount). Note that loss due to dielectrics and loss due to conductors are not considered.

  According to FIG. 11, S11 at 76.5 GHz was -15.0 dB, S21 was -3.71 dB, S31 was -2.75 dB, and the distribution ratio was Port2: Port3 = 0.8: 1. It can be seen that the distribution ratio can be changed with a good characteristic of S11 (reflection amount) of -15 dB or less in a wide band ranging from 72 to 82 GHz.

  From the above results, it can be seen that a branched waveguide line with good characteristics can be obtained even if the distribution ratio is changed by various methods.

It is a schematic perspective view which shows one Embodiment of the branched waveguide track | line of this invention. It is a schematic perspective view which shows other embodiment of the branched waveguide track | line of this invention. It is a schematic perspective view which shows other embodiment of the branched waveguide track | line of this invention. It is a schematic perspective view which shows other embodiment of the branched waveguide track | line of this invention. It is a schematic perspective view which shows other embodiment of the branched waveguide track | line of this invention. It is a schematic explanatory drawing which shows one Embodiment of the antenna board | substrate of this invention. It is explanatory drawing of the use of the antenna board of this invention. It is a graph which shows the evaluation result of the transmission characteristic (frequency characteristic) of the branched waveguide track | line shown in FIG. It is a graph which shows the evaluation result of the transmission characteristic (frequency characteristic) of the branch waveguide line shown in FIG. It is a graph which shows the evaluation result of the transmission characteristic (frequency characteristic) of the branch waveguide line shown in FIG. It is a graph which shows the evaluation result of the transmission characteristic (frequency characteristic) of the branched waveguide path shown in FIG. It is a schematic perspective view which shows one Embodiment of the conventional branch waveguide line. It is explanatory drawing which shows other embodiment of the conventional branching waveguide line.

Explanation of symbols

1: First dielectric waveguide line 11: First upper main conductor layer 12: First lower main conductor layer 13: Sub conductor layer 2: Second dielectric waveguide line 21: Second upper lead Body layer 22: second lower main conductor layer 3: third dielectric waveguide line 31: third upper main conductor layer 32: third lower main conductor layers 41, 42, 43, 44, 45, 46 : Side wall forming via hole conductor group 47: Boundary wall forming via hole conductor group 6: Antenna substrate 61: Substrate body 62: Antenna element

Claims (3)

A branched waveguide line formed on an insulating substrate formed by laminating dielectric layers,
A pair of first main conductor layers including a first upper main conductor layer and a first lower main conductor layer that are vertically opposed to each other with a dielectric layer interposed therebetween are provided, and the pair of first main conductor layers is electrically connected A first dielectric waveguide comprising two rows of first side wall forming via hole conductors in which connected first side wall forming via hole conductors are arranged in the signal transmission direction at intervals of less than half of the signal wavelength. Tracks,
A pair of second main conductor layers each including a second upper main conductor layer and a second lower main conductor layer that are vertically opposed to each other with a dielectric layer interposed therebetween are provided, and the pair of second main conductor layers is electrically connected A second dielectric waveguide comprising two rows of via-hole conductor groups for forming second sidewalls in which connected via-hole conductors for forming second sidewalls are arranged in the signal transmission direction at intervals of less than half the signal wavelength. Tracks,
A pair of third main conductor layers each including a third upper main conductor layer and a third lower main conductor layer that are vertically opposed to each other with the dielectric layer interposed therebetween are provided, and the pair of third main conductor layers are electrically connected to each other. A third dielectric waveguide comprising two rows of third side wall forming via-hole conductor groups in which connected third side wall forming via-hole conductors are arranged in the signal transmission direction at an interval of less than half the signal wavelength. A track,
The second lower main conductor layer and the third upper main conductor layer are composed of a single conductor layer, and the conductor layer is lower than the first upper main conductor layer and is led by the first lower main conductor layer. The end portion of the first upper main conductor layer and the end portion of the second upper main conductor layer are disposed directly above the body layer, or the boundary wall forming via-hole conductor is signaled in a direction perpendicular to the signal transmission direction. An end portion of the first lower main conductor layer and the third lower main conductor are electrically connected via a via-hole conductor group for forming a boundary wall arranged at an interval of less than half the wavelength. Electrically via a boundary wall forming via hole conductor group in which the end of the layer is arranged directly or by arranging boundary wall forming via hole conductors in a direction perpendicular to the signal transmission direction at an interval of less than half the signal wavelength. And the first dielectric waveguide line is disposed so that end faces thereof overlap each other. Opposite to the end face of the dielectric waveguide line and the end face of the third dielectric waveguide line, from the first dielectric waveguide line to the second dielectric waveguide line, and A branching waveguide line characterized in that an upper and lower branching structure to the third dielectric waveguide line is formed. A substrate main body having the branching waveguide line according to claim 1 and a semiconductor element provided on each of the opposing main surfaces of the substrate main body, the semiconductor element provided on one main surface, and the first A high-frequency signal is propagated between the two dielectric waveguide lines, and between the semiconductor element provided on the other main surface and the third dielectric waveguide line. A multilayer wiring board characterized in that a high-frequency signal is propagated. A substrate main body having the branching waveguide line according to claim 1 and a plurality of antenna elements respectively provided on opposing main surfaces of the substrate main body, and a plurality of antennas provided on one main surface A high-frequency signal is propagated between the element and the second dielectric waveguide line, and a plurality of antenna elements provided on the other main surface and the third dielectric waveguide An antenna substrate, wherein high-frequency signals are propagated between lines.

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