JP4203404B2 - Branch structure of waveguide structure and antenna substrate - Google Patents

Description

  The present invention relates to a branched structure of a waveguide structure for transmitting a high frequency signal such as a microwave band or a millimeter wave band.

  In recent years, researches on mobile communication and inter-vehicle radar using high-frequency signals such as microwave band and millimeter wave band have been actively promoted. In these high-frequency circuits, transmission lines for transmitting high-frequency signals are required to be small and have low transmission loss. In particular, since it is advantageous in terms of miniaturization if it can be formed on or in a substrate constituting a high-frequency circuit, conventionally, such transmission lines include strip lines, microstrip lines, coplanar lines, and dielectric waveguides. Tracks and the like have been used.

  Of these, the strip line, microstrip line, and coplanar line are composed of a dielectric substrate, a line conductor layer, and a ground (ground) conductor layer. The space around the line conductor layer and the ground conductor layer and in the dielectric substrate The electromagnetic wave of the high-frequency signal propagates through. These lines have no problem for signal transmission up to, for example, 30 GHz band, but there is a problem that transmission loss tends to occur at 30 GHz or more.

  On the other hand, a waveguide type transmission line formed by a planar conductor and a via-hole conductor as described in Patent Document 1 has a small transmission loss even in a millimeter wave band of 30 GHz or more, and in a multilayer substrate. This is advantageous in that it can be formed freely.

In addition, in a structure using a waveguide line, Patent Documents 2 and 3 describe a structure in which a waveguide line is branched into two waveguide lines in the same plane. A structure that can be branched in the direction has been proposed.
JP-A-6-53711 US Pat. No. 5,532,661 JP-A-11-112210 JP-A-12-77912

  Generally, when configuring a high-frequency circuit using a transmission line, especially when forming a feeder line of an array antenna, etc., the transmission lines are connected to each other in the wiring circuit of the transmission line, or branches are provided to distribute the power. It is necessary to control the ratio.

  However, the strip conductor, microstrip line, and coplanar line do not completely cover the line conductor layer with the ground conductor layer, so if a branch is provided in the middle of the transmission line, radiation of electromagnetic waves occurs from that branch, resulting in a large transmission loss. On the other hand, in the case of a dielectric waveguide line, it is advantageous in that transmission loss can be reduced, but a structure for distributing power using this dielectric waveguide line is as follows. So far it has not been proposed.

Accordingly, the present invention has been devised in view of the above circumstances, and its object is an object to provide a branched structure of the waveguide structure having the transmission characteristics and power distribution functions with excellent compact Is.

Another object of the present invention is to provide a branched structure of a waveguide structure that can be easily manufactured by a conventional multilayering technique.

Furthermore, still another object of the present invention, it is an object to provide an antenna substrate provided with the branched structure of the electrically Namikan structure.

Branched structure waveguide structure of the present invention, the second waveguide structures arranged on top as the transmission direction of the high-frequency signal are perpendicular to the end portion of the first waveguide structure, wherein first waveguide structure and said second waveguide structure of the rewritable form respective coupling windows in the waveguide wall portions overlaid, the second waveguide structure, the binding the thin portion that is narrower than the gap spacing between the walls forming the windows and this is opposed to the wall surface at the other sites, will be provided so that at least a part thereof overlaps with the coupling window, the transmission of the thin portion The center in the direction is shifted from the center of the coupling window.

The branch structure of another electric Namikan structure of the present invention, overlapping second waveguide structure as the transmission direction of the high-frequency signal are parallel to the end portion of the first waveguide structure Te disposed, said first waveguide structure and said second waveguide structure of the rewritable form respective coupling windows in the waveguide wall portions overlaid, said second waveguide structure body, the thin portion that is narrower than the interval at the other portions the distance between the coupling window and the formed wall surface which is opposed to the wall surface, it is provided so that at least a part thereof overlaps with the coupling window, the it is characterized in that the center of the transmission direction of the thin-walled portion is arranged offset from a center of the coupling window.

According to the branch structure of the waveguide structure of the present invention, power can be distributed at a desired power ratio by changing the impedance of the branch by adjusting the center position in the transmission direction of the thin portion in any of the above-described configurations. That is, by disposing the center in the transmission direction of the thin portion from the center of the coupling window, it becomes possible to adjust the impedance of each branch structure, and the thickness of the waveguide in the branching process due to the presence of the thin portion. Since the change is small and the signal transmission proceeds smoothly, the signal can be transmitted efficiently. In impedance matching, it can also be adjusted by changing the width of the overlapping portion of the two waveguide structures or by a coupling window. However, by using the thin portion, it becomes possible to perform matching more flexibly, and the thin portion By making the size smaller than the overlapping portion of the waveguide structure , the power distribution ratio can be controlled in a wider range.

The waveguide structure includes a pair of main conductor layers sandwiching the dielectric substrate, a repetitive interval less than one half of the signal wavelength in the high-frequency signal transmission direction, and a direction orthogonal to the transmission direction. and two rows side-wall through conductor groups which are formed to electrically connect the main conductor layers with a predetermined width, said the main conductor layer formed parallel to the main conductor layers, the side-wall through conductor group And a sub-conductor layer electrically connected to each other can be easily formed in a small size in any multilayer substrate using a conventional multilayer technology.

  Further, since the dielectric substrate is made of low-temperature fired ceramics, it can be fired simultaneously using a low-resistance conductor such as silver or copper as a conductor material, which is advantageous in terms of improving high-frequency characteristics and manufacturing. In addition, the dielectric constant is higher than that of the organic substrate, the size can be reduced, the shape is not bent unlike the fluororesin, and the shape is easily maintained.

  In addition, by providing the above branch structure, it is possible to easily and easily wire in the Z direction and to obtain a highly efficient branch structure. A possible and highly efficient antenna substrate can be easily obtained.

Hereinafter, the branch structure of the waveguide structure according to the present invention will be described with reference to the drawings. FIG. 1 shows a branched structure of a waveguide structure according to the present invention in a case where waveguides are arranged so as to be orthogonal to each other so that transmission directions of high-frequency signals are orthogonal. 2 is a schematic cross-sectional view taken along line AA in the branch structure of the waveguide structure shown in FIG. 1, and FIG. 3 is a schematic cross-sectional view taken along line BB in the branch structure of the waveguide structure shown in FIG. is there.

  According to FIGS. 1 and 2, the waveguide 1 is disposed at the end portion of the waveguide 2 so that the side walls of the waveguide are overlapped so as to be orthogonal to each other. The pipe walls are respectively formed with coupling windows 3 and are arranged so that the coupling windows coincide with each other. The center of the coupling window 3 is provided so as to coincide with the center of the overlapping portion of the waveguides 1 and 2. Further, the shape of the coupling window 3 is a rectangle having a side parallel to the transmission direction of the waveguide 1 as a long side. The size of the coupling window 3 overlaps the waveguides 1 and 2 unless there is a problem such as strength. It is desirable to form the same size as the portion.

  1 and 2, the signal from the waveguide 2 distributes power in the direction 1a and the direction 1b in the waveguide 1, or the signals from the direction 1a and the direction 1b in the waveguide 1 are distributed. This is a branching structure that combines power and transmits signals to the waveguide 2.

  In the vicinity of the portion of the waveguide 1 that overlaps the waveguide 2, as shown in FIG. 2, an interval a ′ between the wall surface on which the coupling window 3 is formed and the opposite waveguide wall surface facing this is set to other A thin portion 5 having a length L in the transmission direction that is narrower than the interval a at the part is formed.

  And the center X with respect to the transmission direction of this thin part 5 and the center Y of the coupling window 3 are shifted from each other by m. The lengths b1 and b2 from the wall surface 2a of the waveguide 2 in the thin portion 5 to both ends of the thin portion 5 change depending on the deviation width m. According to the present invention, the deviation width m and the waveguide are changed. By changing the lengths b1 and b2 of the wall surface 2a of the tube 2, the impedance in the 1a direction and the 1b direction when viewed from the coupling window 3 can be changed. This makes it possible to control the power ratio of signals transmitted in the direction 1b.

In FIGS. 1 and 2, the waveguide width L3 in the portion of the waveguide 2 that overlaps the waveguide 1 is the same as the width L2 of the waveguide 2. However, as shown in FIG. The width L3 of the portion of the tube 2 that overlaps the waveguide 1 can be formed to be different from the waveguide width L2 of other portions of the waveguide 2. As described above, by controlling the width L2 and the width L3, resonance at the coupling portion is generated, and signal transmission can be effectively performed. In the example of FIG. 4, a wide portion 2a is formed in which the width L3 of the coupling portion of the waveguide 2 is wider than the width L2 of other portions.

  For the same reason, it is possible to change the width at the entrance of the portion where the waveguide 1 and the waveguide 2 overlap. For example, as shown in FIG. 5, it is also possible to control the impedance by forming a narrow portion 2b having a small width at the entrance of the overlapping portion.

  Further, the length L of the thin wall portion 5 shown in FIG. 2 is larger than the width L3 of the overlapping portion of the waveguides 1 and 2, but this is a branched structure capable of distributing power even if it is small. However, it is desirable that L> L3. This is because, when L> L3, the power distribution ratio is gradual with respect to the shift amount of the thin portion 5, so that the tolerance for manufacturing deviation is large, whereas when L <L3, the power distribution ratio Since a change with respect to the shift amount becomes large, a change in characteristics due to a shift or the like tends to be large, and the characteristics may become unstable.

Next, FIGS. 6 and 7 are views showing a second example of the branching structure of the waveguide structure according to the present invention, and the two waveguides are arranged so that the transmission directions of the high-frequency signals are parallel to each other. FIG. 6 is a schematic perspective view thereof, and FIG. 7 is a schematic cross-sectional view taken along the line CC of FIG.

  According to FIGS. 6 and 7, the waveguide 12 is disposed above the terminal end of the waveguide 13 so that the transmission directions of the waveguide 12 and the waveguide 13 are parallel to each other. A coupling window 14 is formed on the waveguide wall of each of the waveguides 12 and 13 at a length position where the end distance S is λ / 8 or more, and the coupling windows 14 are arranged to coincide with each other. . As for the shape of the coupling window 14, the width L4 in the signal transmission direction is desirably shorter than the width L5 in the direction orthogonal to the signal transmission direction.

  6 and 7, the signal from the waveguide 13 distributes the power in the direction 12a and the direction 12b in the waveguide 12, or the signal from the direction 12a and the direction 12b in the waveguide 12 is the power. It is a branching structure that combines and transmits a signal to the waveguide 13.

  On the waveguide 12 side in the overlapping portion of the waveguide 12 and the waveguide 13, the distance b ′ between the wall surface on which the coupling window 14 is formed and the wall surface on the opposite side of the waveguide 12 facing the other is b. A thin portion 15 is formed that is narrower than the interval b at the site.

The center X of the thin portion 15 with respect to the transmission direction and the center Y of the coupling window 14 are formed to be shifted by n . The power ratio distributed in the 12a direction and the 12b direction of the waveguide 12 can be controlled by the shift width n . That is, the principle of power distribution is to distribute power by making the impedance viewed from the coupling window different as in the structure shown in FIGS. 1 and 2, and the thin portion 15 is shifted with respect to the coupling window 14. As a result, the impedance in the direction 12a and the direction 12b when viewed from the waveguide 13 is changed, whereby the power distribution ratio in the direction 12a and the direction 12b can be controlled.

As a waveguide in the branch structure of the waveguide structure of the present invention, a pair of main conductor layers sandwiching the dielectric substrate, and a repetition interval of less than half of the signal wavelength in the transmission direction of the high-frequency signal, And two rows of through conductor groups for side walls formed by electrically connecting the main conductor layers with a predetermined width in a direction orthogonal to the transmission direction, and formed between the main conductor layers in parallel with the main conductor layer. A branching structure of the waveguide structure according to the present invention can be obtained by using a waveguide structure configured to include the sub conductor layer electrically connected to the side wall through conductor group. In this case, the circuit can be reduced in size as compared with the conventional waveguide, and since complicated metal processing is unnecessary, it is easy to manufacture and suitable for mass production. Also the branching structure of the waveguide structure of the present invention, while the signal propagation in the Z direction, and for possible power distribution can be downsized with respect to the circuit configured in a conventional dielectric waveguide.

The case where the branch structure of the waveguide structure of the present invention is formed using a dielectric waveguide will be described below.

FIG. 8 is a schematic perspective view for explaining a configuration example of a dielectric waveguide line used in the branching structure of the waveguide structure according to the present invention. In FIG. 8, 16 is a dielectric layer, 17 and 18 are a pair of conductor layers sandwiching the dielectric layer 16, 19 is a repetitive interval c less than half the signal wavelength in the signal transmission direction, and the signal transmission direction. Are two rows of through conductor groups formed so as to electrically connect the pair of conductor layers 17 and 18 with a predetermined width d in a direction perpendicular to the line. Reference numeral 20 denotes an auxiliary conductor layer formed in parallel with the conductor layers 17 and 18 for electrically connecting the through conductors forming each row of the through conductor group 19, and is provided as necessary. Reference numeral 21 denotes a dielectric waveguide line formed by the pair of conductor layers 17 and 18, the through conductor group 19, and the auxiliary conductor layer 20. As described above, when the auxiliary conductor layer 20 is further formed in the region surrounded by the pair of conductor layers 17 and 18 and the through conductor group 19, when viewed from the inside of the dielectric waveguide line 21, the side wall is The through conductor group 19 and the auxiliary conductor layer 20 form a fine lattice, and shield electromagnetic waves in various directions.

  As shown in FIG. 8, a pair of conductor layers 17 and 18 are formed at a position sandwiching the dielectric layer 16 having a predetermined thickness e, and the conductor layers 17 and 18 are at least transmission line formation positions of the dielectric layer 16. It is formed on the upper and lower surfaces sandwiching. A large number of through conductors such as through-hole conductors and via-hole conductors that electrically connect the conductor layers 17 and 18 are provided between the conductor layers 17 and 18, and two rows of through-conductor groups 19 are formed by these many through conductors. Forming.

  As shown in the figure, the two rows of through conductor groups 19 have a predetermined repetition interval c that is less than a half of the signal wavelength in the transmission direction of the high-frequency signal, that is, the line formation direction, and a predetermined direction in the direction orthogonal to the transmission direction. It is formed with a constant interval (width) d. Thereby, an electrical side wall in the dielectric waveguide line 21 is formed.

  Here, there is no particular limitation on the thickness e of the dielectric layer 1, that is, the distance between the pair of conductor layers 17 and 18, but about half or twice the distance d when used in a single mode. In the example of FIG. 8, the portions corresponding to the H surface of the dielectric waveguide line 21 are formed by the conductor layers 17 and 18, and the portions corresponding to the E surface are formed by the through conductor group 19 and the auxiliary conductor layer 20, respectively. . Further, if the thickness e is about twice as large as the distance d, the portions corresponding to the E surface of the dielectric waveguide 21 are the conductor layers 17 and 18, and the portions corresponding to the H surface are the through conductor group 19 and the auxiliary conductor layer. 20 respectively.

In addition, an electrical wall can be formed by the through conductor group 19 by setting the interval c to an interval less than one half of the signal wavelength. The interval c is preferably less than a quarter of the signal wavelength in order to prevent leakage of electromagnetic waves. Since TEM waves can propagate between the pair of conductor layers 17 and 18 arranged in parallel, the distance c between the through conductors in each row of the through conductor group 19 is less than half the signal wavelength λ (λ / 2). Is larger, the electromagnetic wave leaks from between the through conductor groups 19 even if an electromagnetic wave is fed to the dielectric waveguide 21 and does not propagate along the pseudo waveguide formed here. However, if the distance c between the through conductor groups 19 is smaller than λ / 2, an electric side wall is formed, and the electromagnetic wave cannot propagate in the direction perpendicular to the dielectric waveguide line 21. The light is propagated in the signal transmission direction of the dielectric waveguide 21 while being reflected.

  As a result, according to the configuration shown in FIG. 8, the region having a cross-sectional area of d × e surrounded by the pair of conductor layers 17 and 18 and the two rows of through conductor groups 19 and the auxiliary conductor layer 20 is a dielectric. It becomes the waveguide line 21.

  In the embodiment shown in FIG. 8, the through conductor groups 19 are formed in one row on one side of the waveguide. However, the through conductor groups 19 are arranged in two or more rows on one side, and are simulated by the through conductor groups 19. By forming the conductor wall in a double or triple manner, leakage of electromagnetic waves from the conductor wall can be more effectively prevented.

According to the dielectric waveguide line 21 as described above, the transmission line is a dielectric waveguide. Therefore, when the dielectric constant of the dielectric substrate 16 is εr, the waveguide size is that of a normal waveguide. The size is 1 / (εr) ^1/2 . Therefore, the waveguide size can be reduced as the relative dielectric constant εr of the material constituting the dielectric substrate 16 is increased, and the high-frequency circuit can be reduced in size.

  Note that the through conductors constituting the through conductor group 19 are arranged at a repetition interval c of less than half of the signal wavelength as described above, and this interval c is constant in order to realize good transmission characteristics. However, as long as the interval is less than half the signal wavelength, it may be changed as appropriate or some values may be combined.

  The dielectric substrate 16 constituting the dielectric waveguide line 21 is not particularly limited as long as it has a characteristic that functions as a dielectric and does not hinder the transmission of a high-frequency signal. The dielectric substrate 16 is preferably made of ceramics from the viewpoint of accuracy in forming the line and ease of manufacture.

Such as the ceramic ever ceramics with different dielectric constant are known, it to transmit a high-frequency signal at the engagement Ru guide Namikan structure in the present invention is a paraelectric Is desirable. This is because ferroelectric ceramics generally have a large dielectric loss and a large transmission loss in the high frequency region. Accordingly, the relative dielectric constant εr of the dielectric substrate 1 is suitably about 4 to 100.

  In general, the line width of a wiring layer formed in a multilayer wiring board, a semiconductor element storage package, or an inter-vehicle radar is at most about 1 mm. Is used so as to have an electromagnetic field distribution that wraps parallel to the upper surface, the minimum frequency that can be used is calculated as 15 GHz, and can also be used in the microwave band region.

  Examples of the dielectric substrate 16 include low-temperature fired ceramics such as alumina ceramics, aluminum nitride ceramics, and glass ceramics. The dielectric substrate 16 is formed into a slurry shape by adding and mixing an appropriate organic solvent and solvent to the ceramic raw material powder, and this is formed into a sheet shape by employing a conventionally known doctor blade method, calendar roll method or the like. To obtain a plurality of ceramic green sheets, and after that, each of these ceramic green sheets is appropriately punched and laminated, and in the case of alumina ceramics, 1500 to 1700 ° C., in the case of low-temperature fired ceramics Is manufactured by firing at a temperature of 850 to 1000 ° C., and in the case of aluminum nitride ceramics at a temperature of 1600 to 1900 ° C.

Among these, it is desirable that the dielectric substrate 16 is manufactured using low-temperature fired ceramics. Low-temperature fired ceramics have the advantage that copper or silver with high conductivity can be used as a conductor, so that the conductor loss can be reduced, and the advantage is that the dielectric constant is high and the structure can be made compact compared to general organic substrates. There is also. Furthermore, from the viewpoint of reliability, unlike the organic substrate, the steam resistance is high, so that high reliability can be obtained. Examples of the low-temperature fired ceramics are obtained by mixing and firing glass components such as borosilicate glass and alkaline earth-containing glass and ceramic powders such as Al ₂ O ₃ , SiO ₂ , ZnO, and MgO.

  Further, the pair of conductor layers 17 and 18 are, for example, when the dielectric substrate 16 is made of alumina ceramics, oxides such as alumina, silica, and magnesia, organic solvents and solvents suitable for metal powders such as tungsten and molybdenum. Is added on and mixed to form a paste, and is printed on a ceramic green sheet so as to completely cover at least the transmission line by a thick film printing method, and then fired at a high temperature of about 1600 ° C. It is formed to be 15 μm or more.

  As the metal powder, copper, silver and gold are suitable for low-temperature fired ceramics, and tungsten and molybdenum are suitable for aluminum nitride ceramics. The thickness of the conductor layers 17 and 18 is generally about 5 to 50 μm.

  The through conductors constituting the through conductor group 19 may be formed of, for example, a via hole conductor or a through hole conductor. The cross-sectional shape may be a polygon that is easy to manufacture, or a polygon such as a rectangle or a rhombus. These through conductors are formed, for example, by embedding a metal paste similar to the conductor layers 17 and 18 in a through hole produced by punching a ceramic green sheet, and then firing simultaneously with the dielectric substrate 16. The through conductor has a diameter of 50 to 300 μm.

Next, FIG. 9 shows an example of an embodiment of the branch structure of the waveguide structure of the present invention of FIG. 1 using such a dielectric waveguide line.

Here, the waveguide 1 ′ and the waveguide 2 ′ are composed of the through conductor group 19, the sub conductor layer 20, and the conductor layers 17, 18, and have a coupling window 3 ′ at the joint portion. A thin portion 5 ′ is formed in the vicinity of the portion. The basic waveguide arrangement and thin wall configuration in FIG. 9 are the same as in FIG. 1, and the center of the thin wall portion 5 ′ is different from the center of the coupling window 3 ′, thereby realizing power distribution at a constant ratio. is doing. Here, the upper main conductor layer 4 ′ of the waveguide 1 ′ is notched in the thin portion 5 ′, and 4 ′ forms the upper main conductor layer. However, the thin portion 5 'upper part of the conductor layer 4' for being sealed et al in ', it is not necessary to cut away the portion of the conductive layer 4' is necessarily thin portion 5.

The branch structure of the waveguide structure of the present invention shown in FIG. 6 in which two dielectric waveguides are arranged so that the transmission directions of high-frequency signals are parallel to each other is not shown here, but is similar to FIG. Can be realized.

Moreover, a branched structure of the electrically Namikan structure of the present invention described above, as shown in FIG. 10, it may be incorporated in the antenna substrate 22 made of a multilayer wiring board. In the antenna substrate 22, it is necessary to change the radiation ratio of each antenna element 23 in order to reduce the side lobe, for example, in order to make the beam shape a desired shape. For this reason, the feed line to each antenna element 23 is required. When a waveguide is used as 24, the beam shape can be easily designed by utilizing the branch structure of the waveguide structure of the present invention. 10 shows the slot antenna 25 in which a notch is provided in the conductor layer on one side of the dielectric waveguide, but there is no problem even if a patch antenna that feeds power through the slot or via conductor is used. It does not depend on the antenna configuration.

In order to evaluate the high-frequency characteristics of the branched structure of the waveguide structure according to the present invention, S parameters were simulated. The two waveguide structures shown in FIG. 1 and FIG. 9 are used to overlap each other so that the transmission directions of the high-frequency signals are orthogonal to each other. The waveguide is formed of a dielectric waveguide. Shape. The relative dielectric constant εr of the dielectric substrate 16 was 4.9.

  The dimensions in the waveguide coupling structure were as follows. The width L1 of the waveguide 1 = 1.64 mm, the width L2 of the waveguide 2 = 1.9 mm, the thickness a of the waveguides 1 and 2 = 0.6 mm, the thickness a of the thin portion 5 in the waveguide 1 '= 0.3 mm.

The deviation width m between the center of the thin portion 5 and the center of the coupling window 3 was set to 0.1 mm. The size of the coupling window 3 was 1.76 mm on the side parallel to the transmission direction of the waveguide 1 and 1.57 mm on the orthogonal side. The results are shown in FIG. In the figure, the solid line is S11, the broken line is S21, and the dotted line is S31. Position of where port is as shown in FIG. From the result of FIG. 11, reflection is suppressed, and it can be seen that at 62 GHz, S21 is approximately −4.21 dB and S31 is approximately −2.08 dB.

  Moreover, the result of having simulated the structure of FIG. 6 was shown in FIG. In FIG. 12, the solid line is S11, the broken line is S21, and the dotted line is S31. The widths of the waveguides 12 and 13 are both 1.89 mm, the size of the window 14 is L4 = 0.984 mm, L5 = 0.16 mm, and the distance S from the window 14 to the end of the waveguide 13 is 1.32 mm. The length L6 of the thin layer portion is 0.55 mm, the height b ′ = 0.3 mm, and the deviation n between the thin layer portion and the window center is n = 0.13 mm. At 62 GHz, S11 is -19.22 dB, S21 is -4.18 dB, and S31 is -2.21 dB, confirming that power can be distributed.

It is a schematic perspective view for demonstrating an example of 1st invention of the branched structure of the waveguide structure of this invention. It is a schematic sectional drawing of the AA in FIG. It is a schematic sectional drawing of the BB line in FIG. It is a schematic perspective view for demonstrating other examples of the branched structure of the waveguide structure of this invention. It is a schematic perspective view for demonstrating other examples of the branched structure of the waveguide structure of this invention. It is a schematic perspective view for demonstrating an example of 2nd invention of the branched structure of the waveguide structure of this invention. It is a schematic sectional drawing of CC line of FIG. It is a schematic perspective view for demonstrating the basic structure of a dielectric waveguide line. FIG. 9 is a schematic transparent perspective view when the dielectric waveguide of FIG. 8 is applied to the branch structure of the waveguide structure of FIG. 1. It is a general | schematic permeation | transmission perspective view at the time of using the branch structure of the waveguide structure of this invention for an antenna board | substrate. It is a transmission characteristic figure in the simulation based on 1st invention. It is a transmission characteristic figure in the simulation based on 2nd invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... 2nd waveguide 1a ... One port of the waveguide 1
1b... Another port of the waveguide 1
2... First waveguide 3... Coupling window 4... Upper main conductor 5. Waveguide 13... Waveguide 14... Coupling window 15... Thin portion 16... Dielectric substrates 17 and 18. .... Subconductor layer 21 ... Dielectric waveguide

Claims (5)

A second waveguide structure is arranged to overlap as the transmission direction of the high-frequency signal are perpendicular to the end portion of the first waveguide structure, said first waveguide structure and said second to form the respective coupling windows in the waveguide wall portion of repeated waveguide structure Rutotomoni, the the second waveguide structure, the formation of the coupling window wall surface of which facing the wall the thin portion that is narrower than the interval of the interval in the other sites, at least a part is provided so as to overlap with the coupling window, the center of the transmission direction of the thin portion is shifted from the center of the coupling window arrangement A branched structure of a waveguide structure characterized by the above. A second waveguide structure is the transmission direction of the high-frequency signal are arranged to overlap so as to be parallel to the end portion of the first waveguide structure, said first waveguide structure and said second of the waveguide structure of the superposed the rewritable form the respective coupling windows in the waveguide wall portions, said the second waveguide structure, and the wall opposite the wall formed with the coupling window and therewith intervals a thin portion which is narrower than the distance at the other sites, it will be provided so that at least a part thereof overlaps with the coupling window, shifting the center of the transmission direction of the thin portion from a center of the coupling window A branched structure of a waveguide structure characterized by being arranged. The waveguide structure has a pair of main conductor layers sandwiching a dielectric substrate and a predetermined interval in a direction orthogonal to the transmission direction at a repetition interval of less than half of the signal wavelength in the transmission direction of the high-frequency signal. and two rows side-wall through conductor group of the main conductor layers are formed by electrically connecting a width of the main conductor layer and formed in parallel to the main conductor layers, the side-wall through conductor group and electric branched structure waveguide structure according to claim 1 or claim 2, characterized by being provided to connected a sub conductive layers. The branched structure of the waveguide structure according to any one of claims 1 to 3, wherein the dielectric substrate is made of low-temperature fired ceramics. An antenna substrate comprising the branching structure of the waveguide structure according to any one of claims 1 to 4.

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