JP3464104B2 - Coupling structure of laminated waveguide line - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for coupling a laminated waveguide line for transmitting high frequency signals such as microwaves and millimeter waves with another signal transmission line.

[0002]

2. Description of the Related Art Conventionally, coaxial lines, waveguides, dielectric waveguides, microstrip lines, and the like are known as lines for transmitting high-frequency signals such as microwaves and millimeter waves.

Further, recently, a plurality of lines of different types are provided in a wiring circuit, and a technique for coupling these lines is required, and various coupling methods have been reported. For example, the coaxial line and the waveguide or the dielectric waveguide are coupled by inserting the signal line of the coaxial line into the waveguide. In addition, the coupling with the strip line and the microwave line is performed by electromagnetic coupling.

[0004]

Recently, it has been desired to form a dielectric waveguide line in a wiring board having a multi-layer structure by a laminating technique. For example, JP-A-6-53.
No. 711 proposes a waveguide line in which a dielectric substrate is sandwiched between a pair of main conductor layers, and side walls are formed by via hole groups arranged in two rows connecting the conductor layers. This waveguide line is a dielectric line for signal transmission in the inner region of the conductor wall by surrounding the dielectric material on four sides with a pair of main conductor layers and a pseudo conductor wall composed of a group of via holes.

Since the laminated waveguide line disposed inside such a wiring board is intended to be used mainly as a transmission line of a multilayer wiring board for microwaves and millimeter waves or a semiconductor package, The connection destination is a semiconductor element or a high frequency element. These elements are usually mounted on the surface of the substrate, whereas the laminated waveguide line is formed inside the insulating substrate. For this reason, it is desired to connect via a microstrip line that is easier to connect to a semiconductor element or a high frequency element than to connect directly to an element. Further, since the laminated waveguide line is formed in the plane direction of the substrate, it is necessary to couple with other signal transmission lines formed in the upper and lower layers of the laminated waveguide line.

Therefore, the present invention provides a laminated waveguide line which can be easily manufactured by a conventional multilayering technique, and
It is an object of the present invention to provide a coupling structure of microstrip lines or laminated waveguide lines.

[0007]

According to the present invention, a dielectric
A pair of main conductor layers formed in parallel sandwiching the
Electrical connection between the conductor layers at intervals below the cutoff wavelength
And two rows of via holes formed to
Coupling a laminated waveguide line with a microstrip line
And a microstrip line.
A transmission via hole from the end of the
A hole is electrically connected to the main conductor layer of the laminated waveguide line.
The laminated waveguide line without any physical connection.
It is characterized by being inserted inside.

Further, according to the present invention, the dielectrics are sandwiched and formed in parallel.
A pair of main conductor layers that are made up of the cut-off wavelength in the signal transmission direction.
Formed so as to electrically connect the conductor layers at the lower interval
Stacked waveguide having two rows of via holes
A structure for coupling a line to another stacked waveguide line
Both ends of the transmission via hole are connected to each laminated waveguide line.
Pass through without electrically connecting to the main conductor layer of the path
And is inserted in each laminated waveguide line.
To do.

[0009]

[0010]

As described above, according to the present invention, the laminated waveguide line and the microstrip line or the laminated waveguide lines can be easily connected to each other. Further, since it can be produced by using the ceramic multilayering technique which has been used conventionally, it is possible to form a highly reliable bonding structure at low cost.

[0012]

1 shows an example in which a laminated waveguide line and a coplanar line are connected by a transmission via hole.
FIG. 1 is a perspective view of this coupling structure, FIG. 2 is a plan view of FIG. 1, FIG. 3 is a sectional view, and FIG. 4 is another embodiment. In the figure, 1
Is a dielectric, 2 and 3 are main conductor layers, 4 is a via hole, 5
Is a coplanar line, and 6 is a transmission via hole. 1 and 4, the dielectric 1 is omitted for convenience of description, and only the arrangement relationship of the conductor portions of the coplanar line 5, the main conductor layers 2 and 3, the transmission via hole 6, and the via hole 4 group is shown. It was

According to FIG. 1, a pair of main conductor layers 2 and 3 are formed at positions sandwiching a dielectric (not shown) having a predetermined thickness a. The main conductor layers 2 and 3 are formed on one surface of the upper and lower surfaces of the dielectric 1 that sandwich at least the line formation position. Further, between the main conductor layers 2 and 3, a large number of via holes 4 that electrically connect the main conductor layers 2 and 3 are provided. The via holes 4 are formed in two rows at a predetermined distance b with a predetermined distance c in the signal transmission direction, that is, in the line forming direction. The predetermined interval c forms an electrical wall by being set to an interval equal to or less than the cutoff wavelength, and as a result, a structure similar to the waveguide, that is, the laminated waveguide line 10 is formed. Since the upper surface of the laminated waveguide line 10 is the uniform main conductor layer 2, the coplanar line 5 can be formed by forming an appropriate slit pair on this surface.

According to this example , this coplanar line 5
To the end of the laminated waveguide line 10 to be connected,
The via hole 6 for transmission is formed from the end portion thereof, and the other end portion of the via hole 6 for transmission is inserted into the laminated waveguide line 10 to form the coplanar line 5 and the laminated waveguide line 10. Join. At this time, the other end of the transmission via hole 6 is formed so as not to be electrically connected to the main conductor layer 3 on the lower surface. This is because connecting the transmission via hole 6 to the lower main conductor layer 3 deteriorates the transmission characteristics. Therefore, as shown in FIG. 3, the insertion length of the transmission via hole 6 into the waveguide line 10 is set to be shorter than the thickness a of the dielectric 1 forming the waveguide line 10. . For example, when the thickness a of the laminated waveguide line 10 is composed of two or more dielectric layers, the transmission via hole may not be formed in the lowest dielectric layer.

If the laminated waveguide line 10 has a thickness a of 1
When it is formed of a dielectric layer, as shown in FIG. 4, the other end portion of the transmission via hole 6 is the lower surface of the main conductor layer 3.
This can be realized by providing a hole 7 larger than the diameter of the transmission via hole so as not to be connected to. However, in FIG. 4, the via holes 4 constituting the side surface are omitted.

Since a large main conductor layer 2 is formed on the upper surface of the transmission via hole 6, the transmission via hole 6 can also have a function as a quarter-wave monopole antenna. That is, if the introduction length of the transmission via hole 6 into the waveguide line is configured to be ¼ of the signal wavelength to be used, the electromagnetic wave propagating through the coplanar line 5 will be transmitted through this transmission via hole. It is radiated into the laminated waveguide line 10 by the antenna of 6. Therefore, if the thickness a of the laminated waveguide line 10 is designed to be about b / 2, the upper and lower surfaces of the laminated waveguide line have an H plane, that is, a magnetic field distribution TE1 in which the magnetic field winds parallel to the upper and lower surfaces.
Since 0 propagates as the main mode, it couples well with the electromagnetic wave radiated from the transmission via hole 6 acting as an antenna, and the high frequency signal can propagate to the laminated waveguide line 10.

The coupling structure shown in FIGS. 1 to 4 is, for example, as shown in FIG. 3, in a four-layer structure of dielectric layers 1A to 1D, via holes and conductor layers are provided for each dielectric layer green sheet. To form. For example, in the dielectric layer 1A,
A group of via holes 4 and holes for transmission via holes 6 are opened and filled with a conductor, and the main conductor layer 2 and the coplanar line 5 are printed on the surface of the sheet. Also, the dielectric layer 1B
Via holes 4 and a transmission via hole 6 are formed on the dielectric layer 1C, only the via hole 4 group is formed on the dielectric layer 1C, and the main conductor layer 3 is formed by printing on the dielectric layer 1D. Then, the dielectric layers 1A to 1D are aligned and laminated, and they can be integrally fired. The dielectric layers 1A to 1C in the waveguide line and the dielectric layer 1
D does not necessarily have to be made of the same material.

Next, FIG. 5 shows an embodiment of the present invention in which the laminated waveguide line and the microstrip line are connected by a transmission via hole. FIG. 5 is a perspective view of this structure, FIG. 6 is a plan view, and FIG. 7 is a sectional view. 5 to 7, 1
Is a dielectric, 2 and 3 are main conductor layers, 4 is a via hole, 6
Is a via hole for transmission, 8 is a microstrip line,
9 is a hole formed in the main conductor layer. Reference numeral 10 denotes a laminated waveguide line composed of the main conductor layers 2 and 3 and the via hole 4 group. Note that in FIG. 5, the dielectric 1 is omitted for convenience of description, and only the arrangement relationship of the conductor portions of the microstrip line 8, the main conductor layers 2 and 3, the transmission via hole, and the via hole 4 group is shown.

In this embodiment, as shown in FIG.
A dielectric layer (not shown) located above the waveguide line 10
The microstrip line 8 is formed on the top. According to the present invention, the tip of the microstrip line 8 is wired to the vicinity of the tip of the laminated waveguide line 10 to be connected, the transmission via hole is formed from the end of the microstrip line 8, and the main conductor layer 2 is formed. It penetrates so as not to make electrical contact and extends into the laminated waveguide line 10.

At this time, a hole 9 is made in the main conductor layer 2 in the main conductor layer 2 on the upper surface of the laminated waveguide line 10 so as not to be electrically connected to the transmission via hole 6, and the hole 9 is formed. Through the transmission via hole 6. It is necessary to adjust the size of the hole 9 in consideration of the diameter, position, length, etc. of the transmission via hole 6 so as to improve the transmission characteristics. As described in connection with the coplanar line, in order for the transmission via hole 6 to function as a quarter-wave monopole antenna, the insertion length of the transmission via hole 6 into the waveguide line is It may be configured so as to be ¼ of the signal wavelength used.

With the coupling structure shown in FIG. 5, the electromagnetic wave propagating through the microstrip line has a good transmission electromagnetic field acting as an antenna and its electromagnetic field and the electromagnetic field propagating through the laminated waveguide line. Signal can be propagated into the laminated waveguide line with low loss.

The coupling structure shown in FIGS. 5 to 7 can also be easily manufactured by a well-known lamination technique. For example, as shown in FIG. 7, the dielectric layer 1 is composed of at least 6 layers 1A to 1F, the transmission via hole 6 and the microstrip line 8 are printed on the dielectric layer 1A, and the dielectric layer 1B is formed. On the dielectric layer 1C, the via hole 4 group, the transmission via hole 6 and the main conductor layer 2 are formed on the dielectric layer 1C, and the dielectric layer 1D is formed with the via hole 4 group and the transmission hole. The via hole 6 is formed, only the group of via holes 4 is formed in the dielectric layer 1E, and the main conductor layer 3 is formed by printing on the dielectric layer 1F. Then, the dielectric layers 1A to 1F are aligned and laminated, and they can be integrally fired to be manufactured.

Incidentally, the dielectric layers 1C to 1E in the waveguide line.
The dielectric layers 1A, 1B and 1F may be made of the best material for forming the laminated waveguide line and the microstrip line, respectively, and are not necessarily made of the same material.

Next, FIG. 8 shows another embodiment of the present invention in which the laminated waveguide lines are connected to each other by a transmission via hole. 8 to 9, 1A and 1B are dielectric layers, 2A and 2B,
3A and 3B are main conductor layers, 4A and 4B are via holes,
6A and 6B are transmission via holes, and 9 is a hole in the main conductor layer. Further, 10A is a lower laminated waveguide line formed of the main conductor layers 2A and 3A and the like, and 10B is an upper laminated waveguide line formed of the main conductor layers 2B and 3B.
The side surface of each of the laminated waveguide lines 10A and 10B has its line region defined by a group of via holes (not shown) as shown in FIG. Note that, in FIG. 8, for convenience of description, the dielectric layers 1A and 1B and the bihole 4 are illustrated.
The group omitted.

As shown in FIG. 8, the laminated waveguide line 10B is formed by the upper dielectric layer 1B, and the lower dielectric layer 1 is formed.
A constitutes a laminated waveguide line 10A. The laminated waveguide line 1 is wired up to the tip of the lower laminated waveguide line 10A that connects the tip of the upper laminated waveguide line 10B.
Transmission via holes 6A, 6B are formed from the inside of 0B, penetrating the main conductor layer 3B and the main conductor layer 2A and extending inside the laminated waveguide line 10A. At this time, the main conductor layer 3
Holes 9A and 9B are formed in B and 2A so as not to make electrical contact with the transmission via hole 6. The size of the hole 9 should be adjusted so as to improve the transmission characteristics in consideration of the diameter, position, length, etc. of the transmission via hole 6 as in the case of the connection with the macrostrip line of FIG. Is desirable.

With such a structure, the electromagnetic wave propagating through the laminated waveguide line 10B acts as a monopole antenna by the transmission via hole, and the electromagnetic field and the laminated conductor are transmitted as described above. Since the electromagnetic field propagating in the waveguide is well coupled, the signal can propagate in the stacked waveguide with low loss.

Like the above-described coupling structure, the coupling structure shown in FIGS. 8 and 9 can be easily manufactured by a combination of via hole formation and conductor layer printing technology and lamination technology. In addition, the main conductor layers 2A and 3
B may be composed of the same conductor layer.

The dielectric layers 1A and 1B may be made of the most convenient material for forming the respective laminated waveguide lines, and are not necessarily made of the same material. For example, when the laminated waveguide line 10A is used as a signal circuit, high-density wiring can be performed by using a material having a large relative dielectric constant as the material of the dielectric layer 1A, and at the same time, the laminated waveguide. When the line 10B is used as a waveguide slot antenna, for example, the radiation characteristic can be improved by using a material having a small relative dielectric constant as the material of the dielectric layer 1B.

Further, in the laminated waveguide in the present invention, for example, as shown in FIG. 10, waveguide 1
By further providing the sub-conductor layer 11 between the two main conductor layers 2 and 3 in parallel with the main conductor layer, the sub-conductor layer 11 being electrically connected to the via hole group 4, further improving the transmission characteristics in the waveguide line. You can Note that the dielectric layer is omitted in FIG. 10 for the convenience of description. FIG. 11 shows the measurement results of the transmission characteristics, and excellent characteristics of S21 of about -2.5 dB are obtained at 25 GHz to 40 GHz.

[0030]

As described in detail above, since the present invention has a simple structure as described above, it is possible to perform via hole formation, conductor layer printing and lamination, and co-firing at the time of manufacturing a conventional multilayer wiring board made of ceramics. It can be easily manufactured by a series of techniques, and the laminated dielectric waveguide line and the microstrip line, or the laminated dielectric waveguide lines can be easily connected to each other.

Further, according to the junction structure of the present invention, the transmission via hole is used for coupling, and this can be made to act as a quarter-wave monopole antenna. It couples well with the field and obtains good transmission characteristics.

[Brief description of drawings]

FIG. 1 is a perspective view for explaining one aspect of a coupling structure of a laminated waveguide line and a coplanar line.

FIG. 2 is a plan view of the coupling structure shown in FIG.

FIG. 3 is a cross-sectional view taken along line XX ′ in the coupling structure of FIG.

FIG. 4 is a perspective view for explaining another aspect of the coupling structure of the laminated waveguide line and the coplanar line.

FIG. 5 is a perspective view for explaining one aspect of a coupling structure of a laminated waveguide line and a microstrip line.

6 is a plan view of the coupling structure of FIG. 1. FIG.

7 is a cross-sectional view taken along the line YY 'in the combined structure of FIG.

FIG. 8 is a perspective view for explaining one aspect of a coupling structure of stacked waveguide lines.

9 is a cross-sectional view taken along the line ZZ 'in the combined structure of FIG.

FIG. 10 is a perspective view for explaining a coupling structure of a laminated waveguide line having a sub conductor layer and a coplanar line.

11 is a diagram showing measurement results of transmission characteristics in the case of the configuration of FIG.

[Explanation of symbols]

1 dielectric 2,3 Main conductor layer 4 via holes 5 coplanar tracks 6 Transmission via holes 7,9 Main conductor layer holes 8 microstrip lines 10, 12 Multilayer waveguide line 11 Sub conductor layer

─────────────────────────────────────────────────── ─── Continuation of front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H01P 5/107 H01P 3/12

Claims (2)

(57) [Claims] 1. A pair of leads formed in parallel with a dielectric material sandwiched therebetween.
The body layer and the conductor at an interval equal to or less than the cutoff wavelength in the signal transmission direction.
Two rows of vias formed to electrically connect the layers
Laminated waveguide line with holes and microst
A structure for coupling with a lip line,
Extend the transmission via hole from the end of the cross trip line.
And the via hole for transmission is provided in the laminated waveguide line.
Before passing through without electrically connecting with the main conductor layer,
It is characterized in that it is inserted in the laminated waveguide line.
Coupling structure of stacked waveguide lines. 2. A pair of leaders formed in parallel with a dielectric material sandwiched therebetween.
The body layer and the conductor at an interval equal to or less than the cutoff wavelength in the signal transmission direction.
Two rows of vias formed to electrically connect the layers
Stacked waveguide line with holes and other stacked conductors
A structure for coupling with a wave guide line,
Both ends of the a hole are connected to the main conductor layer of each laminated waveguide line.
Each laminated type waveguide line penetrates without electrically connecting
Laminated waveguide line characterized by being inserted in a channel
Bond structure.