JP3517148B2 - Connection structure between dielectric waveguide line and high-frequency line conductor - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection structure between a dielectric waveguide line that mainly transmits high-frequency signals such as microwaves and millimeter waves and a high-frequency line conductor, and particularly to a dielectric waveguide line. The present invention relates to a connection structure in which a high frequency line conductor is electromagnetically connected via a slot hole.

[0002]

2. Description of the Related Art In recent years, research on mobile communication and inter-vehicle radar using high-frequency signals in the microwave band, millimeter wave band, etc. has been actively pursued. As high-frequency transmission lines for transmitting high-frequency signals in these high-frequency circuits, coaxial lines, line waveguides such as rectangular waveguides, dielectric waveguides, and microstrip lines have been conventionally known.

Further, recently, a plurality of high-frequency lines of different types such as the above-mentioned high-frequency transmission line and antenna element are arranged for transmitting a high-frequency signal in a wiring circuit which constitutes a high-frequency circuit. A connection technology between lines is required, and connection structures of various structures have been reported for this.

For example, in the connection structure of the coaxial line and the rectangular waveguide or the dielectric waveguide, the signal line of the coaxial line is inserted into the waveguide and is coupled by high-frequency coupling.

Further, in the connection structure of the waveguide and the microstrip line, for example, when the waveguide and the microstrip line are connected at a right angle, a dielectric substrate in which the microstrip line is formed in the waveguide. Is used. When the waveguide and the microstrip line are connected in the same transmission direction, a so-called ridge waveguide in which the width of the waveguide is narrowed toward the end to which the microstrip line is connected is curved. A structure has been proposed in which a signal line of a microstrip line is inserted into the inside of the waveguide and a slot hole is provided in a waveguide or a dielectric waveguide, and connection is made by electromagnetic coupling through the slot hole. .

[0006]

Recently, since it is advantageous in terms of downsizing when formed on or in a substrate that constitutes a high-frequency circuit, a technique of laminating a dielectric waveguide line in a multilayer wiring substrate is proposed. Is desired to be formed by.
For example, in Japanese Patent Laid-Open No. 6-53711, a dielectric substrate is sandwiched between a pair of main conductor layers, and the main conductor layers are connected to each other.
A waveguide line has been proposed in which a sidewall is formed by a group of via holes arranged in rows. In this waveguide line, a region inside the conductor wall is used as a signal transmission line by surrounding the dielectric material on four sides with a pseudo conductor wall composed of a pair of main conductor layers and via holes.

The laminated dielectric waveguide line arranged inside such a multilayer wiring board is mainly used as a transmission line of a microwave or millimeter wave ceramic multilayer wiring board or a high frequency semiconductor package. Above, connection with other high frequency lines is required.

On the other hand, the present inventor has already disclosed in Japanese Unexamined Patent Publication No. 10-10.
In Japanese Patent No. 7518, a connection structure using electromagnetic coupling by slot holes is proposed. According to this, a pair of main conductor layers are formed in parallel on the upper and lower surfaces that sandwich at least the line formation position with a predetermined interval sandwiching the dielectric.
Further, a through conductor group that electrically connects the main conductor layers is provided between the main conductor layers. The through conductor groups are arranged in two rows with a predetermined interval (width), and each of the through conductors is formed with an interval of less than ½ of the signal wavelength in the transmission direction of the high-frequency signal, that is, the line forming direction. . As a result, the region surrounded by the main conductor layer and the through conductor group becomes the dielectric waveguide line. In addition, between the main conductor layers, a sub-conductor layer that is electrically connected to the through conductor group that forms the sidewall of the dielectric waveguide line and is formed in parallel with the main conductor layer is formed. The side walls of the are made grid-shaped to enhance the electromagnetic wave shielding effect. Then, at least one of the main conductor layers, here the main conductor layer on the upper side, has a slot hole in which a conductor is not formed, and the dielectric waveguide line and other microstrip lines are formed through the slot hole. Etc. to connect with a high frequency line conductor such as.

According to this connection structure, by forming a slot hole in a part of the main conductor layer, it is possible to easily electromagnetically couple with another high-frequency line conductor, and further, the dielectric waveguide having such a structure. The line and the multilayer wiring board using the line can be easily manufactured by applying the conventional ceramic lamination technique.

However, the characteristic impedance of such a laminated dielectric waveguide line and the characteristic impedance of another high frequency line conductor connected through the slot hole 7 do not normally match. Therefore, there is a problem in that the high-frequency signal is reflected at the connection portion due to the mismatch of the characteristic impedance, and at the same time, the transmission characteristic is deteriorated.

The present invention has been devised in view of the above problems of the prior art, and its object is to provide a laminated dielectric waveguide line and other high frequency lines such as microstrip lines and coplanar lines. Providing a connection structure between a dielectric waveguide line and a high-frequency line conductor that can be electromagnetically coupled to a conductor using a slot hole and can be connected with good characteristics even if they have different characteristic impedances To do.

[0012]

As a result of repeated studies on the above problems, the present inventor has found that the dielectric conductor is located at a predetermined position from the slot hole formed in the main conductor layer of the dielectric waveguide line. By forming a short-circuited end of the waveguide line and forming an internal conductor layer facing the high-frequency line conductor from the short-circuited end to the lower part of the slot hole in parallel with the main conductor layer, the internal conductor layer has a characteristic impedance. It has been found that it functions as a matching conductor layer of, and excellent transmission characteristics are obtained at the connection part.

That is, the connection structure of the dielectric waveguide line and the high frequency line conductor of the present invention has a pair of main conductor layers sandwiching the dielectric substrate and a signal wavelength in the transmission direction of the high frequency signal between the main conductor layers. Of the side wall through conductor groups of two rows electrically connected to each other with a repeating interval of less than 1/2 and a predetermined width, and the side wall through conductor groups are electrically formed in parallel with each other between the main conductor layers. A pair of sub conductor layers to be connected, a slot hole formed in one of the main conductor layers in a rectangular shape in a direction orthogonal to the side wall through conductor group, and from this slot hole, approximately two minutes of the guide wavelength in the transmission direction is divided. ½ of the signal wavelength in the width direction between the main conductor layers at a position of
An end face through conductor group electrically connected at a repeating interval of less than, an end face through conductor group electrically connected to the end face through conductor group and the pair of sub conductor layers, and the end face through conductor group An inner conductor layer that is electrically connected to the other main conductor layer and that is formed parallel to the position of less than a quarter of the guide wavelength from the other of the main conductor layers to the lower portion of the slot hole. A high-frequency line conductor, which is arranged to face the slot hole, is electromagnetically coupled to the body waveguide line.

Further, the connection structure of the dielectric waveguide line and the high frequency line conductor of the present invention has a pair of main conductor layers sandwiching the dielectric substrate and a signal wavelength in the transmission direction of the high frequency signal between the main conductor layers. Of the side wall through conductor groups of two rows electrically connected to each other with a repeating interval of less than 1/2 and a predetermined width, and the side wall through conductor groups are electrically formed in parallel with each other between the main conductor layers. A pair of sub conductor layers to be connected, a slot hole formed in one of the main conductor layers in a rectangular shape in a direction orthogonal to the side wall through conductor group, and from this slot hole, approximately two minutes of the guide wavelength in the transmission direction is divided. End face through conductor group for electrically connecting the main conductor layers in the width direction at a repeating interval of less than ½ of the signal wavelength, and the end face through conductor group and the pair of Electrically connected to the sub-conductor layer A surface for the sub conductive layer, one end is electrically connected to the end face through-conductor group, and the internal conductor layer formed to the bottom of the parallel said slot hole in the main conductor layer,
A dielectric waveguide line comprising an inner penetrating conductor group for electrically connecting the other end of the inner conductor layer and the other of the main conductor layers at a repeating interval of less than one half of the guide wavelength. In addition, the high-frequency line conductor arranged to face the slot hole is electromagnetically coupled.

According to the connection structure of the dielectric waveguide line and the high-frequency line conductor of the present invention, the short-circuit end is formed at a predetermined position from the slot hole of the dielectric waveguide line, and the slot is formed from this short-circuit end. An internal penetrating conductor group that forms an internal conductor layer at a predetermined position between the lower part of the hole and in parallel with the main conductor layer so as to face the high-frequency line conductor and electrically connects the end portion to the main conductor layer. By forming the, the effective thickness of the dielectric waveguide line in this part changes,
As a result, the characteristic impedance of the connection portion with the high-frequency line conductor changes, and the characteristic impedance matching between the dielectric waveguide line and the high-frequency line conductor can be achieved. Then, by matching the characteristic impedances of the both, the connection structure can sufficiently reduce the occurrence of reflection of the high frequency signal at the connection portion and obtain good transmission characteristics. Moreover, the internal conductor layer and the group of internal through conductors that function as such a matching unit can be manufactured simultaneously with the dielectric waveguide line integrally with the conventional ceramic lamination technology and co-firing technology. Is also excellent.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION A connection structure of a dielectric waveguide line and a high frequency line conductor of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially cutaway perspective view showing an example of an embodiment of a connection structure between a dielectric waveguide line and a high frequency line conductor according to the present invention. In FIG. 1, 1 is a dielectric substrate, 2 and 3 are a pair of main conductor layers that sandwich the dielectric substrate 1 from above and below, 4 is a signal transmission direction at a repeating interval of less than one half of a signal wavelength, and signal transmission. It is a two-row side wall through conductor group formed so as to electrically connect a pair of main conductor layers 2 and 3 with a predetermined width in a direction orthogonal to the direction. Note that a part of the main conductor layer 2 is shown in a cutaway manner so that the internal structure can be seen. Further, 5 is a main conductor layer 2/3 which electrically connects the through conductors forming each row of the sidewall through conductor group 4.
Is a sub-conductor layer formed in parallel with. Reference numeral 6 denotes the pair of main conductor layers 2 and 3, the sidewall through conductor group 4 and the sub conductor layer 5.
It is a dielectric waveguide line formed by.

As described above, the pair of main conductor layers 2 and 3 are formed on the upper and lower surfaces sandwiching at least the transmission line forming position, which sandwiches the dielectric substrate 1 having a predetermined thickness, and two rows of sidewall through conductor groups. 4 is formed. By forming a sub conductor layer 5 in a region surrounded by the pair of main conductor layers 2 and 3 and the sidewall through conductor group 4, the dielectric waveguide line 6 is formed. Seen from the inside of the side wall, the side walls are
The sub-conductor layer 5 and the sub-conductor layer 5 form a fine grid, and shield electromagnetic waves in various directions.

Reference numeral 7 denotes a slot hole formed in the upper main conductor layer 2, and the upper main conductor layer 2 with respect to the slot hole 7.
The high-frequency line conductors 8 arranged in parallel with each other face each other, and the dielectric waveguide line 6 and the high-frequency line conductor 8 are connected to each other by the slot holes 7.
A high-frequency signal is transmitted by electromagnetically coupling via.

In this example, a part of the main conductor layer 2 of the dielectric waveguide line 6 also serves as a ground plane for the high frequency line conductor 8. In this case, the space between the high frequency line conductor 8 and the main conductor layer 2 may be air or a dielectric. Further, the high-frequency line conductor 8 may be one formed on another dielectric substrate having a ground layer formed on the back surface (microstrip line), or one formed on the surface of the dielectric substrate together with the same-plane ground layer. (Coplanar railway) may be used.

Reference numeral 9 denotes a slot hole 7 of the dielectric waveguide line 6.
To half of the guide wavelength λg in the transmission direction of the high frequency signal
A group of end face through conductors formed by electrically connecting between the main conductor layers 2 and 3 at a position of double (~ λg / 2) at intervals of less than one-half of the signal wavelength in the direction orthogonal to the transmission direction. Is. Also,
Reference numeral 10 denotes an end face sub-conductor layer which is formed between the main conductor layers 2 and 3 in parallel with the main conductor layers 2 and 3 and is electrically connected to the sub conductor layer 5 and the end face through conductor group 9. By the end face through conductor group 9 and the end face sub-conductor layer 10, the dielectric waveguide line 6 is formed.
The short-circuited end of the dielectric waveguide line 6 is formed at a position ˜λg / 2 from the slot hole 7.

Reference numeral 11 is opposed to the high-frequency line conductor 8 in parallel with the main conductor layers 2 and 3 at a position which is less than a quarter of the guide wavelength of the high-frequency signal from the lower main conductor layer 3. The inner conductor layer has one end electrically connected to the end face through conductor group 9 and the other end reaching the lower portion of the slot hole 7. In this way, by forming the short-circuited end of the dielectric waveguide line 6 and forming the internal conductor layer 11 extending from the short-circuited end to the lower part of the slot hole 7, the lower side of the internal conductor layer 11, that is, the lead. A high-frequency signal cannot penetrate into the body layer 3, and the same result can be obtained by reducing the thickness of the dielectric waveguide line 6 from the slot hole 7 to the short-circuit end. Therefore, by adjusting the height of forming the inner conductor layer 11 and adjusting the width and the length, the impedances of the dielectric waveguide line 6 and the high frequency line conductor 8 can be matched at the connection portion. As a result, the reflection of the transmission signal at the connection portion can be sufficiently reduced, and good transmission characteristics can be obtained.

The connection structure between the dielectric waveguide line and the high frequency line conductor of the present invention having the structure shown in FIG. 1 has a pair of main conductor layers that sandwich the dielectric substrate from above and below, and a high frequency signal transmission. Group of two side wall through conductors formed by electrically connecting the main conductor layers with a predetermined interval in the direction and a predetermined width in the direction orthogonal to the transmission direction. And a sub conductor layer formed in parallel with the main conductor layer between the main conductor layers and electrically connected to the sidewall through conductor group, the main conductor layer, the sidewall through conductor group, and With respect to the dielectric waveguide line that transmits a high frequency signal by the area surrounded by the sub conductor layer, the high frequency line conductor that transmits a high frequency signal is disposed parallel to the main conductor layer on the upper side, Rectangle in the body layer in the direction orthogonal to the side wall through conductor group Through the formed slot holes are opposed causes electromagnetically coupled, to 1 times the position of approximately half of the transmission direction in the guide wavelength from the slot hole,
A group of end face through conductors formed by electrically connecting the main conductor layers at intervals of less than ½ of the signal wavelength in a direction orthogonal to the transmission direction, and between the main conductor layers in parallel with the main conductor layer. A short-circuited end formed of the sub-conductor layer and the end-face sub-conductor layer electrically connected to the end-face penetrating conductor group is formed, and the in-tube wavelength of 4 from the lower main conductor layer is formed.
One of the ends is electrically connected to the end face through conductor group and the other end is located below the slot hole so as to face the high-frequency line conductor in parallel with the main conductor layer at a position less than one-half the height. The internal conductor layer is formed.

In FIG. 1, one end of the inner conductor layer 11 is formed integrally with the end face sub-conductor layer 10 and both sides thereof are formed together with the sub-conductor layer 5, but the inner conductor layer 11 is formed. It is not necessary to match the height with the sub conductor layers 5 and 10, and the width may be at least the width facing the high frequency line conductor 8.

For example, in the example shown in FIG. 1, the dielectric substrate 1 has a three-layer structure to form the dielectric waveguide 6, and the inner conductor layer 11 is formed on the first dielectric substrate 1. However, by adjusting the thickness of each layer of the dielectric substrate or adjusting the number of laminated layers, the internal conductor layer 11 can be provided at a position of arbitrary height.

The length of the inner conductor layer 11 is set so as to extend from the short-circuited end to the lower part of the slot hole 7, and the other end is about λg / from the center of the slot hole 7 to the side opposite to the short-circuited end. It is desirable to form so as to come to the position of 8.

The two rows of the side wall through conductor groups 4 have a half of the signal wavelength in the transmission direction of the high frequency signal, that is, in the line forming direction.
It is formed with a predetermined repeating interval of less than and a predetermined constant interval (width) in the direction orthogonal to the transmission direction. As a result, the electrical side wall of the dielectric waveguide line 6 is formed.

Here, there is no particular limitation on the thickness of the dielectric substrate 1, that is, the distance between the pair of main conductor layers 2 and 3,
When used in the single mode, the width is preferably about ½ or twice the width of the sidewall through conductor group 4. In the example of FIG. 1, the portion corresponding to the H surface of the dielectric waveguide line 6 is formed of the main conductor layers 2 and 3, and the portion corresponding to the E surface is formed of the sidewall through conductor group 4 and the sub conductor layer 5. If the thickness of the dielectric substrate 1 is about twice the width of the sidewall through conductor group 4, the portion corresponding to the E surface of the dielectric waveguide line 6 is the main conductor layers 2 and 3 and the H surface. The portions corresponding to are formed by the sidewall through conductor group 4 and the sub conductor layer 5, respectively.

By setting the repeating interval of the through conductors to be less than half the signal wavelength, the side wall through conductor group 4 can form an electrical wall. This interval is
It is preferably less than a quarter of the signal wavelength.

Since the TEM wave can propagate between the pair of main conductor layers 2 and 3 arranged in parallel, the repetition interval of the through conductors in each row of the sidewall through conductor group 4 is 2 of the signal wavelength λ.
If it is larger than 1 / (λ / 2), the gap acts as a slot and the electromagnetic wave leaks. Therefore, even if the electromagnetic wave is fed to this dielectric waveguide 6, the electromagnetic wave is not generated by the side wall through conductor group 4. It leaks from the space and does not propagate along the pseudo waveguide line created here. However, if the repetition interval of the side wall through conductor groups 4 is smaller than λ / 2, an electric side wall is formed, and the electromagnetic wave causes the dielectric waveguide line 6 to pass.
It is not possible to propagate in the direction perpendicular to, and is propagated in the signal transmission direction of the dielectric waveguide 6 while reflecting. As a result, according to the configuration as shown in FIG. 1, the pair of main conductor layers 2
A region surrounded by 3 and two rows of the side wall through conductor groups 4 and the sub conductor layer 5 becomes the dielectric waveguide line 6.

The high-frequency signal propagating in the dielectric waveguide 6 is partially or entirely part of the main conductor layer 2.
Through the slot hole 7 formed in the above, it propagates by being electromagnetically coupled to various high frequency line conductors 8 arranged facing the upper portion of the slot hole 7.

In the embodiment shown in FIG. 1, the sidewall through conductor group 4 is used.
Is formed in two rows. By arranging the side wall through conductor groups 4 in four rows or six rows, and forming the pseudo conductor walls by the side wall through conductor groups 4 in double or triple layers. It is also possible to more effectively prevent leakage of electromagnetic waves from the conductor wall.

According to such a dielectric waveguide line 6,
Since the transmission line is a dielectric waveguide, the dielectric substrate 1
When the relative permittivity of is ε _r , the waveguide size is 1 / √ε _r of a normal waveguide. Therefore, the larger the relative permittivity ε _r of the material forming the dielectric substrate 1 is, the smaller the size of the waveguide can be, and the size of the high frequency circuit can be reduced. It is possible to use the dielectric waveguide line 6 of a size that can be used as a transmission line for a multilayer wiring board, a package for housing semiconductor elements, or an inter-vehicle radar.

As described above, the through conductors forming the sidewall through conductor group 4 are arranged at a repeating interval of less than one half of the signal wavelength, and this repeating interval realizes good transmission characteristics. For this purpose, it is desirable to set a constant repetition interval, but if the interval is less than ½ of the signal wavelength, it may be appropriately changed or some values may be combined.

The dielectric substrate 1 constituting such a dielectric waveguide line 6 is not particularly limited as long as it functions as a dielectric and has characteristics that do not hinder the transmission of high frequency signals. However, it is desirable that the dielectric substrate 1 be made of ceramics from the viewpoint of accuracy and ease of manufacturing when forming the transmission line.

Ceramics having various relative dielectric constants have been known as such ceramics.
In order to transmit a high frequency signal by the dielectric waveguide line according to the present invention, a paraelectric material is desirable. This is because ferroelectric ceramics generally have large dielectric loss and high transmission loss in the high frequency region. Therefore, it is suitable that the dielectric constant ε _r of the dielectric substrate 1 is about 4 to 100.

In general, the wiring layer formed on the multilayer wiring board, the package for storing semiconductor elements, or the inter-vehicle radar has a maximum line width of about 1 mm. Therefore, a material having a relative permittivity of 100 is used and the upper portion is H. When used so that the surface, that is, the magnetic field, has an electromagnetic field distribution that winds parallel to the upper surface,
The minimum frequency that can be used is calculated as 15 GHz, and it can be used in the microwave band region.

On the other hand, since a dielectric made of resin which is generally used as the dielectric substrate 1 has a relative dielectric constant ε _r of about 2, when the line width is 1 mm, it should be used unless it is about 100 GHz or more. Will not be possible.

Although many paraelectric ceramics such as alumina and silica have a very small dielectric loss tangent, not all paraelectric ceramics can be used. In the case of the dielectric waveguide line, there is almost no loss due to the conductor, and most of the loss during signal transmission is due to the dielectric. The loss α (dB / m) due to the dielectric is expressed as follows. α = 27.3 × tan δ / [λ / {1- (λ / λc) ² }
^1/2 ] In the formula, tan δ: dielectric loss tangent of the dielectric λ: wavelength in the dielectric λc: cutoff wavelength According to the standardized rectangular waveguide (WRJ series) shape, {1- ( λ / λc) ² } ^1/2 is about 0.75.

Therefore, the transmission loss can be put to practical use-
In order to achieve 100 dB / m or less, it is necessary to select a dielectric material so that the following relationship holds. f × ε _r ^1/2 × tan δ ≦ 0.8 In the formula, f is the frequency (GHz) of the high frequency signal used.

Examples of such a dielectric substrate 1 include alumina ceramics, aluminum nitride ceramics and glass ceramics. The dielectric substrate 1 made of these is formed into a slurry form by adding and mixing an appropriate organic solvent / solvent to the ceramic raw material powder, and is formed into a sheet form by adopting the conventionally known doctor blade method, calendar roll method, or the like. By doing so, a plurality of ceramic green sheets are obtained, and then each of these ceramic green sheets is appropriately punched and laminated, and in the case of alumina ceramics, 15
00 to 1700 ℃, 850 to 1000 for glass ceramics
° C, 1600 to 1900 for aluminum nitride ceramics
It is manufactured by firing at a temperature of ℃.

Further, the pair of main conductor layers 2 and 3 and sub conductor layer 5 are, for example, when the dielectric substrate 1 is made of alumina ceramics, an oxide of alumina, silica, magnesia, etc. suitable for metal powder such as tungsten. Using a thick film printing method, a paste is prepared by adding and mixing materials, organic solvents, solvents, etc., and printing on a ceramic green sheet so as to completely cover at least the transmission line, and then about 1600
It is fired at a high temperature of ℃ to form a thickness of about 5 to 15 μm. As the metal powder, copper / gold / silver is suitable for glass ceramics, and tungsten / molybdenum is suitable for aluminum nitride ceramics.
The thickness of the main conductor layers 2 and 3 and the sub conductor layer 5 is generally about 5 to 15 μm.

The through conductors forming the side wall through conductor group 4 may be formed of, for example, via hole conductors or through hole conductors. The cross-sectional shape may be a polygon such as a rectangle or a rhombus, as well as a circle which is easy to manufacture. These penetrating conductors are formed by, for example, embedding a metal paste similar to that of the main conductor layers 2 and 3 in a penetrating hole formed by punching a ceramic green sheet, and then firing the dielectric substrate 1 at the same time. The through conductor has a diameter of 50 to 300.
μm is suitable. Further, the slot hole 7 formed in the upper main conductor layer 2 is provided with a high frequency line conductor 8 and a dielectric waveguide line which are arranged facing the slot hole 7 in parallel with the main conductor layer 2. 6 is electromagnetically coupled to connect a high frequency signal. The position, shape, size, etc. of forming the slot hole 7 are set as follows.

As shown in FIG. 1, the shape of the slot hole 7 is such that the length thereof is half the signal wavelength in the width direction of the dielectric waveguide line 6, that is, in the direction orthogonal to the side wall through conductor group 4. 1. The rectangular shape may have a width of about one third to one tenth of the length. The position of the slot hole 7 may be any position as long as the dielectric waveguide line 6 and the high frequency line conductor 8 can be electromagnetically coupled by an electromagnetic field. Specifically, when the high-frequency line conductor 8 is a microstrip line, a coplanar line, or the like, the high-frequency line conductor 8 is coupled unless it is completely parallel to the longitudinal direction of the slot hole 7, and when it is orthogonal, the coupling is best performed.

As shown in FIG. 1, in the dielectric waveguide line 6 according to the connection structure of the present invention, from the slot hole 7 of the dielectric waveguide line 6 to the transmission direction, approximately 2 minutes of the guide wavelength is divided. At a position n times as large as 1 (n is a natural number), a short-circuited end composed of the end face through conductor group 9 and the end face sub conductor layer 10 is formed, and the lower main conductor layer 3 is divided into four minutes of the guide wavelength. By forming the internal conductor layer 11 from the short-circuited end to the lower part of the slot hole 7 at a position less than 1 of the above, the portion from the slot hole 7 to the short-circuited end functions as a quarter-wavelength matching circuit. The feature is that the thin portion of the dielectric waveguide line 6 is formed. As a result, by adjusting the thickness of the matching circuit portion, the characteristic impedance of this portion can be adjusted, and the high frequency line conductors 8 having different characteristic impedances can be electromagnetically coupled through the slot holes 7 in a low reflection state. You can Such adjustment of the thickness of the matching circuit portion can be performed by adjusting the position, width and length of the internal conductor layer 11.

By forming the matching circuit portion of the dielectric waveguide line 6 in this way, various other high-frequency line conductors 8 and the dielectric waveguide line 6 can be connected with high performance, Moreover, since this matching circuit portion can be easily produced and built in by a sheet laminating technique such as a green sheet laminating method in a dielectric substrate that constitutes a high frequency multilayer wiring substrate or a high frequency semiconductor element housing package, The connection structure has high productivity and can be manufactured at low cost.

Next, FIG. 2 shows another example of the embodiment of the connection structure of the dielectric waveguide line and the high-frequency line conductor of the present invention in a partially cutaway perspective view similar to FIG.

In FIG. 2, the same parts as those in FIG. 1 are designated by the same reference numerals. In FIG. 2, reference numeral 12 is formed in place of the internal conductor layer 11 in FIG. 1 and is opposed to the high-frequency line conductor 8 between the main conductor layers 2 and 3 in parallel with the main conductor layer, and one end of the through conductor group for an end face. 9 is an internal conductor layer that is electrically connected to 9 and the other end reaches the lower part of the slot hole 7, and 13 is an internal conductor layer with a repeating interval of less than half of the guide wavelength of the high frequency signal.
It is an internal through conductor group formed so as to electrically connect the other end of 12 and the main conductor layer 3 therebelow.

Such an internal conductor layer 12 and an internal through conductor group
By forming 13 and 13, even if the height of the inner conductor layer 12 exceeds the quarter of the guide wavelength from the lower main conductor layer 3, the inner conductor layer located below the slot hole 7 Since the transmission signal from the other end side of 12 to the lower side of the internal conductor layer 12 is blocked by the internal through conductor group 13, it is more electrically stable than the example of the connection structure shown in FIG. Moreover, it is possible to configure the matching circuit portion in which the range in which the height of the internal conductor layer 12 can be set is wider. This allows
The impedance of the dielectric waveguide line 6 and the high-frequency line conductor 8 is better matched at the connecting portion by adjusting the height of the inner conductor layer 12 and adjusting the width and length. Therefore, it is possible to more effectively reduce the reflection of the transmission signal at the connection portion and obtain a very good transmission characteristic.

In such a connection structure, the inner conductor layer
Group of internal through conductors 13 that together with 12 form a matching circuit part
If the repeating interval is set to be smaller than 1/2 of the guide wavelength, the leakage of electromagnetic waves from between the through conductors is eliminated, so that the interval of the internal through conductor group 13 is 1/2 of the guide wavelength. Must be less than. In the example of FIG. 2, the inner through conductor groups 13 are arranged in one row along the other end of the inner conductor layer 12, but they may be arranged in a plurality of rows, or in a so-called staggered arrangement. Good.

As for the inner conductor layer 12, the length of the inner conductor layer 12 in the transmission direction is
Since it becomes λg / 2, this portion functions as a matching device for the impedances of the dielectric waveguide line 6 and the high-frequency line conductor 8 at the connecting portion. As a result, by adjusting the height of forming the inner conductor layer 12 and adjusting the width and the length, the impedances of the dielectric waveguide line 6 and the high-frequency line conductor 8 are well matched at the connection portion. Therefore, the reflection of the transmission signal at the connection portion can be more sufficiently reduced, and extremely good transmission characteristics can be obtained.

The connection structure between the dielectric waveguide line and the high-frequency line conductor of the present invention having the structure shown in FIG. 2 has a pair of main conductor layers that sandwich the dielectric substrate from above and below, and a high-frequency signal transmission. Group of two side wall through conductors formed by electrically connecting the main conductor layers with a predetermined interval in the direction and a predetermined width in the direction orthogonal to the transmission direction. And a sub conductor layer formed in parallel with the main conductor layer between the main conductor layers and electrically connected to the sidewall through conductor group, the main conductor layer, the sidewall through conductor group, and With respect to the dielectric waveguide line that transmits a high frequency signal by the area surrounded by the sub conductor layer, the high frequency line conductor that transmits a high frequency signal is disposed parallel to the main conductor layer on the upper side, Rectangle in the body layer in the direction orthogonal to the side wall through conductor group Through the formed slot holes are opposed causes electromagnetically coupled, to 1 times the position of approximately half of the transmission direction in the guide wavelength from the slot hole,
A group of end face through conductors formed by electrically connecting the main conductor layers at intervals of less than ½ of the signal wavelength in a direction orthogonal to the transmission direction, and between the main conductor layers in parallel with the main conductor layer. And forming a short-circuited end formed of the sub-conductor layer and the end-face sub-conductor layer electrically connected to the end-face penetrating conductor group, and between the main conductor layers in parallel with the main conductor layer. While facing the high frequency line conductor, one end is electrically connected to the end face penetrating conductor group and the other end forms an inner conductor layer reaching the lower part of the slot hole, and the inner conductor layer has a length of less than half of the guide wavelength. An inner penetrating conductor group for electrically connecting the other end of the inner conductor layer and the lower main conductor layer is formed at repeating intervals.

In FIG. 2, one end of the inner conductor layer 12 is integrated with the end face sub-conductor layer 10 and both sides are formed with the sub-conductor layer 5, but the inner conductor layer 12 is formed. It is not necessary to match the height with the sub conductor layers 5 and 10, and the width may be at least the width facing the high frequency line conductor 8.

The length of the inner conductor layer 12 is also
Similar to 11, it is desirable to form the other end of the slot hole 7 at a position of about λg / 8 from the center to the side opposite to the short-circuit end.

The end face through conductor group 9 and the inner through conductor group 13 may be formed in the same manner as the side wall through conductor group 4, and the end face sub conductor layer 10 and the inner conductor layers 11 and 12 are the main conductor layers. It may be formed in the same manner as the second and third or the sub-conductor layer 5.

The cross-sectional shapes and diameters of the end face through conductor groups 9 and the inner through conductor groups 13 may be formed in the same manner as the side wall through conductors 4.

[0057]

EXAMPLES Next, specific examples of the connection structure between the dielectric waveguide line and the high frequency line conductor of the present invention will be described.

The dielectric substrate 1 is formed by laminating four 0.15 mm-thick dielectric layers made of a ceramic material having a relative dielectric constant ε _r of 4.8, and the dielectric substrate 1 has a cross-sectional size of 1.
A 5 mm × 0.6 mm dielectric waveguide line 6 was formed. In addition, a slot hole 7 having a length of 0.894 mm and a width of 0.3 mm is formed in the main conductor layer 2, and the distance from the slot hole 7 is half the guide wavelength of the high frequency signal of 76.5 GHz in the transmission direction. The through conductor group 9 for the end face and the sub conductor layer 10 for the end face were formed at a position of approximately 1.20 mm, which corresponds to the short-circuit end. In addition, an internal conductor layer 12 is formed at a height of 0.30 mm from the main conductor layer 3 up to a distance of 1.48 mm from this short-circuited end to the lower part of the slot hole 7. Electrically connected with.

The line width of the high frequency line conductor 8 is set to 0.26.
7 mm, the gap between the dielectric waveguide 6 and the high frequency line conductor 8 is 0.15 mm, the stub length of the high frequency line conductor 8 (the length from the center of the slot hole 7 to the tip of the high frequency line conductor 8)
Is 0.351 mm and the high frequency line conductor 8 is opposed to the slot hole 7 to form the connection structure of the dielectric waveguide line 6 and the high frequency line conductor 8 of the present invention shown in FIG.

Then, for this example and the comparative example in which the matching circuit portion (internal conductor layer 12 and internal through conductor group 13) in the dielectric waveguide line 6 is not provided, the reflection coefficient S ₁₁ of the connection structure is measured by a network analyzer. I asked. The result is shown in FIG.

FIG. 3 is a diagram showing the frequency characteristic of the reflection coefficient S ₁₁ in the connection structure of the dielectric waveguide line and the high frequency line conductor, and the horizontal axis shows the frequency FREQUENCY (unit: GHz).
And the vertical axis represents the reflection coefficient S ₁₁ (unit: dB). Of the characteristic curves showing the frequency characteristics of the reflection coefficient S ₁₁ , A
Indicates the characteristics of the comparative example, and B indicates the characteristics of the example of the present invention.

From the results shown in FIG. 3, the reflection coefficient S ₁₁ is -6d in A which is the result of the comparative example having no matching circuit portion.
However, according to B, which is the result of the connection structure of the present invention, the short-circuit end is provided at a predetermined position from the slot hole 7 and the internal conductor layer 12 and the internal through conductor group 13 are provided. It can be seen that, by providing the matching circuit portion, a good characteristic with a reflection coefficient S ₁₁ of −20 dB or less was obtained. This indicates that the matching circuit portion according to the connection structure of the present invention matches the characteristic impedances of the dielectric waveguide line 6 and the high frequency line conductor 8.

In the comparative example and the example of the present invention, the position of the frequency where the reflection coefficient S ₁₁ is the smallest is slightly deviated, but this is due to the position of the short-circuited end of the dielectric waveguide line 6 or the internal conductor. It can be easily adjusted by adjusting the length from the short-circuited end of the layer 12 to the end of the lower portion of the slot hole 7 or the width of the inner conductor layer 12.

In this embodiment of the present invention, the internal through conductor group 13 is not formed and the height of the internal conductor layer 12 is 0.3 m.
When m is the internal conductor layer 11 in the example shown in FIG. 1 and the others are constructed and evaluated in the same manner as the connection structure of the present invention shown in FIG. Matching of the characteristic impedance with the line conductor 8 was performed, and good characteristics with a reflection coefficient S ₁₁ of −20 dB or less were obtained.

The present invention is not limited to the above examples, and various modifications and improvements can be made without departing from the gist of the present invention. For example, in the above example, the case where the high-frequency line conductor 8 connected to the dielectric waveguide line 6 is arranged so that the transmission directions of both are parallel to each other has been shown. The high frequency line conductors 8 may be orthogonal to each other or may intersect at an arbitrary angle. In such a case, the same good connection characteristics can be obtained by appropriately adjusting the position, shape, size, etc. of the slot hole 7. can get.

[0066]

As described in detail above, according to the connection structure of the dielectric waveguide and the high frequency line conductor of the present invention, the short-circuited end is formed at a predetermined position from the slot hole of the dielectric waveguide line. At the same time, by forming an internal conductor layer at a predetermined position from the short-circuited end to the lower part of the slot hole, and by forming an internal through conductor group that electrically connects the end portion to the main conductor layer, It became possible to change the characteristic impedance of the connection part between the dielectric waveguide line and the high frequency line conductor by the part to achieve the characteristic impedance matching between them. Then, by matching the characteristic impedances of both, the occurrence of reflection of the high frequency signal at the connection portion was sufficiently reduced, and good transmission characteristics could be obtained.

In addition, the connection structure of the present invention can easily manufacture the dielectric waveguide line having such a matching circuit portion by the sheet laminating technique such as the green sheet laminating method. It is expensive and can be manufactured at low cost.

As described above, according to the present invention, a laminated dielectric waveguide line and another high frequency line conductor such as a microstrip line or a coplanar line are electromagnetically coupled to each other by using a slot hole. It was possible to provide a connection structure between a dielectric waveguide line and a high-frequency line conductor, which can be connected with good characteristics even if they have different characteristic impedances.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing an example of an embodiment of a connection structure between a dielectric waveguide line and a high-frequency line conductor according to the present invention.

FIG. 2 is a partially cutaway perspective view showing another example of the embodiment of the connection structure of the dielectric waveguide line and the high frequency line conductor of the present invention.

FIG. 3 is a diagram showing a frequency characteristic of a reflection coefficient in a connection structure of a dielectric waveguide line and a high frequency line conductor.

[Explanation of symbols]

1. Dielectric substrate 2, 3 ... Main conductor layer 4 ... Side wall through conductor group 5 ... Sub conductor layer 6 ... Dielectric waveguide line 7: Slot hole 8: High frequency line conductor 9 ... Through conductor group for end face 10 ・ ・ ・ ・ ・ Sub-conductor layer for end face 11、12 ・ ・ ・ Inner conductor layer 13 ・ ・ ・ ・ ・ Internal through conductor group

Claims (2)

(57) [Claims] 1. A pair of main conductor layers sandwiching a dielectric substrate, and the main conductor layers are electrically connected to each other in a transmission direction of a high frequency signal at a repeating interval of less than one-half of a signal wavelength and a predetermined width. In one of the main conductor layers, a pair of side wall through conductor groups and a pair of sub conductor layers which are formed in parallel between the main conductor layers and electrically connect the side wall through conductor groups, respectively.
Wherein a slot hole formed in a rectangular shape in a direction orthogonal to the side-wall through conductor group, said main conductor layers in 1x position approximately half the guide wavelength in the transmission direction from the slot hole in the width direction An end face through conductor group electrically connected at a repeating interval of less than one half of a signal wavelength, and an end face sub conductor layer electrically connected to the end face through conductor group and the pair of sub conductor layers. An inner conductor layer that is electrically connected to the end face through conductor group and that is formed parallel to the lower portion of the slot hole at a height lower than a quarter of the guide wavelength from the other of the main conductor layers. A structure for connecting a dielectric waveguide line and a high-frequency line conductor, wherein a high-frequency line conductor arranged opposite to the slot hole is electromagnetically coupled to the dielectric waveguide line comprising: 2. A pair of main conductor layers sandwiching a dielectric substrate, and the main conductor layers are electrically connected to each other in a transmission direction of a high frequency signal at a repeating interval of less than one half of a signal wavelength and a predetermined width. In one of the main conductor layers, a pair of side wall through conductor groups and a pair of sub conductor layers which are formed in parallel between the main conductor layers and electrically connect the side wall through conductor groups, respectively.
Wherein a slot hole formed in a rectangular shape in a direction orthogonal to the side-wall through conductor group, said main conductor layers in 1x position approximately half the guide wavelength in the transmission direction from the slot hole in the width direction An end face through conductor group electrically connected at a repeating interval of less than one half of a signal wavelength, and an end face sub conductor layer electrically connected to the end face through conductor group and the pair of sub conductor layers. An inner conductor layer whose one end is electrically connected to the end face through conductor group and which is formed in parallel to the main conductor layer to the lower part of the slot hole, and the other end of the inner conductor layer and the main conductor layer. A high-frequency line conductor disposed opposite to the slot hole is provided in a dielectric waveguide line including an inner penetrating conductor group that electrically connects the other with a repeating interval of less than one-half of the guide wavelength. Dielectric conductor characterized by electromagnetic coupling Connection structure between the tube line and the high-frequency line conductor.