JP3512626B2 - Branch structure of dielectric waveguide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a branch structure of a dielectric waveguide line for transmitting a high-frequency signal in a microwave band, a millimeter wave band, or the like. The present invention relates to a branch structure of a dielectric waveguide line which branches into three different dielectric waveguide lines, and in which the power ratio after the branch can be set arbitrarily.

[0002]

2. Description of the Related Art In a high-frequency circuit for handling a high-frequency signal such as a microwave band or a millimeter wave band, a transmission line for transmitting a high-frequency signal is required to be small and small in transmission loss. Conventionally, strip lines, microstrip lines, coplanar lines, dielectric waveguide lines, and the like have been used as such transmission lines because forming them on or within a substrate is advantageous in terms of miniaturization. .

Of these, strip lines, microstrip lines, and coplanar lines are composed of a signal line composed of a dielectric substrate and a conductor layer, and a ground conductor layer.
Electromagnetic waves of high-frequency signals propagate in the space around the signal line and the ground conductor layer and in the dielectric. These lines have no problem for signal transmission up to the 30 GHz band. Tends to occur.

On the other hand, a waveguide type line is advantageous in that transmission loss is small even in a millimeter wave band of 30 GHz or more. Formable lines have also been proposed.

For example, according to JP-A-6-53711,
There has been proposed a waveguide line in which a dielectric substrate is sandwiched between a pair of conductor layers, and a plurality of through conductors in two rows connecting between the conductor layers, for example, sidewalls formed by via holes. According to this waveguide line, the area inside the conductor wall is used as a line for signal transmission by surrounding the four sides of the dielectric material with a pseudo conductor wall composed of a conductor layer and a via hole. Thus, the size of the entire apparatus can be reduced.

[0006]

In general, when a high-frequency circuit is formed, particularly when a feed line or the like of an array antenna is formed, it is necessary to provide a branch in a wiring circuit of a transmission line.

However, since the signal line of the strip line, the microstrip line, and the coplanar line is not completely covered with the ground conductor layer, if a branch is provided in the middle of the transmission line, electromagnetic waves are emitted from the branch, resulting in transmission loss. However, there was a problem that the size became large.

Further, as the dielectric waveguide line, for example, an NRD guide having a structure in which a dielectric line is sandwiched between two ground conductor plates and a portion between the ground conductor plates other than the dielectric line is filled with air. There is. In order to provide a branch, a method of forming a directional coupler by combining two bent lines is used. However, if the line has a bent portion, a different propagation mode occurs depending on its shape. There is a problem in that transmission loss may be large and design restrictions are large. In addition, the dielectric line is usually made of a fluororesin or the like, but especially for those used in a high frequency region, since the line size becomes small, there is also a problem that it is difficult to process a bent portion and the like and mass production is difficult. there were. Further, there is a problem that it is difficult to form a wiring for a high-frequency circuit on or in a dielectric substrate.

In addition, a normal waveguide has a structure in which an electromagnetic wave propagates in a space surrounded by a metal wall. Since there is no loss due to a dielectric, a loss at a high frequency is small, and even if there is a branch, radiation occurs. Although there is no loss, there is a problem that the size is larger than that of a transmission line using a dielectric. On the other hand, a dielectric waveguide in which a dielectric having a relative permittivity of ε _r is filled in a waveguide can be manufactured with a normal dimension of 1 / √ε _r .
This also has the problem that it is difficult to form it on or in a dielectric substrate.

Furthermore, in a dielectric waveguide line proposed in Japanese Patent Application Laid-Open No. 6-53711, a signal transmission line surrounded by a quasi conductor wall formed by a pair of conductor layers and two rows of via holes. When a branch is simply provided on a line, there is a problem that a transmission loss increases because an electromagnetic field is disturbed.

Therefore, in order to form a high-frequency circuit by forming a transmission line wiring circuit provided with a branch for forming a feed line or the like of an array antenna in the dielectric substrate, it can be formed in the dielectric substrate. There has been a demand for a branch structure of a dielectric waveguide line which does not emit electromagnetic waves and has a small transmission loss.

The present invention has been made in view of the above circumstances, and an object of the present invention is to form a single line into three lines without being radiated or leaked from a high frequency signal electromagnetic wave, which can be formed in a dielectric substrate. An object of the present invention is to provide a branch structure of a dielectric waveguide line that can be branched into a line, can set an arbitrary power ratio after the branch, has a small transmission loss, and has good transmission characteristics.

[0013]

Means for Solving the Problems The inventors of the present invention have studied the above problems, and as a result, have found that a dielectric waveguide line has two rows of penetrating conductors arranged above and below a dielectric substrate. A transmission line composed of a dielectric waveguide line having a structure completely formed by a pair of conductor layers electrically connected to the through conductor group is provided, and the transmission lines are arranged parallel to the first transmission line. The second and third transmission lines are connected so that the transmission directions of the high-frequency signals are parallel to each other, and the second and third transmission lines are further connected.
4th to 5th arranged in parallel to each other
In the branch where the transmission lines of the high-frequency signals are connected so that the transmission directions of the high-frequency signals are parallel to each other, the arrangement of the penetrating conductors of the two rows of penetrating conductors has a predetermined arrangement structure. It has been found that there is almost no branching structure of the transmission line which can set the power ratio after branching arbitrarily and has good transmission characteristics with low transmission loss.

The branch structure of the dielectric waveguide according to the present invention is as follows.
A pair of conductor layers sandwiching the dielectric substrate, and a repetition interval of a half or less of a cutoff wavelength of the high-frequency signal in a transmission direction of the high-frequency signal, and a constant width d in a direction orthogonal to the transmission direction. A first to a sixth dielectric body, comprising: two rows of through conductor groups formed so as to electrically connect the conductor layers; and transmitting a high-frequency signal by a region surrounded by the conductor layers and the through conductor groups. One end of the waveguide line is connected to one end of the first dielectric waveguide so that the transmission direction of the high-frequency signal is parallel to the second and third dielectric waveguides. The fourth and sixth dielectric waveguide lines are provided on opposite sides of the fifth dielectric waveguide line at the other ends of the second and third dielectric waveguide lines. And the fourth and sixth dielectric waveguide lines are arranged in The second and third dielectric waveguide lines are arranged such that the ends on one end and the other end are aligned with each other to form the outer through conductor group. The interval A is 2d ≦ for the constant width d.
A first and a second auxiliary connection penetrating conductor group respectively connect between the one end side and the other end side of the penetrating conductor group in the adjacent row and are arranged in parallel so that A ≦ 3d. On the other hand the transmission direction of the length L ₁ of the two ends of the end side and the tip of one end of the first dielectric waveguide line said high-frequency signal is 0 <L 1 _<first connection through conductor groups of _d And the fourth to sixth dielectric waveguide lines are arranged such that their ends on one end side are aligned with each other and are outside of the fourth and sixth dielectric waveguide lines. The through-conductor groups are arranged in parallel so that the distance B between the through-conductor groups is 3d ≦ B ≦ 4d with respect to the constant width d, and the adjacent through-conductor groups of the fourth and fifth dielectric waveguide lines are arranged. Third between tips
Of the through-conductor groups for auxiliary connection, the tip ends of the through-conductor groups adjacent to the fifth and sixth dielectric waveguide lines are connected by a fourth through-conductor group for auxiliary connection, and one end of the wherein between the two ends of the other end side of both ends and the second and third dielectric waveguide line transmission direction of the length L ₂ of the high-frequency signal is 0 <
The connection is made by a second connection through conductor group of L ₂ <d.

Further, according to the branch structure of the dielectric waveguide line of the present invention, in the branch structure of the dielectric waveguide line of the present invention having the above-mentioned structure, the branch structure of the second and third dielectric waveguide lines is provided. Between at least one of the two rows of through conductor groups and / or at least one of the fourth and fifth dielectric waveguide lines;
A through conductor for adjusting the power ratio after branching is formed between the two rows of through conductor groups.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A branch structure of a dielectric waveguide according to the present invention will be described below with reference to the drawings.

FIGS. 1A and 1B are schematic perspective views for explaining an example of the configuration of a dielectric waveguide line according to the branching structure of the dielectric waveguide line of the present invention. In FIG. 1, reference numeral 1 denotes a dielectric substrate, 2 denotes a pair of conductor layers sandwiching the dielectric substrate 1, 3 denotes a through conductor formed to electrically connect the pair of conductor layers 2, and 4 denotes a high frequency. 2 formed by arranging the through conductors 3 in the signal transmission direction at a repetition interval p of not more than half the cutoff wavelength of the high-frequency signal and with a constant width d in a direction orthogonal to the transmission direction. It is a group of through conductors in a row.

According to FIG. 1, a pair of conductor layers 2 are formed at positions sandwiching a flat dielectric substrate 1 having a predetermined thickness a. The conductor layers 2 are formed on the upper and lower surfaces of at least the transmission line forming position of the dielectric substrate 1. A large number of through conductors 3 are provided between the conductor layers 2 to electrically connect the conductor layers 2 to each other. As shown in the figure, the through conductors 3 have a predetermined repetition interval p of not more than half the cutoff wavelength of the high-frequency signal transmitted by the line in the transmission direction of the high-frequency signal, that is, the line forming direction, and Are formed in two rows at a predetermined constant interval (width) d in a direction orthogonal to the above, thereby forming a through conductor group 4 serving as a transmission line.

Since the TEM wave can propagate between the pair of conductor layers 2 arranged in parallel, the distance p between the through conductors 3 in each row of the through conductor group 4 is larger than one half of the cutoff wavelength. Then, even if this line is supplied with electromagnetic waves, it does not propagate along the pseudo waveguide made here. However, if the distance p between the penetrating conductors 3 is less than half the cutoff wavelength, an electric side wall is formed, and the electromagnetic wave cannot propagate in the direction perpendicular to the transmission line, and is not reflected. The light is then propagated in the direction of the transmission line. As a result, a good transmission characteristic very similar to that of a dielectric waveguide can be obtained in a region having a cross section of a × d size surrounded by the conductor layer 2 and the through conductor group 4 having such a structure.

Here, there is no particular limitation on the thickness a of the dielectric substrate 1, but when used in the single mode, it is preferable that the thickness is about one half or two times the predetermined width d. In the example of FIG. 1, portions corresponding to the H plane and the E plane of the dielectric waveguide are formed by the conductor layer 2 and the through conductor group 4, respectively.
If the thickness a is about half the width d as shown in FIG. 1A, portions corresponding to the H plane and the E plane of the dielectric waveguide are formed by the conductor layer 2 and the through conductor group 4, respectively. If the thickness a is about twice as large as the width d as shown in FIG. 1B, the portions corresponding to the E-plane and the H-plane of the dielectric waveguide are respectively the conductor layer 2 and the through conductor group. 4 will be formed.

Reference numeral 5 denotes an auxiliary conductor layer for electrically connecting the through conductors 3 forming each column of the through conductor group 4 to each other.
It is formed appropriately as required. By forming such an auxiliary conductor layer, when viewed from the inside of the waveguide line, the side wall of the line is formed into a fine lattice shape by the through conductor group 4 and the auxiliary conductor layer 5, and the shielding effect of electromagnetic waves from the line is reduced. Can be more enhanced.

Further, in the example shown in FIG.
Although the through conductor groups 4 are arranged in four or six rows, the pseudo conductor walls formed by the through conductor groups 4 are doubled.
By forming it three times, it is possible to more effectively prevent leakage of electromagnetic waves from the conductor wall.

According to such a waveguide structure, a waveguide size when the relative dielectric constant of the dielectric substrate 1 and epsilon _r is the magnitude of 1 / √ε _r of conventional waveguide. Therefore, as the material forming the dielectric substrate 1 has a higher relative dielectric constant, the waveguide size can be reduced, the high-frequency circuit can be reduced in size, and the wiring can be formed with high density. The size can be used as a transmission line of a multilayer wiring board or a package for housing a semiconductor element.

The through conductors 3 constituting the through conductor group 4
Are arranged at a repetition interval p equal to or less than a half of the cutoff wavelength as described above. The repetition interval p is desirably a constant repetition interval in order to realize good transmission characteristics. As long as the interval is equal to or less than a half of the cutoff wavelength, the interval may be appropriately changed or some values may be combined.

The dielectric substrate 1 is not particularly limited as long as it functions as a dielectric and does not hinder the transmission of a high-frequency signal. It is desirable that the dielectric substrate 1 be made of ceramics from the viewpoint of ease of manufacture.

As such ceramics, ceramics having various relative dielectric constants are known.
In order to transmit a high-frequency signal by the dielectric waveguide according to the present invention, it is preferable that the dielectric waveguide is a paraelectric. This is because ferroelectric ceramics generally have large dielectric loss and high transmission loss in a high frequency range. Therefore, the relative permittivity ε _r of the dielectric substrate 1 is suitably about 4 to 100.

In general, the line width of a wiring layer formed on a multilayer wiring board or a package for housing a semiconductor element has a maximum of 1
mm, the minimum frequency that can be used is 15 GHz when a material having a relative dielectric constant of 100 is used and the upper part is an H plane, that is, an electromagnetic field distribution in which the magnetic field is wound parallel to the upper surface. , And can be used in the microwave band region. On the other hand, a dielectric made of a resin generally used as the dielectric substrate 1 has a relative dielectric constant ε _r of about 2, and therefore cannot be used unless the line width is 1 mm or more than about 100 GHz. It becomes.

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

Therefore, the transmission loss is practically usable.
In order to make it 100 (dB / m) or less, it is necessary to select a dielectric so that the following relationship is satisfied. f × ε _r ^1/2 × tan δ ≦ 0.8 In the equation, f is a frequency (GHz) to be used.

Examples of such a dielectric substrate 1 include alumina ceramics, glass ceramics, and aluminum nitride ceramics. For example, an appropriate organic solvent or a solvent is added to and mixed with ceramic raw material powder to form a slurry. A plurality of ceramic green sheets are obtained by forming a sheet by employing a conventionally known doctor blade method, calender roll method, or the like. Thereafter, each of these ceramic green sheets is subjected to appropriate punching and laminated. It is manufactured by firing at a temperature of 1500 to 1700 ° C for alumina ceramics, 850 to 1000 ° C for glass ceramics, and 1600 to 1900 ° C for aluminum nitride ceramics.

When the dielectric substrate 1 is made of alumina ceramics, for example, a suitable oxide such as alumina, silica, magnesia, or an organic solvent or solvent is added to a metal powder such as tungsten when the dielectric substrate 1 is made of alumina ceramics. The mixed paste is printed on a ceramic green sheet by a thick film printing method so as to completely cover at least the transmission line, and then fired at a high temperature of about 1600 ° C. to a thickness of 10 to
It is formed to have a thickness of 15 μm or more.

The metal powder is preferably copper / gold / silver for glass ceramics, and tungsten / molybdenum for aluminum nitride ceramics.
The thickness of the conductor layer 2 is generally about 5 to 50 μm.

The through conductor 3 may be formed of, for example, a via-hole conductor or a through-hole conductor.
The cross-sectional shape may be a polygon, such as a rectangle or a rhombus, in addition to a circle which is easy to manufacture. The through conductors 3 are formed by embedding a metal paste similar to that of the conductor layer 2 in a through hole formed by, for example, punching a ceramic green sheet, and then firing the same at the same time as the dielectric substrate 1.
The diameter of the through conductor 3 is suitably 50 to 300 μm. FIG. 2 is a plan view showing an example of the embodiment of the branch structure of the dielectric waveguide line of the present invention using such a dielectric waveguide line.

In FIG. 2, reference numeral 3 denotes a direction in a dielectric substrate (not shown) at a repetition interval p equal to or less than half the cutoff wavelength of the high-frequency signal in the transmission direction of the high-frequency signal and at a direction orthogonal to the transmission direction. The through conductors 4a to 4h are formed to electrically connect a pair of conductor layers (not shown) sandwiching the dielectric substrate with a constant width d.
Is a group of through conductors constituted by: Reference numeral 5 denotes a first dielectric waveguide line composed of a pair of conductor layers and a group of through conductors 4a, and reference numeral 6 denotes a second dielectric waveguide composed of a pair of conductor layers and a group of through conductors 4b and 4c. 7 is a third dielectric waveguide line composed of a pair of conductor layers and through conductor groups 4c and 4d, and 8 is a third dielectric waveguide line composed of a pair of conductor layers and through conductor groups 4e and 4f. 9 is a fifth dielectric waveguide line composed of a pair of conductor layers and through conductor groups 4f and 4g, and 10 is a pair of conductor layers. The figure shows a sixth dielectric waveguide line composed of through conductor groups 4g and 4h.

The second dielectric waveguide line 6 and the third dielectric waveguide line 7 are arranged so as to share the through conductor group 4c in one row with each other. The line 8 and the sixth dielectric waveguide line 10 are respectively provided on both sides of the fifth dielectric waveguide line 9 with the through conductor groups 4f and 4g in one row and the fifth dielectric waveguide line 9 respectively. The dielectric waveguide lines 5 to 10 are arranged so that the transmission directions of the respective high-frequency signals are parallel to each other. In this example, the distance A between the through conductor groups 4b and 4d outside the second and third dielectric waveguide lines 6 and 7 is 2d = A with respect to the constant width d, and the fourth and the fourth 6 shows a case where the distance B between the through conductor groups 4e and 4h outside the dielectric waveguide lines 8 and 10 is 3d = B with respect to the constant width d.

Reference numeral 4i denotes a second and a third juxtaposed one end of the first dielectric waveguide line 5 and one end of the first dielectric waveguide line 5 opposing each other so that the transmission direction of the high-frequency signal is parallel. Is a first group of through conductors for connection that connects between both ends on one end side of the dielectric waveguide lines 6 and 7.
And a through conductor group disposed in a direction perpendicular to the transmission direction of the high-frequency signal with respect to the through conductor 5a at the tip of the dielectric waveguide line 5, and the through conductor groups 4b and 4c are arranged to extend. An example in which a through conductor group is used to form a step is shown. Reference numeral 11 denotes a first connection dielectric waveguide line constituted by the first connection through conductor group 4i.

Reference numeral 4j denotes a pair of second and third dielectric waveguide lines 6 and 7, one end of which is opposed to the other end so that the transmission direction of the high-frequency signal is parallel. The second through-conductor group for connection connects between both ends of the fourth to sixth dielectric waveguide lines 8 to 10 on one end side, and in this example, the second and third dielectric conductors are used. The penetrating conductor group disposed in the direction perpendicular to the transmission direction of the high-frequency signal with respect to the penetrating conductors 6a and 7a at the other ends of the body waveguide lines 6, 7 and the penetrating conductor groups 4e and 4h are extended. An example is shown in which the through conductor group is arranged in a stepwise manner. 12
Indicates a second dielectric waveguide line for connection constituted by the second through conductor group for connection 4j.

According to such a configuration, the width d of the first dielectric waveguide line 5 before branching is set to the first connecting through conductor group 4.
i and the second dielectric waveguide line 6 and the third
And the width 2d of the second and third dielectric waveguide lines 6 and 7 is changed to the second through conductor for connection. It is spread through the group 4j and connected to the fourth to sixth dielectric waveguide lines 8 to 10 so that the transmission direction of the high-frequency signal becomes parallel.
4th to 6th dielectric waveguide lines 8 from the 2nd and 3rd dielectric waveguide lines 6 and 7 from the dielectric waveguide line 5 of FIG.
By branching the high-frequency signal to each of the first through third through ten, a single dielectric waveguide line can be branched into three dielectric waveguide lines with a small structure, and the first and second connections can be made. By branching through the through conductor groups 4i and 4j for use, mismatching of characteristic impedance due to branching can be reduced, and the direction of the surface of the electric field having the same phase before and after branching does not change. The reflection is reduced, and as a result, a branch structure with small transmission loss is obtained.

Note that the length L _{1 of} the first connection through conductor group 4i in the signal transmission direction and the second connection through conductor group 4j
The length L ₂ in the signal transmission direction is 0 <L ₁ <d and 0 <
It is preferable to set L ₂ <d, and the lengths L ₁ and L ₂
Is longer than a certain width d, the effect of reducing the mismatch of the characteristic impedance and reducing the reflection of the high-frequency signal at the branch portion is small.

The repetition interval of the penetrating conductors 3 in the first and second connection penetrating conductor groups 4i and 4j is the same as the repetition interval p in each of the dielectric waveguide lines 4a to 4h. It is desirable that the thickness be equal to or less than one-half of that, so that the first and second connecting dielectric waveguide lines 11 and 12 also form electrical side walls.

Further, the first dielectric waveguide line 5
Power ratio after branching to third and third dielectric waveguide lines 6.7, and second and third dielectric waveguide lines 6.7
The power ratio after branching from the first to sixth dielectric waveguide lines 8 to 10 is respectively the center line of the first dielectric waveguide line 5 and the second and third dielectric waveguide lines. The positional relationship between the center lines of the pipe lines 6 and 7, that is, the straight lines passing through the shared through conductor group 4 c, and the second and third dielectric waveguide lines 6 and 7.
7 and the fourth and fifth dielectric waveguide lines 8.
9 and a center line (a straight line passing through the through conductor group 4g) of the fifth and sixth dielectric waveguide lines 9 and 10 (a straight line passing through the through conductor group 4g). Can be set to any power ratio without changing the characteristic impedance at That is, each center line is perpendicular to the signal transmission direction at a distance h (0 <h <d /
By moving only by 2), the power ratio after branching can be arbitrarily set according to the magnitude of the distance h.

For example, as shown in FIG. 2, the center line of the first dielectric waveguide line 5 and the center lines of the second and third dielectric waveguide lines 6 and 7 are made substantially coincident with each other. , The center line of the second dielectric waveguide line 6, the center line of the fourth and fifth dielectric waveguide lines 8 and 9, and the center line of the third dielectric waveguide line 7. And fifth and sixth dielectric waveguide lines 9
When the center line of 10 is substantially matched, the power after branching when branching from the first dielectric waveguide line 5 to the second and third dielectric waveguide lines 6 and 7 The ratio becomes approximately 1: 1 equally branched, and the second and third dielectric waveguide lines 6.
The power ratio after branching from the seventh to fourth to sixth dielectric waveguide lines 8 to 10 is approximately 1: 3: 1. The value of the power ratio changes depending on the frequency of the signal.

FIG. 3 is a plan view showing another example of the embodiment of the branch structure of the dielectric waveguide according to the present invention.

In FIG. 3, reference numeral 3 denotes a direction in which a high-frequency signal is transmitted in a dielectric substrate (not shown) at a repetition interval p equal to or less than half the cutoff wavelength of the high-frequency signal and orthogonal to the transmission direction. A through conductor formed to electrically connect a pair of conductor layers (not shown) sandwiching the dielectric substrate with a constant width d.
Is a group of through conductors constituted by: Reference numeral 15 denotes a first dielectric waveguide line constituted by a pair of conductor layers and a group of through conductors 14a, and reference numeral 16 denotes a second dielectric waveguide constituted by a pair of conductor layers and a group of through conductors 14b and 14c. A waveguide line 17 is a third dielectric waveguide line composed of a pair of conductor layers and through conductor groups 14d and 14e, and 18 is a third dielectric waveguide line composed of a pair of conductor layers and through conductor groups 14f and 14g. The fourth dielectric waveguide line is constituted, 19 is a fifth dielectric waveguide line constituted by a pair of conductor layers and through conductor groups 14h and 14i, and 20 is a pair of conductor layers. A sixth dielectric waveguide line constituted by through conductor groups 14j and 14k is shown.

The second dielectric waveguide 16 and the third dielectric waveguide 17 are spaced apart from each other at the ends of the one end side and the other end side so that the distance between the outer through conductor groups 14b and 14e is equal. A is arranged in parallel so that A is 2d ≦ A ≦ 3d with respect to the constant width d (in this example, 2d ≠ A), and the through conductor groups 14c and 14d in adjacent rows are arranged in parallel. A first auxiliary connection through-conductor group 14n and a second auxiliary connection through-conductor group 14o are connected between the one end and the other end, respectively. Further, the fourth to sixth dielectric waveguide lines 18 to 20 are arranged outside the fourth dielectric waveguide line 18 and the sixth dielectric waveguide line 20 by aligning the ends at one end. Are arranged in parallel so that the distance B between the through conductor groups 14f and 14k is 3d ≦ B ≦ 4d (in this example, 3d ≠ B) with respect to the constant width d. 4
A third auxiliary connection penetrating conductor group 14p connects the distal ends of the penetrating conductor groups 14g and 14h in the adjacent rows of the fifth dielectric waveguide lines 18 and 19 to form the fifth and sixth dielectric conductors. The end portions of the through conductor groups 14i and 14j in adjacent rows of the body waveguide lines 19 and 20 are connected by a fourth auxiliary connection through conductor group 14q and arranged. 15 to 20 are arranged such that the transmission directions of the respective high-frequency signals are parallel.

Reference numeral 14l denotes a second and a third juxtaposed with one end of the first dielectric waveguide line 15 opposed to one end so that the transmission direction of the high-frequency signal is parallel. A first group of through conductors for connection that connects between both ends on one end side of the dielectric waveguide lines 16 and 17 of the first embodiment.
And a through-conductor group disposed in a direction perpendicular to the transmission direction of the high-frequency signal with respect to the through-conductor 15a at the tip of the dielectric waveguide line 15, and the through-conductor groups 14b and 14e are arranged to extend. An example in which a through conductor group is used to form a step is shown. Reference numeral 21 denotes a first connection dielectric waveguide line constituted by the first connection through conductor group 14l.

Further, 14 m is provided with both ends on the other end side of the second and third dielectric waveguide lines 16 and 17 such that one end side thereof is opposed so that the transmission direction of the high-frequency signal is parallel. The second through-conductor group for connection connects between the first and second ends of the fourth to sixth dielectric waveguide lines 18 to 20. In this example, the second and third dielectric conductors are used. The through-conductor groups disposed in the direction perpendicular to the transmission direction of the high-frequency signal with respect to the through-conductors 16a and 17a at the other ends of the body waveguide lines 16 and 17, and the through-conductor groups 14f and 14k are extended. An example is shown in which the through conductor group is arranged in a stepwise manner. twenty two
Indicates a second dielectric waveguide line for connection constituted by the second through conductor group 14m for connection.

According to such a configuration, the width d of the first dielectric waveguide line 15 before branching is set to the first connecting through conductor group 14.
The second dielectric waveguide lines are extended in parallel to each other so that the distance between the penetrating conductor groups 14b and 14e at both ends becomes the distance A by extending the distance A through 2d ≦ A ≦ 3d. 16 and the third dielectric waveguide line 17 are connected so that the transmission direction of the high-frequency signal is parallel, and the width A of the second and third dielectric waveguide lines 16 and 17 is set to the second width. Connection through conductor group
Fourth to sixth dielectric waveguide lines 18 to 20 which are extended in parallel to each other so that the distance between both ends becomes the distance B by extending the distance B between 3d ≦ B ≦ 4d via 14m. The first and second dielectric waveguide lines 15 and 16 are connected so that the transmission directions of the high-frequency signals are parallel.
By dividing a high-frequency signal into each of the fourth to sixth dielectric waveguide lines 18 to 20 via 17, one dielectric waveguide line can be reduced to three dielectric members with a small structure. By branching through the waveguide line, and branching through the first and second connection through conductor groups 14l and 14m, mismatching of characteristic impedance due to branching can be reduced. Since the direction of the surface of the electric field does not change, the reflection of the high-frequency signal at each branching portion decreases, and as a result, a branching structure having a small transmission loss is obtained.

According to such a configuration, the second dielectric waveguide line 16 and the third dielectric waveguide line are separated from each other at an interval of A-2d, and the fourth dielectric waveguide line is separated from the fourth dielectric waveguide line. The pipe line 18, the fifth dielectric waveguide line 19 and the sixth dielectric waveguide line 20 are
3d to be be arranged apart at intervals divided in any ratio, S ₁₁ of S parameters at each bifurcation
Is somewhat deteriorated, but the degree of freedom of wiring is increased, and the isolation is also improved.

In this case, the first through conductor group for connection is used.
Length L ₂ is also the signal transmission direction of 14l length L ₁ and the signal transmission direction of the second connection through conductor groups 14m, 0 <L ₁ <d
And 0 <L ₂ <d, and even if the lengths L ₁ and L ₂ are made longer than a certain width d, the characteristic impedance mismatch is reduced and the high-frequency signal at the branch portion is reduced. The effect of reducing the reflection of light is small.

Further, the first and second through conductor groups for connection
The repetition interval of the through conductor 3 at 14 l · 14 m is preferably not more than half the cutoff wavelength of the high-frequency signal, similarly to the repetition interval p of each of the dielectric waveguide lines 14 a to 14 k. Also, electrical side walls are formed in the second connecting dielectric waveguide lines 21 and 22 as well.

In addition, the first through fourth auxiliary connection through conductor groups
The lengths L ₃ , L ₄ , and L ₅ of 14n to 14q are each 0 <L
₃ <it is preferable to a _{d, 0 <L 4 <d} , 0 <L 5 <d. If the length of each of the auxiliary connection through conductor groups 14n to 14q is made longer, the loss due to reflection may increase. Further, the first to fourth auxiliary connection through conductor groups 14n to 14n
Also, it is desirable that the repetition interval of the through conductors 3 in q is not more than one half of the cutoff wavelength of the high-frequency signal, so that the first to fourth auxiliary connection through conductor groups 14n to 14q also have electric side walls. Is formed.

The first dielectric waveguide line 15 is connected to the second
Power ratio after branching to the second and third dielectric waveguide lines 16 and 17, and the second and third dielectric waveguide lines 16 and 17
The power ratio after branching from the first to sixth dielectric waveguide lines 18 to 20 is the center ratio of the first dielectric waveguide line 15 and the second and third dielectric waveguide lines, respectively. The positional relationship between the center line between the pipe lines 16 and 17, that is, the center line between the through conductor groups 14c and 14d, and the second and third dielectric waveguide lines 16 and 17
Center lines and the fourth and fifth dielectric waveguide lines 18 and 19
Between the center line between them (the center line between the through conductor groups 14g and 14h) and the center lines of the fifth and sixth dielectric waveguide lines 19 and 20 (the center line between the through conductor groups 14i and 14j). By relationship
Any power ratio can be set without changing the characteristic impedance at each branch. That is, each center line is perpendicular to the signal transmission direction at a distance h.
By moving by (0 <h <d / 2), the power ratio after branching can be set arbitrarily according to the magnitude of the distance h.

For example, as shown in FIG. 3, the center line of the first dielectric waveguide line 15 and the center lines of the second and third dielectric waveguide lines 16 and 17 are substantially matched. , The center line of the second dielectric waveguide 16, the center line of the fourth and fifth dielectric waveguides 18 and 19, and the center line of the third dielectric waveguide 17. And fifth and sixth dielectric waveguide lines 19
When the center line of 20 is substantially coincident with the first dielectric waveguide line 15, the second and third dielectric waveguide lines
The power ratio after branching to 16 and 17 is approximately equal to 1: 1 and the second and third dielectric waveguide lines 16 and 17 have the same power ratio.
The power ratio after branching from the 17 to the fourth to sixth dielectric waveguide lines 18 to 20 is approximately 1: 3: 1. The value of the power ratio differs depending on the frequency of the signal.

In the example of FIG. 2, A = 2d and B =
Although the case of 3d is shown in the example of FIG. 3 where A ≠ 2d and B ≠ 3d, 2d ≦ A ≦ 3d and 3d ≦ B ≦
Needless to say, any combination may be set within the range of 4d.

Next, still another example of the embodiment of the branch structure of the dielectric waveguide line of the present invention is shown in a plan view in FIG.

FIG. 4 shows a configuration of the second dielectric waveguide line 16.
This is the same as FIG. 3 except that a through conductor 23 for adjusting the power ratio after branching is provided between the two rows of through conductor groups 14b and 14c. It is.

According to such a configuration, the cutoff frequency of the second dielectric waveguide 16 provided with the through conductor 23 is increased. Therefore, considering the lowest order TE ₁₀ mode of the waveguide is less than the cut-off frequency of the second dielectric waveguide line 16 signal is propagated only in the third dielectric waveguide line 17, the cut-off frequency The second and third dielectric waveguide lines 16 have been described above.
The signal propagates to both of the two, and the lower the frequency at which the higher-order mode occurs, the higher the frequency, the greater the ratio of signal propagation to the second dielectric waveguide line 16. Therefore, when the first dielectric waveguide line 15 before branching is branched into the second and third dielectric waveguide lines 16 and 17, the power ratio after branching is not equal branching of 1: 1. Thereby, the through conductor 23 provided in the second dielectric waveguide line 16 is formed.
By appropriately selecting the position and the number of the power supply, the power after branching can be adjusted to an arbitrary power ratio.

The through conductor 23 for adjusting the power ratio after branching
May be provided on any of the other dielectric waveguide lines 17 to 20, may be provided simultaneously on a plurality of dielectric waveguide lines 16 to 20, or may be provided on the connecting dielectric waveguide lines 21 and 22. May be provided. Also, the through conductor groups 14c and 14d, 14g and 14h and 14
An arbitrary power ratio may be set in combination with shifting the center line between j and 14k.

[0060]

EXAMPLE For the branch structure of the dielectric waveguide line of the present invention having the structure shown in FIG. 2, the transmission characteristics of the transmission line including the branch were calculated by the finite element method. The conductor layer 2 and the through conductor 3 are made of pure copper having a conductivity of 5.8 × 10 ⁷ (1 / Ωm), and the dielectric substrate 1 has a relative permittivity ε _r of 5 and a dielectric loss tangent t.
75% by weight of borosilicate glass having an δ of 0.001 and 25 of alumina
% Of the dielectric substrate 1 and a through conductor 3
Is 0.1 mm, and the repetition interval of the through conductor group 4 is p = 0.
The frequency characteristics of the S parameters were calculated by assuming that 25 mm, the fixed width d of the through conductor group 4 was 1.2 mm, and the lengths of the first to sixth dielectric waveguide lines 5 to 10 were 2.25 mm, respectively. .

The results are shown in a diagram in FIG. In FIG. 5, the horizontal axis represents the frequency (GHz), and the vertical axis represents the values (dB) of S ₁₁ , S ₂₁ , S _31, and S ₄₁ among the S parameters, and the characteristic curve in the figure represents the frequency characteristic of each S parameter. It represents.
Incidentally, here S ₁₁ comes out of the first dielectric waveguide line 5 enters from the first dielectric waveguide line 5 component, S ₂₁
It is a component exiting from the fourth dielectric waveguide line 8 enters the first dielectric waveguide line 5, S ₃₁ is the fifth in from the first dielectric waveguide line 5 S ₄₁ represents a component coming out of the dielectric waveguide line 9, and S ₄₁ represents a component coming out of the sixth dielectric waveguide line 10 entering from the first dielectric waveguide line 5. .

[0062] From this result, it S ₁₁ in 66~90GHz -10
dB or less, and in particular, the length L1 of the _first connecting through conductor group 4i (the first connecting dielectric waveguide line 11) is _{１ ／} of the guide wavelength of the dielectric waveguide line. It can be seen that the signal reflection is small in the vicinity of 77 GHz which is the frequency corresponding to the above, and that the high frequency signal is transmitted well through the first dielectric waveguide line 5 on the input side. Further, the ratio of the output power from the three dielectric waveguide lines 8, 9, and 10 on the output side is 3: 10: 3 at 77 GHz.

Next, the center lines of the second and third dielectric waveguide lines 6 and 7 are perpendicular to the center line of the first dielectric waveguide line 5 by d / 10. In the same manner, the frequency characteristic of the S parameter was obtained by shifting to the left side. The output power ratio from the fourth to sixth dielectric waveguide lines 8 to 10 was 6: 10: 3 at 77 GHz, It was confirmed that the power ratio could be adjusted.

Next, a penetrating conductor 23 is provided at the end of the second dielectric waveguide line 6 at a position of d / 10 in a direction perpendicular to the line from the penetrating conductor group 4b, and the frequency characteristic of the S parameter is similarly determined. As a result, the output power ratio from the fourth to sixth dielectric waveguide lines 8 to 10 was 5: 12: 3 at 77 GHz, and it was confirmed that the power ratio after branching could also be adjusted.

Further, the dielectric waveguide line of the present invention having the structure shown in FIG. 3 was similarly evaluated by obtaining the S-parameter frequency characteristics. It has been confirmed that the power ratio after branching can be adjusted by setting the positional relationship of the center line and disposing the through conductor 23 for adjusting the power ratio.

As described above, according to the branch structure of the dielectric waveguide line of the present invention, one line can be formed into a dielectric substrate without radiation / leakage of electromagnetic waves of high-frequency signals, and one line can be replaced with three lines. It can be confirmed that the transmission ratio can be set to any value, the power ratio after the branching can be set arbitrarily, and the transmission characteristics are good and the transmission characteristics are small.

It should be noted that the present invention is not limited to the above-described embodiments, and that various changes and improvements can be made without departing from the scope of the present invention.
For example, the widths of the first to third dielectric waveguide lines may be different values. Further, the first and second connection through conductor groups may be arranged not only in a step shape but also in a linear shape or in an arc shape, or in any other shape. May be arranged.

[0068]

As described in detail above, according to the branch structure of the dielectric waveguide line of the present invention, the first to sixth dielectric waveguide lines are connected in the above-mentioned predetermined configuration. A structure in which one dielectric waveguide line is branched into three dielectric waveguide lines. Since the mismatch in characteristic impedance of the dielectric waveguide lines before and after the branch portion can be reduced, Since the reflection of the high-frequency signal is reduced and the propagation mode of the high-frequency signal is not disturbed at the branch portion, a good branching structure of the dielectric waveguide line with small transmission loss can be provided.

Further, according to the branch structure of the dielectric waveguide line of the present invention, a through conductor is formed between two rows of through conductor groups of the second to sixth dielectric waveguide lines. , The power ratio after the branch can be arbitrarily adjusted.

According to the branch structure of the dielectric waveguide line of the present invention, the structure of the branch structure of the first to third dielectric waveguide lines is repeatedly provided to thereby form one dielectric waveguide. It is also possible to branch the waveguide line into any number of four or more dielectric waveguide lines.

As described above, according to the present invention, a single line can be branched into three lines without radiation and leakage of high-frequency signal electromagnetic waves, and the power ratio after the branch can be formed. Can be set arbitrarily and a branch structure of the dielectric waveguide line having good transmission characteristics with small transmission loss can be provided.

[Brief description of the drawings]

FIGS. 1A and 1B are schematic perspective views illustrating examples of a dielectric waveguide according to the present invention.

FIG. 2 is a plan view for explaining an example of an embodiment of a branch structure of a dielectric waveguide according to the present invention.

FIG. 3 is a plan view for explaining another example of the embodiment of the branch structure of the dielectric waveguide according to the present invention.

FIG. 4 is a plan view for explaining another example of the embodiment of the branch structure of the dielectric waveguide according to the present invention.

FIG. 5 is a diagram showing frequency characteristics of S parameters in a branch structure of a dielectric waveguide according to the present invention.

[Explanation of symbols]

1. Dielectric substrate 2 Conductive layer 3 Through conductor 4a 4h, 14a to 14k: through conductor groups 4i, 4j, 14l, 14m: connection through conductor groups 14n to 14q: auxiliary connection through conductor groups 5 to 10, 15 ... 20 first through sixth dielectric waveguide lines 23 through conductor d for power ratio adjustment・ ・ ・ ・ ・ ・ Constant width (width between through conductor groups)

Claims (2)

(57) [Claims] A pair of conductor layers sandwiching a dielectric substrate;
In the transmission direction of the high frequency signal, the cutoff wavelength of the high frequency signal is 2
Two rows of through conductor groups formed so as to electrically connect the conductor layers with a constant width d in a direction orthogonal to the transmission direction at a repetition interval equal to or less than 1 / And first to sixth dielectric waveguide lines for transmitting a high-frequency signal by a region surrounded by the through conductor group; and the second and third dielectric waveguide lines on one end side of the first dielectric waveguide line. Of the second and third dielectric waveguide lines is provided at one end side of the second and third dielectric waveguide lines so that the transmission directions of the high-frequency signals are parallel. The fourth to sixth dielectric waveguide lines are arranged on both sides of the fifth dielectric waveguide line, and the fourth and sixth dielectric waveguide lines are arranged so that the transmission direction of the high-frequency signal is parallel. And the second and third dielectric waveguides are provided side by side so as to face each other. The paths are arranged in parallel so that the ends A on the one end side and the other end side are aligned so that the interval A between the outer through-hole conductor groups is 2d ≦ A ≦ 3d with respect to the constant width d. The first and second auxiliary through-conductor groups for auxiliary connection are respectively connected between the one end side and the other end side of the through-conductor group, and both ends on one end side and the first dielectric waveguide line are connected to each other. wherein a distal end of the one end side transmission direction of the length L ₁ of the high-frequency signal is 0 <L 1 _<d
And the fourth through sixth dielectric waveguide lines are aligned at one end and the fourth dielectric waveguide line and the sixth through hole are connected together. The distance B between the through conductor groups outside the dielectric waveguide line is set in parallel so that 3d ≦ B ≦ 4d with respect to the constant width d, and the fourth and fifth dielectric waveguides are arranged. A third auxiliary connection through-conductor group is provided between the ends of adjacent through-conductor groups of the pipe line, and a fourth auxiliary connection group is provided between the adjacent through-conductor groups of the fifth and sixth dielectric waveguide lines. connected by connection through conductor groups, and the between the ends of the other end side of both ends and the second and third dielectric waveguide line of one end
Transmission direction of the length _{L 2} of the high-frequency signal is 0 _<L 2 <second d
A branch structure of a dielectric waveguide line characterized by being connected by a connecting through conductor group. 2. The branch structure of a dielectric waveguide line according to claim 1, wherein at least one of said second and third dielectric waveguide lines is between said two rows of through conductor groups and / or
Alternatively, a through conductor for adjusting a power ratio after branching is formed between at least one of the two rows of through conductor groups of the fourth and fifth dielectric waveguide lines. Branch structure of pipe line.