JP2003258512A - Directional coupler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a directional coupler the directivity of which is enhanced to improve detection accuracy of a signal of its main line 3 by its sub line 4. <P>SOLUTION: The main line 3 and the sub line 4 are formed on a base 2 at an interval. A part of the main line 3 which is electromagnetically coupled to the sub line 4 is formed to be a straight line part. The sub line 4 is formed to be almost a spiral shape having a straight line part at least at its part, the straight line part of the sub line 4 placed along the main line 3 at an interval acts like a part electromagnetically coupled to the main line 3. The sub line 4 is formed nearly to be a spiral shape to increase the inductance of the sub line 4 so as to enhance the isolation characteristic between the main line 3 and the sub line 4. Thus, the directivity being a ratio of a degree of coupling to the isolation characteristic can be enhanced. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a directional coupler that takes out a part of an output signal and outputs it as a signal for feedback control.

[0002]

BACKGROUND ART FIG. 9 is a schematic plan view showing an example of a directional coupler. The directional coupler 1 is configured to include a base 2, and a main line 3 and a sub line 4 formed on the base 2. Main line 3 and sub line 4
Are partly arranged in parallel with each other with a gap therebetween, and electromagnetically couple at this arranged part. The sub line 4 can extract a part of the signal flowing through the main line 3 by its electromagnetic coupling.

For example, when the directional coupler 1 is incorporated in a mobile phone, it is used in a high frequency circuit on the transmitting side. One end side 3α of the main line 3 is connected to the high frequency amplifier circuit, and the other end side 3β is connected to the antenna side. Further, one end side 4α of the sub line 4 is connected to a circuit that controls the high frequency amplifier circuit, and the other end side 4β is terminated by a terminating resistor. The sub line 4 takes out (detects) a part of the electric power passing through the main line 3, and the detection signal is sent to a circuit that controls the high frequency amplifier circuit, and the high frequency power output from the high frequency amplifier circuit by the circuit is output. By controlling, the magnitude of the signal emitted from the antenna is kept within a predetermined range.

Input from one end 3α of the main line 3,
The loss that occurs when the other end is output to 3β is the "insertion loss".
In addition, the power input from one end 3α of the main line 3 and output to one end 4α of the sub line 4 is referred to as “coupling degree”,
Further, the electric power input from one end 3α of the main line 3 is reflected at the inside of the coupler or the output end (other end) 3β and the like, and the input end 3α is reflected.
The minute electric power that appears at the other end 4β of the sub line 4 with respect to the electric power output to is called "isolation", and the ratio of "coupling degree" to "isolation" is called "directivity".

[0005]

The directional coupler 1 has been downsized along with the downsizing of devices to be incorporated such as portable telephones. For this reason, the base 2 becomes smaller, and inevitably the length of the portion where the main line 3 and the sub line 4 are juxtaposed becomes shorter. That is, the portion where the main line 3 and the sub line 4 are electromagnetically coupled is shortened. From this, there is a problem that a sufficient degree of coupling cannot be obtained.

Therefore, in order to obtain a sufficient degree of coupling, it is conceivable to reduce the distance between the main line 3 and the sub line 4. However, if the space is made too narrow, there is a risk that dielectric breakdown may occur between the main line 3 and the sub line 4, and there is a limit to making the space between the main line 3 and the sub line 4 narrow, so that satisfactory coupling is achieved. I can't get the degree.

Therefore, a directional coupler 1 as shown in FIG. 10 has been proposed. This proposed directional coupler 1
Then, on both sides of the main line 3, the sub-line 4 is provided with a space between them.
(4A, 4B) are arranged in parallel, and both ends of these sub lines 4A, 4B are short-circuited. In this configuration, the number of sub line portions that are parallel to the main line 3 is increased to obtain a satisfactory degree of coupling.

As another proposal, both lines 3,
It is conceivable to arrange a long line on the substrate 2 by reducing the line width of 4. However, in this case, since the line loss increases, the insertion loss also increases, which causes a large power consumption of the device incorporating the directional coupler 1. This is a problem that shortens the driving time in a mobile phone terminal or the like, which is generally driven by a battery.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a directional coupling capable of reducing the size of a device while ensuring a desired degree of coupling and sufficient directivity. To provide a container.

[0010]

In order to achieve the above object, the present invention has the following constitution as means for solving the above problem. That is, in the first aspect of the invention, the main line and the sub line are formed on the base body with a gap therebetween, and at least a part of them are arranged in parallel so that they can be electromagnetically coupled, and the sub line is longer than the line length of the main line. In the directional coupler having a length and having a configuration for extracting a part of the signal flowing through the main line by electromagnetic coupling, in the main line, the electromagnetic coupling portion that electromagnetically couples with the sub line is formed in a linear shape, The sub line has a substantially spiral shape having a linear portion at least in a part,
It is characterized in that the straight line portions of the sub line are arranged side by side along the electromagnetic coupling portion of the main line with a space therebetween to perform electromagnetic coupling.

A second invention comprises the configuration of the first invention,
The main line is characterized by being formed in a straight line over the entire length.

A third invention comprises the structure of the first or second invention, wherein the base has a multi-layer structure, and the sub line is formed over a plurality of layers of the base. The straight line portion of the sub-line includes a portion which is arranged in parallel above the electromagnetic coupling portion of the main line with a gap, a portion which is arranged in parallel below the electromagnetic coupling portion of the main line with a gap, and the main line. A part that is provided side by side with a gap on one side on the same plane as the electromagnetic coupling part of,
It is characterized in that it has two or more portions of an electromagnetic coupling portion of the main line and a portion arranged in parallel on the other lateral side on the same plane with a gap.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1A is a schematic plan view of the directional coupler of the first embodiment, and FIG. 1B is an exploded view of the directional coupler of the first embodiment. Is shown in FIG.
FIG. 1C schematically shows a cross-sectional view taken along the line AA of FIG. In the description of the first embodiment, the same components as those of the directional coupler shown in FIGS. 9 and 10 are designated by the same reference numerals, and duplicate description of the common portions will be omitted.

In the first embodiment, the base 2 is made of an insulating material and has a multi-layer structure. This base 2
The main line 3 is formed on the first layer 2a. This main line 3 is formed in a linear shape over the entire length from one end side to the other end side of the base body 2. At both ends of the main line 3, respectively,
An external connection electrode 6 is provided. The main line 3 is conductively connected to an external circuit such as an antenna or a signal supply source via the external connection electrode 6.

The sub line 4 is formed from the first layer 2a of the base 2 to the second layer 2b, and a portion (first layer forming portion) 4a formed on the first layer 2a of the base 2 is formed. The portion (second layer formation portion) 4b formed on the second layer 2b is connected via a via hole 7. This sub line 4
Has a substantially spiral shape.

In the first embodiment, the first layer forming portion 4a of the sub line 4 is a straight line portion, and the main line 3 is formed over the entire length.
Are arranged side by side along the main line 3 with a space therebetween. In addition, a part of the straight line portion P of the second layer forming portion 4b is arranged above the main line 3 along the main line 3 in parallel. Similarly to the main line 3, external connection electrodes X and Y are provided at both ends of the sub line 4, and the sub line 4 is formed by the external connection electrodes X and Y.
It can be electrically connected to an external circuit. Although only two layers of the base 2 are shown in FIG. 1, an exterior insulating layer for protecting the sub line 4 may be formed above the second layer 2b, for example.

In the first embodiment, as described above,
The sub line 4 has a portion 4 a that is arranged side by side on the side of the main line 3 with a gap, and a portion P that is arranged side by side on the upper side of the main line 3 with a gap. Part of the sub line 4 4a, P
And almost the entire length of the main line 3 are electromagnetic coupling portions E that are electromagnetically coupled to each other. That is, as compared with the directional coupler 1 shown in FIG. 9 in which the sub line 4 is provided side by side only on one lateral side of the main line 3, the sub line 4 and the main line 3 are electromagnetically coupled. The length of the portion to be made can be increased. As a result, the degree of coupling between the main line 3 and the sub line 4 can be increased without increasing the size of the base 2.

This has been confirmed by the inventor's experiment. In the experiment, for the directional coupler 1 of the first embodiment, the directional coupler 1 of FIG. 9, and the directional coupler 1 of FIG. I checked. The result is shown in FIG. In FIG. 2, the solid line A is for the directional coupler 1 of the first embodiment, the solid line B is for the directional coupler 1 of FIG. 9, and the dotted line C is for the directional coupler of FIG. It is that of the coupler 1.
As shown in FIG. 2, by having the configuration of the first embodiment, the degree of coupling between the main line 3 and the sub line 4 can be increased as compared with the configurations of FIGS. 9 and 10. it can.

Further, in the first embodiment, the sub line 4
Has a substantially spiral shape, and the inductance value of the sub line 4 can be increased. Therefore, the isolation characteristic can be improved.

Therefore, as shown in the experimental results for examining the directivity shown in FIG. 3, the directional coupler 1 having the configuration of the first embodiment (see the solid line A).
Are those shown in FIG. 9 (see solid line B) and those in FIG. 10 (dotted line C).
It is possible to significantly improve the directivity as compared with (see). In the first embodiment, in order to improve the directivity by making the inductance value of the sub line 4 as large as possible, the sub line 4 is formed by the base 2
Is formed in the vicinity of the edge along the edge, thereby increasing the line length.

As described above, by providing the configuration of the first embodiment, it is possible to improve the directivity and to improve the detection accuracy of the signal detected by the sub line 4 from the main line 3 and to reduce the size. It becomes easy to provide the directional coupler 1 capable of performing the above.

Further, in the first embodiment, the main line 3
Is formed in a straight line over the entire length, suppressing the length of the line. As a result, the following effects can be obtained. For example, if the main line 3 is long, there is a problem that insertion loss increases and power consumption of the device in which the directional coupler 1 is incorporated increases. For example, when the directional coupler 1 is mounted on a battery-driven device such as a mobile phone, there is a problem that the insertion loss of the main line 3 increases the battery consumption of the device. On the other hand, in the first embodiment, since the main line 3 is formed linearly and short, the insertion loss can be suppressed and the power consumption of the device in which the directional coupler 1 is incorporated is reduced. The amount can be suppressed.

The directional coupler 1 of the first embodiment will be described below.
An example of the manufacturing process will be briefly described with reference to FIG. First, a parent substrate 10 for taking out and forming a plurality of directional couplers 1 as shown in FIG. 4A is prepared. The parent substrate 10 is an insulating substrate, and examples of constituent materials of the parent substrate 10 include ceramics such as alumina and glass ceramics, ferrite, and dielectrics other than these.

In each of the directional coupler forming regions 12 of the parent substrate 10, as shown in FIG.
The line formed on the second layer 2a (that is, the first layer formation portion 4a of the main line 3 and the sub line 4) is formed.

One of the techniques for forming this line is, for example, a photolithography technique. In the case of the photolithography technique, first, a conductive film is formed on the entire upper surface of the parent substrate 10 by, for example, a printing method or a film forming method (for example, sputtering or vapor deposition). Next, a photoresist material is coated on the conductive film, and a mask is formed on the conductive film by the pattern shape of the first layer forming portion 4a of the main line 3 and the sub line 4 to perform exposure. Then, the unnecessary resist material is removed with a solvent or the like. After that, the conductor layer is processed by a method such as wet etching, dry etching, lift-off, additive or semi-additive to form the first layer forming portion 4a of the main line 3 and the sub line 4.

Further, instead of forming the first layer forming portion 4a of the main line 3 and the sub line 4 by the photolithography technique, for example, the first layer forming portion 4a of the main line 3 and the sub line 4 is formed by a printing method. It can also be formed. In this case, the conductive paste is printed on the surface of the main board 10 using the mask pattern, so that the main line 3 and the sub-line 4 of the main line 3 and the sub-line 4 are formed in the respective directional coupler forming regions 12 of the main board 10. The first layer forming portion 4a can be formed.

As described above, one of the main line 3 and the sub line 4
After forming the layer forming portion 4a, as shown in FIG. 4C, a layer 13 of an insulating material thicker than the thickness of the line is formed on the entire upper surface of the parent substrate 10, for example, by a printing method or a spin coating method. Formed by. Examples of the material forming the insulating layer 13 include, for example, glass, polyimide,
Further, there are a photosensitive glass containing a photosensitive component, a photosensitive polyimide, and the like.

Then, a via hole (7) is formed in each directional coupler forming region 12 of the insulating layer 13.

After that, as shown in FIG.
On the upper side of the insulating layer 13, for each directional coupler forming region 12, a line formed on the second layer 2b of the base body 2 in the same manner as described above (that is, in the first embodiment, the line 2 of the sub-line 4 is formed). The layer forming portion 4b) is formed.

Thereafter, as shown in FIG. 4E, the insulating layer 1 thicker than the line is formed on the entire upper surface of the insulating layer 13.
4 is formed as an exterior insulating layer in the same manner as the insulating layer 13 is formed.

Then, the parent substrate 10 is divided along the boundary line L between the directional coupler forming regions 12 to form the structure shown in FIG.
A large number of directional couplers 1 as shown in (f) can be taken out. As a method of dividing the parent substrate 10, there are, for example, a construction method such as dicing or scribe break. In the step of dividing the parent board 10, in order to accurately position the parent board 10 at the set mounting position,
For example, a positioning mark or the like may be formed on the upper surface of the insulating layer 14 of the parent substrate 10 before the step of dividing the parent substrate 10.

The directional coupler 1 can be produced as described above.

The second embodiment will be described below. In the description of the second embodiment, the same components as those of the first embodiment will be designated by the same reference numerals, and duplicate description of the common parts will be omitted.

FIG. 5A schematically shows a top view of the directional coupler of the second embodiment, and FIG. 5B schematically shows the directional coupler of the second embodiment. An exploded view is shown. In this second embodiment example, the main line 3 is formed by
The layer 2a is formed in a substantially U-shape. This main line 3
Similarly to the first embodiment, the external connection electrodes 6 are provided at both ends of each of them, and are connected to each circuit through the terminals provided on the side surface of the base body.

Similar to the first embodiment, the sub line 4 is formed over the first layer 2a and the second layer 2b of the base 2 and is formed in a substantially spiral shape, and the first layer forming portion 4a.
And the second layer forming portion 4b are connected via a via hole 7. Most of the first-layer forming portion 4a of the sub line 4 is arranged in a straight line along the main line 3 on the lateral side of the main line 3 with a space therebetween. A portion P of the second layer forming portion 4b of the sub line 4 is linearly arranged along the main line 3 above the main line 3 with a space therebetween. Similarly to the main line 3, external connection electrodes X and Y are provided at both ends of the sub line 4 and are connected to each circuit through terminals provided on the side surface of the base body.

Also in the second embodiment, as in the first embodiment, the sub line 4 is arranged in parallel to the upper portion of the main line 3 and to the side of the main line 3. Since the electromagnetic coupling portion E that has the portion 4a and is electromagnetically coupled to the main line 3 can be lengthened, the main line 3 can be formed without increasing the size of the base body 2.
The degree of coupling between the sub line 4 and the sub line 4 can be increased.

In addition, since the sub line 4 is formed in a substantially spiral shape, the inductance value of the sub line 4 can be increased, so that the isolation characteristic can be improved. The effect of improving the isolation characteristic and the effect of improving the coupling degree are combined to make the directional coupler 1
It is possible to significantly improve the directivity while reducing the size of the. Thereby, the detection accuracy of the signal of the main line 3 by the sub line 4 can be improved.

The present invention is not limited to the first and second embodiments, but various embodiments can be adopted. For example, in each of the first and second exemplary embodiments, the sub line 4 is a portion P arranged in parallel above the main line 3 with a gap.
And a portion 4a arranged side by side on the lateral side of the main line 3 with a gap therebetween. For example, as shown in the cross-sectional view of FIG. 6B, the sub-line 4 having a substantially spiral shape is As a configuration having a portion that is linearly arranged side by side on one side of the main line 3 on the same plane with a space, and a portion that is linearly arranged side by side on the other side by a space. Good. In this case,
For example, by forming the main line 3 and the sub line 4 into a shape as shown in the exploded view of FIG.
It is possible to form the main line 3 and the sub line 4 having the arrangement relationship shown in the sectional view of FIG. Note that FIG. 6B is a sectional view corresponding to a portion AA of FIG.

Further, for example, as shown in the sectional view of FIG. 7B, the sub line 4 having a substantially spiral shape is the main line 3
On the upper side of the main line 3 in a straight line, on one side of the main line 3 on the same side in a straight line, and on the other side on the same side. It may be configured to have a portion arranged in a straight line with a gap. In this case, for example, by forming the main line 3 and the sub line 4 into a shape as shown in the exploded view of FIG.
It is possible to form the main line 3 and the substantially spiral sub-line 4 having the positional relationship shown in the sectional view of FIG. Note that FIG. 7B is a sectional view corresponding to a portion AA of FIG.

Further, for example, as shown in the cross-sectional view of FIG. 8B, the sub-line 4 having a substantially spiral shape is provided on the upper side of the main line 3 in a linear manner with a space therebetween. It may be configured to have a portion which is arranged in a straight line below the main line 3 with a space therebetween. In this case, for example, by forming the main line 3 and the sub-line 4 in a shape as shown in the exploded view of FIG. 8A, an arrangement as shown in the sectional view of FIG. It is possible to form the main line 3 and the sub-line 4 having a substantially spiral shape which are related to each other. Note that FIG.
8B is a sectional view corresponding to the portion AA of FIG.

As shown in FIGS. 8 (a) and 8 (b), in the base 2, the layers on which the lines 3 and 4 are formed may be three or more layers. Is not limited.

Further, the sub line 4 has a portion which is arranged on the upper side of the main line 3 with a space therebetween and a portion which is arranged on the lower side of the main line 3 with a space therebetween on the same plane of the main line 3. It is also possible to have a configuration in which all of the portions that are arranged side by side on the one lateral side on the upper side and the portions that are arranged side by side on the other lateral side on the other side are spaced apart.

[0044]

According to the present invention, since the sub line has a substantially spiral shape, the inductance value of the sub line can be increased. Therefore, the isolation characteristics of the main line and the sub line can be improved, and the directivity can be improved. This allows
It is possible to improve the detection accuracy of the signal of the main line by the sub line, and to provide a directional coupler with high performance reliability.

Further, according to the present invention, the electromagnetic coupling portion of the main line is linear, so that the length of the main line can be easily suppressed, and an increase in insertion loss of the main line can be suppressed. be able to. In particular, in the case where the main line is formed linearly over the entire length, the main line can be shortened and increase in insertion loss can be prevented more reliably.

As described above, since the increase of the insertion loss of the main line can be suppressed, the increase of the power consumption of the device to be incorporated can be prevented. Therefore, for example, when the directional coupler is incorporated in a battery-powered device, the battery consumption of the device to be incorporated can be suppressed,
The usability of the device can be improved.

Further, the sub line is constructed to be formed over a plurality of layers of the base body, and the straight line portion of the sub line is arranged in parallel above the electromagnetic coupling portion of the main line with a gap. When,
A portion of the main line that is placed side by side with a gap below the electromagnetic coupling portion, a portion of the main line that is placed side by side with a gap on one side on the same plane as the electromagnetic coupling portion of the main line, Increasing the size of the base body by having two or more portions of the electromagnetic coupling portion and the portion arranged side by side on the other side on the same plane with a space therebetween. Without
The length of the portion of the sub line that is electromagnetically coupled to the main line can be significantly increased. As a result, the degree of coupling between the main line and the sub line can be increased, and the directivity can be further improved. Therefore, it becomes possible to provide a directional coupler with better performance.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a directional coupler according to a first embodiment.

FIG. 2 is a graph for explaining the effect of improving the degree of coupling between the main line and the sub line according to the configuration shown in the first embodiment.

FIG. 3 is a graph for explaining the effect of improving the directivity by the configuration shown in the first embodiment.

FIG. 4 is a diagram for explaining an example of a manufacturing process of the directional coupler of the first embodiment example.

FIG. 5 is a diagram for explaining a directional coupler according to a second embodiment.

FIG. 6 is a diagram for explaining another embodiment example.

FIG. 7 is a diagram for explaining another embodiment example.

FIG. 8 is a diagram for explaining another embodiment example.

FIG. 9 is a plan view showing a conventional example of a directional coupler.

FIG. 10 is a plan view showing another conventional example of the directional coupler.

[Explanation of symbols]

1 directional coupler 2 base 3 main lines 4 Sub track E Electromagnetic coupling site

Claims (3)

[Claims] 1. A main line and a sub line are formed on a base body with a space therebetween, and at least a part of them are arranged side by side so as to be electromagnetically coupled, and the sub line has a line length longer than the line length of the main line. Then, in the directional coupler having a configuration for extracting a part of the signal flowing through the main line by electromagnetic coupling, the main line is
An electromagnetic coupling portion that is electromagnetically coupled to the sub line is formed in a linear shape, the sub line is formed in a substantially spiral shape having a linear portion in at least a part, and the linear portion of the sub line is an electromagnetic coupling portion of the main line. A directional coupler characterized in that it is arranged side by side along a line and is electromagnetically coupled. 2. The directional coupler according to claim 1, wherein the main line is linearly formed over the entire length. 3. The base has a multi-layer structure, the sub-line is formed over a plurality of layers of the base, and the straight line portion of the sub-line is above the electromagnetic coupling portion of the main line. On the side of one side on the same plane as the electromagnetic coupling part of the main line, and on the same plane as the electromagnetic coupling part of the main line And two or more of a portion arranged in parallel with the main line and a portion arranged in parallel on the other side on the same plane as the electromagnetic coupling portion of the main line with a space therebetween. The directional coupler according to claim 1 or 2, wherein