JP2004096347A - Multilayer directional coupler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a downsized multilayer directional coupler with excellent characteristics in spite of its simplified structure. <P>SOLUTION: The multilayer directional coupler adopts a strip line structure having two coupling lines 20, 22 opposed to each other via a dielectric layer in a stacking direction. Both coupling lines have a combination of a first spiral pattern winding round in one direction and a second spiral pattern winding round reverse to the first spiral pattern and wound out in parallel with the first spiral pattern. A lead-out pattern is formed so as not to be overlapped in the stacking direction at the outer side end of the first and second spiral patterns and led out up to the side face of the layered body, and earth patterns 26, 28 are formed to cover nearly the entire face via a dielectric layer at the outside of the coupling lines in the stacking direction. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stacked directional coupler having a stripline structure, and more particularly, to a stacked directional coupler having connection lines formed by combining spiral patterns having opposite directions. This laminated directional coupler is used in, for example, a high-frequency circuit such as a mobile communication device.
[0002]
[Prior art]
The directional coupler has, for example, a structure in which two coupling lines are arranged close to each other on a dielectric substrate. In the process where an electromagnetic wave travels in one direction in one coupling line, the electromagnetic wave energy is transferred to the other coupling line. It is a device that functions.
[0003]
As an example of a structure in which two coupling lines are arranged close to each other on a dielectric substrate, there is a laminated structure in which the two coupling lines are arranged to face each other with a dielectric layer interposed therebetween. In this case, the coupling line is formed into a spiral shape as shown in FIG. 8 or a meander line shape as shown in FIG. In the example of FIG. 9, the pattern shown in A and the pattern shown in B are stacked so as to overlap with each other via the dielectric layer.
[0004]
[Problems to be solved by the invention]
When the connection line is formed into a simple spiral shape, as shown in FIG. 8, when the connection line is drawn from the center of the spiral pattern 10 to the side surface of the dielectric substrate, a lead pattern 12 is formed in another layer, and the interlayer connection is formed by the via 14. There is a need to do. Therefore, the number of steps increases, which leads to an increase in cost. In addition, since an extra pattern is added, there is a concern that the characteristics may be deteriorated. Further, since the shapes of the two coupling lines are different, a phase shift occurs.
[0005]
When the coupling line is formed in a meandering line pattern 16 as shown in FIG. 9, the amount of generated magnetic field is small and the directionality is weak. In addition, the pattern draws a steep curve continuously, and the electric field is concentrated at that location, which has an adverse effect on the passing characteristics.
[0006]
An object of the present invention is to provide a stacked directional coupler that has good characteristics despite its simplified structure and can be reduced in size.
[0007]
[Means for Solving the Problems]
The present invention relates to a stacked directional coupler having a strip line structure having two coupling lines facing each other via a dielectric layer in a laminating direction, wherein both coupling lines are respectively wound in one direction. A stack-type direction having a combination of a spiral pattern and a second spiral pattern which is continuous from the center of the spiral and is wound in a direction opposite to the first spiral pattern and unwinding in parallel with the first spiral pattern. It is a sex coupler.
[0008]
The present invention also provides a stacked directional coupler having a strip line structure having two coupling lines facing each other via a dielectric layer in the laminating direction, wherein both coupling lines are respectively wound in one direction. And a second spiral pattern that is continuous from the center of the spiral and is unwound in a direction opposite to and parallel to the first spiral pattern. A drawing pattern is formed at the outer end of the spiral pattern so as not to overlap in the laminating direction, and is drawn out to the side surface of the laminate. A stacked directional coupler characterized in that a pattern is formed.
[0009]
In these, usually, the end of the extraction pattern and the terminal electrode formed on one main surface of the laminate are connected by a line connection pattern formed on the side surface of the laminate, and the end of the ground pattern is connected to the end of the ground pattern. An earth electrode formed on one main surface of the multilayer body is connected to an earth connection pattern formed on a side surface of the multilayer body to provide a structure compatible with surface mounting. By adopting a structure in which the coupling line is sandwiched between the ground patterns, the structure is less likely to be affected by the outside. Preferably, both connecting lines have the same shape. The phase shift can be reduced by making the shape of both coupling lines the same.
[0010]
It is also effective that part or all of the first and second spiral patterns of both connection lines have a smaller pattern width than the pattern width of the lead pattern. In the coupling line of the directional coupler, there are some coupled parts and some parts not coupled. Since the characteristic impedance of the line is reduced at the connection point, the return loss increases. Therefore, impedance matching can be performed by reducing the line width of the coupling portion (the first and second spiral patterns) entirely or partially, thereby suppressing an increase in reflection loss.
[0011]
【Example】
FIG. 1 is an explanatory diagram of an internal structure showing one embodiment of a laminated directional coupler according to the present invention, FIG. 2 is an explanatory diagram of its line pattern, and FIG. 3 is a perspective view showing an example of a product appearance.
[0012]
This laminated directional coupler has a strip line structure having two coupling lines 20 and 22 facing each other via a dielectric layer in the laminating direction. The upper coupling line 20 has a first spiral pattern 20a wound in one direction (clockwise) and a direction continuous from the center of the spiral (counterclockwise) and opposite to the first spiral pattern 20a. And a combination of the second spiral patterns 20b that are unwound so as to run in parallel. At the end of the first spiral pattern 20a, a short first extraction pattern 20c is continuously extended to one side of the dielectric layer 24, and at the end of the second spiral pattern 20b, a long second extraction pattern 20c is formed. The extraction pattern 20d is continuously extracted to the same side surface of the dielectric layer 24. The lower coupling line 22 also has a first spiral pattern 22a wound in one direction (clockwise) and a direction continuous from the center of the spiral (counterclockwise) and opposite to the first spiral pattern 22a. And a combination of the second spiral patterns 22b that unwind in parallel. At the end of the first spiral pattern 22a, a long first extraction pattern 22c is continuously extended to the side opposite to the one side of the dielectric layer 24, and is extended to the end of the second spiral pattern 22b. Are drawn out to the same side surface of the dielectric layer 24 in succession by a short second extraction pattern 22d. In FIG. 2, the extraction patterns 20c, 20d, 22c, and 22d are represented by fine oblique lines.
[0013]
In this embodiment, the upper connecting line 20 and the lower connecting line 22 have the same shape. Further, the first spiral patterns 20a and 22a, the second spiral patterns 20b and 22b, and all the extraction patterns 20c, 20d, 22c and 22d are all designed to have the same pattern width.
[0014]
Then, ground patterns 26 and 28 are formed on the outside (that is, above and below) in the stacking direction of the coupling lines 20 and 22 via a dielectric layer. The ground patterns 26 and 28 only reach the front and rear (front and back) outer peripheral edges only in the central portion in the lateral direction (the horizontal direction of the paper surface in FIG. 1), and are otherwise slightly recessed as a whole. It is a planar pattern.
[0015]
Structurally, a lower ground pattern 28 is formed in the lowermost dielectric layer, a lower coupling line 22 is formed in the dielectric layer above, and an upper coupling line 20 is formed in the dielectric layer above. Then, an upper earth pattern 26 is formed on the dielectric layer thereon, and the uppermost dielectric layer is further provided. Each pattern is a conductor layer. The dielectric layer is one or more dielectric sheets, or a dielectric pattern printed once or more than once. In any case, the dielectric layers 24 are laminated and integrated in the order described above. As a result, the upper coupling line 20 and the lower coupling line 22 face each other via the dielectric layer, and are sandwiched between the ground patterns 26 and 28 from above and below via the dielectric layer. The first and second spiral patterns (20a and 22a and 20b and 22b) overlap (join), but the extraction patterns (20c and 22c and 20d and 22d) do not overlap (do not join).
[0016]
Finally, as shown in FIG. 3, terminal electrodes 32a, 32b, 32c, and 32d are printed at four locations on one main surface (mounting surface) of the laminate 30, and ground electrodes 34a and 34b are printed at two locations. . Then, the lead patterns 22c and 22d are connected to the terminal electrodes 30a and 30b through one side surface of the laminated body 30 via the side surface lead patterns 34a and 34b. The connection is made with the side-drawing-out pattern 36a. The opposite side surface of the laminate 30 has the same structure. Such a laminated directional coupler is mounted on a circuit board, and a terminal electrode and a ground electrode are fixedly connected by soldering.
[0017]
FIG. 4 shows an example of the frequency characteristics of the stacked directional coupler using the coupling lines of the above-described pattern. Curves a, b, and c show frequency characteristics of insertion loss, coupling degree, and directivity, respectively. From this graph, it can be seen that the directional coupler functions well.
[0018]
As a method of manufacturing such a laminated directional coupler, there are a sheet laminating method and a print laminating method. In the sheet lamination method, an unfired dielectric ceramic sheet (green sheet) is used, and a conductor pattern is printed thereon with a conductor paste (for example, silver paste) by a screen printing method or the like, and laminated in a predetermined order (sheet lamination). Then, the pressure is integrated. In the print lamination method, a dielectric ceramic layer is formed by printing a dielectric ceramic paste on required times to form a dielectric layer, a conductor pattern is printed with a conductor paste (for example, silver paste), and the conductor patterns are laminated in a predetermined order (print lamination). Is the way. Usually, a large number of pieces are integrally formed regularly and vertically, and then cut vertically and horizontally to form a single laminate. Then, in any lamination method, a side surface drawing pattern is printed on the side surface of the laminated body and fired.
[0019]
5 and 6 are explanatory diagrams of a line pattern showing another embodiment of the laminated directional coupler according to the present invention. Since the basic pattern is the same as that of the above-described embodiment, corresponding portions are denoted by the same reference numerals for easy understanding. In the example shown in FIG. 5, all the pattern widths of the first spiral patterns 20a and 22a and the second spiral patterns 20b and 22b of both the connection lines 20 and 22 are determined by extracting the widths of the lead patterns 20c, 20d, 22c and 22d. Is formed narrower than the pattern width. In the example shown in FIG. 6, the pattern widths of the second spiral patterns 20b and 22b of both the connection lines 20 and 22 are set to the pattern widths of the first spiral patterns 20a and 22a and the extraction patterns 20c, 20d and 22c. , 22d. In any case, the upper first and second spiral patterns 20a and 20b and the lower first and second spiral patterns 22a and 22b have the same shape, and the pattern A and the pattern B are dielectric layers. Are laminated so as to overlap each other.
[0020]
In the coupling line of the directional coupler, there is a coupling portion (first and second spiral patterns) and a non-coupling portion (drawing pattern). Since the characteristic impedance of the line decreases at the coupling point, impedance matching is performed by narrowing the pattern width entirely or partially as in these embodiments, and it is possible to suppress an increase in reflection loss. it can.
[0021]
FIG. 7 shows that the curve a shows the reflection when the first and second spiral patterns have the same width as the extraction pattern, and the curve b shows the reflection when the first and second spiral patterns have a narrower width than the extraction pattern. The characteristics are shown. From FIG. 7, it can be seen that the reflection loss is improved by making the pattern width of the joined portion narrower than the drawing pattern. However, when the pattern width is reduced, the reflection characteristic may be deteriorated if the pattern width is excessively reduced.
[0022]
The present invention is not limited to only the above embodiments. The number of turns (length) and shape of the spiral pattern are appropriately adjusted according to required characteristics. As a manufacturing method, a method may be used in which a conductor pattern is provided on a dielectric substrate, laminated in a predetermined order via an adhesive layer, and integrated. In that method, a sintered dielectric ceramic substrate can be used, or another resin substrate can be used.
[0023]
【The invention's effect】
As described above, according to the present invention, both of the connecting lines have a first spiral pattern which is wound in one direction, and a continuous direction from the center of the spiral and opposite to and parallel to the first spiral pattern. Since it is a laminated directional coupler having a combination of the second spiral patterns that are unwound so as to run, good characteristics can be obtained, and each connection line can be formed in one layer. Is unnecessary, the process can be simplified, the size can be reduced, and it can be easily manufactured with high accuracy. Further, since the structure is sandwiched between the ground patterns, it is hardly affected by outside.
[0024]
In the present invention, the coupling line can be made the same, so that the phase shift can be reduced. Further, by forming the pattern width of part or all of the first and second spiral patterns of both coupling lines smaller than the pattern width of the extraction pattern, impedance matching is performed, and an increase in reflection loss is achieved. Can be suppressed.
[Brief description of the drawings]
FIG. 1 is an explanatory view of an internal structure showing one embodiment of a laminated directional coupler according to the present invention.
FIG. 2 is an explanatory diagram of the connection line.
FIG. 3 is a perspective view showing an example of a product appearance.
FIG. 4 is a graph showing an example of a frequency characteristic of the multilayer directional coupler according to the present invention.
FIG. 5 is an explanatory view of a coupling line showing another embodiment of the laminated directional coupler according to the present invention.
FIG. 6 is an explanatory view of a coupling line showing another embodiment of the laminated directional coupler according to the present invention.
FIG. 7 is a graph showing a change in reflection characteristics depending on a line pattern.
FIG. 8 is an explanatory diagram showing an example (simple spiral pattern) of the related art.
FIG. 9 is an explanatory view showing another example (meander line pattern) of the conventional technology.
[Explanation of symbols]
20, 22 Coupling line 20a, 22a First spiral pattern 20b, 22b Second spiral pattern 20c, 20d, 22c, 22d Leading pattern 24 Dielectric layer 26, 28 Earth pattern

Claims (5)

In a laminated directional coupler having a strip line structure having two coupling lines facing each other via a dielectric layer in a laminating direction,
Both coupling lines are each provided with a first spiral pattern wound in one direction and a second spiral pattern continuing from the center of the spiral and unwinding in a direction opposite to and parallel to the first spiral pattern. Characterized in that it has a combination of spiral patterns. In a laminated directional coupler having a strip line structure having two coupling lines facing each other via a dielectric layer in a laminating direction,
Both coupling lines are each provided with a first spiral pattern wound in one direction and a second spiral pattern continuing from the center of the spiral and unwinding in a direction opposite to and parallel to the first spiral pattern. Of the first and second spiral patterns are formed at the outer ends thereof so as not to overlap in the laminating direction, and are pulled out to the side surfaces of the laminate. A laminated directional coupler, wherein an earth pattern is formed almost entirely on the outer side in the laminating direction via a dielectric layer. The end of the lead pattern and the terminal electrode formed on one main surface of the laminate are connected by a line connection pattern formed on the side surface of the laminate, and the end of the ground pattern and one of the laminates are connected. The multilayer directional coupler according to claim 2, wherein the multilayer directional coupler is connected to an earth electrode formed on the main surface by an earth connection pattern formed on a side surface of the multilayer body, and has a structure compatible with surface mounting. 4. The laminated directional coupler according to claim 1, wherein both coupling lines have the same shape. The stacking direction according to any one of claims 1 to 4, wherein a pattern width of a part or all of the first and second spiral patterns of both connection lines is formed smaller than a pattern width of the lead pattern. Sex coupler.

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