JP2003069317A - Layered directional coupler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a small-sized layered directional coupler suitable for low frequency applications with an enhanced insertion loss that can extend the length of lines without narrowing the wide of main and sub lines. SOLUTION: The main line 19 is configured by electrically connecting first and second coupling lines 19a, 19b in series with each other through via a via- hole 25 formed respectively to sheets 13 to 15. The sub line 20 is configured by electrically connecting first and second coupling lines 20a, 20b in series with each other through via a via-hole 25 formed respectively to sheets 14 to 16. The first coupling line 19a of the main line 19 and the first coupling line 20a of the sub line 20 are formed opposite to each other with the sheet 13 inbetween. The second coupling line 19b of the main line 19 and the second coupling line 20b of the sub line 20 are formed opposite to each other with the sheet 16 inbetween.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated directional coupler, and more particularly to a laminated directional coupler used in a wireless communication device such as a mobile phone.

[0002]

2. Description of the Related Art A directional coupler using a transmission line having an electrical length corresponding to a quarter wavelength has been conventionally used for high frequency equipment. Further, the laminated directional coupler is also widely used in small wireless communication devices such as mobile phones because of its small size.

As this type of directional coupler, the dielectric sheet 2 having the main line 3 and the sub line 4 shown in FIG. 6 on the surface, and the dielectric sheet 2 having the ground electrodes 5 and 6 provided on the surface, respectively. It is known that a plurality of layers are laminated. The main line 3 and the sub line 4 have a spiral pattern and each have a line length corresponding to a quarter wavelength. The main line 3 and the sub line 4 face each other with the dielectric sheet 2 in between, and run side by side in the length direction. That is, the main line 3 and the sub line 4 are overlapped with each other in the stacking direction of the dielectric sheets 2 and are so-called broadside type electromagnetic coupling.

[0004]

The conventional laminated directional coupler 1 has only one electromagnetic coupling portion in which the main line 3 and the sub line 4 sandwich the dielectric sheet 2. . Therefore, the center frequency of the directional coupler 1 is lowered (for example, 420 MHz) without changing the size of the directional coupler 1.
In order to increase the electromagnetic coupling between the main line 3 and the sub line 4, the line width of the main line 3 and the sub line 4 must be reduced to increase the line length. . However, when the line width is reduced, there is a problem that the insertion loss characteristic of the directional coupler 1 deteriorates.

Therefore, it is an object of the present invention to increase the line length without reducing the line width of the main line and the sub line, and to achieve a miniaturization, a low frequency, and an insertion loss improvement in a laminated direction. Providing a sex coupler.

[0006]

In order to achieve the above-mentioned object, a laminated directional coupler according to the present invention is mainly composed of (a) at least a first coupled line portion and a second coupled line portion. A line, and (b) a sub-line having a first coupling line part and a second coupling line part that are electromagnetically coupled to the first coupling line part and the second coupling line part of the main line, respectively (c) A ground electrode facing at least one of the main line and the sub line; (d) first and second coupled line portions of the main line and first and second coupled line portions of the sub line. (E) first and second coupled line portions of the main line, first and second coupled line portions of the sub-line, and the ground electrode. And the dielectric layer are stacked to form a laminated body, The electromagnetic coupling portion in which the first coupling line portion of the main line and the first coupling line portion of the sub line sandwich the dielectric layer, and the second coupling line portion of the main line and the sub line The second coupling line portion has electromagnetic coupling portions formed by sandwiching the dielectric layer in parallel in the stacking direction of the laminated body.

An electromagnetic coupling portion of the first coupling line portion of the main line and a first coupling line portion of the sub line, and an electromagnetic coupling portion of the second coupling line portion of the main line and the second coupling line portion of the sub line. To
By arranging the stacked bodies side by side in the stacking direction, the line lengths of the main line and the sub line can be doubled as compared with the conventional directional coupler having the same occupied area. For this reason,
The line length can be increased without reducing the line width, and the directional coupler can be downsized, the frequency can be reduced, and the insertion loss can be improved.

Further, by omitting the ground electrode facing the transmission line of the main line and the sub line, it is possible to reduce the eddy current loss generated in the ground electrode due to the magnetic field of the transmission line.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a directional coupler according to the present invention will be described below with reference to the accompanying drawings.
In each embodiment, the same reference numerals are given to the same parts and the same parts.

[First Embodiment, FIGS. 1 to 3] As shown in FIG. 1, the laminated directional coupler 11 includes a first main line 19 and a first main line 19.
Dielectric sheets 13 and 16 each having a coupling line portion 19a and a second coupling line portion 19b on its surface, and a sub line 20.
Dielectric sheets 14 and 17 having the first and second coupling line portions 20a and 20b provided on the surfaces thereof, and dielectric sheets 12, 15 and 18 having ground electrodes 21, 22 and 23 provided on the surfaces thereof, respectively. It is composed of.

The materials for the dielectric sheets 12-18 are:
A resin such as epoxy or a ceramic dielectric is used. In the first embodiment, as the material of the dielectric sheets 12 to 18, sheets obtained by kneading the dielectric ceramic powder with the binder and then forming the sheet were used. Each dielectric sheet 1
The sheet thickness of 2 to 18 is set to a predetermined dimension. Usually, the distance between the first coupled line portions 19a-20a and the distance between the second coupled line portions 19b-20b are equal, and the first coupled line portions 19a, 20a and the second coupled line portions 19b, 20 are the same.
The distances between b and the ground electrodes 21 to 23 are set to be thicker and equal to them.
Further, the sheets 12, 14, 15, and 17 are set thicker than the other sheets 13, 16, and 18. At this time,
The thickness of the sheets 12, 14, 15, 17 is the same as that of the other sheets 1.
A plurality of sheets having the same sheet thickness as 3 may be stacked and secured, or one thick sheet may be used and secured.

The main line 19 is constructed by electrically connecting the spiral first coupling line portion 19a and the second coupling line portion 19b in series through via holes 25 provided in the sheets 13 to 15, respectively. ing. The sub line 20 includes a first coupling line portion 20a and a second coupling line portion 20b having a spiral shape.
Via holes 25 provided on the sheets 14 to 16 respectively.
It is configured by electrically connecting in series via. The main line 19 and the sub line 20 each have an electrical length corresponding to a quarter wavelength of the used center frequency.

Here, the first coupled line portion 19 of the main line 19
a and the first coupled line portion 20a of the sub line 20 are
They are formed so as to face each other with the pinch in between. Therefore, the first
The spiral patterns of the coupling line portions 19a and 20a are substantially overlapped with each other in a plan view, and broadside type electromagnetic coupling is performed at the facing portions. Similarly,
The spiral patterns of the second coupling line portions 19b and 20b are also substantially overlapped with each other in a plan view, and the portions facing each other with the sheet 16 interposed therebetween are broadside-type electromagnetically coupled.

Further, in order to make the line length of the main line 19 equal to the line length of the sub line 20, the lead-out portions of the first coupling line portion 19a and the second coupling line portion 19b are placed on the sheets 13 and 16, respectively. The connecting portion A between the lead-out portion and the spiral portion has a folded structure. Although the number of turns of the electromagnetic coupling portion of the first coupling line portions 19a and 20a of the first embodiment and the number of turns of the electromagnetic coupling portion of the second coupling line portions 19b and 20b are substantially equal, both are It goes without saying that they may be different.

The ground electrodes 21, 22, and 23 are provided on substantially the entire surfaces of the sheets 12, 15, and 18, respectively.
A window 22a is formed in the center of the ground electrode 22 to avoid a short circuit with the via hole 25. These ground electrodes 21 to 23 are preferably arranged at positions separated from the main line 19 and the sub line 20 by a predetermined distance in consideration of the characteristics of the directional coupler. Main line 19,
The sub line 20 and the ground electrodes 21 to 23 are formed by a method such as a sputtering method, a vapor deposition method, a printing method, or a photolithography method, and are made of Ag-Pd, Ag, Pd, Cu.
It is made of materials such as.

Each of the sheets 12 to 18 is stacked, and protective sheets are arranged on the upper and lower sides of the sheets, and the sheets are integrally fired to form a rectangular laminated body 30 as shown in FIG. . Four input / output external electrodes 31a, 31b, 32a, 32b and four ground external electrodes G are formed on the side surface of the laminated body 30. These external electrodes 31a
32b and G are formed by a method such as a sputtering method, a vapor deposition method, a coating method and a printing method, and Ag-Pd, Ag,
It is made of a material such as Pd, Cu, or a Cu alloy.

The input / output external electrode 31a formed on the left side of the front side surface of the laminated body 30 is electrically connected to one end portion of the main line 19 (specifically, the lead-out portion of the first coupled line portion 19a). Input / output external electrode 31b formed on the right side of the inner side surface is electrically connected to the other end of the main line 19 (specifically, the lead-out portion of the second coupled line portion 19b). Connected to each other.

The input / output external electrode 32a formed on the left side of the inner side surface of the laminate 30 is electrically connected to one end of the sub line 20 (lead-out portion of the first coupling line portion 20a). The input / output external electrode 32b formed on the right side of the front side surface is electrically connected to the other end of the sub line 20 (lead-out portion of the second coupling line portion 20b). The ground external electrode G is electrically connected to the ground electrodes 21 to 23. FIG. 3 is an equivalent circuit diagram of the directional coupler 11.

The laminated directional coupler 11 thus obtained
Is an electromagnetic coupling portion of the first coupling line portion 19a of the main line 19 and the first coupling line portion 20a of the sub line 20, and the second coupling line portion 20a.
Since the two electromagnetic coupling portions, which are the electromagnetic coupling portions of the coupling line portions 19b and 20b, are arranged side by side in the stacking direction of the stacked body 30, the conventional directional coupler (one electromagnetic The line lengths of the main line 19 and the sub line 20 can be doubled as compared with those having only a coupling portion). Therefore, the line length can be increased without reducing the line widths of the main line 19 and the sub line 20, and the directional coupler 11 can be downsized, the frequency can be reduced, and the insertion loss can be improved. Here, the size (typical value) of the directional coupler 11 is 5.7 mm in length and 5.0 m in width.
m, height 2.0 mm.

[Second Embodiment, FIGS. 4 and 5] In the second embodiment, instead of the ground electrode 22 provided with the window 22a in the directional coupler 11 of the first embodiment,
The ground electrode having no window is used.

As shown in FIG. 4, the laminated directional coupler 4
Reference numeral 1 denotes the extraction electrodes 45, 4 between the dielectric sheet 14 provided with the first coupled line portion 20a of the sub line 20 and the dielectric sheet 16 provided with the second coupled line portion 19b of the main line 19.
The dielectric sheet 42 provided with 6, the dielectric sheet 43 provided with the ground electrode 49, and the dielectric sheet 44 provided with the extraction electrodes 47 and 48 are provided. In FIG. 4, the dielectric sheets 12 and 18 provided with the ground electrodes 21 and 23 shown in FIG. 1 are not shown.

Each sheet 12-14, 42-44, 16-
The layers 18 are stacked, and protective sheets are arranged on the upper and lower sides thereof, and then integrally fired to form a rectangular laminated body 50 as shown in FIG. Input / output external electrodes 31a, 32b and a ground external electrode G are provided on the front side surface of the stacked body 50, and input / output electrodes 32a, 31b and a ground external electrode G are provided on the rear side surface, and the left and right end surfaces are provided. The relay external electrodes 51 and 52 are provided in each.

The relay external electrode 51 includes a lead electrode 45,
One end of 47 is electrically connected, and one ends of the lead-out electrodes 46 and 48 are electrically connected to the relay external electrode 52. As a result, the first coupling line portion 19a and the second coupling line portion 19b of the main line 19 are provided in the via hole 25, the lead electrode 46, the relay external electrode 52, the lead electrode 48, and the sheet 44, which are provided in the sheets 13 and 14, respectively. The via holes 25 are sequentially connected electrically in series.
Similarly, the first coupling line portion 20a and the second coupling line portion 20b of the sub line 20 are the via holes 25 provided in the sheet 14,
Lead-out electrode 45, relay external electrode 51, lead-out electrode 47, and via holes 25 provided in sheets 44 and 16, respectively.
Are sequentially electrically connected in series.

The laminated directional coupler 4 having the above structure
1 has the same effect as the directional coupler 11 of the first embodiment. Moreover, since there is no window portion in the ground electrode 49 arranged between the first coupled line portion 20a of the sub line 20 and the second coupled line portion 19b of the main line 19, there is no window in the first coupled line portion 19a-20a. It is possible to further prevent the electromagnetic coupling and the electromagnetic coupling of the second coupling line portions 19b-20b from interfering with each other.

[Other Embodiments] The laminated directional coupler according to the present invention is not limited to the above embodiment, but can be variously modified within the scope of the invention.
For example, the directional coupler may be composed of two or more main lines and one sub line electromagnetically coupled to the two or more main lines. Alternatively, the directional coupler may be composed of two or more sub lines and one main line that is electromagnetically coupled to the two or more sub lines.

Further, the number of coupled line portions of each of the main line and the sub line may be three or more. In this case, the three or more electromagnetically coupled portions formed by coupling the respective coupled line portions of the main line and the sub line are arranged side by side in the stacking direction of the stacked body.

The main line and the sub line may have any shape, and may have a meandering shape or a linear shape in addition to the spiral shape.
The main line and the sub line do not necessarily have to be set to have a length of ¼ wavelength, and the line width does not have to be set to have the same dimension for all lines.

Further, the main line and the sub line are not limited to the stripline structure arranged between the two ground electrodes, and may be a so-called microstripline structure in which one of the ground electrodes is omitted. Good.

Further, in the first and second embodiments, the ground electrodes 21 to 23, 49 and the ground external electrode G may be omitted. Generally, when an electrode is provided near the transmission line, an eddy current is generated in the electrode by the magnetic field of the transmission line, and the Q of the transmission line is deteriorated. Therefore, by omitting the ground electrodes 21 to 23 and 49, the electrodes where the eddy current is generated are eliminated. As a result, the Q of the main line 19 and the sub line 20 is increased, and the insertion loss of the directional couplers 11 and 41 is improved. In addition, in the first and second embodiments, the first coupling line portions 19a and 20a and the second coupling line portion 1 are included.
The coupling line portions 19a, 19b, 20a, 2 are arranged so that the directions of the magnetic fluxes generated by 9b and 20b are opposite to each other.
0b is wound. As a result, the ground electrode 2
Even if 2, 49 are omitted, the first coupled line portions 19a, 20a
The magnetic flux generated in 2 and the magnetic flux generated in the second coupling line portions 19b and 20b are hard to be electromagnetically coupled.

Furthermore, in the above-mentioned embodiment, the dielectric sheets each having the conductor pattern formed thereon are stacked and then integrally fired, but the invention is not necessarily limited to this. The dielectric sheet may be pre-baked. Moreover, you may manufacture a directional coupler by the manufacturing method demonstrated below. After forming a dielectric layer with a paste dielectric material by a method such as printing, a paste conductive material is applied to the surface of the dielectric layer to form a conductor pattern. Next, a paste dielectric material is applied from above to form a dielectric layer. Similarly, a directional coupler having a laminated structure can be obtained by sequentially coating the layers.

[0031]

As is apparent from the above description, according to the present invention, the electromagnetic coupling portions of the first coupling line portion of the main line and the first coupling line portion of the sub line, and the second coupling line portion of the main line. Since the electromagnetic coupling portions of the coupling line portion and the second coupling line portion of the sub line are juxtaposed in the stacking direction of the stacked body, the main line and the sub line are compared to the conventional directional coupler having the same occupied area. The line length of can be doubled. For this reason, the line length can be increased without reducing the line width, and the directional coupler can be downsized, the frequency can be lowered, and the insertion loss can be improved.

Further, by omitting the ground electrode facing the transmission line of the main line or the sub line, the eddy current loss generated in the ground electrode by the magnetic field of the transmission line can be reduced.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of a laminated directional coupler according to the present invention.

FIG. 2 is a perspective view showing an appearance of the laminated directional coupler shown in FIG.

3 is an equivalent circuit diagram of the stacked directional coupler shown in FIG.

FIG. 4 is an exploded perspective view showing a second embodiment of the laminated directional coupler according to the present invention.

5 is a perspective view showing the outer appearance of the laminated directional coupler shown in FIG. 4. FIG.

FIG. 6 is an exploded perspective view showing a conventional laminated directional coupler.

[Explanation of symbols]

11, 41 ... Laminated directional coupler 12-18, 42-44 ... Dielectric sheet 19 ... Main track 20 ... Sub track 19a, 20a ... 1st coupling line part 19b, 20b ... Second coupled line section 21-23, 49 ... Ground electrode 30, 50 ... Laminated body

Claims (2)

[Claims] 1. A main line having at least a first coupling line section and a second coupling line section, and a first coupling electromagnetically coupled to the first coupling line section and the second coupling line section of the main line, respectively. A sub-line having a line section and a second coupled line section; a ground electrode facing at least one of the main line and the sub-line; and first and second coupled line sections of the main line. First and second coupling line portions of the sub line and dielectric layers respectively disposed between the ground electrode and the first and second coupling line portions of the main line and the first of the sub lines. The second coupled line portion, the ground electrode, and the dielectric layer are stacked to form a laminated body, and the first coupled line portion of the main line and the first coupled line portion of the sub line are the dielectric layers. And an electromagnetic coupling part sandwiched between A second coupling line portion of the main line and a second coupling line portion of the sub-line have electromagnetic coupling portions formed by sandwiching the dielectric layer in parallel in a stacking direction of the laminated body. Stacked directional coupler. 2. A main line having at least a first coupling line portion and a second coupling line portion, and a first coupling electromagnetically coupled to the first coupling line portion and the second coupling line portion of the main line, respectively. A sub-line having a line section and a second coupled line section, and a dielectric disposed between the first and second coupled line sections of the main line and the first and second coupled line sections of the sub-line, respectively. A body layer, the first and second coupled line portions of the main line, the first and second coupled line portions of the sub-line, and the dielectric layer are stacked to form a laminated body, and the main line is provided. Electromagnetic coupling part formed by sandwiching the dielectric layer between the first coupling line part and the first coupling line part of the sub-line, and the second coupling line part of the main line and the second coupling of the sub-line. An electromagnetically coupled portion formed by sandwiching the dielectric layer between the line portions is used to stack the laminated body. 2. The laminated directional coupler, wherein the laminated bodies are arranged side by side in the vertical direction and the ground electrode is not provided in the laminated body.