JP4803295B2 - Multilayer directional coupler - Google Patents

Description

  The present invention relates to a stacked directional coupler, and more particularly to a stacked directional coupler used for wireless communication equipment such as a mobile phone.

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

  As this type of directional coupler, the dielectric sheet 2 provided with the main line 3 and the sub line 4 shown in FIG. 6 on the surface, the dielectric sheet 2 provided with the ground electrodes 5 and 6 on the surface, respectively, are laminated. Is known. The main line 3 and the sub line 4 are spiral patterns, each having a line length corresponding to a quarter wavelength. The main line 3 and the sub line 4 are opposed to each other with the dielectric sheet 2 interposed therebetween, and run in parallel in the length direction. That is, the main line 3 and the sub line 4 are overlapped in the stacking direction of the dielectric sheets 2 and have a so-called broadside type electromagnetic coupling.

  The conventional laminated directional coupler 1 has only one electromagnetic coupling portion in which the main line 3 and the sub line 4 are configured with the dielectric sheet 2 interposed therebetween. For this reason, the center frequency of the directional coupler 1 is lowered (for example, in the 420 MHz band) without changing the size of the directional coupler 1 or the electromagnetic coupling degree between the main line 3 and the sub line 4 is increased. Therefore, the line length of the main line 3 and the sub-line 4 had to be narrowed to increase the line length. However, when the line width is narrowed, there is a problem that the insertion loss characteristic of the directional coupler 1 is deteriorated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a multilayer directional coupler that can increase the line length without reducing the line width of the main line and the sub-line, and can reduce the size, reduce the frequency, and improve the insertion loss. Is to provide.

In order to achieve the above object, a laminated directional coupler according to the present invention is provided.
(A) a main line having at least a first coupled line part and a second coupled line part;
(B) a sub-line having a first coupled line portion and a second coupled line portion that are electromagnetically coupled to the first coupled line portion and the second coupled line portion of the main line, respectively.
(C) a ground electrode facing at least one of the main line and the sub line;
(D) comprising first and second coupled line portions of the main line, first and second coupled line portions of the sub-line, and dielectric layers respectively disposed between the ground electrodes;
(E) The first and second coupled line portions of the main line, the first and second coupled line portions of the sub line, the ground electrode, and the dielectric layer are stacked to form a laminate, and the main line A first electromagnetic coupling portion in which the first coupling line portion of the 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 A second electromagnetic coupling portion configured by sandwiching the dielectric layer between the second coupled line portions, and juxtaposed in the stacking direction of the stacked body so as to sandwich the ground electrode;
(F) The first electromagnetic coupling portion and the ground electrode are connected to one end of the first coupling line portion of the main line and one end of the first coupling line portion of the sub line, respectively. A dielectric layer provided with a first extraction electrode and a second extraction electrode is disposed;
(G) The second electromagnetic coupling portion and the ground electrode are connected to one end of the second coupling line portion of the main line and one end of the second coupling line portion of the sub line, respectively. A dielectric layer provided with three extraction electrodes and a fourth extraction electrode is disposed;
It is characterized by.

  A first coupling line portion of the main line and an electromagnetic coupling portion of the 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 are laminated. By juxtaposing them in the stacking direction of the bodies, the line length of the main line and the sub line can be increased by a factor of about two as compared with a conventional directional coupler having the same occupation area. Therefore, 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 or the sub line, eddy current loss generated in the ground electrode due to the magnetic field of the transmission line can be reduced.

  Also, one end of the first coupled line portion and the second coupled line portion of the main line is connected to the first lead electrode, the third lead electrode, and a relay external electrode for the main line provided on a side surface of the laminate. And one end of the first coupled line portion and the second coupled line portion of the sub-line are provided on the side surfaces of the second and fourth lead electrodes and the laminate. It may be connected via a relay external electrode for the line.

  The distance between the first extraction electrode, the second extraction electrode, and the first electromagnetic coupling portion in the stacking direction is the stacking direction of the first extraction electrode, the second extraction electrode, and the ground electrode. The interval between the third extraction electrode, the fourth extraction electrode, and the second electromagnetic coupling portion in the stacking direction is wider than the interval between the third extraction electrode, the fourth extraction electrode, and the ground electrode. May be wider than the interval in the stacking direction.

  As is apparent from the above description, according to the present invention, the first coupling line portion of the main line and the electromagnetic coupling portion of the first coupling line portion of the sub line, and the second coupling line portion of the main line and the sub coupling line portion. Since the electromagnetic coupling part of the second coupled line part of the line is juxtaposed in the stacking direction of the laminated body, the line length of the main line and the sub line is reduced as compared with the conventional directional coupler having the same occupied area. Can be twice as long. Therefore, 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, eddy current loss generated in the ground electrode due to the magnetic field of the transmission line can be reduced.

1 is an exploded perspective view showing a first embodiment of a laminated directional coupler according to the present invention. The perspective view which shows the external appearance of the lamination type directional coupler shown by FIG. FIG. 3 is an equivalent circuit diagram of the stacked directional coupler shown in FIG. 2. The disassembled perspective view which shows 2nd Embodiment of the lamination type directional coupler which concerns on this invention. The perspective view which shows the external appearance of the lamination type directional coupler shown by FIG. The exploded perspective view which shows the conventional lamination type directional coupler.

  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 parts and the same parts are denoted by the same reference numerals.

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

  As the material of the dielectric sheets 12 to 18, a resin such as epoxy or a ceramic dielectric is used. In the first embodiment, as a material for the dielectric sheets 12 to 18, a dielectric ceramic powder that is kneaded with a binder and then formed into a sheet shape is used. The sheet thickness of each dielectric sheet 12-18 is set to a predetermined dimension. Usually, the distance between the first coupled line portions 19a-20a is equal to the distance between the second coupled line portions 19b-20b, and the first coupled line portions 19a, 20a and the second coupled line portions 19b, 20b are connected to the ground electrode. Each distance between 21 to 23 is set to be thicker and equal to each other. Further, the sheets 12, 14, 15, and 17 are set to be thicker than the other sheets 13, 16, and 18. At this time, the thickness of the sheets 12, 14, 15, and 17 may be secured by stacking a plurality of sheets having the same sheet thickness as the other sheets 13 or the like, or secured by using one thick sheet. Also good.

  The main line 19 is configured by electrically connecting a spiral first coupled line portion 19a and a second coupled line portion 19b in series via via holes 25 provided in the sheets 13 to 15, respectively. The sub line 20 is configured by electrically connecting a spiral first coupled line part 20a and a second coupled line part 20b in series via via holes 25 provided in the sheets 14 to 16, respectively. 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 19a of the main line 19 and the first coupled line portion 20a of the sub line 20 are formed so as to face each other with the sheet 13 interposed therebetween. Accordingly, the spiral patterns of the first coupling line portions 19a and 20a are substantially overlapped in a plan view, and are broadside electromagnetically coupled at the facing portions. Similarly, the spiral patterns of the second coupled line portions 19b and 20b are also substantially overlapped in plan view, and are broadside electromagnetically coupled at the portions facing each other with the sheet 16 therebetween. .

  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 portions of the first coupled line portion 19 a and the second coupled line portion 19 b are extended on the sheets 13 and 16. And the connection part A of this drawer | drawing-out part and a spiral part has a folding structure. Note that the number of turns of the electromagnetic coupling portion of the first coupling line portions 19a and 20a and the number of turns of the electromagnetic coupling portion of the second coupling line portions 19b and 20b of the first embodiment are substantially equal. 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 portion 22 a for avoiding a short circuit with the via hole 25 is formed in the center portion of the ground electrode 22. 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. The 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 a material such as Ag-Pd, Ag, Pd, or Cu.

  The sheets 12 to 18 are stacked, and further, protective sheets are arranged on the upper and lower sides thereof, and then integrally fired, thereby forming a rectangular laminate 30 as shown in FIG. Four input / output external electrodes 31 a, 31 b, 32 a, 32 b and four ground external electrodes G are formed on the side surface of the multilayer body 30. These external electrodes 31a to 32b, G are formed by a method such as sputtering, vapor deposition, coating, or printing, and are made of a material such as Ag—Pd, Ag, Pd, Cu, or Cu alloy.

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

  The input / output external electrode 32a formed on the left side of the side surface on the back side of the multilayer body 30 is electrically connected to one end portion of the sub line 20 (the lead portion of the first coupled line portion 20a), and this side The input / output external electrode 32b formed on the right side of the side surface is electrically connected to the other end of the sub line 20 (the lead portion of the second coupled 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 includes the first coupling line portion 19a of the main line 19 and the electromagnetic coupling portion of the first coupling line portion 20a of the sub line 20, and the second coupling line portions 19b and 20b. Since two electromagnetic coupling portions of the electromagnetic coupling portions are juxtaposed in the stacking direction of the stacked body 30, a conventional directional coupler having the same occupation area (having only one electromagnetic coupling portion) The line length of the main line 19 and the sub line 20 can be increased by a factor of about two. 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 reduced in size, frequency can be reduced, and insertion loss can be improved. Here, the size (representative value) of the directional coupler 11 is 5.7 mm in length, 5.0 mm in width, and 2.0 mm in height.

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

  As shown in FIG. 4, the laminated directional coupler 41 includes a dielectric sheet 14 provided with the first coupled line portion 20 a of the sub line 20 and a dielectric provided with the second coupled line portion 19 b of the main line 19. Between the sheet 16, a dielectric sheet 42 provided with extraction electrodes 45, 46, a dielectric sheet 43 provided with ground electrodes 49, and a dielectric sheet 44 provided with extraction electrodes 47, 48 are disposed. In FIG. 4, the dielectric sheets 12 and 18 provided with the ground electrodes 21 and 23 shown in FIG. 1 are not shown.

  The sheets 12 to 14, 42 to 44, and 16 to 18 are stacked, and further, protective sheets are disposed on the upper and lower sides thereof, and then integrally fired to form a rectangular laminate as shown in FIG. The body 50 is used. Input / output external electrodes 31a and 32b and a ground external electrode G are provided on the side surface on the front side of the laminate 50, and input / output electrodes 32a and 31b and a ground external electrode G are provided on the side surface on the back side. Are provided with relay external electrodes 51 and 52, respectively.

  One end of extraction electrodes 45 and 47 is electrically connected to the relay external electrode 51, and one end of extraction electrodes 46 and 48 is electrically connected to the relay external electrode 52. Thereby, the first coupled line portion 19a and the second coupled line portion 19b of the main line 19 are provided in the via hole 25, the extraction electrode 46, the relay external electrode 52, the extraction electrode 48, and the sheet 44 provided in the sheets 13 and 14, respectively. The via holes 25 are sequentially connected in series via the via holes 25. Similarly, the first coupled line portion 20a and the second coupled line portion 20b of the sub line 20 are provided in the via hole 25, the extraction electrode 45, the relay external electrode 51, the extraction electrode 47, and the sheets 44 and 16 provided in the sheet 14, respectively. The via holes 25 are sequentially connected in series via the via holes 25.

  The laminated directional coupler 41 having the above configuration has the same effects as the directional coupler 11 of the first embodiment. In addition, since the ground electrode 49 disposed between the first coupled line portion 20a of the sub line 20 and the second coupled line portion 19b of the main line 19 has no window portion, the first coupled line portions 19a-20a The electromagnetic coupling and the electromagnetic coupling of the second coupling line portions 19b-20b can be further suppressed from interfering with each other.

[Other Embodiments]
The laminated directional coupler according to the present invention is not limited to the above embodiment, and can be variously modified within the scope of the gist thereof. For example, it may be a directional coupler configured by two or more main lines and one sub line that is electromagnetically coupled to the two or more main lines. Alternatively, it may be a directional coupler 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 the main line and the sub line may be three or more. In this case, three or more electromagnetic coupling portions formed by coupling the coupling line portions of the main line and the sub-line are juxtaposed in the stacking direction of the stacked body.

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

  Further, the main line and the sub line are not limited to the strip line structure disposed between the two ground electrodes, but may be a so-called microstrip line structure in which one of the ground electrodes is omitted.

  Further, in the first and second embodiments, the ground electrodes 21 to 23 and 49 and the ground external electrode G may be omitted. In general, when there is an electrode 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, the electrodes that generate eddy currents are eliminated by omitting the ground electrodes 21 to 23 and 49. 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 the first and second embodiments, the coupled line portions 19a and 19b are arranged so that the directions of magnetic fluxes generated in the first coupled line portions 19a and 20a and the second coupled line portions 19b and 20b are opposite to each other. , 20a, 20b are wound. Thereby, even if the ground electrodes 22 and 49 are omitted, the magnetic flux generated in the first coupled line portions 19a and 20a and the magnetic flux generated in the second coupled line portions 19b and 20b are not easily coupled electromagnetically. ing.

  Further, in the above-described embodiment, the dielectric sheets each having the conductor pattern formed thereon are stacked and then integrally fired. However, the embodiment is not necessarily limited thereto. A dielectric sheet fired in advance may be used. Moreover, you may manufacture a directional coupler by the manufacturing method demonstrated below. After a dielectric layer is formed of a paste-like dielectric material by a method such as printing, a paste-like conductive material is applied to the surface of the dielectric layer to form a conductor pattern. Next, a paste-like dielectric material is applied from above to form a dielectric layer. In the same manner, a directional coupler having a laminated structure is obtained by sequentially overcoating.

  As described above, the present invention is useful for a laminated directional coupler, and is particularly excellent in that the directional coupler can be reduced in size, frequency can be reduced, and insertion loss can be improved.

DESCRIPTION OF SYMBOLS 11, 41 ... Laminated type directional coupler 12-18, 42-44 ... Dielectric sheet 19 ... Main line 20 ... Sub line 19a, 20a ... 1st coupling line part 19b, 20b ... 2nd coupling line part 21-23 49 ... Ground electrode 30,50 ... Laminated body

Claims (3)

A main line having at least a first coupled line portion and a second coupled line portion;
A sub-line having a first coupled line part and a second coupled line part electromagnetically coupled to the first coupled line part and the second coupled line part of the main line, respectively;
A ground electrode facing at least one of the main line and the sub line; and
Dielectric layers disposed between the first and second coupled line portions of the main line, the first and second coupled line portions of the sub line, and the ground electrode, respectively.
The first and second coupled line portions of the main line, the first and second coupled line portions of the sub line, the ground electrode, and the dielectric layer are stacked to form a stacked body, and the first line of the main line A first coupling line portion formed by sandwiching the dielectric layer, and a second coupling line portion of the main line and a second coupling of the sub line. The second electromagnetic coupling portion constituted by the line portion sandwiching the dielectric layer is juxtaposed in the stacking direction of the stacked body so as to sandwich the ground electrode,
Between the first electromagnetic coupling portion and the ground electrode, a first extraction electrode connected to one end of the first coupling line portion of the main line and one end of the first coupling line portion of the sub line, respectively. And a dielectric layer provided with a second extraction electrode,
Between the second electromagnetic coupling portion and the ground electrode, a third extraction electrode connected to one end of the second coupling line portion of the main line and one end of the second coupling line portion of the sub line, respectively. And a dielectric layer provided with a fourth extraction electrode is disposed,
A laminated directional coupler characterized by the above. One ends of the first coupled line portion and the second coupled line portion of the main line are connected to the first lead electrode, the third lead electrode, and a main line relay external electrode provided on a side surface of the laminate. Connected through
One ends of the first coupled line portion and the second coupled line portion of the sub-line include the second lead electrode, the fourth lead electrode, and a sub-line relay external electrode provided on a side surface of the laminate. Connected through the
The laminated directional coupler according to claim 1. The interval between the first extraction electrode, the second extraction electrode, and the first electromagnetic coupling portion in the stacking direction is the interval between the first extraction electrode, the second extraction electrode, and the ground electrode in the stacking direction. Wider than
The distance between the third extraction electrode, the fourth extraction electrode, and the second electromagnetic coupling portion in the stacking direction is the distance between the third extraction electrode, the fourth extraction electrode, and the ground electrode in the stacking direction. Wider than,
The laminated directional coupler according to claim 1 or 2, characterized by

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