JP2006014276A - Laminated balun transformer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a laminated balun transformer having an excellent electric characteristic, capable of stably attenuating a harmonic wave. <P>SOLUTION: The laminated balun transformer is structured of a lamination 10a having laminated ceramic dielectric layers 11-20. In the lamination 10a, unbalanced signal terminal P<SB>1</SB>, ground terminal G<SB>1</SB>, balanced signal terminal P<SB>2</SB>, balanced signal terminal P<SB>3</SB>, ground terminal G<SB>2</SB>and dummy terminal P<SB>4</SB>are formed. In the dielectric layers 13, 15 and 16, there are formed a first line 13a, a second line 15a and a third line 16a, each having a line length sufficiently shorter than a 1/4 wavelength of an input signal wave. The second line 15a is electromagnetically coupled with the first line 13a so as to sandwich the dielectric layers 13, 14, and also electromagnetically coupled with the third line 16a so as to sandwich the dielectric layer 15. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a stacked balun transformer, and more particularly to a stacked balun transformer used for a balanced-unbalanced signal converter, a phase converter, and the like of an integrated circuit for wireless communication equipment.

  The balun transformer is, for example, for mutually converting the balanced signal of the balanced transmission line (balanced transmission line) and the unbalanced signal of the unbalanced transmission line (unbalanced transmission line). Abbreviation for balance. A balanced transmission line includes two signal lines forming a pair, and a signal (balanced signal) propagates as a potential difference between the two signal lines. In the balanced transmission line, the external noise has the same phase (common mode) and affects the two signal lines equally. Therefore, the external noise is canceled out and is not easily affected by the external noise.

  Also, the input / output terminals for analog IC signals are often of a balanced type in which signals are input or output as potential differences between the two terminals. On the other hand, an unbalanced transmission line means that a signal (unbalanced signal) propagates as a potential of one transmission line with respect to a ground potential (zero potential). For example, a coaxial line or a microstrip line on a substrate is used. It corresponds to this.

  Conventionally, as a balanced-unbalanced converter for a transmission line in a high-frequency circuit, a balun transformer having a structure in which a coil is wound around a magnetic core such as ferrite is used. However, the balun transformer having this structure has a large conversion loss, for example, in a high frequency band higher than the UHF band, and has a limit in miniaturization.

  For such a frequency band, a balun transformer 60 having a coaxial structure as shown in FIG. 6 has been used. The balun transformer 60 has a center electrode 65, and an input / output terminal 62 a is connected to one end of the center electrode 65. The other end of the center electrode 65 is open. Around the center electrode 65, two internal electrodes 66a and 66b are provided so as to be electromagnetically coupled to the center electrode 65. The opposite inner ends of the internal electrodes 66a and 66b are connected to the other input / output terminals 62b and 62c via lead wires 67a and 67b, respectively. Further, a ground electrode 68 is provided around the internal electrodes 66a and 66b with a dielectric interposed therebetween. Both ends of the ground electrode 68 are connected to the outer ends of the internal electrodes 66a and 66b. The balun transformer 60 in FIG. 6 has an equivalent circuit as shown in FIG.

  Since the balun transformer 60 has a coaxial structure, it is difficult to reduce the size of the balun transformer 60. For example, the balun transformer 60 is not suitable for a device that requires a small balun transformer such as a mobile radio.

  In order to solve the above-described problems of the balun transformer having the coaxial structure, for example, Patent Document 1 proposes a chip-type balun transformer as shown in FIG. The balun transformer 70 has a dielectric layer 72 having an extraction electrode 72a on the surface, a dielectric layer 73 having a half-wave strip line 73ab on the surface, and quarter-wave strip lines 74a and 74b on the surface. The dielectric layer 74 is provided, and dielectric layers 71 and 75 having ground electrodes 71a and 75a provided on the surface thereof, respectively.

The half-wave strip line 73ab has a spiral first portion 73a and a second portion 73b. The quarter-wave strip lines 74a and 74b are electromagnetically coupled to the first portion 73a and the second portion 73b of the strip line 73ab, respectively.

  Since the balun transformer 70 is formed as a chip, the balun transformer 70 is smaller than the balun transformer 60 having a coaxial structure. However, in the ½ wavelength strip line 73ab, the spiral first portion 73a and the second portion 73b constitute a set of coupled lines having a ¼ wavelength, and these ¼ wavelength coupled lines are formed. Since 73a and 73b have a structure in which each of a pair of quarter-wave strip lines 74a and 74b is electromagnetically coupled, a total of two quarter-wave coupling lines are required.

  Further, in principle, these coupled lines 73a, 73b, 74a, and 74b cannot have a line length shorter than ¼ wavelength. Further, the first portion 73a and the second portion 73b of the half-wave strip line 73ab are formed side by side on the same surface of the dielectric layer 73, and the quarter-wave strip lines 74a and 74b are also dielectric. Since the body layers 74 are formed side by side on the same surface, the required areas of the dielectric layers 73 and 74 are also increased. For this reason, the chip-type balun transformer described in Patent Document 1 has a limit in miniaturization.

  Patent Document 2 proposes a laminated balun transformer as shown in FIG. The laminated balun transformer 80 includes a dielectric sheet 82 provided with an extraction electrode 82a on the surface, and dielectric sheets 83, 84, 86 provided with quarter-wave strip lines 83a, 84a, 86a, 87a on the surface, respectively. 87, and dielectric sheets 81, 85, 88 having ground electrodes 81a, 85a, 88a provided on the surface thereof, respectively.

  The strip lines 83a and 84a are provided facing each other with the dielectric sheet 83 interposed therebetween, and are electromagnetically coupled. The strip lines 86a and 87a are provided opposite to each other with the dielectric sheet 86 interposed therebetween, and are electromagnetically coupled. The end of the strip line 83a and the end of the strip line 87a are electrically connected via an external electrode.

  In the laminated balun transformer 80, quarter-wave strip lines 83a and 87a are formed on different dielectric sheets 83 and 87, respectively, and quarter-wave strip lines 84a and 86a are formed on different dielectric sheets 84 and 86, respectively. Therefore, the quarter-wave strip lines 83a, 84a, 86a, 87a are arranged in the stacking direction of the dielectric sheets 81-88. For this reason, although the area of the dielectric sheets 81 to 88 can be reduced, there is a problem that the laminated thickness is increased.

In the laminated balun transformer 80, the quarter-wave strip lines 83a, 84a, 86a and 87a are used, so that the odd-order harmonics pass almost without being attenuated and the even-order harmonics. In addition, it was difficult to make specifications for traps because the trap frequency with a steep attenuation characteristic varies with the center frequency of the trap for each product or lot. For this reason, there is a problem that harmonics must be removed by providing a trap filter or the like separately.
JP-A-7-176918 JP-A-9-260145

  Therefore, an object of the present invention is to provide a small stacked balun transformer having excellent electrical characteristics capable of stably attenuating harmonics.

In order to achieve the above object, the laminated balun transformer according to the present invention is:
A first line is formed on one side and the other side in the thickness direction of the dielectric layer in which the second line is formed, and is formed of a laminated body including a dielectric layer in which the first, second, and third lines are respectively formed. And a third balun transformer in which the first and third lines are electromagnetically coupled to the second line. Because
The lengths of the first, second and third lines are all shorter than a quarter wavelength of the input signal wave,
One end of the second line is an unbalanced signal terminal, and the other end is grounded.
The first line is grounded at one end on the side having the same polarity as the one end of the second line, and the other end is a first balanced signal terminal,
The third line has one end on the side having the same polarity as the one end of the second line as a second balanced signal terminal, and the other end is grounded.
It is characterized by.

  According to the multilayer balun transformer according to the present invention, only three lines of the first, second, and third lines are required, and the line length is shorter than ¼ wavelength. In addition to reducing the electromagnetic coupling between the lines, when using the same dielectric material as the conventional multilayer balun transformer, the thickness of the dielectric layer can be reduced, resulting in a small-sized laminate. A type balun transformer can be obtained. Furthermore, since the line lengths of the first, second and third lines are shorter than ¼ wavelength, it is possible to obtain good attenuation up to several times the input signal frequency, and stable attenuation characteristics. Can be obtained. As a result, it is possible to specify the attenuation characteristics.

  In the laminated balun transformer according to the present invention, the laminated body is preferably made of ceramic. Ceramic has a high Q and dielectric constant, and has good characteristics as a material of this type of laminate. The first, second, and third lines preferably have a spiral shape. By adjusting the number of turns of the spiral of each line, the inductance of the line can be adjusted, and the input / output matching can be easily adjusted.

  The first, second and third lines may have different widths and lengths. By adjusting the width and length of the spiral of each line, the inductance of the line can be changed, and input / output matching can be easily adjusted.

  A capacitor may be connected between the unbalanced signal terminal and the ground. Since the resonance frequency of the second line connected to the unbalanced signal terminal is lowered by the connection of the capacitor, the line length of the second line can be shortened accordingly. Thereby, the stacked balun transformer can be further downsized.

  Furthermore, a capacitor may be connected between each of the balanced signal terminals and the ground. Since the resonance frequency of the first and third lines connected to the balanced signal terminal is lowered by the connection of such a capacitor, the line lengths of these lines can be shortened accordingly. Thereby, the stacked balun transformer can be further downsized.

  Further, a shield electrode may be provided on the dielectric layer below the third line. The inductance of the third line is reduced by the presence of the shield electrode, and the interval T2 between the third line and the second line can be set smaller than the interval T1 between the first line and the second line. That is, by reducing the thickness of the dielectric layers of the second line and the third line, it is possible to make them closer together, and reducing the thickness of the dielectric layer to reduce the thickness of the ceramic laminate. be able to. Thereby, a smaller stacked balun transformer can be obtained.

  Hereinafter, embodiments of the laminated balun transformer according to the present invention will be described with reference to the accompanying drawings.

(Refer 1st Example and FIGS. 1-3)
FIG. 1 shows the external appearance of the laminated balun transformer according to the first embodiment of the present invention, and FIG. 2 shows its specific configuration.

  The multilayer balun transformer 10 includes a chip-shaped ceramic laminate 10a in which ceramic dielectric layers 11 to 20 are laminated. The dielectric layers 11 to 20 are all fired after a ceramic green sheet obtained by molding a dielectric ceramic material by a technique such as a doctor blade method or a pulling method is laminated / press-bonded to form the laminated body 10a. Further, the ceramic green sheet is formed by sintering. For this reason, in FIG. 1, no section line is actually generated between layers adjacent to each other in the stacking direction of the dielectric layers 11 to 20.

One of the stacking surface of the stack 10a of the stack of dielectric layers 11 to 20 are formed from the dielectric layer 11 toward the dielectric layer 20, an unbalanced signal terminal P _1, the ground terminal G _1, the balanced signal terminal P ₂ Is formed. In addition, a balanced signal terminal P ₃ , a ground terminal G ₂ , and a dummy terminal P ₄ are formed on the other stacked surface facing one stacked surface of the stacked body 10a. These ground terminals G ₁ and G ₂ , unbalanced signal terminal P ₁ , balanced signal terminals P ₂ and P _3, and dummy terminal P ₄ may be formed in advance by printing before sintering the ceramic green sheet. The laminate 10a may be formed after firing.

  A first line 13a, a second line 15a, and a third line 16a each having a spiral line pattern in the same winding direction are formed on one main surface of each of the dielectric layers 13, 15, and 16. ing. In the first embodiment, these lines 13a, 15a, and 16a have constant widths equal to each other, and have a line length sufficiently shorter than a quarter wavelength of the input signal wave, for example, a line having a 1/12 wavelength. It is formed to be long. The second line 15a is electromagnetically coupled to the first line 13a with the dielectric layers 13 and 14 stacked on the upper side therebetween, and the dielectric layer 15 formed on the second line 15a is also connected to the second line 15a. In the meantime, it is electromagnetically coupled to the third line 16a.

  The line lengths of the lines 13a, 15a, and 16a are shorter than the quarter wavelength of the input signal wave. When three lines are coupled, if the line length is a quarter wavelength, either two are strong. This is because the other one is not connected. By shortening the line length, the stronger coupling is weakened, and on the contrary, the weaker coupling is stronger, and a balance can be achieved by an appropriate length interval or the like.

The second line 15a has one end located outside of the spiral is electrically connected to the unbalanced signal terminal P ₁ through via hole Vh ₁ and the extraction electrode 14a formed on the dielectric layer 14, on the inside of the spiral A via hole Vh ₂ whose other end is formed in the dielectric layer 14.
And it is electrically connected to the ground terminal G ₁ through the extraction electrode 14b. The first line 13a is connected to the ground terminal G ₂ through a via hole Vh ₃ having one end on the side having the same polarity as the one end of the second line 15a (outside of the spiral) formed in the dielectric layer 12 and the extraction electrode 12a. to be electrically connected, the second line 15a balanced signal terminal P through hole Vh ₄ and the extraction electrode 12b whose other end is formed in the dielectric layer 12 on the side (inside of the spiral) with different polarity to one end of ₃ is electrically connected. Here, the fact that one end of two lines has the same polarity is generally used in the same meaning as that shown by adding a black circle to one end of a symbol representing a coil with a transformer or the like. Therefore, for example, if the winding direction of the first line 13a is opposite to the second line 15a, the inside of the spiral is referred to as one end and the outside is referred to as the other end in the first line 13a. .

Third line 16a is lead electrode whose one end side (outer spiral) having the same polarity as the one end of the second line 15a is formed in the via hole Vh ₅ and dielectric layer 17 formed on the dielectric layer 16 The second line 1 is electrically connected to the other balanced signal terminal P ₂ through 17a.
Side having one end different from the polarity of 5a (spiral inside) the other end a ground terminal G ₂ to electrically through extraction electrode 17b formed in the via hole Vh ₆ and dielectric layer 17 formed on the dielectric layer 16 of the It is connected.

On one main surface of the dielectric layer 18 and the ground electrode 18a is formed, the ground electrode 18a is electrically connected to the ground terminal G ₁ by the extraction electrode 18b. Further, on one main surface of the dielectric layer 19 and the capacitor electrode 19a is formed, the capacitor electrode 19a is electrically connected to the unbalanced signal terminal P ₁ by the extraction electrode 19b.

Further, on one main surface of the dielectric layer 20 is formed a ground electrode 20a is also, the ground electrode 20a is electrically connected to the ground terminal G ₁ by the extraction electrode 20b. The capacitor electrode 19a faces the ground electrode 18a with the dielectric layer 18 in between, and faces the ground electrode 20a with the dielectric layer 19 in between. As a result, a capacitance C ₁ described in FIG. 3 is formed between the unbalanced signal terminal P ₁ and the ground terminal G ₁ .

The laminated balun transformer 10 described above has the equivalent circuit shown in FIG. That is, in the laminated balun transformer 10, the second line 15a has one end and the other end is connected to the unbalanced signal terminal P ₁ and the ground terminal G _1. The first line 13a has one end having the same polarity as the one end of the second line 15a is connected to the ground terminal G _2, the second line 15a
The other end having an end with different polarities are connected to the unbalanced signal terminal P _3. Third line 16a
One end having the same polarity as the one end of the second line 15a is connected to the balanced signal terminal P _2, the other end having one end different from the polarity of the second line 15a is connected to the ground terminal G _2. The electrostatic capacitance (capacitor) C ₁ is connected between the unbalanced signal terminal P ₁ and the ground terminal G ₁ .

  In FIG. 3, black circles attached to the respective ends of the first line 13a, the second line 15a, and the third line 16a indicate that these one ends have the same polarity. .

In the laminated balun transformer 10 having the above configuration, the ground terminals G ₁ and G ₂ are normally grounded at the same potential, but temporarily biased to the first line 13a, the second line 15a, and the third line 16a. when such use by applying a voltage, a ground terminal G ₂ is grounded via a sufficiently small capacitor of the impedance at the signal frequency. When an unbalanced signal is input between the unbalanced signal terminal P ₁ and the ground terminal G ₁ , the unbalanced signal is electromagnetically coupled to the second line 15a, the first line 13a and the third line 13a. Is converted to a balanced signal by the line 16a and output from between the balanced signal terminals P ₂ and P ₃ . Conversely, when a balanced signal is input between the balanced signal terminals P ₂ and P ₃ , the balanced signal is unbalanced by the second line 15a electromagnetically coupled to the first line 13a and the third line 16a. The signal is converted into a signal and output from between the unbalanced signal terminal P ₁ and the ground terminal G ₁ .

The laminated balun transformer 10 requires only three lines, the first, second, and third lines 13a, 15a, and 16a, and the line length is also set to 1/12 wavelength that is sufficiently shorter than 1/4 wavelength. Therefore, the size of the laminated body 10a can be significantly reduced, and the size of the laminated balun transformer 10 can be greatly reduced. Further, when the line length of each line 13a, 15a, 16a is shorter than a quarter wavelength of the input signal wave, the electromagnetic coupling between the lines becomes relatively small, and the generated magnetic field is less likely to leak to the outside. Become. For this reason, it is not necessary to provide a shielding electrode on the upper side of the first line 13a. Moreover, when the same dielectric material as that of the conventional laminated balun transformer is used, the thickness of the dielectric layers 13, 14, and 15 can be reduced. From this point of view, the stacked balun transformer 10 can be further reduced in size.

  Furthermore, since the line length of each of the lines 13a, 15a, and 16a is 1/12 wavelength of the input signal wave, the frequency of the signal that becomes 1/4 wavelength by that length is three times the frequency of the input signal. . That is, a 1/4 wavelength line is provided for a signal having a frequency three times that of the input signal. In such a device, the first attenuation pole appears at twice that frequency, and as a result, it is possible to obtain a good attenuation characteristic without spurious frequency up to six times the input signal frequency. Therefore, with respect to the second harmonic and the third harmonic of the input signal frequency, the frequency characteristic is not trapped, and a stable attenuation characteristic can be obtained. As a result, it is possible to specify the attenuation characteristics.

Furthermore, the capacitor C ₁ connected between the unbalanced signal terminal P ₁ and the ground terminal G ₁ not only can easily match the input / output on the unbalanced signal side of the multilayer balun transformer 10. , resonant circuit and the capacitor C ₁ second line 15a is formed, since the resonance frequency is lowered with an increase in the capacitance of the capacitor C _1, to be further shortened line length of the second line 15a it can. Thereby, further miniaturization of the laminated balun transformer 10 can be achieved.

  In the first embodiment, as shown in FIG. 2, the interval T1 between the first line 13a and the second line 15a and the interval T2 between the third line 16a and the second line 15a are There is a relationship of T1> T2. That is, since the ground electrode 18a is formed on the dielectric layer 18 below the third line 16a, the presence of the ground electrode 18a reduces the inductance of the third line 16a, and the third line An interval T2 between 16a and the second line 15a can be set smaller than an interval T1 between the first line 13a and the second line 15a. Thereby, the 3rd track | line 16a and the 2nd track | line 15a come closer, and the lamination | stacking thickness of the ceramic laminated body 10 can be made small.

(Refer to the second embodiment, FIG. 4)
A laminated balun transformer according to the second embodiment of the present invention is shown in FIG. This laminated balun transformer 30 is the same as the laminated balun transformer 10 according to the first embodiment described with reference to FIGS. 1 and 2, but between the dielectric layer 17 and the dielectric layer 18 of the laminated body 10a. A laminated body 10b is formed of dielectric layers 11 to 21 via a dielectric layer 21 having two capacitor electrodes 21a and 21b formed on the main surface, and the two capacitor electrodes 21a and 21b are connected to balanced signal terminals P ₂ and P _3. Are connected to each other. The capacitor electrodes 21a and 21b face the ground electrode 18a formed on the dielectric layer 18 with the dielectric layer 21 therebetween, and electrostatic capacitances C ₂ and C ₃ indicated by dotted lines in FIG. 3 are formed therebetween. Is done. In FIG. 4, portions corresponding to those in FIG. 2 are denoted by the corresponding reference numerals, and redundant description is omitted.

This laminated balun transformer 30 has the same effects as the laminated balun transformer 10 of the first embodiment. Further, the multilayer balun transformer 30 includes a capacitor C ₂ connected between the balanced signal terminal P ₂ and the ground terminal G ₁ and a capacitor C ₃ connected between the balanced signal terminal P ₃ and the ground terminal G _1. It is possible to easily match the input / output on the balanced signal side. In addition, a resonance circuit is formed by the first line 13a, the third line 16a, and the capacitors C ₂ and C _3, and the resonance frequency thereof decreases as the capacitances of the capacitors C ₂ and C ₃ increase. The line length of the two lines including the first line 13a and the third line 16a can be further shortened. Thereby, the further miniaturization of the multilayer balun transformer 30 can be achieved.

(Refer to the third embodiment, FIG. 5)
A laminated balun transformer according to a third embodiment of the present invention is shown in FIG. In the multilayer balun transformer 40, the width of the first line 13a and the third line 16a is larger than the width of the second line 15a in the multilayer balun transformer 10 according to the first embodiment. The lengths of the first line 13a and the third line 16a are both shorter than the length of the second line 15a, and the lengths of the lead electrodes 12a, 12b, 17a, 17b and the via holes Vh _{3 to} Vh ₆ are set. In consideration of the influence on the first line 13a and the third line 16a, the inductance of the lines 13a and 16a is adjusted to a necessary value.

Thus, the first to third lines 13a, 15a, and 16a do not necessarily have the same length and the same width, and may be appropriately changed according to the specifications. Thus, the first line 13a and the third line 16a, the lead electrodes 12a, 12b, 17a, depending on 17b and the length of the via hole Vh ₃ ~Vh _6, etc., the the the second line 15a in opposite In comparison, the width may be narrow or the line length may be long.

  In FIG. 5, portions corresponding to those in FIGS. 1 and 2 are denoted by corresponding reference numerals, and redundant description is omitted.

(Other examples)
The laminated balun transformer according to the present invention is not limited to the above-described embodiments, and various configurations can be made within the scope of the gist thereof.

  In particular, in each of the above embodiments, the first, second and third lines 13a, 15a and 16a have been described as having a spiral shape, but these lines 13a, 15a and 16a have, for example, a meander shape. There may be.

  Moreover, although the said laminated body was comprised with the ceramic, you may comprise with resin. However, ceramic has a high Q and dielectric constant and is preferable as a material for this type of laminate.

1 is a perspective view showing an appearance of a first embodiment of a laminated balun transformer according to the present invention. FIG. 2 is an exploded perspective view of the laminated balun transformer shown in FIG. 1. FIG. 2 is an equivalent circuit diagram of the multilayer balun transformer shown in FIG. 1. It is a disassembled perspective view of 2nd Example of the laminated | stacked balun transformer which concerns on this invention. FIG. 6 is an exploded perspective view of a third embodiment of the laminated balun transformer according to the present invention. It is explanatory drawing of the balun transformer of the conventional coaxial structure. FIG. 7 is an equivalent circuit diagram of the balun transformer shown in FIG. 6. It is a disassembled perspective view of the conventional laminated balun transformer. It is an exploded perspective view of another conventional laminated balun transformer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10, 30, 40 ... Laminated balun transformer 10a, 10b ... Laminated body 11-21 ... Dielectric layer 13a ... 1st line 15a ... 2nd line 16a ... 3rd line 18a ... Ground electrode 19a ... Capacitor electrode 20a ... ground electrodes 30, 40 ... stacked balun transformers P ₁ ... unbalanced signal terminals P ₂ and P ₃ ... balanced signal terminals G ₁ and G ₂ ... ground terminals C ₁ , C ₂ and C ₃ ... capacitors

Claims (8)

A first line is formed on one side and the other side in the thickness direction of the dielectric layer in which the second line is formed, and is formed of a laminated body including a dielectric layer in which the first, second, and third lines are respectively formed. And a third balun transformer in which the first and third lines are electromagnetically coupled to the second line. Because
The lengths of the first, second and third lines are all shorter than a quarter wavelength of the input signal wave,
One end of the second line is an unbalanced signal terminal, and the other end is grounded.
The first line is grounded at one end on the side having the same polarity as the one end of the second line, and the other end is a first balanced signal terminal,
The third line has one end on the side having the same polarity as the one end of the second line as a second balanced signal terminal, and the other end is grounded.
Multi-layer balun transformer characterized by   The multilayer balun transformer according to claim 1, wherein the multilayer body is made of ceramic.   The laminated balun transformer according to claim 1 or 2, wherein the first, second, and third lines have a spiral shape.   4. The multilayer balun transformer according to claim 1, wherein the first, second, and third lines have different widths and lengths. 5.   5. The multilayer balun transformer according to claim 1, wherein a capacitor is connected between the unbalanced signal terminal and the ground.   6. The multilayer balun transformer according to claim 5, wherein a capacitor is connected between each of the balanced signal terminals and the ground.   The laminate according to claim 1, 2, 3, 4, 5, or 6, wherein a shield electrode is provided on a dielectric layer below the third line. Type balun transformer.   8. The distance T1 between the first line and the second line and the distance T2 between the third line and the second line are in a relationship of T1> T2. The laminated balun transformer described.

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