JP2005244000A

JP2005244000A - Balun transformer

Info

Publication number: JP2005244000A
Application number: JP2004053020A
Authority: JP
Inventors: Masahide Takashima; 政秀高嶋
Original assignee: Toko Inc
Current assignee: Toko Inc
Priority date: 2004-02-27
Filing date: 2004-02-27
Publication date: 2005-09-08

Abstract

【課題】電子機器によっては２種類の周波数帯域の信号が互いに混信しない様にする必要があるものや、使用周波数の２倍又は１／２倍の周波数のノイズを除去する必要があるものがある。しかし、通過帯域以外の減衰量を調整することが難しく、必要な特性が得られない場合がある。
【解決手段】直列接続された第１コイルと第２コイル、第１コイルに結合し、第１平衡端子とアース間に接続された第３コイル、第２コイルに結合し、第２平衡端子とアース間に接続された第４コイル、第１コイルの第２コイルとの接続点と反対側の端と第３コイルのアース側の端間に接続されてアースされる第１コンデンサ、第２コイルの第１コイルとの接続点と反対側の端と第４コイルのアース側の端間に接続されてアースされる第２コンデンサ、第１平衡端子と該第２平衡端子間に接続された第３コンデンサを備える。第１コイルと第２コイルのいずれか一方が不平衡端子に接続される。
【選択図】図１PROBLEM TO BE SOLVED: Some electronic devices need to prevent signals of two types of frequency bands from interfering with each other, and some need to remove noise having a frequency twice or half the frequency used. . However, it may be difficult to adjust the attenuation other than the passband, and necessary characteristics may not be obtained.
A first coil and a second coil connected in series, coupled to a first coil, a third coil connected between a first balanced terminal and a ground, and a second coil are coupled to each other. A fourth coil connected between the ground, a first capacitor connected between the end of the first coil opposite to the connection point with the second coil and an end on the ground side of the third coil, and the second coil. A second capacitor connected between the end opposite to the connection point of the first coil and the ground end of the fourth coil and grounded, and a second capacitor connected between the first balanced terminal and the second balanced terminal. 3 capacitors are provided. One of the first coil and the second coil is connected to the unbalanced terminal.
[Selection] Figure 1

Description

本発明は、移動体通信機器等の電子機器において、伝送線路インピーダンスを変換するためのインピーダンス変換器や、平衡用伝送線路の信号及び不平衡用伝送線路の信号を相互に変換するための信号変換器ないし位相変換器等に用いられるバラントランスに関するものであり、不用信号を除去し、特性を改善するものである。 The present invention relates to an impedance converter for converting a transmission line impedance in an electronic device such as a mobile communication device, and a signal conversion for mutually converting a signal of a balanced transmission line and a signal of an unbalanced transmission line. The present invention relates to a balun transformer used in a transformer or a phase converter, and removes unnecessary signals and improves characteristics.

従来のバラントランスに、図８、図９に示す様に、アース電極９２が形成された絶縁体層９１Ａ、２つのコイル用導体パターン９３、９４が形成された複数の絶縁体層９１Ｂ、９１Ｃ、２つのコイル用導体パターン９５、９６が形成された複数の絶縁体層９１Ｄ、９１Ｅ及び、保護用の絶縁体層９１Ｆを積層し、積層体内に不平衡端子８１とダミー端子８４間に直列に接続された第１のコイルＬ５と第２のコイルＬ６、第１のコイルに電磁気的に結合し、平衡端子８２に接続された第３のコイルＬ７及び、第２のコイルに電磁気的に結合し、平衡端子８３に接続された第４のコイルＬ８が形成されたものがある（例えば、特許文献１を参照。）。
特開２００１−１７６７２６号公報 As shown in FIGS. 8 and 9, a conventional balun transformer has an insulator layer 91A in which a ground electrode 92 is formed, and a plurality of insulator layers 91B and 91C in which two coil conductor patterns 93 and 94 are formed. A plurality of insulator layers 91D and 91E on which two coil conductor patterns 95 and 96 are formed and a protective insulator layer 91F are stacked, and connected in series between the unbalanced terminal 81 and the dummy terminal 84 in the stack. Electromagnetically coupled to the first coil L5, the second coil L6, the first coil, and the third coil L7 connected to the balanced terminal 82 and the second coil; There is one in which a fourth coil L8 connected to the balanced terminal 83 is formed (see, for example, Patent Document 1).
JP 2001-176726 A

この様なバラントランスは、主に平衡回路と不平衡回路間の信号を相互に変換するために用いられている。この種のバラントランスは、使用される電子機器によっては２種類の周波数帯域の信号が互いに混信しない様に一方の帯域で他方の帯域の信号を除去し、他方の帯域で一方の帯域の信号を除去する必要があるものや、イメージ混信を防ぐために使用周波数の２倍又は１／２倍の周波数のノイズを除去する必要があるものがある。また、近年の通信機器等の電子機器の小型化に伴ってバラントランスの小型化も望まれるようになってきている。
しかしながら、従来のバラントランスは、コイルを電磁気的に結合させているだけなので、通過帯域以外の減衰量を使用される電子機器に応じて調整することが難しく、それらの電子機器に用いるのに必要な特性が得られない場合があった。 Such a balun transformer is mainly used to mutually convert signals between a balanced circuit and an unbalanced circuit. This type of balun transformer removes the signal of the other band in one band and the signal of the other band in the other band so that the signals of two frequency bands do not interfere with each other depending on the electronic equipment used. There are some that need to be removed and some that need to remove noise at a frequency that is twice or half the frequency used to prevent image interference. In addition, with the recent miniaturization of electronic devices such as communication devices, it has become desirable to reduce the size of balun transformers.
However, since the conventional balun transformer only has the coils electromagnetically coupled, it is difficult to adjust the attenuation amount other than the passband according to the electronic equipment used, and it is necessary to use these electronic equipment. In some cases, it was not possible to obtain proper characteristics.

本発明は、フィルタの機能も備えたバラントランスを提供することを目的とする。 It is an object of the present invention to provide a balun transformer having a filter function.

本発明のバラントランスは、直列に接続された第１のコイルと第２のコイル、第１のコイルに電磁気的に結合し、第１の平衡端子とアース間に接続された第３のコイル、第２のコイルに電磁気的に結合し、第２の平衡端子とアース間に接続された第４のコイル、第１のコイルの第２のコイルとの接続点と反対側の端と第３のコイルのアース側の端間に接続されてアースされる第１のコンデンサ、第２のコイルの第１のコイルとの接続点と反対側の端と第４のコイルのアース側の端間に接続されてアースされる第２のコンデンサ、第１の平衡端子と第２の平衡端子間に接続された第３のコンデンサを備え、第１のコイルと第２のコイルのいずれか一方が不平衡端子に接続される。
また、本発明のバラントランスは、絶縁体層と導体パターンを積層し、これらの積層体内に、直列に接続された第１のコイルと第２のコイル、第１のコイルに電磁気的に結合し、第１の平衡端子とアース間に接続された第３のコイル、第２のコイルに電磁気的に結合し、第２の平衡端子とアース間に接続された第４のコイル、第１のコイルの第２のコイルとの接続点と反対側の端とアース間に接続される第１のコンデンサ、第２のコイルの第１のコイルとの接続点と反対側の端とアース間に接続される第２のコンデンサ、第１の平衡端子と第２の平衡端子間に接続された第３のコンデンサが形成され、第１のコイルと第２のコイルのいずれか一方が不平衡端子に接続される。 The balun transformer of the present invention includes a first coil and a second coil connected in series, a third coil electromagnetically coupled to the first coil, and connected between the first balanced terminal and the ground, A fourth coil coupled electromagnetically to the second coil and connected between the second balanced terminal and the ground; an end opposite to the connection point of the first coil with the second coil; and a third coil A first capacitor connected between the ground side ends of the coil and grounded, and connected between the end of the second coil opposite to the connection point with the first coil and the ground side end of the fourth coil. A second capacitor to be grounded, a third capacitor connected between the first balanced terminal and the second balanced terminal, wherein either the first coil or the second coil is an unbalanced terminal Connected to.
The balun transformer according to the present invention includes an insulator layer and a conductor pattern laminated, and electromagnetically coupled to the first coil, the second coil, and the first coil connected in series in the laminate. A third coil connected between the first balanced terminal and the ground; a fourth coil coupled electromagnetically to the second coil; and connected between the second balanced terminal and the ground; A first capacitor connected between the end opposite to the connection point with the second coil and ground, and a second capacitor connected between the end opposite to the connection point with the first coil and ground. A second capacitor, a third capacitor connected between the first balanced terminal and the second balanced terminal is formed, and one of the first coil and the second coil is connected to the unbalanced terminal. The

本発明のバラントランスは、直列に接続された第１のコイルと第２のコイル、第１のコイルに電磁気的に結合し、第１の平衡端子とアース間に接続された第３のコイル、第２のコイルに電磁気的に結合し、第２の平衡端子とアース間に接続された第４のコイル、第１のコイルの第２のコイルとの接続点と反対側の端と第３のコイルのアース側の端間に接続されてアースされる第１のコンデンサ、第２のコイルの第１のコイルとの接続点と反対側の端と第４のコイルのアース側の端間に接続されてアースされる第２のコンデンサ、第１の平衡端子と第２の平衡端子間に接続された第３のコンデンサを備え、第１のコイルと第２のコイルのいずれか一方が不平衡端子に接続されるので、バラントランスにフィルタの機能を備えることができる。
また、本発明のバラントランスは、絶縁体層と導体パターンを積層し、これらの積層体内に、直列に接続された第１のコイルと第２のコイル、第１のコイルに電磁気的に結合し、第１の平衡端子とアース間に接続された第３のコイル、第２のコイルに電磁気的に結合し、第２の平衡端子とアース間に接続された第４のコイル、第１のコイルの第２のコイルとの接続点と反対側の端とアース間に接続される第１のコンデンサ、第２のコイルの第１のコイルとの接続点と反対側の端とアース間に接続される第２のコンデンサ、第１の平衡端子と第２の平衡端子間に接続された第３のコンデンサが形成され、第１のコイルと第２のコイルのいずれか一方が不平衡端子に接続されるので、形状を大きくすることなくバラントランスにフィルタの機能を一体に備えることができる。 The balun transformer of the present invention includes a first coil and a second coil connected in series, a third coil electromagnetically coupled to the first coil, and connected between the first balanced terminal and the ground, A fourth coil coupled electromagnetically to the second coil and connected between the second balanced terminal and the ground, an end opposite to the connection point of the first coil with the second coil, and a third coil; A first capacitor connected between the ground side ends of the coil and grounded, and connected between the end of the second coil opposite to the connection point with the first coil and the ground side end of the fourth coil. A second capacitor to be grounded, a third capacitor connected between the first balanced terminal and the second balanced terminal, wherein either the first coil or the second coil is an unbalanced terminal Therefore, the balun transformer can have a filter function.
The balun transformer according to the present invention includes an insulator layer and a conductor pattern which are electromagnetically coupled to the first coil, the second coil, and the first coil connected in series in the laminate. A third coil connected between the first balanced terminal and the ground; a fourth coil coupled electromagnetically to the second coil; and connected between the second balanced terminal and the ground; A first capacitor connected between the end opposite to the connection point with the second coil and ground, and a second capacitor connected between the end opposite to the connection point with the first coil and ground. A second capacitor, a third capacitor connected between the first balanced terminal and the second balanced terminal is formed, and one of the first coil and the second coil is connected to the unbalanced terminal. Therefore, the filter function can be added to the balun transformer without increasing the shape. It can be provided to the body.

本発明のバラントランスは、第１の絶縁体層とコイル用導体パターンを積層し、第１の絶縁体層間のコイル用導体パターンをらせん状に接続して、直列に接続された第１のコイルと第２のコイル、第１のコイルに電磁気的に結合し、第１の平衡端子とアース間に接続された第３のコイル、第２のコイルに電磁気的に結合し、第２の平衡端子とアース間に接続された第４のコイルが形成される。この第１の絶縁体層とコイル用導体パターンの積層体の裏面に第２の絶縁体層とコンデンサ用導体パターンを積層して、第１のコイルの第２のコイルとの接続点と反対側の端をアースするための第１のコンデンサと、第２のコイルの第１のコイルとの接続点と反対側の端をアースするための第２のコンデンサが形成される。また、第１の絶縁体層とコイル用導体パターンの積層体の表面に第３の絶縁体層とコンデンサ用導体パターンを積層して、第１の平衡端子と第２の平衡端子間に接続された第３のコンデンサが形成される。第１のコイルと第２のコイルは、いずれか一方が不平衡端子に接続される。
また、本発明のバラントランスは、表面に第１のコイル用導体パターンと第２のコイル用導体パターンが形成された複数の第１の絶縁体層を積層し、第１のコイル用導体パターン同士及び第２のコイル用導体パターン同士を接続して第１のコイルと第２のコイルが形成され、表面に第３のコイル用導体パターンと第４のコイル用導体パターンが形成された複数の第２の絶縁体層を積層し、第３のコイル用導体パターン同士及び第４のコイル用導体パターン同士を接続して第３のコイルと第４のコイルが形成される。これらのコイルは、第１のコイルと第３のコイルが電磁気的に結合し、第２のコイルと第４のコイルが電磁気的に結合するように第１のコイルと第２のコイルを第２の絶縁体層を介して第３のコイルと第４のコイルに対向させる。第３のコイルは第１の平衡端子とアース間に接続される。また、第４のコイルは第２の平衡端子とアース間に接続される。この第１の絶縁体層と第２の絶縁体層の積層体の裏面には、第３の絶縁体層とコンデンサ用導体パターンを積層して、第１のコイルの第２のコイルとの接続点と反対側の端をアースするための第１のコンデンサと、第２のコイルの第１のコイルとの接続点と反対側の端をアースするための第２のコンデンサが形成される。また、第１の絶縁体層と第２の絶縁体層の積層体の表面に第４の絶縁体層とコンデンサ用導体パターンを積層して、第１の平衡端子と第２の平衡端子間に接続された第３のコンデンサが形成される。第１のコイルと第２のコイルは、いずれか一方が不平衡端子に接続される。
従って、本発明のバラントランスは、コイル用導体パターンとコンデンサ用導体パターンによって積層体内にバラントランスとフィルタが一体に形成される。また、本発明のバラントランスは、第１のコイルと第２のコイルがアース電極と対向することがないので、浮遊容量の影響を小さくすることができる。さらに、本発明のバラントランスは、第１のコイルと第２のコイルの接続点と、第３のコイルの平衡端子側や第４のコイルの平衡端子側の距離を離すことができるので、第１のコイルの第２のコイルとの接続点側と第３のコイルの平衡端子側間及び、第２のコイルの第１のコイルとの接続点側と第４のコイルの平衡端子間に浮遊容量が発生することがない。 In the balun transformer of the present invention, the first insulator layer and the coil conductor pattern are laminated, the coil conductor patterns between the first insulator layers are spirally connected, and the first coil connected in series And the second coil, the first coil, electromagnetically coupled to the first coil, the third coil connected between the first balanced terminal and the ground, and the second coil, electromagnetically coupled to the second coil, and the second balanced terminal. And a fourth coil connected between and ground. The second insulator layer and the conductor pattern for the capacitor are laminated on the back surface of the laminate of the first insulator layer and the coil conductor pattern, and the opposite side of the connection point between the first coil and the second coil. And a second capacitor for grounding the end of the second coil opposite to the connection point between the first coil and the first coil. Also, a third insulator layer and a capacitor conductor pattern are laminated on the surface of the laminate of the first insulator layer and the coil conductor pattern, and connected between the first balanced terminal and the second balanced terminal. A third capacitor is formed. One of the first coil and the second coil is connected to the unbalanced terminal.
Further, the balun transformer of the present invention is formed by laminating a plurality of first insulator layers each having a first coil conductor pattern and a second coil conductor pattern formed on a surface thereof, And the second coil conductor patterns are connected to each other to form a first coil and a second coil, and a plurality of first coil conductor patterns and a fourth coil conductor pattern are formed on the surface. Two insulator layers are laminated, and the third coil conductor pattern and the fourth coil conductor pattern are connected to each other to form a third coil and a fourth coil. In these coils, the first coil and the second coil are electromagnetically coupled to each other, and the second coil and the fourth coil are electromagnetically coupled to each other. The third coil and the fourth coil are opposed to each other through the insulating layer. The third coil is connected between the first balanced terminal and ground. The fourth coil is connected between the second balanced terminal and the ground. A third insulator layer and a conductor pattern for a capacitor are laminated on the back surface of the laminate of the first insulator layer and the second insulator layer, and connected to the second coil of the first coil. A first capacitor for grounding the end opposite to the point and a second capacitor for grounding the end of the second coil opposite to the connection point of the first coil are formed. Also, a fourth insulator layer and a capacitor conductor pattern are laminated on the surface of the laminate of the first insulator layer and the second insulator layer, and between the first balanced terminal and the second balanced terminal. A connected third capacitor is formed. One of the first coil and the second coil is connected to the unbalanced terminal.
Accordingly, in the balun transformer of the present invention, the balun transformer and the filter are integrally formed in the multilayer body by the coil conductor pattern and the capacitor conductor pattern. In the balun transformer of the present invention, since the first coil and the second coil do not face the ground electrode, the influence of stray capacitance can be reduced. Furthermore, the balun transformer of the present invention can separate the connection point between the first coil and the second coil from the balanced terminal side of the third coil and the balanced terminal side of the fourth coil. Floating between the connection point side of the first coil with the second coil and the balanced terminal side of the third coil, and between the connection point side of the second coil with the first coil and the balanced terminal of the fourth coil. No capacity is generated.

以下、本発明のバラントランスの実施例を図１乃至図７を参照して説明する。
図１は本発明のバラントランスの回路図、図２は本発明のバラントランスの実施例を示す分解斜視図、図３は本発明のバラントランスの実施例の斜視図である。図１において、１１は不平衡端子、１２、１３は平衡端子である。
不平衡端子１１には、直列に接続されたコイルＬ１とコイルＬ２が接続される。平衡端子１２とアース間にはコイルＬ３が接続される。また、平衡端子１３とアース間にはコイルＬ４が接続される。これらのコイルは、コイルＬ１とコイルＬ２が同じターン数になる様に形成され、コイルＬ３とコイルＬ４が同じターン数になる様に形成される。そして、コイルＬ１とコイルＬ３が電磁気的に結合し、コイルＬ２とコイルＬ４が電磁気的に結合する。
コイルＬ１は、不平衡端子側の端がコンデンサＣ１を介してコイルＬ３のアース側の端に接続される。また、コイルＬ２は、コイルＬ１との接続点と反対側の端がコンデンサＣ２を介してコイルＬ４のアース側の端に接続される。コイルＬ３の平衡端子１２側の端とコイルＬ４の平衡端子１３側の端間には、コンデンサＣ３が接続される。
このバラントランスは、不平衡端子１１に不平衡伝送線路が接続され、平衡用端子１３、１４に平衡伝送線路が接続される。
不平衡端子１１から入力された信号は、コイルＬ１からコイルＬ３に伝達されると共に、コイルＬ２からコイルＬ４に伝達される。このとき、コイルＬ１とコイルＬ２は同じターン数を有するので、コイルＬ３とコイルＬ４に伝達される信号の大きさは等しくなる。このコイルＬ３とコイルＬ４に伝達された信号は、平衡端子１３、１４から出力される。このとき、コイルＬ３とコイルＬ４は同じターン数を有するので、平衡端子１３から出力される信号の大きさと平衡端子１４から出力される信号の大きさが等しくなる。
また、平衡端子から入力された信号は、コイルＬ３とコイルＬ４からそれぞれコイルＬ１とＬ２に伝送される。このコイルＬ１とＬ２に伝送された信号は、合成されて不平衡端子１１から出力される。 Hereinafter, embodiments of the balun transformer of the present invention will be described with reference to FIGS.
FIG. 1 is a circuit diagram of the balun transformer of the present invention, FIG. 2 is an exploded perspective view showing an embodiment of the balun transformer of the present invention, and FIG. 3 is a perspective view of the embodiment of the balun transformer of the present invention. In FIG. 1, 11 is an unbalanced terminal, and 12 and 13 are balanced terminals.
A coil L1 and a coil L2 connected in series are connected to the unbalanced terminal 11. A coil L3 is connected between the balanced terminal 12 and the ground. A coil L4 is connected between the balanced terminal 13 and the ground. These coils are formed such that the coil L1 and the coil L2 have the same number of turns, and the coil L3 and the coil L4 have the same number of turns. Then, the coil L1 and the coil L3 are electromagnetically coupled, and the coil L2 and the coil L4 are electromagnetically coupled.
The coil L1 has an unbalanced terminal side end connected to the ground side end of the coil L3 via a capacitor C1. Further, the end of the coil L2 opposite to the connection point with the coil L1 is connected to the ground end of the coil L4 through the capacitor C2. A capacitor C3 is connected between the end of the coil L3 on the balanced terminal 12 side and the end of the coil L4 on the balanced terminal 13 side.
In this balun transformer, an unbalanced transmission line is connected to the unbalanced terminal 11, and a balanced transmission line is connected to the balancing terminals 13 and 14.
A signal input from the unbalanced terminal 11 is transmitted from the coil L1 to the coil L3 and also transmitted from the coil L2 to the coil L4. At this time, since the coils L1 and L2 have the same number of turns, the magnitudes of signals transmitted to the coils L3 and L4 are equal. The signals transmitted to the coils L3 and L4 are output from the balanced terminals 13 and 14. At this time, since the coil L3 and the coil L4 have the same number of turns, the magnitude of the signal output from the balanced terminal 13 is equal to the magnitude of the signal output from the balanced terminal 14.
In addition, signals input from the balanced terminal are transmitted from the coils L3 and L4 to the coils L1 and L2, respectively. The signals transmitted to the coils L1 and L2 are combined and output from the unbalanced terminal 11.

この様な回路構成のバラントランスは、図２に示す様に絶縁体層と導体パターンを積層して積層体内に回路素子が形成される。
絶縁体層２１Ａ〜２１Ｐは、誘電体材料又は磁性体材料で形成される。
絶縁体層２１Ａの表面には、コンデンサ用導体パターン２２が形成される。このコンデンサ用導体パターン２２は、引き出し端が絶縁体層２１Ａの対向する側面まで引き出される。
絶縁体層２１Ｂの表面には、コンデンサ用導体パターン２３Ａとコンデンサ用導体パターン２３Ｂが形成される。コンデンサ用導体パターン２３Ａ、２３Ｂは、絶縁体層２１Ｂの表面に、互いに接触しない様に離間し、かつ、コンデンサ用導体パターン２２と対向する位置に形成される。コンデンサ用導体パターン２３Ａの引き出し端は、絶縁体層２１Ｂの側面まで引き出される。また、コンデンサ用導体パターン２３Ｂの引き出し端は、絶縁体層２１Ｂのコンデンサ用導体パターン２３Ａの引き出し端が引き出された側面と対向する側面まで引き出される。
絶縁体層２１Ｃの表面には、コンデンサ用導体パターン２２が形成される。このコンデンサ用導体パターン２２は、コンデンサ用導体パターン２３Ａ、２３Ｂと対向する位置に形成され、引き出し端が絶縁体層２１Ｃの対向する側面まで引き出される。
絶縁体層２１Ｄの表面には、コイル用導体パターン２４Ａが形成される。このコイル用導体パターン２４Ａは、一端が絶縁体層２１Ｄの側面まで引き出される。
絶縁体層２１Ｅの表面には、コイル用導体パターン２４Ｂが形成される。コイル用導体パターン２４Ｂは、一端がコイル用導体パターン２４Ａの他端に接続される。
絶縁体層２１Ｆの表面には、コイル用導体パターン２４Ｃが形成される。コイル用導体パターン２４Ｃは、一端がコイル用導体パターン２４Ｂの他端に接続され、他端が絶縁体層２１Ｆの側面まで引き出される。この様にコイル用導体パターン２４Ａ、２４Ｂ、２４Ｃが螺旋状に接続されてコイルＬ４が形成される。
絶縁体層２１Ｇの表面には、コイル用導体パターン２５Ａが形成される。コイル用導体パターン２５Ａは、一端が絶縁体層２１Ｇの側面まで引き出される。
絶縁体層２１Ｈの表面には、コイル用導体パターン２５Ｂが形成される。コイル用導体パターン２５Ｂは、一端がコイル用導体パターン２５Ａの他端に接続される。このコイル用導体パターン２５Ｂとコイル用導体パターン２５ＡによってコイルＬ２が形成される。
絶縁体層２１Ｉの表面には、コイル用導体パターン２６Ａが形成される。コイル用導体パターン２６Ａは、一端がコイル用導体パターン２５Ｂの他端に接続される。
絶縁体層２１Ｊの表面には、コイル用導体パターン２６Ｂが形成される。コイル用導体パターン２６Ｂは、一端がコイル用導体パターン２６Ａの他端に接続され、他端が絶縁体層２１Ｊの側面まで引き出される。このコイル用導体パターン２６Ｂとコイル用導体パターン２６ＡによってコイルＬ１が形成される。コイルＬ１とコイルＬ２は、コイル用導体パターン２５Ｂの他端とコイル用導体パターン２５Ａの一端が接続されることにより直列に接続される。
絶縁体層２１Ｋの表面には、コイル用導体パターン２７Ａが形成される。コイル用導体パターン２７Ａは、一端が絶縁体層２１Ｋの側面まで引き出される。
絶縁体層２１Ｌの表面には、コイル用導体パターン２７Ｂが形成される。コイル用導体パターン２７Ｂは、一端がコイル用導体パターン２７Ａの他端に接続される。
絶縁体層２１Ｍの表面には、コイル用導体パターン２７Ｃが形成される。コイル用導体パターン２７Ｃは、一端がコイル用導体パターン２７Ｂの他端に接続され、他端が絶縁体層２１Ｍの側面まで引き出される。この様にコイル用導体パターン２７Ａ、２７Ｂ、２７Ｃが螺旋状に接続されてコイルＬ３が形成される。
絶縁体層２１Ｎの表面には、コンデンサ用導体パターン２８が形成される。コンデンサ用導体パターン２８は、引き出し端が絶縁体層２１Ｎの側面まで引き出される。
絶縁体層２１Ｏの表面には、コンデンサ用導体パターン２９が形成される。コンデンサ用導体パターン２９は、コンデンサ用導体パターン２８と対向する位置に形成され、引き出し端が絶縁体層２１Ｏの側面まで引き出される。
絶縁体層２１Ａから絶縁体層２１Ｏまで順次積層し、保護用の絶縁体層２１Ｐで覆われた積層体の側面には、図３に示す様に端子電極３１、３２、３３、３４、３５、３６が形成される。そして、コイル用導体パターン２６Ｂの他端が端子電極３１に、コイル用導体パターン２５Ａの一端が端子電極３４に接続されることにより直列に接続されたコイルＬ１とコイルＬ２が不平衡端子１１に接続される。また、コイル用導体パターン２７Ｃの他端が端子電極３６に、コイル用導体パターン２７Ａの一端とコンデンサ用導体パターン２２の引き出し端が端子電極３２に接続されることにより平衡端子１２とアース間にコイルＬ３が接続される。さらに、コイル用導体パターン２４Ａの一端が端子電極３３に、コイル用導体パターン２４Ｃの他端とコンデンサ用導体パターン２２の引き出し端が端子電極３５に接続されることにより平衡端子１３とアース間にコイルＬ４が接続される。またさらに、コンデンサ用導体パターン２８の引き出し端が端子電極３３に、コンデンサ用導体パターン２９の引き出し端が端子電極３６に接続されることにより平衡端子１２と平衡端子１３間にコンデンサＣ３が接続される。さらに、コンデンサ用導体パターン２３Ａが端子電極３１に接続されることによりコイルＬ１の不平衡端子１１側の端とコイルＬ３のアース側の端間にコンデンサＣ１が接続される。また、コンデンサ用導体パターン２３Ｂが端子電極３４に接続されることによりコイルＬ２のコイルＬ１との接続点と反対側の端とコイルＬ４のアース側の端間にコンデンサＣ２が接続される。なお、端子電極３２、３５はアースに接続される。 In the balun transformer having such a circuit configuration, as shown in FIG. 2, an insulating layer and a conductor pattern are laminated to form a circuit element in the laminated body.
The insulator layers 21A to 21P are formed of a dielectric material or a magnetic material.
A capacitor conductive pattern 22 is formed on the surface of the insulating layer 21A. The conductor pattern 22 for the capacitor is drawn out to the opposite side surface of the insulating layer 21A.
A capacitor conductor pattern 23A and a capacitor conductor pattern 23B are formed on the surface of the insulator layer 21B. The capacitor conductor patterns 23A and 23B are formed on the surface of the insulator layer 21B so as not to contact each other and at positions facing the capacitor conductor pattern 22. The lead end of the capacitor conductor pattern 23A is drawn to the side surface of the insulator layer 21B. Further, the lead-out end of the capacitor conductor pattern 23B is drawn out to the side surface opposite to the side surface from which the lead-out end of the capacitor conductor pattern 23A of the insulator layer 21B is drawn out.
A capacitor conductive pattern 22 is formed on the surface of the insulating layer 21C. The capacitor conductor pattern 22 is formed at a position facing the capacitor conductor patterns 23A and 23B, and the lead-out end is drawn out to the side surface facing the insulator layer 21C.
A coil conductor pattern 24A is formed on the surface of the insulating layer 21D. One end of the coil conductor pattern 24A is drawn to the side surface of the insulating layer 21D.
A coil conductor pattern 24B is formed on the surface of the insulating layer 21E. One end of the coil conductor pattern 24B is connected to the other end of the coil conductor pattern 24A.
A coil conductor pattern 24C is formed on the surface of the insulator layer 21F. One end of the coil conductor pattern 24C is connected to the other end of the coil conductor pattern 24B, and the other end is drawn to the side surface of the insulator layer 21F. Thus, the coil conductor patterns 24A, 24B, and 24C are spirally connected to form the coil L4.
A coil conductor pattern 25A is formed on the surface of the insulator layer 21G. One end of the coil conductor pattern 25A is drawn to the side surface of the insulator layer 21G.
A coil conductor pattern 25B is formed on the surface of the insulator layer 21H. One end of the coil conductor pattern 25B is connected to the other end of the coil conductor pattern 25A. The coil L2 is formed by the coil conductor pattern 25B and the coil conductor pattern 25A.
A coil conductor pattern 26A is formed on the surface of the insulator layer 21I. One end of the coil conductor pattern 26A is connected to the other end of the coil conductor pattern 25B.
A coil conductor pattern 26B is formed on the surface of the insulator layer 21J. One end of the coil conductor pattern 26B is connected to the other end of the coil conductor pattern 26A, and the other end is drawn to the side surface of the insulator layer 21J. A coil L1 is formed by the coil conductor pattern 26B and the coil conductor pattern 26A. The coil L1 and the coil L2 are connected in series by connecting the other end of the coil conductor pattern 25B and one end of the coil conductor pattern 25A.
A coil conductor pattern 27A is formed on the surface of the insulator layer 21K. One end of the coil conductor pattern 27A is drawn to the side surface of the insulating layer 21K.
A coil conductor pattern 27B is formed on the surface of the insulating layer 21L. One end of the coil conductor pattern 27B is connected to the other end of the coil conductor pattern 27A.
A coil conductor pattern 27C is formed on the surface of the insulator layer 21M. One end of the coil conductor pattern 27C is connected to the other end of the coil conductor pattern 27B, and the other end is drawn to the side surface of the insulator layer 21M. In this way, the coil conductor patterns 27A, 27B, and 27C are spirally connected to form the coil L3.
A capacitor conductor pattern 28 is formed on the surface of the insulator layer 21N. Capacitor conductor pattern 28 is drawn out to the side surface of insulator layer 21N.
A capacitor conductive pattern 29 is formed on the surface of the insulating layer 21O. The capacitor conductor pattern 29 is formed at a position facing the capacitor conductor pattern 28, and the leading end is drawn to the side surface of the insulator layer 21O.
As shown in FIG. 3, terminal electrodes 31, 32, 33, 34, 35, and so on are stacked on the side surfaces of the laminated body sequentially laminated from the insulating layer 21 </ b> A to the insulating layer 21 </ b> O and covered with the protective insulating layer 21 </ b> P. 36 is formed. The other end of the coil conductor pattern 26B is connected to the terminal electrode 31, and one end of the coil conductor pattern 25A is connected to the terminal electrode 34, so that the coil L1 and the coil L2 connected in series are connected to the unbalanced terminal 11. Is done. Further, the other end of the coil conductor pattern 27C is connected to the terminal electrode 36, and one end of the coil conductor pattern 27A and the lead end of the capacitor conductor pattern 22 are connected to the terminal electrode 32. L3 is connected. Furthermore, one end of the coil conductor pattern 24A is connected to the terminal electrode 33, and the other end of the coil conductor pattern 24C and the lead-out end of the capacitor conductor pattern 22 are connected to the terminal electrode 35. L4 is connected. Furthermore, the lead-out end of the capacitor conductor pattern 28 is connected to the terminal electrode 33, and the lead-out end of the capacitor conductor pattern 29 is connected to the terminal electrode 36, whereby the capacitor C3 is connected between the balanced terminal 12 and the balanced terminal 13. . Further, the capacitor conductor pattern 23A is connected to the terminal electrode 31, whereby the capacitor C1 is connected between the end of the coil L1 on the unbalanced terminal 11 side and the end of the coil L3 on the ground side. Further, by connecting the capacitor conductive pattern 23B to the terminal electrode 34, the capacitor C2 is connected between the end of the coil L2 opposite to the connection point with the coil L1 and the end of the coil L4 on the ground side. The terminal electrodes 32 and 35 are connected to ground.

この様に形成されたバラントランスにおいて、絶縁体層２１Ａ〜２１Ｐに誘電率が４．６の材料を用い、コイル用導体パターン２４Ａ〜２４Ｃ、２５Ａ、２５Ｂ、２６Ａ、２６Ｂ、２７Ａ〜２７Ｃの線幅を７５μｍとして全体の大きさを２．０×１．２×０．８ｍｍにしたところ、不平衡端子１１と平衡端子１２、１３間のインピーダンス比が５０Ω：２００Ωとなり、図４（Ａ）、（Ｂ）に示す様に４７０〜７７０ＭＨｚの使用周波数帯域が得られ、その使用周波数帯域内において１７８度の位相特性が得られた。なお、図４（Ａ）において横軸は周波数、縦軸は減衰量を、４１は４７０〜７７０ＭＨｚにおける挿入損失、４２は不平衡端子におけるリターンロス、４３は平衡端子におけるリターンロスを示している。また、図４（Ｂ）において横軸は周波数、縦軸は位相を、４４は平衡端子間の出力の差、４５は位相差特性を示している。
この様なバラントランスは、使用周波数帯域の４７０〜７７０ＭＨｚにおいて、挿入損失が１．６５ｄＢ、不平衡端子におけるリターンロスが１０．０５ｄＢ、平衡端子におけるリターンロスが１０．０４ｄＢ、平衡端子間の出力の差が０．２４ｄＢとなり、１００〜２２０ＭＨｚの減衰量が１８．３１ｄＢとなった。
この様なバラントランスは、コイルＬ１の不平衡端子側の端とコイルＬ３のアース側の端間に接続されてアースされるコンデンサＣ１、コイルＬ２のコイルＬ１との接続点と反対側の端とコイルＬ４のアース側の端間に接続されてアースされるコンデンサＣ２、平衡端子１２と平衡端子１３間に接続されたコンデンサＣ３を備えるので、コイルＬ１〜Ｌ４のインダクタンス値やコンデンサＣ１〜Ｃ３の容量値及び、これらの回路素子を構成する導体パターンの位置を調整することで、通過帯域幅の調整や、不平衡端子と平衡端子間のインピーダンス比の調整を従来のものよりも簡単に行うことができる。 In the balun transformer formed as described above, a material having a dielectric constant of 4.6 is used for the insulator layers 21A to 21P, and the line widths of the coil conductor patterns 24A to 24C, 25A, 25B, 26A, 26B, and 27A to 27C are used. Is 75 μm, and the overall size is 2.0 × 1.2 × 0.8 mm. As a result, the impedance ratio between the unbalanced terminal 11 and the balanced terminals 12 and 13 is 50Ω: 200Ω, and FIG. As shown in B), a use frequency band of 470 to 770 MHz was obtained, and a phase characteristic of 178 degrees was obtained within the use frequency band. 4A, the horizontal axis represents frequency, the vertical axis represents attenuation, 41 represents insertion loss at 470 to 770 MHz, 42 represents return loss at an unbalanced terminal, and 43 represents return loss at a balanced terminal. 4B, the horizontal axis represents frequency, the vertical axis represents phase, 44 represents output difference between balanced terminals, and 45 represents phase difference characteristics.
Such a balun transformer has an insertion loss of 1.65 dB, a return loss of 10.05 dB at the unbalanced terminal, a return loss of 10.04 dB at the balanced terminal, and an output between the balanced terminals in the used frequency band of 470 to 770 MHz. The difference was 0.24 dB, and the attenuation of 100 to 220 MHz was 18.31 dB.
Such a balun transformer is connected between the end on the unbalanced terminal side of the coil L1 and the end on the ground side of the coil L3, and is connected to the grounded capacitor C1 and the end on the opposite side to the connection point of the coil L2 with the coil L1. Since the capacitor C2 connected between the ground ends of the coil L4 and grounded and the capacitor C3 connected between the balanced terminal 12 and the balanced terminal 13 are provided, the inductance values of the coils L1 to L4 and the capacitances of the capacitors C1 to C3 are provided. By adjusting the values and the positions of the conductor patterns constituting these circuit elements, it is possible to adjust the pass bandwidth and the impedance ratio between the unbalanced terminal and the balanced terminal more easily than the conventional one. it can.

図５は本発明のバラントランスの別の実施例の分解斜視図であり、絶縁体層と導体パターンを積層し、積層体内に回路素子を形成し、図１の回路を構成したものである。
絶縁体層５１Ａの表面には、コンデンサ用導体パターン５２が形成される。コンデンサ用導体パターン５２は、引き出し端が絶縁体層５１Ａの側面まで引き出される。
絶縁体層５１Ｂの表面には、コンデンサ用導体パターン５３Ａ、５３Ｂが形成される。コンデンサ用導体パターン５３Ａ、５３Ｂは、絶縁体層５１Ｂの表面に、互いに接触しない様に離間し、かつ、コンデンサ用導体パターン５２と対向する位置に形成される。コンデンサ用導体パターン５３Ａの引き出し端とコンデンサ用導体パターン５３Ｂの引き出し端は、絶縁体層５１Ｂの同じ側面まで引き出される。
絶縁体層５１Ｃの表面、絶縁体層５１Ｄの表面、絶縁体層５１Ｅの表面、絶縁体層５１Ｆの表面、絶縁体層５１Ｇの表面には、それぞれコイル用導体パターン５４とコイル用導体パターン５５が互いに線対称になる様に形成される。このコイル用導体パターン５４、５５は、絶縁体層５１Ｃ〜５１Ｇのコイル用導体パターン５４を螺旋状に接続してコイルＬ１が形成され、絶縁体層５１Ｃ〜５１Ｇのコイル用導体パターン５５を螺旋状に接続してコイルＬ２が形成される。このコイルＬ１とコイルＬ２は、同じターン数になる様に形成され、絶縁体層５１Ｃのコイル用導体パターン５４とコイル用導体パターン５５を互いに接続することにより、直列に接続される。そして、絶縁体層５１Ｇのコイル用導体パターン５４の一端とコイル用導体パターン５５の一端が絶縁体層５１Ｇの同じ側面まで引き出される。
絶縁体層５１Ｈの表面、絶縁体層５１Ｉの表面、絶縁体層５１Ｊの表面、絶縁体層５１Ｋの表面、絶縁体層５１Ｌの表面には、それぞれコイル用導体パターン５６とコイル用導体パターン５７が互いに線対称になる様に形成される。このコイル用導体パターン５６、５７は、絶縁体層５１Ｈ〜５１Ｌのコイル用導体パターン５６を螺旋状に接続してコイルＬ３が形成され、絶縁体層５１Ｈ〜５１Ｌのコイル用導体パターン５７を螺旋状に接続してコイルＬ４が形成される。この時、絶縁体層５１Ｈのコイル用導体パターン５６、５７は、絶縁体層５１Ｇのコイル用導体パターン５４、５５と対向する位置に形成される。このコイルＬ３とコイルＬ４は、同じターン数になる様に形成され、絶縁体層５１Ｈのコイル用導体パターン５４とコイル用導体パターン５５を接続することにより互いに接続される。この絶縁体層５１Ｈのコイル用導体パターン５４とコイル用導体パターン５５の共通接続端は、絶縁体層５１Ｈの側面まで引き出される。また、絶縁体層５１Ｌのコイル用導体パターン５６の一端とコイル用導体パターン５７の一端は、絶縁体層５１Ｌの同じ側面まで引き出される。
絶縁体層５１Ｍの表面には、コンデンサ用導体パターン５８Ａ、５９Ａが形成される。コンデンサ用導体パターン５８Ａ、５９Ａは、絶縁体層５１Ｍの表面に、互いに接触しない様に離間して形成され、コンデンサ用導体パターン５８Ａの引き出し端とコンデンサ用導体パターン５９Ａの引き出し端が絶縁体層５１Ｍの同じ側面まで引き出される。
絶縁体層５１Ｎの表面には、コンデンサ用導体パターン５８Ｂ、５９Ｂが形成される。コンデンサ用導体パターン５８Ｂ、５９Ｂは、絶縁体層５１Ｎの表面に、互いに接触しない様に離間して形成される。コンデンサ用導体パターン５８Ｂは、コンデンサ用導体パターン５９Ａと対向する位置に形成されると共に、コンデンサ用導体パターン５８Ａに接続される。また、コンデンサ用導体パターン５９Ｂは、コンデンサ用導体パターン５８Ａと対向する位置に形成されると共に、コンデンサ用導体パターン５９Ａに接続される。
絶縁体層５１Ａから絶縁体層５１Ｎまで順次積層し、保護用の絶縁体層５１Ｏで覆われた積層体の側面には、図６に示す様に端子電極６１、６２、６３、６４、６５、６６が形成される。そして、絶縁体層５１Ｇのコイル用導体パターン５４の一端が端子電極６１に、絶縁体層５１Ｇのコイル用導体パターン５５の一端が端子電極６３に接続されることにより直列に接続されたコイルＬ１とコイルＬ２が不平衡端子１１に接続される。また、絶縁体層５１Ｌのコイル用導体パターン５６の一端が端子電極６４に、絶縁体層５１Ｌのコイル用導体パターン５７の一端が端子電極６６に接続されることによりコイルＬ３とコイルＬ４が平衡端子１２と平衡端子１３間に接続される。さらに、絶縁体層５１Ｈのコイル用導体パターン５６とコイル用導体パターン５７の共通接続端が端子電極６５に接続されてアースされることにより、コイルＬ３とコイルＬ４の共通接続点がアースされる。またさらに、コンデンサ用導体パターン５８Ａの引き出し端が端子電極６４に、コンデンサ用導体パターン５９Ａの引き出し端が端子電極６６に接続されることにより平衡端子１２と平衡端子１３間にコンデンサＣ３が接続される。さらに、コンデンサ用導体パターン５３Ａが端子電極６１に接続されることによりコイルＬ１の不平衡端子１１側の端とコイルＬ３のアース側の端間にコンデンサＣ１が接続される。また、コンデンサ用導体パターン５３Ｂが端子電極６３に接続されることによりコイルＬ２のコイルＬ１との接続点と反対側の端とコイルＬ４のアース側の端間にコンデンサＣ２が接続される。なお、端子電極６２はアースに接続される。 FIG. 5 is an exploded perspective view of another embodiment of the balun transformer of the present invention, in which an insulator layer and a conductor pattern are laminated, and a circuit element is formed in the laminate to constitute the circuit of FIG.
A capacitor conductive pattern 52 is formed on the surface of the insulating layer 51A. Capacitor conductor pattern 52 is drawn out to the side surface of insulator layer 51A.
Capacitor conductor patterns 53A and 53B are formed on the surface of the insulating layer 51B. The capacitor conductor patterns 53A and 53B are formed on the surface of the insulating layer 51B so as not to contact each other and at a position facing the capacitor conductor pattern 52. The lead end of the capacitor conductor pattern 53A and the lead end of the capacitor conductor pattern 53B are drawn to the same side surface of the insulator layer 51B.
A coil conductor pattern 54 and a coil conductor pattern 55 are formed on the surface of the insulator layer 51C, the surface of the insulator layer 51D, the surface of the insulator layer 51E, the surface of the insulator layer 51F, and the surface of the insulator layer 51G, respectively. They are formed so as to be symmetrical with each other. The coil conductor patterns 54 and 55 are formed by connecting the coil conductor patterns 54 of the insulator layers 51C to 51G in a spiral shape to form a coil L1, and the coil conductor patterns 55 of the insulator layers 51C to 51G are spirally connected. To form a coil L2. The coils L1 and L2 are formed to have the same number of turns, and are connected in series by connecting the coil conductor pattern 54 and the coil conductor pattern 55 of the insulator layer 51C to each other. Then, one end of the coil conductor pattern 54 and one end of the coil conductor pattern 55 of the insulator layer 51G are drawn to the same side surface of the insulator layer 51G.
A coil conductor pattern 56 and a coil conductor pattern 57 are respectively formed on the surface of the insulator layer 51H, the surface of the insulator layer 51I, the surface of the insulator layer 51J, the surface of the insulator layer 51K, and the surface of the insulator layer 51L. They are formed so as to be symmetrical with each other. The coil conductor patterns 56 and 57 are formed by connecting the coil conductor patterns 56 of the insulator layers 51H to 51L in a spiral shape to form a coil L3, and the coil conductor patterns 57 of the insulator layers 51H to 51L are spirally connected. To form a coil L4. At this time, the coil conductor patterns 56 and 57 of the insulator layer 51H are formed at positions facing the coil conductor patterns 54 and 55 of the insulator layer 51G. The coils L3 and L4 are formed to have the same number of turns, and are connected to each other by connecting the coil conductor pattern 54 and the coil conductor pattern 55 of the insulator layer 51H. The common connection end of the coil conductor pattern 54 and the coil conductor pattern 55 of the insulator layer 51H is drawn to the side surface of the insulator layer 51H. Also, one end of the coil conductor pattern 56 of the insulator layer 51L and one end of the coil conductor pattern 57 are drawn to the same side surface of the insulator layer 51L.
Capacitor conductor patterns 58A and 59A are formed on the surface of the insulating layer 51M. The capacitor conductor patterns 58A and 59A are formed on the surface of the insulator layer 51M so as not to contact each other, and the lead end of the capacitor conductor pattern 58A and the lead end of the capacitor conductor pattern 59A are the insulator layer 51M. Pulled out to the same side.
Capacitor conductor patterns 58B and 59B are formed on the surface of the insulating layer 51N. The capacitor conductor patterns 58B and 59B are formed on the surface of the insulating layer 51N so as not to contact each other. The capacitor conductor pattern 58B is formed at a position facing the capacitor conductor pattern 59A and is connected to the capacitor conductor pattern 58A. The capacitor conductor pattern 59B is formed at a position facing the capacitor conductor pattern 58A and is connected to the capacitor conductor pattern 59A.
As shown in FIG. 6, terminal electrodes 61, 62, 63, 64, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65, 65 66 is formed. Then, one end of the coil conductor pattern 54 of the insulator layer 51G is connected to the terminal electrode 61, and one end of the coil conductor pattern 55 of the insulator layer 51G is connected to the terminal electrode 63, thereby connecting the coil L1 connected in series. The coil L2 is connected to the unbalanced terminal 11. Also, one end of the coil conductor pattern 56 of the insulator layer 51L is connected to the terminal electrode 64, and one end of the coil conductor pattern 57 of the insulator layer 51L is connected to the terminal electrode 66, whereby the coil L3 and the coil L4 are balanced terminals. 12 and the balanced terminal 13. Furthermore, the common connection end of the coil conductor pattern 56 and the coil conductor pattern 57 of the insulator layer 51H is connected to the terminal electrode 65 and grounded, whereby the common connection point of the coil L3 and the coil L4 is grounded. Furthermore, the lead-out end of the capacitor conductor pattern 58A is connected to the terminal electrode 64, and the lead-out end of the capacitor conductor pattern 59A is connected to the terminal electrode 66, whereby the capacitor C3 is connected between the balanced terminal 12 and the balanced terminal 13. . Further, the capacitor conductive pattern 53A is connected to the terminal electrode 61, whereby the capacitor C1 is connected between the end of the coil L1 on the unbalanced terminal 11 side and the end of the coil L3 on the ground side. Further, by connecting the capacitor conductive pattern 53B to the terminal electrode 63, the capacitor C2 is connected between the end of the coil L2 opposite to the connection point with the coil L1 and the end of the coil L4 on the ground side. The terminal electrode 62 is connected to the ground.

この様に形成されたバラントランスにおいて、絶縁体層５１Ａ〜５１Ｏに誘電率が４．６の材料を用い、コイル用導体パターン５４〜５７の線幅を７５μｍとして全体の大きさを２．０×１．２×０．８ｍｍにしたところ、不平衡端子１１と平衡端子１２、１３間のインピーダンス比が５０Ω：２００Ωとなり、図７（Ａ）、（Ｂ）に示す様に４７０〜７１０ＭＨｚの使用周波数帯域が得られ、その使用周波数帯域内において１７８度の位相特性が得られた。なお、図７（Ａ）において横軸は周波数、縦軸は減衰量を、７１は４７０〜７１０ＭＨｚにおける挿入損失、７２は不平衡端子におけるリターンロス、７３は平衡端子におけるリターンロスを示している。また、図７（Ｂ）において横軸は周波数、縦軸は位相を、７４は平衡端子間の出力の差、７５は位相差特性を示している。
この様なバラントランスは、使用周波数帯域の４７０〜７１０ＭＨｚにおいて、挿入損失が１．５２ｄＢ、不平衡端子におけるリターンロスが１１．４３ｄＢ、平衡端子におけるリターンロスが１１．９２ｄＢ、平衡端子間の出力の差が０．２１ｄＢとなり、１００〜２２０ＭＨｚの減衰量が１８．４３ｄＢとなった。 In the balun transformer formed in this way, a material having a dielectric constant of 4.6 is used for the insulator layers 51A to 51O, the line width of the coil conductor patterns 54 to 57 is 75 μm, and the overall size is 2.0 ×. When 1.2 × 0.8 mm, the impedance ratio between the unbalanced terminal 11 and the balanced terminals 12 and 13 is 50Ω: 200Ω, and the operating frequency is 470 to 710 MHz as shown in FIGS. 7 (A) and 7 (B). A band was obtained, and a phase characteristic of 178 degrees was obtained within the used frequency band. 7A, the horizontal axis represents frequency, the vertical axis represents attenuation, 71 represents insertion loss at 470 to 710 MHz, 72 represents return loss at an unbalanced terminal, and 73 represents return loss at a balanced terminal. In FIG. 7B, the horizontal axis represents frequency, the vertical axis represents phase, 74 represents output difference between balanced terminals, and 75 represents phase difference characteristics.
Such a balun transformer has an insertion loss of 1.52 dB, an unbalanced terminal return loss of 11.43 dB, a balanced terminal return loss of 11.92 dB, and an output between the balanced terminals of 470 to 710 MHz in the use frequency band. The difference was 0.21 dB, and the attenuation of 100 to 220 MHz was 18.43 dB.

この様に形成されたバラントランスは、端子電極６５に直流電源を接続することにより、差動アンプなどの平衡駆動デバイスにＤＣバイアスを印加することができる。 The balun transformer formed in this way can apply a DC bias to a balanced drive device such as a differential amplifier by connecting a DC power source to the terminal electrode 65.

本発明のバラントランスの回路図である。It is a circuit diagram of the balun transformer of the present invention. 本発明のバラントランスの実施例を示す分解斜視図である。It is a disassembled perspective view which shows the Example of the balun transformer of this invention. 本発明のバラントランスの実施例の斜視図である。It is a perspective view of the Example of the balun transformer of this invention. 本発明のバラントランスの実施例の特性図である。It is a characteristic view of the Example of the balun transformer of this invention. 本発明のバラントランスの別の実施例を示す分解斜視図である。It is a disassembled perspective view which shows another Example of the balun transformer of this invention. 本発明のバラントランスの別の実施例の斜視図である。It is a perspective view of another Example of the balun transformer of this invention. 本発明のバラントランスの別の実施例の特性図である。It is a characteristic view of another Example of the balun transformer of this invention. 従来のバラントランスの回路図である。It is a circuit diagram of the conventional balun transformer. 従来のバラントランスの分解斜視図である。It is a disassembled perspective view of the conventional balun transformer.

Explanation of symbols

１１不平衡端子
１２、１３平衡端子 11 Unbalanced terminals 12, 13 Balanced terminals

Claims

A first coil and a second coil connected in series, electromagnetically coupled to the first coil, a third coil connected between the first balanced terminal and the ground, and the second coil A fourth coil that is electromagnetically coupled and connected between the second balanced terminal and the ground, an end of the first coil opposite to the connection point with the second coil, and a ground side of the third coil A first capacitor connected between the ends of the second coil and grounded, connected between the end of the second coil opposite to the connection point with the first coil and the end of the fourth coil on the ground side And a third capacitor connected between the first balanced terminal and the second balanced terminal, and one of the first coil and the second coil is unbalanced. A balun transformer characterized by being connected to a terminal.

An insulating layer and a conductor pattern are laminated, and in the laminated body, a first coil and a second coil connected in series are electromagnetically coupled to the first coil, and a first balanced terminal and a ground are connected. A third coil connected between, a second coil electromagnetically coupled to the second coil and connected between a second balanced terminal and ground, a second coil of the first coil; A first capacitor connected between the end of the second coil opposite to the connection point and the ground, and a second capacitor connected between the end opposite to the connection point of the second coil with the first coil and the ground A third capacitor connected between the first balanced terminal and the second balanced terminal is formed, and either one of the first coil or the second coil is connected to the unbalanced terminal. This is a balun transformer.

The first insulator layer and the coil conductor pattern are laminated, the coil conductor pattern between the first insulator layers is spirally connected, and the first coil and the second coil connected in series, Electromagnetically coupled to the first coil, a third coil connected between the first balanced terminal and ground, and electromagnetically coupled to the second coil and connected between the second balanced terminal and ground Formed fourth coil,
A second insulator layer and a conductor pattern for a capacitor are laminated on the back surface of the laminate of the first insulator layer and the coil conductor pattern, and a connection point between the first coil and the second coil; A first capacitor for grounding the opposite end and a second capacitor for grounding the opposite end of the second coil to the connection point of the first coil;
A third insulator layer and a conductor pattern for a capacitor are laminated on the surface of the laminate of the first insulator layer and the coil conductor pattern, and between the first balanced terminal and the second balanced terminal. A balun transformer, wherein a third capacitor connected is formed, and one of the first coil and the second coil is connected to an unbalanced terminal.

A plurality of first insulator layers each having a first coil conductor pattern and a second coil conductor pattern formed thereon are laminated, and the first coil conductor patterns and the second coil conductor are laminated. A first coil and a second coil are formed by connecting the patterns,
A plurality of second insulator layers each having a third coil conductor pattern and a fourth coil conductor pattern formed thereon are laminated, and the third coil conductor patterns and the fourth coil conductor are laminated. A third coil and a fourth coil are formed by connecting the patterns,
The first coil and the third coil are electromagnetically coupled, and the first coil and the second coil are coupled to each other so that the second coil and the fourth coil are electromagnetically coupled. The third and fourth coils are opposed to each other through two insulator layers,
Connecting the third coil between a first balanced terminal and ground; connecting the fourth coil between a second balanced terminal and ground;
A third insulator layer and a conductor pattern for a capacitor are laminated on the back surface of the laminate of the first insulator layer and the second insulator layer, and connected to the second coil of the first coil. A first capacitor for grounding the end opposite to the point and a second capacitor for grounding the end of the second coil opposite to the connection point of the first coil;
A fourth insulator layer and a conductor pattern for a capacitor are laminated on the surface of the laminate of the first insulator layer and the second insulator layer, and the first balanced terminal and the second balanced terminal A balun transformer characterized in that a third capacitor connected in between is formed, and one of the first coil and the second coil is connected to an unbalanced terminal.