JP2004180035A

JP2004180035A - Laminated strip line filter

Info

Publication number: JP2004180035A
Application number: JP2002344688A
Authority: JP
Inventors: Shigetoshi Ogawa; 成敏小川
Original assignee: Kyocera Corp
Current assignee: Kyocera Corp
Priority date: 2002-11-27
Filing date: 2002-11-27
Publication date: 2004-06-24

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated strip line filter where the variance of an attenuation pole of filter characteristics caused by lamination deviation occurring in a process of laminating a plurality of dielectric layers can be reduced. <P>SOLUTION: The laminated strip line filter has first and second resonators 71 and 72 arranged in parallel in first to fourth successively laminated dielectric layers 40 to 43 so that the resonators at least partially overlap with the second dielectric layer 41 between them when viewed from the lamination direction and has first and third resonators 71 and 73 arranged in parallel so that the resonators at least partially overlap with second and third dielectric layer 41 and 42 between them when viewed from the lamination direction. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は、例えば携帯電話や無線ＬＡＮ等の無線通信機器その他の各種通信機器等において使用される積層ストリップラインフィルタに関するものである。
【０００２】
【従来の技術】
近年、携帯電話機等の移動体通信機器等に使用されるフィルタは、移動体通信機器等の薄型化・小型化の要求に伴い、誘電体同軸型共振器を用いたフィルタから分布定数回路を共振器に用いた積層ストリップラインフィルタへと進展してきている。
【０００３】
この積層ストリップラインフィルタは、特開平８−７０２０１号公報に、図４に透視斜視図、および図５に透視平面図、図６に図５におけるｂ−ｂ’線断面図で示す構成のものが提案されている。
【０００４】
図４〜図６において、１０は第１の誘電体層、１１は第１の誘電体層１０の上に積層された第２の誘電体層、１２は第２の誘電体層１１の上に積層された第３の誘電体層、２０は第１の誘電体層１０の下面に配された第１の接地電極、２１は第３の誘電体層１２の上面に配された第２の接地電極、２２および２５は第１および第２の誘電体層１０・１１の間に配した第１の片端開放矩形状共振電極および第１の片端短絡矩形状共振電極、２３および２６は第２および第３の誘電体層１１・１２の間に配した第２の片端開放矩形状共振電極および第２の片端短絡矩形状共振電極、２４および２７は第２および第３の誘電体層１１・１２の間に配した第３の片端開放矩形状共振電極、および第３の片端短絡矩形状共振電極、２８は第１〜第３の片端開放矩形状共振電極２２〜２４のそれぞれの開放端、２９は第１〜第３の片端短絡矩形状共振電極２５〜２７のそれぞれの短絡端である。
【０００５】
そして、図５および図６のＷＡ〜ＷＤに示すように、第１および第２の片端開放矩形状共振電極２２・２３は第２の誘電体層１１を挟んでそれぞれの少なくとも一部が積層方向から見て重なるように平行に配されるとともに、第１および第３の片端開放矩形状共振電極２２・２４は第２の誘電体層１１を挟んでそれぞれの少なくとも一部が積層方向から見て重なるように平行に配されている。また、第１および第２の片端短絡矩形状共振電極２５・２６は第２の誘電体層１１を挟んでそれぞれの少なくとも一部が積層方向から見て重なるように平行に配されるとともに、第１および第３の片端短絡矩形状共振電極２５・２７は第２の誘電体層１１を挟んでそれぞれの少なくとも一部が積層方向から見て重なるように平行に配されている。また、第１および第２の接地電極２０・２１は積層方向から見て第１〜第３の片端開放矩形状共振電極２２〜２４ならびに第１〜第３の片端短絡矩形状共振電極２５〜２７を覆うように配されている。
【０００６】
そして、第１の片端開放矩形状共振電極２２の開放端２８と反対側の端部と、第１の片端短絡矩形状共振電極２５の短絡端２９と反対側の端部とを電気的に接続して第１の共振器を形成し、
第２の片端開放矩形状共振電極２３の開放端２８と反対側の端部と、第２の片端短絡矩形状共振電極２６の短絡端２９と反対側の端部とを電気的に接続して第２の共振器を形成し、
第３の片端開放矩形状共振電極２４の開放端２８と反対側の端部と、第３の片端短絡矩形状共振電極２７の短絡端２９と反対側の端部とを電気的に接続して第３の共振器を形成している。
【０００７】
そして、さらに、第２の共振器に入力端子３０が電気的に接続され、第３の共振器に出力端子３１が電気的に接続されている。
【０００８】
そして、第１〜第３の片端開放矩形状共振電極２２〜２４の幅Ｗ２２〜Ｗ２４、第１〜第３の片端短絡矩形状共振電極２５〜２７の幅Ｗ２５〜Ｗ２７、第１の片端開放矩形状共振電極２２と第２の片端開放矩形状共振電極２３とが第２の誘電体層１１を挟んで互いに重なる幅ＷＡ、第１の片端開放矩形状共振電極２２と第３の片端開放矩形状共振電極２４とが第２の誘電体層１１を挟んで互いに重なる幅ＷＢ、第１の片端短絡矩形状共振電極２５と第２の片端開放矩形状共振電極２６とが第２の誘電体層１１を挟んで互いに重なる幅ＷＣ、第１の片端短絡矩形状共振電極２５と第３の片端短絡矩形状共振電極２７とが第２の誘電体層１１を挟んで互いに重なる幅ＷＤを調整することにより、通過帯域に対して高域側および低域側にそれぞれ減衰極を１個有するフィルタ特性を実現していた。
【０００９】
【特許文献１】
特開平８−７０２０１号公報
【００１０】
【発明が解決しようとする課題】
しかしながら、このような従来の積層ストリップラインフィルタにおいては、所望のフィルタ特性を実現させるためには、第１の片端開放矩形状共振電極２２と第２の片端開放矩形状共振電極２３とが第２の誘電体層１１を挟んで互いに重なる幅ＷＡおよび、第１の片端開放矩形状共振電極２２と第３の片端開放矩形状共振電極２４とが第２の誘電体層１１を挟んで互いに重なる幅ＷＢおよび、第１の片端短絡矩形状共振電極２５と第２の片端開放矩形状共振電極２６とが第２の誘電体層１１を挟んで互いに重なる幅ＷＣおよび、第１の片端短絡矩形状共振電極２５と第３の片端短絡矩形状共振電極２７とが第２の誘電体層１１を挟んで互いに重なる幅ＷＤのいずれか、もしくはそのうちのいくつかの幅を狭く設定しなければならない場合があり、第１〜第３の誘電体層１０〜１２を積層する工程において発生する積層ずれにより、第１および第２の片端開放矩形状共振電極２２・２３間の電磁界結合量および、第１および第３の片端開放矩形状共振電極間２２・２４の電磁界結合量および、第１および第２の片端短絡矩形状共振電極間２５・２６の電磁界結合量および、第１および第３の片端短絡矩形状共振電極間２５・２７のいずれか、もしくはそのうちのいくつかの電磁界結合量の変化が大きくなり、このため、所望のフィルタ特性に対して減衰極が大きく変動するという問題があった。
【００１１】
本発明は上記問題点に鑑みて案出されたものであり、その目的は、積層ストリップラインフィルタにおいて、複数の誘電体層を積層する工程において発生する積層ずれによるフィルタ特性の減衰極の変動を低減することができる積層ストリップラインフィルタを提供することにある。
【００１２】
【課題を解決するための手段】
本発明の積層ストリップラインフィルタは、第１の誘電体層と、この第１の誘電体層の上に積層された第２の誘電体層と、この第２の誘電体層の上に積層された第３の誘電体層と、この第３の誘電体層の上に積層された第４の誘電体層と、前記第１の誘電体層の下面に配された第１の接地電極と、前記第１および第２の誘電体層の間に配された第１の片端開放矩形状共振電極および第１の片端短絡矩形状共振電極と、前記第２および第３の誘電体層の間に配された第２の片端開放矩形状共振電極および第２の片端短絡矩形状共振電極と、前記第３および第４の誘電体層の間に配された第３の片端開放矩形状共振電極および第３の片端短絡矩形状共振電極と、前記第４の誘電体層の上面に配された第２の接地電極とから成り、
前記第１および第２の片端開放矩形状共振電極は前記第２の誘電体層を挟んでそれぞれの少なくとも一部が積層方向から見て重なるように平行に配されるとともに、前記第１および第３の片端開放矩形状共振電極は前記第２および第３の誘電体層を挟んでそれぞれの少なくとも一部が積層方向から見て重なるように平行に配され、
前記第１および第２の片端短絡矩形状共振電極は前記第２の誘電体層を挟んでそれぞれの少なくとも一部が積層方向から見て重なるように平行に配されるとともに、前記第１および第３の片端短絡矩形状共振電極は前記第２および第３の誘電体層を挟んでそれぞれの少なくとも一部が積層方向から見て重なるように平行に配され、
前記第１および第２の接地電極は積層方向から見て前記第１〜第３の片端開放矩形状共振電極ならびに前記第１〜第３の片端短絡矩形状共振電極を覆うように配され、
前記第１の片端開放矩形状共振電極の開放端と反対側の端部と、前記第１の片端短絡矩形状共振電極の短絡端と反対側の端部とを電気的に接続して第１の共振器を形成し、
前記第２の片端開放矩形状共振電極の開放端と反対側の端部と、前記第２の片端短絡矩形状共振電極の短絡端と反対側の端部とを電気的に接続して第２の共振器を形成し、
前記第３の片端開放矩形状共振電極の開放端と反対側の端部と、前記第３の片端短絡矩形状共振電極の短絡端と反対側の端部とを電気的に接続して第３の共振器を形成し、
前記第２の共振器に入力端子ならびに前記第３の共振器に出力端子が電気的に接続されるか、または前記第２の共振器に出力端子ならびに前記第３の共振器に入力端子が電気的に接続されていることを特徴とするものである。
【００１３】
本発明の積層ストリップラインフィルタによれば、第３の片端開放矩形状共振電極および第３の片端短絡矩形状共振電極を第２および第３の２層の誘電体層を挟んで配したことから、第１の片端開放矩形状共振電極と第３の片端開放矩形状共振電極とが第２の誘電体層および第３の誘電体層を挟んで互いに重なる幅および、第１の片端短絡矩形状共振電極と第３の片端短絡矩形状共振電極とが第２の誘電体層および第３の誘電体層を挟んで互いに重なる幅を十分確保することができ、積層ずれによる共振電極間の電磁界結合の変化に対する許容範囲を十分に確保することができ、この結果、フィルタ特性の減衰極の変動を低減することができる。
【００１４】
また、本発明の積層ストリップラインフィルタは、上記構成において、前記各接地電極が、または前記各片端短絡矩形状共振電極の短絡端および前記各接地電極が、前記誘電体層の内部に形成された貫通導体および／または側面に形成された側面導体により積層方向に電気的に接続されていることを特徴とするものである。
【００１５】
これにより、積層された複数の誘電体層の内部に形成する積層ストリップラインフィルタの設計自由度が向上するとともに、小型で高性能な積層ストリップラインフィルタを提供することができる。
【００１６】
【発明の実施の形態】
以下、本発明の積層ストリップラインフィルタを図面を参照しつつ説明する。
【００１７】
図１は本発明の積層ストリップラインフィルタの実施の形態の一例を示す透視斜視図であり、図２は図１を積層方向から見た透視平面図、図３は図２におけるａ−ａ’線断面図である。図１〜図３において、４０は第１の誘電体層、４１は第１の誘電体層４０の上に積層された第２の誘電体層、４２は第２の誘電体層４１の上に積層された第３の誘電体層、４３は第３の誘電体層４２の上に積層された第４の誘電体層、５０は第１の誘電体層４０の下面に配された第１の接地電極、５１は第４の誘電体層４３の上面に配された第２の接地電極、５２および５５は第１および第２の誘電体層４０・４１の間に配した第１の片端開放矩形状共振電極および第１の片端短絡矩形状共振電極、５３および５６は第２および第３の誘電体層４１・４２の間に配した第２の片端開放矩形状共振電極および第２の片端短絡矩形状共振電極、５４および５９は第３および第４の誘電体層４２・４３の間に配した第３の片端開放矩形状共振電極、および第３の片端短絡矩形状共振電極、５８は第１〜第３の片端開放矩形状共振電極５２〜５４のそれぞれの開放端、５９は第１〜第３の片端短絡矩形状共振電極５５〜５７のそれぞれの短絡端である。
【００１８】
そして、図２および図３のＷＡ〜ＷＤに示すように、第１および第２の片端開放矩形状共振電極５２・５３は第２の誘電体層４１を挟んでそれぞれの少なくとも一部が積層方向から見て重なるように平行に配されるとともに、第１および第３の片端開放矩形状共振電極５２・５４は第２および第３の誘電体層４１・４２を挟んでそれぞれの少なくとも一部が積層方向から見て重なるように平行に配されている。また、第１および第２の片端短絡矩形状共振電極５５・５６は第２の誘電体層４１を挟んでそれぞれの少なくとも一部が積層方向から見て重なるように平行に配されるとともに、第１および第３の片端短絡矩形状共振電極５５・５７は第２および第３の誘電体層４１・４２を挟んでそれぞれの少なくとも一部が積層方向から見て重なるように平行に配されている。また、第１および第２の接地電極５０・５１は積層方向から見て第１〜第３の片端開放矩形状共振電極５２〜５４ならびに第１〜第３の片端短絡矩形状共振電極５５〜５７を覆うように配されている。
【００１９】
そして、第１の片端開放矩形状共振電極５２の開放端５８と反対側の端部と、第１の片端短絡矩形状共振電極５５の短絡端５９と反対側の端部とを電気的に接続して第１の共振器７１を形成し、
第２の片端開放矩形状共振電極５３の開放端５８と反対側の端部と、第２の片端短絡矩形状共振電極５６の短絡端５９と反対側の端部とを電気的に接続して第２の共振器７２を形成し、
第３の片端開放矩形状共振電極５４の開放端５８と反対側の端部と、第３の片端短絡矩形状共振電極５７の短絡端５９と反対側の端部とを電気的に接続して第３の共振器７３を形成している。
【００２０】
そして、さらに、第２の共振器７２に入力端子６０が電気的に接続され、第３の共振器７３に出力端子６１が電気的に接続されて外部回路に接続される。なお、必要に応じて入力端子を６１の側とし、出力端子を６０の側とすることもできる。
【００２１】
このような構成の本発明の積層ストリップラインフィルタは、第１および第２の接地電極５０・５１間、または第１および第２の接地電極５０・５１および第１〜第３の片端短絡矩形状共振電極５５〜５７の短絡端５９を積層方向に電気的に接続する接地接続導体として誘電体層の内部に形成された貫通導体（図示せず）および／または側面に形成された側面導体（図示せず）を用いて構成することにより、３次元的な配線設計が可能となり、積層された複数の誘電体層の内部に形成する積層ストリップラインフィルタの設計自由度が向上するので、小型で高性能な積層ストリップラインフィルタを提供することができる。
【００２２】
本発明の積層ストリップラインフィルタを形成するに当たり、第１〜第４の誘電体層４０〜４３、第１および第２の接地電極５０・５１、第１〜第３の片端開放矩形状共振電極５２〜５４、第１〜第３の片端短絡矩形状共振電極５５〜５７は、周知の高周波用配線基板に使用される種々の材料・形態のものを使用することができる。
【００２３】
本発明の積層ストリップラインフィルタに用いる第１〜第４の誘電体層４０〜４３としては、例えばアルミナセラミックス・ムライトセラミックス等のセラミックス材料やガラスセラミックス等の無機系材料、あるいは四ふっ化エチレン樹脂（ポリテトラフルオロエチレン；ＰＴＦＥ）・四ふっ化エチレン−エチレン共重合樹脂（テトラフルオロエチレン−エチレン共重合樹脂；ＥＴＦＥ）・四ふっ化エチレン−パーフルオロアルコキシエチレン共重合樹脂（テトラフルオロエチレン−パーフルテロアルキルビニルエーテル共重合樹脂；ＰＦＡ）等のフッ素樹脂やガラスエポキシ樹脂・ポリイミド等の樹脂系材料等が用いられる。これらの材料による第１〜第４の誘電体層４０〜４３の形状や寸法（厚みや幅・長さ）は、使用される周波数や用途等に応じて設定される。
【００２４】
本発明の積層ストリップラインフィルタにおける第１および第２の接地電極５０・５１・第１〜第３の片端開放矩形状共振電極５２〜５４・第１〜第３の片端短絡矩形状共振電極５５〜５７・貫通導体または側面導体は、高周波信号伝送用の金属材料の導体層、例えばＣｕ層・Ｍｏ−Ｍｎのメタライズ層上にＮｉメッキ層およびＡｕメッキ層を被着させたもの・Ｗのメタライズ層上にＮｉメッキ層およびＡｕメッキ層を被着させたもの・Ｃｒ−Ｃｕ合金層・Ｃｒ−Ｃｕ合金層上にＮｉメッキ層およびＡｕメッキ層を被着させたもの・Ｔａ_２Ｎ層上にＮｉ−Ｃｒ合金層およびＡｕメッキ層を被着させたもの・Ｔｉ層上にＰｔ層およびＡｕメッキ層を被着させたもの、またはＮｉ−Ｃｒ合金層上にＰｔ層およびＡｕメッキ層を被着させたもの等を用いて、厚膜印刷法あるいは各種の薄膜形成方法やメッキ法等により形成される。その厚みや幅も、伝送される高周波信号の周波数や用途等に応じて設定される。
【００２５】
本発明の積層ストリップラインフィルタに用いる第１〜第４の誘電体層４０〜４３の作製にあたっては、例えば誘電体層がガラスセラミックスから成る場合であれば、まず誘電体層となるガラスセラミックスのグリーンシートを準備し、これに所定の打ち抜き加工を施して貫通導体となる貫通孔を形成した後、スクリーン印刷法によりＣｕ等の導体ペーストを貫通孔に充填するとともに、所定の伝送線路パターンおよびその他の導体層のパターンを印刷塗布する。次に、８５０〜１０００℃で焼成を行ない、最後に外表面に露出している導体層上にＮｉメッキおよびＡｕメッキを施す。
【００２６】
図１〜図３に示す構成の本発明の積層ストリップラインフィルタならびに図４〜図６に示す従来の積層ストリップラインフィルタは、同一のフィルタ特性を実現でき、図７はその代表的なフィルタ特性を示したものである。図７において横軸は周波数（単位：ＧＨｚ）を、縦軸は挿入損失（単位：ｄＢ）を表す。第１および第２の共振器７１・７２間で形成される電磁界結合によって第１の減衰極ｆｒ１が発生し、第１および第３の共振器７１・７３間で形成される電磁界結合によって第２の減衰極ｆｒ２が発生する。
【００２７】
実施例として、図１〜図３に示す構成の本発明の積層ストリップラインフィルタならびに図４〜図６に示す従来の積層ストリップラインフィルタにおいて図７のフィルタ特性を実現する構造モデルを３次元電磁界解析シミュレータで作成し、幅方向の積層ずれ量を考慮した場合のシミュレーション解析を行なった。
【００２８】
例えば、図１〜図３に示す構成の本発明の積層ストリップラインフィルタにおけるシミュレーションの場合、第１〜第４の誘電体層４０〜４３の厚みをそれぞれ第１の誘電体層ｈ１＝０．２ｍｍ、第２の誘電体層ｈ２＝０．１ｍｍ、第３の誘電体層ｈ３＝０．１ｍｍ、第４の誘電体層ｈ４＝０．２ｍｍとし、
第１〜第３の片端開放矩形状共振電極５２〜５４の各共振電極の幅Ｗ５２〜Ｗ５４ならびに各共振電極の長さＬ５２〜Ｌ５４をそれぞれ、Ｗ５２＝２．５４ｍｍ、Ｗ５３＝１．１９ｍｍ、Ｗ５４＝１．３ｍｍ、Ｌ５２＝Ｌ５３＝Ｌ５４＝２．３６７ｍｍとし、
第１〜第３の片端短絡矩形状共振電極５５〜５７の各共振電極の幅Ｗ５５〜Ｗ５７ならびに各共振電極の長さＬ５５〜Ｌ５７をそれぞれ、Ｗ５５＝２．５ｍｍ、Ｗ５６＝１．３３ｍｍ、Ｗ５７＝１．２ｍ、Ｌ５５＝Ｌ５６＝Ｌ５７＝２．３６７ｍｍとし、
第１および第２の片端開放矩形状共振電極５２・５３が積層方向から見て重なる部分の幅ＷＡ＝０．５５ｍｍ、第１および第２の片端短絡矩形状共振電極５５・５６が積層方向から見て重なる部分の幅ＷＣ＝０．１９ｍｍとし、
第１および第３の片端開放矩形状共振電極５２・５４が積層方向から見て重なる部分の幅ＷＢ＝０．２３ｍｍ、第１および第３の片端短絡矩形状共振電極５５・５７が積層方向から見て重なる部分の幅ＷＤ＝０．８８ｍｍとしている。
【００２９】
また図４〜図６に示す従来の積層ストリップラインフィルタにおけるシミュレーションモデルの各寸法は、第１〜第３の誘電体層１０〜１２の厚みをそれぞれ第１の誘電体層ｈ１＝０．２ｍｍ、第２の誘電体層ｈ２＝０．１ｍｍ、第３の誘電体層ｈ３＝０．３ｍｍとし、
第１〜第３の片端開放矩形状共振電極２２〜２４の各共振電極の幅Ｗ２２〜Ｗ２４ならびに各共振電極の長さＬ２２〜Ｌ２４をそれぞれ、Ｗ２２＝２．３８ｍｍ、Ｗ２３＝１．１９ｍｍ、Ｗ２４＝１．４７ｍｍ、Ｌ５２＝Ｌ５３＝Ｌ５４＝２．３６７ｍｍとし、第１〜第３の片端短絡矩形状共振電極２５〜２７の各共振電極の幅Ｗ２５〜Ｗ２７ならびに各共振電極の長さＬ２５〜Ｌ２７をそれぞれ、Ｗ２５＝２．４５ｍｍ、Ｗ２６＝１．３３ｍｍ、Ｗ２７＝１．２５ｍｍ、Ｌ２５＝Ｌ２６＝Ｌ２７＝２．３６７ｍｍとし、
第１および第２の片端開放矩形状共振電極２２・２３が積層方向から見て重なる部分の幅ＷＡ＝０．５４ｍｍ、第１および第２の片端短絡矩形状共振電極２５・２６が積層方向から見て重なる部分の幅ＷＣ＝０．２３ｍｍとし、
第１および第３の片端開放矩形状共振電極２２・２４が積層方向から見て重なる部分の幅ＷＢ＝０．０４ｍｍ、第１および第３の片端短絡矩形状共振電２５・２７が積層方向から見て重なる部分の幅ＷＤ＝を０．３５ｍｍとしている。
【００３０】
そして、図１〜図３に示す構成の本発明の積層ストリップラインフィルタの第１の共振器がある面に対し、第２の共振器がある面ならびに第３の共振器がある面、および図４〜図６に示す従来の積層ストリップラインフィルタの、第１の共振器がある面に対し、第２および第３の共振器がある面が幅方向（紙面に平行な面で左右方向）に積層ずれした量として±５０μｍを考慮した場合についてシミュレーションを実施した。各シミュレーションの際に用いた各誘電体層の比誘電率は７．７に設定した。
【００３１】
本実施例における本発明の積層ストリップラインフィルタモデルと従来の積層ストリップラインフィルタモデルとの大きな違いは、第１および第３の片端開放矩形状共振電極の重なり幅ＷＢである。所望のフィルタ特性を実現するための第１および第３の片端開放矩形状共振電極の重なり幅ＷＢは、従来の積層ストリップラインフィルタの場合はＷＢ＝４０μｍであり、本発明の積層ストリップラインフィルタの場合はＷＢ＝２３０μｍである。ＷＢは図７に示すフィルタ特性における減衰極ｆｒ２を形成する。よって、本発明の積層ストリップラインフィルタと従来の積層ストリップラインフィルタにおいて、減衰極ｆｒ２の積層ずれによる変化量の比較を実施した。
【００３２】
図８において、横軸は幅方向（紙面に平行な面で左右方向）の積層ずれ量（単位：μｍ）を、縦軸は図７における減衰極ｆｒ２の変化量（単位：ＭＨｚ）を表し、各特性曲線は、Ｂが図１〜図３に示す本発明の積層ストリップラインフィルタにおける第１の共振器７１がある面に対し、第３の共振器７３がある面が幅方向に±５０μｍ積層ずれした場合の結果を、Ａが図４〜図６に示す従来の積層ストリップラインフィルタにおける第１の共振器がある面に対し、第２および第３の共振器がある面が幅方向に±５０μｍ積層ずれした場合の結果を示している。
【００３３】
図８に示す結果から明らかなように、本発明の積層ストリップラインフィルタによれば、複数の誘電体層を積層する工程において発生する積層ずれによる、フィルタ特性の減衰極の変動を低減することができる。
【００３４】
例えば、積層ずれ量−５０μｍにおける減衰極ｆｒ２の変化量についてみると、
Ａ…減衰極ｆｒ２の変化量：−２３１ＭＨｚ
Ｂ…減衰極ｆｒ２の変化量：−１２６ＭＨｚ
である。従来の積層ストリップラインフィルタにおける減衰極の変化量の結果（Ａ）に比べて、本発明の積層ストリップラインフィルタにおける減衰極の変化量の結果（Ｂ）で変動を低減できるのは、第１の共振器７１と第３の共振器７３を第２および第３の誘電体層４１・４２の２層を挟んで配したことから、１層を挟んで配した場合と同じ強さの容量性の電磁界結合量を確保するためには第１の共振器７１および第３の共振器７３の片端開放矩形状共振電極の重なり幅ＷＢを大きく設定しなければならないこととなり、第１の共振器７１および第３の共振器７３の片端開放矩形状共振電極の重なり幅ＷＢを十分確保することができることから、積層ずれによる共振電極間の電磁界結合の変化に対する許容範囲を十分に確保することができて、減衰極ｆｒ２の変化量を低減することができるからである。
【００３５】
また、従来の積層ストリップラインフィルタでは第１の共振器７１と第２の共振器７２の片端開放（短絡）矩形状共振電極５２・５３（５３・５６）の重なり幅もしくは、第１の共振器および第３の共振器の片端開放（短絡）矩形状共振電極５２・５４（５５・５７）の重なり幅の一方を狭く設計しなければならない場合において、本発明の積層ストリップラインフィルタでは、重なり幅の狭い方の電極の側を第２の誘電体層４１と第３の誘電体層４２を挟んで配することにより、十分な重なり幅を確保することができ、結果として各々の電極同士の十分な重なり幅を同時に確保することができることとなる。
【００３６】
例えば、図１における第１の片端開放矩形状共振電極５２と第２の片端開放矩形状共振電極５３とが第２の誘電体層４１を挟んで互いに重なる幅ＷＡおよび、第１の片端短絡矩形状共振電極５５と第３の片端短絡矩形状共振電極５６とが第２の誘電体層４１を挟んで互いに重なる幅ＷＣの幅が十分確保できない場合は、これら電極を上記説明の第１の片端開放（短絡）矩形状共振電極５２（５５）と第３の片端開放（短絡）矩形状共振電極５４（５７）との関係と同じと読み替えて、第２の片端開放矩形状共振電極５３と第２の片端短絡矩形状共振電極５６の方を第２の誘電体層４１および第３の誘電体層４２の２層を挟んで配し、第３の片端開放矩形状共振電極５４と第３の片端短絡矩形状共振電極５７の方を第２の誘電体層４１を挟んで配しても差し支えない。
【００３７】
また、本発明の積層ストリップラインフィルタは、上記構成において、第１および第２の接地電極５０・５１を積層方向に電気的に接続する接地接続導体および第１〜第３の片端短絡矩形状共振電極５５〜５７の短絡端５９を積層方向に電気的に接続する接続導体が誘電体層の内部に形成された貫通導体および／または側面に形成された側面導体であることを特徴とするものであり、これにより、積層された複数の誘電体層の内部に形成する積層ストリップラインフィルタの設計自由度が向上するとともに、小型で高性能な積層ストリップラインフィルタを提供することができる。
【００３８】
なお、本発明は以上の実施の形態の例に限定されるものではなく、本発明の要旨を逸脱しない範囲で種々の変更・改良を加えることは何ら差し支えない。
【００３９】
また、第１の片端開放矩形状共振電極５２と第２の片端開放矩形状共振電極５３とが第２の誘電体層４１を挟んで互いに重なる幅ＷＡおよび、第１の片端短絡矩形状共振電極５５と第２の片端短絡矩形状共振電極５６とが第２の誘電体層４１を挟んで互いに重なる幅ＷＣおよび、第１の片端開放矩形状共振電極５２と第３の片端開放矩形状共振電極５４とが第２の誘電体層４１および第３の誘電体層４２を挟んで互いに重なる幅ＷＢおよび、第１の片端短絡矩形状共振電極５５と第３の片端短絡矩形状共振電極５７とが第２の誘電体層４１および第３の誘電体層４２を挟んで互いに重なる幅ＷＤを調整することにより、通過帯域に対して高域側および低域側にそれぞれ減衰極を１個有するフィルタまたは、通過帯域に対して高域側に減衰極を２個有するフィルタまたは、通過帯域に対して低域側に減衰極を２個有するフィルタ特性を実現することができる。
【００４０】
【発明の効果】
本発明の積層ストリップラインフィルタによれば、第３の片端開放矩形状共振電極および第３の片端短絡矩形状共振電極を第２および第３の２層の誘電体層を挟んで配したことから、第１の片端開放矩形状共振電極５２と第３の片端開放矩形状共振電極５４とが第２の誘電体層４１および第３の誘電体層４２を挟んで互いに重なる幅ＷＢおよび、第１の片端短絡矩形状共振電極５５と第３の片端短絡矩形状共振電極５７とが第２の誘電体層４１および第３の誘電体層４２を挟んで互いに重なる幅ＷＤを十分確保することができ、積層ずれによる共振電極間の電磁界結合の変化に対する許容範囲を十分に確保することができ、この結果、フィルタ特性の減衰極の変動を低減することができる積層ストリップラインフィルタを実現することができる。
【００４１】
また、本発明の積層ストリップラインフィルタによれば、上記構成において、各接地電極が、または各片端短絡矩形状共振電極の短絡端および各接地電極が、誘電体層の内部に形成された貫通導体および／または側面に形成された側面導体により積層方向に電気的に接続されているときには、積層された複数の誘電体層の内部に形成する積層ストリップラインフィルタの設計自由度が向上するとともに、小型で高性能な積層ストリップラインを提供することができる。
【００４２】
以上のように、本発明によれば、積層ストリップラインフィルタにおいて、複数の誘電体層を積層する工程において発生する積層ずれによるフィルタ特性の減衰極の変動を低減することができる積層ストリップラインフィルタを提供することができた。
【図面の簡単な説明】
【図１】本発明の積層ストリップラインフィルタの実施の形態の一例を示す透視斜視図である。
【図２】本発明の積層ストリップラインフィルタの実施の形態の一例を示す透視平面図である。
【図３】本発明の積層ストリップラインフィルタの実施の形態の一例を示す図２におけるａ−ａ’線断面図である。
【図４】従来の積層ストリップラインフィルタの例を示す透視斜視図である。
【図５】従来の積層ストリップラインフィルタの例を示す透視平面図である。
【図６】従来の積層ストリップラインフィルタの例を示す図５におけるｂ−ｂ’線断面図である。
【図７】本発明の積層ストリップラインフィルタおよび従来の積層ストリップラインフィルタにおける挿入損失の例を示す線図である。
【図８】本発明の積層ストリップラインフィルタおよび従来の積層ストリップラインフィルタにおける幅方向の積層ずれ量に対する、減衰極ｆｒ２の変化量の例を示す線図である。
【符号の説明】
４０・・・第１の誘電体層
４１・・・第２の誘電体層
４２・・・第３の誘電体層
４３・・・第４の誘電体層
５０・・・第１の接地電極
５１・・・第２の接地電極
５２・・・第１の片端開放矩形状共振電極
５３・・・第２の片端開放矩形状共振電極
５４・・・第３の片端開放矩形状共振電極
５５・・・第１の片端短絡矩形状共振電極
５６・・・第２の片端短絡矩形状共振電極
５７・・・第３の片端短絡矩形状共振電極
５８・・・開放端
５９・・・短絡端
６０・・・入力端子（出力端子）
６１・・・出力端子（入力端子）
７１・・・第１の共振器
７２・・・第２の共振器
７３・・・第３の共振器[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a laminated strip line filter used in a wireless communication device such as a mobile phone and a wireless LAN, and various other communication devices.
[0002]
[Prior art]
In recent years, filters used in mobile communication devices such as mobile phones have been resonating from distributed filters using filters using dielectric coaxial resonators in response to demands for thinner and smaller mobile communication devices. To the multilayer stripline filter used in the vessel.
[0003]
This laminated strip line filter has a configuration shown in FIG. 4 in a perspective view, FIG. 5 in a perspective plan view, and FIG. 6 in a sectional view taken along the line bb ′ in FIG. Proposed.
[0004]
4 to 6, reference numeral 10 denotes a first dielectric layer, 11 denotes a second dielectric layer laminated on the first dielectric layer 10, and 12 denotes a second dielectric layer on the second dielectric layer 11. The laminated third dielectric layer, 20 is a first ground electrode disposed on the lower surface of the first dielectric layer 10, and 21 is the second ground electrode disposed on the upper surface of the third dielectric layer 12. The electrodes, 22 and 25, are a first one-end open rectangular resonance electrode and a first one-end short-circuit rectangular resonance electrode disposed between the first and second dielectric layers 10, 11, and 23 and 26 are the second and The second one-end open rectangular resonance electrode and the second one-end short-circuit rectangular resonance electrode, 24 and 27, disposed between the third dielectric layers 11 and 12, respectively, are the second and third dielectric layers 11 and 12. A third one-end open rectangular resonance electrode and a third one-end short-circuit rectangular resonance electrode, which are disposed between the first and third pieces Each of the open end of the open rectangular shaped resonant electrodes 22 to 24, 29 are each of a short-circuit ends of the first to third one end shorted rectangular resonant electrodes 25-27.
[0005]
As shown in WA to WD in FIGS. 5 and 6, at least a part of each of the first and second rectangular open-ended resonant electrodes 22 and 23 sandwiches the second dielectric layer 11 in the stacking direction. The first and third open-ended rectangular resonant electrodes 22 and 24 have at least a part of each of the first and third open-ended rectangular resonant electrodes 22 and 24 with the second dielectric layer 11 interposed therebetween when viewed from the stacking direction. They are arranged in parallel so as to overlap. The first and second one-end short-circuited rectangular resonance electrodes 25 and 26 are arranged in parallel so that at least a part of each of the first and second short-circuited rectangular resonance electrodes overlaps when viewed from the lamination direction with the second dielectric layer 11 interposed therebetween. The first and third one-end short-circuited rectangular resonance electrodes 25 and 27 are arranged in parallel so that at least a part of each of them intersects with the second dielectric layer 11 therebetween when viewed from the lamination direction. Further, the first and second ground electrodes 20 and 21 are first to third single-ended rectangular resonant electrodes 22 to 24 and first to third single-ended short-circuit rectangular resonant electrodes 25 to 27 when viewed from the lamination direction. It is arranged to cover.
[0006]
Then, an end of the first one-end open rectangular resonance electrode 22 opposite to the open end 28 and an end of the first one-end short-circuit rectangular resonance electrode 25 opposite to the short-circuit end 29 are electrically connected. To form a first resonator,
An end of the second one-end open rectangular resonance electrode 23 opposite to the open end 28 and an end of the second one-end short-circuit rectangular resonance electrode 26 opposite to the short-circuit end 29 are electrically connected. Forming a second resonator;
An end of the third one-end open rectangular resonance electrode 24 opposite to the open end 28 and an end of the third one-end short-circuit rectangular resonance electrode 27 opposite to the short-circuit end 29 are electrically connected. A third resonator is formed.
[0007]
Further, the input terminal 30 is electrically connected to the second resonator, and the output terminal 31 is electrically connected to the third resonator.
[0008]
Then, the widths W22 to W24 of the first to third one-end open rectangular resonant electrodes 22 to 24, the widths W25 to W27 of the first to third one-end short-circuit rectangular resonant electrodes 25 to 27, and the first one-end open rectangular shape. The width WA in which the shape resonance electrode 22 and the second one end open rectangular resonance electrode 23 overlap each other with the second dielectric layer 11 interposed therebetween, the first one end open rectangular resonance electrode 22 and the third one end open rectangular shape The width WB of the resonance electrode 24 overlapping with the second dielectric layer 11 therebetween, and the first one-end short-circuited rectangular resonance electrode 25 and the second one-end open rectangular resonance electrode 26 are formed of the second dielectric layer 11. And the width WD of the first one-end short-circuited rectangular resonance electrode 25 and the third one-end short-circuited rectangular resonance electrode 27 overlapping each other with the second dielectric layer 11 interposed therebetween. , To the high band and low band with respect to the pass band. It was realized filter characteristic having one pole.
[0009]
[Patent Document 1]
JP-A-8-70201
[0010]
[Problems to be solved by the invention]
However, in such a conventional laminated strip line filter, in order to realize desired filter characteristics, the first one-end open rectangular resonance electrode 22 and the second one-end open rectangular resonance electrode 23 are connected to the second end. And a width where the first open-ended rectangular resonant electrode 22 and the third open-ended rectangular resonant electrode 24 overlap each other with the second dielectric layer 11 interposed therebetween. WB, the width WC where the first one-end short-circuited rectangular resonance electrode 25 and the second one-end open rectangular resonance electrode 26 overlap each other with the second dielectric layer 11 interposed therebetween, and the first one-end short-circuit rectangular resonance The electrode 25 and the third one-end short-circuited rectangular resonance electrode 27 may overlap with each other with the second dielectric layer 11 interposed therebetween. In addition, the electromagnetic coupling between the first and second open-ended rectangular resonant electrodes 22 and 23 and the first and second dielectric layers 10 and 12 caused by the misalignment occurring in the step of laminating the first to third dielectric layers 10 to 12 And the third one-side open rectangular resonance electrodes 22 and 24, the electromagnetic field coupling amount, the first and second one-side short-circuit rectangular resonance electrodes 25 and 26 the electromagnetic field coupling amount, and the first and third ones. The change in the amount of electromagnetic field coupling in one or some of the rectangular resonance electrodes 25 and 27 between one end short-circuited rectangular electrodes becomes large, and therefore, there is a problem that the attenuation pole greatly fluctuates with respect to desired filter characteristics. Was.
[0011]
The present invention has been devised in view of the above problems, and an object of the present invention is to provide a multilayer strip line filter that suppresses a variation in a filter characteristic attenuation pole due to a lamination shift generated in a step of laminating a plurality of dielectric layers. An object of the present invention is to provide a laminated strip line filter that can be reduced.
[0012]
[Means for Solving the Problems]
The laminated strip line filter of the present invention has a first dielectric layer, a second dielectric layer laminated on the first dielectric layer, and a laminated layer on the second dielectric layer. A third dielectric layer, a fourth dielectric layer laminated on the third dielectric layer, a first ground electrode disposed on a lower surface of the first dielectric layer, A first open-ended rectangular resonant electrode and a first short-circuited rectangular resonant electrode disposed between the first and second dielectric layers, and the second and third dielectric layers; A second one-end open rectangular resonance electrode and a second one-end short-circuit rectangular resonance electrode, and a third one-end open rectangular resonance electrode arranged between the third and fourth dielectric layers; A third short-circuited rectangular resonance electrode having one end, and a second ground electrode disposed on the upper surface of the fourth dielectric layer;
The first and second open-ended rectangular resonant electrodes are arranged in parallel so that at least a part of each of the first and second rectangular open-ended resonant electrodes overlaps when viewed from the laminating direction, and the first and second open-ended resonant electrodes are arranged in parallel. The three open-ended rectangular resonant electrodes are arranged in parallel so that at least a part of each of the two resonant electrodes sandwiches the second and third dielectric layers when viewed from the laminating direction.
The first and second one-end short-circuited rectangular resonance electrodes are arranged in parallel so that at least a part of each of the first and second short-circuited rectangular resonance electrodes overlaps when viewed from the laminating direction, with the second dielectric layer interposed therebetween. 3 is arranged in parallel so that at least a part of each of the two short-circuited rectangular resonant electrodes overlaps each other with the second and third dielectric layers interposed therebetween when viewed from the laminating direction.
The first and second ground electrodes are arranged so as to cover the first to third single-ended rectangular resonant electrodes and the first to third single-ended short-circuited rectangular resonant electrodes when viewed from the lamination direction,
An end opposite to the open end of the first one-end open rectangular resonance electrode and an end opposite to the short-circuit end of the first one-end short-circuit rectangular resonance electrode are electrically connected to each other to form a first end. Forming a resonator of
An end of the second one-end open rectangular resonance electrode opposite to the open end and an end of the second one-end short-circuit rectangular resonance electrode opposite to the short-circuit end are electrically connected to form a second end. Forming a resonator of
An end of the third one-end open rectangular resonance electrode opposite to the open end and an end of the third one-end short-circuit rectangular resonance electrode opposite to the short-circuit end are electrically connected to form a third end. Forming a resonator of
An input terminal is electrically connected to the second resonator and an output terminal is electrically connected to the third resonator, or an output terminal is electrically connected to the second resonator and an input terminal is electrically connected to the third resonator. It is characterized by the fact that the connection is made.
[0013]
According to the laminated strip line filter of the present invention, the third one-end open rectangular resonance electrode and the third one-end short-circuit rectangular resonance electrode are disposed with the second and third two dielectric layers interposed therebetween. A width at which the first open-ended rectangular resonant electrode and the third open-ended rectangular resonant electrode overlap each other with the second dielectric layer and the third dielectric layer interposed therebetween; The width of the resonance electrode and the third one-end short-circuited rectangular resonance electrode overlapping each other with the second dielectric layer and the third dielectric layer interposed therebetween can be sufficiently ensured. It is possible to sufficiently secure the allowable range for the change in coupling, and as a result, it is possible to reduce the fluctuation of the attenuation pole of the filter characteristic.
[0014]
Further, in the laminated strip line filter according to the present invention, in the above-described configuration, each of the ground electrodes, or each of the short-circuited ends of each of the short-circuited rectangular resonant electrodes and each of the ground electrodes is formed inside the dielectric layer. It is characterized by being electrically connected in the laminating direction by a through conductor and / or a side conductor formed on a side surface.
[0015]
Thereby, the degree of freedom in designing the laminated strip line filter formed inside the plurality of laminated dielectric layers is improved, and a compact and high-performance laminated strip line filter can be provided.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the laminated strip line filter of the present invention will be described with reference to the drawings.
[0017]
FIG. 1 is a perspective view showing an example of an embodiment of the laminated strip line filter of the present invention. FIG. 2 is a perspective plan view of FIG. 1 viewed from the laminating direction. FIG. 3 is a line aa ′ in FIG. It is sectional drawing. 1 to 3, reference numeral 40 denotes a first dielectric layer, 41 denotes a second dielectric layer laminated on the first dielectric layer 40, and 42 denotes a second dielectric layer on the second dielectric layer 41. The laminated third dielectric layer, 43 is a fourth dielectric layer laminated on the third dielectric layer 42, and 50 is a first dielectric layer disposed on the lower surface of the first dielectric layer 40. A ground electrode, 51 is a second ground electrode disposed on the upper surface of the fourth dielectric layer 43, and 52 and 55 are first open ends disposed between the first and second dielectric layers 40, 41. The rectangular resonance electrode and the first one-end short-circuited rectangular resonance electrodes, 53 and 56, are a second one-end open rectangular resonance electrode and the second one end disposed between the second and third dielectric layers 41 and. Short-circuited rectangular resonant electrodes, 54 and 59 are third open-ended rectangular resonant electrodes disposed between the third and fourth dielectric layers 42 and 43; And third one-end short-circuited rectangular resonance electrodes 58, 58 are open ends of the first to third one-end open rectangular resonance electrodes 52 to 54, 59 is first to third one-end short-circuited rectangular resonance electrodes 55 to 55. 57 are short-circuit ends.
[0018]
As shown in WA to WD in FIGS. 2 and 3, at least a part of each of the first and second open-ended rectangular resonant electrodes 52 and 53 has the second dielectric layer 41 interposed therebetween. And the first and third rectangular open-ended resonant electrodes 52 and 54 are at least partially sandwiched between the second and third dielectric layers 41 and 42, respectively. They are arranged in parallel so as to overlap when viewed from the laminating direction. The first and second single-ended short-circuited rectangular resonance electrodes 55 and 56 are arranged in parallel so that at least a part of each of the first and second short-circuited rectangular resonance electrodes overlaps when viewed from the laminating direction with the second dielectric layer 41 interposed therebetween. The first and third one-end short-circuited rectangular resonance electrodes 55 and 57 are arranged in parallel with the second and third dielectric layers 41 and 42 interposed therebetween so that at least a part of each of them overlaps when viewed from the lamination direction. . The first and second ground electrodes 50 and 51 are formed of first to third single-ended rectangular resonant electrodes 52 to 54 and first to third single-ended short-circuited rectangular resonant electrodes 55 to 57 when viewed from the stacking direction. It is arranged to cover.
[0019]
Then, an end of the first one-end open rectangular resonance electrode 52 opposite to the open end 58 and an end of the first one-end short-circuit rectangular resonance electrode 55 opposite to the short-circuit end 59 are electrically connected. To form a first resonator 71,
An end of the second one-end open rectangular resonance electrode 53 opposite to the open end 58 and an end of the second one-end short-circuit rectangular resonance electrode 56 opposite to the short-circuit end 59 are electrically connected. Forming a second resonator 72,
An end of the third one-end open rectangular resonance electrode 54 opposite to the open end 58 and an end of the third one-end short-circuit rectangular resonance electrode 57 opposite to the short-circuit end 59 are electrically connected. A third resonator 73 is formed.
[0020]
Further, the input terminal 60 is electrically connected to the second resonator 72, and the output terminal 61 is electrically connected to the third resonator 73, and is connected to an external circuit. If necessary, the input terminal may be on the 61 side and the output terminal may be on the 60 side.
[0021]
The laminated strip line filter of the present invention having such a configuration has a rectangular shape between the first and second ground electrodes 50 and 51 or between the first and second ground electrodes 50 and 51 and the first to third single-ended short-circuits. A through conductor (not shown) formed inside the dielectric layer and / or a side conductor formed on the side surface as a ground connection conductor for electrically connecting the short-circuited ends 59 of the resonance electrodes 55 to 57 in the stacking direction. (Not shown), three-dimensional wiring design becomes possible, and the degree of freedom in designing a laminated strip line filter formed inside a plurality of laminated dielectric layers is improved. A high performance laminated strip line filter can be provided.
[0022]
In forming the laminated strip line filter of the present invention, the first to fourth dielectric layers 40 to 43, the first and second ground electrodes 50 and 51, and the first to third single-ended open rectangular resonant electrodes 52 are provided. As the first to third single-ended short-circuited rectangular resonance electrodes 55 to 57, various materials and forms used for a known high-frequency wiring board can be used.
[0023]
As the first to fourth dielectric layers 40 to 43 used in the laminated strip line filter of the present invention, for example, ceramic materials such as alumina ceramics and mullite ceramics, inorganic materials such as glass ceramics, or ethylene tetrafluoride resin ( Polytetrafluoroethylene; PTFE) / ethylene tetrafluoride-ethylene copolymer resin (tetrafluoroethylene-ethylene copolymer resin; ETFE) / ethylene tetrafluoride-perfluoroalkoxyethylene copolymer resin (tetrafluoroethylene-perflutero) Fluorine resins such as alkyl vinyl ether copolymer resins (PFA) and resin materials such as glass epoxy resins and polyimides are used. The shapes and dimensions (thickness, width and length) of the first to fourth dielectric layers 40 to 43 made of these materials are set according to the frequency used, the application, and the like.
[0024]
First and second ground electrodes 50 and 51, first to third one-end open rectangular resonance electrodes 52 to 54, and first to third one-end short-circuited rectangular resonance electrodes 55 to 55 in the laminated strip line filter of the present invention. 57-Through conductors or side conductors are conductor layers of a metal material for high frequency signal transmission, for example, a Cu layer, a Mo-Mn metallized layer with a Ni plated layer and an Au plated layer adhered, and a W metallized layer. A Ni-plated layer and an Au-plated layer are adhered thereon.- A Cr-Cu alloy layer- A Ni-plated layer and an Au-plated layer are deposited on a Cr-Cu alloy layer- Ta ₂ Ni-Cr alloy layer and Au plating layer deposited on N layer-Pt layer and Au plating layer deposited on Ti layer, or Pt layer and Au plating on Ni-Cr alloy layer It is formed by a thick film printing method, various thin film forming methods, a plating method, or the like, using a material having a layer adhered thereto. The thickness and width are also set according to the frequency of the transmitted high-frequency signal, the application, and the like.
[0025]
In producing the first to fourth dielectric layers 40 to 43 used in the laminated strip line filter of the present invention, for example, when the dielectric layer is made of glass ceramic, first, a green ceramic glass to be a dielectric layer is used. A sheet is prepared, and a predetermined punching process is performed on the sheet to form a through hole serving as a through conductor. Then, the through hole is filled with a conductive paste such as Cu by a screen printing method, and a predetermined transmission line pattern and other Print and apply the conductor layer pattern. Next, baking is performed at 850 to 1000 ° C., and finally Ni plating and Au plating are performed on the conductor layer exposed on the outer surface.
[0026]
The multilayer strip line filter of the present invention having the configuration shown in FIGS. 1 to 3 and the conventional multilayer strip line filter shown in FIGS. 4 to 6 can realize the same filter characteristics, and FIG. It is shown. In FIG. 7, the horizontal axis represents frequency (unit: GHz), and the vertical axis represents insertion loss (unit: dB). The first attenuation pole fr1 is generated by the electromagnetic field coupling formed between the first and second resonators 71 and 72, and the first attenuation pole fr1 is generated by the electromagnetic field coupling formed between the first and third resonators 71 and 73. A second attenuation pole fr2 occurs.
[0027]
As an example, a three-dimensional electromagnetic field model is used to realize the filter characteristics of FIG. 7 in the multilayer strip line filter of the present invention having the configuration shown in FIGS. 1 to 3 and the conventional multilayer strip line filter shown in FIGS. A simulation analysis was performed using an analysis simulator, taking into account the amount of stacking deviation in the width direction.
[0028]
For example, in the case of the simulation in the laminated strip line filter of the present invention having the configuration shown in FIGS. 1 to 3, the thickness of each of the first to fourth dielectric layers 40 to 43 is set to the first dielectric layer h1 = 0.2 mm. , The second dielectric layer h2 = 0.1 mm, the third dielectric layer h3 = 0.1 mm, the fourth dielectric layer h4 = 0.2 mm,
The width W52 to W54 of each of the first to third one-end open rectangular resonance electrodes 52 to 54 and the length L52 to L54 of each resonance electrode are W52 = 2.54 mm, W53 = 1.19 mm, and W54. = 1.3 mm, L52 = L53 = L54 = 2.367 mm,
The width W55-W57 of each of the first through third one-end short-circuited rectangular resonance electrodes 55-57 and the length L55-L57 of each resonance electrode are W55 = 2.5 mm, W56 = 1.33 mm, W57, respectively. = 1.2m, L55 = L56 = L57 = 2.367mm,
The width WA of the portion where the first and second open-ended rectangular resonant electrodes 52 and 53 overlap when viewed in the stacking direction is 0.55 mm, and the first and second short-circuited rectangular resonant electrodes 55 and 56 are stacked in the stacked direction. The width WC of the overlapping part is set to 0.19 mm,
The width WB = 0.23 mm of the portion where the first and third open-ended rectangular resonant electrodes 52 and 54 overlap in the stacking direction, and the first and third short-circuited rectangular resonant electrodes 55 and 57 are stacked in the stacking direction. The width WD of the overlapping portion is set to 0.88 mm.
[0029]
In addition, each dimension of the simulation model in the conventional laminated strip line filter shown in FIGS. 4 to 6 is such that the thickness of the first to third dielectric layers 10 to 12 is the first dielectric layer h1 = 0.2 mm, respectively. The second dielectric layer h2 = 0.1 mm, the third dielectric layer h3 = 0.3 mm,
The width W22 to W24 of each of the first to third one-end open rectangular resonance electrodes 22 to 24 and the length L22 to L24 of each resonance electrode are W22 = 2.38 mm, W23 = 1.19 mm, and W24, respectively. = 1.47 mm, L52 = L53 = L54 = 2.367 mm, the width W25-W27 of each of the first through third one-end short-circuited rectangular resonance electrodes 25-27 and the length L25-L27 of each resonance electrode Are respectively set as W25 = 2.45 mm, W26 = 1.33 mm, W27 = 1.25 mm, L25 = L26 = L27 = 2.367 mm,
The width WA of the portion where the first and second one-end open rectangular resonant electrodes 22 and 23 overlap when viewed in the laminating direction is WA = 0.54 mm, and the first and second one-end short-circuit rectangular resonant electrodes 25 and 26 are arranged in the laminating direction. The width WC of the overlapping part is set to 0.23 mm,
The width WB of the portion where the first and third one-end open rectangular resonant electrodes 22 and 24 overlap when viewed in the laminating direction is WB = 0.04 mm, and the first and third one-end short-circuit rectangular resonant electrodes 25 and 27 are from the laminating direction. The width WD = of the overlapping portion is set to 0.35 mm.
[0030]
Then, in the laminated strip line filter of the present invention having the configuration shown in FIGS. 1 to 3, the surface where the first resonator is located, the surface where the second resonator is located, and the surface where the third resonator is located are illustrated. In the conventional laminated strip line filters shown in FIGS. 4 to 6, the surface on which the second and third resonators are located is in the width direction (the horizontal direction parallel to the paper surface) with respect to the surface on which the first resonator is located. A simulation was performed for a case where ± 50 μm was considered as the amount of misalignment. The relative dielectric constant of each dielectric layer used in each simulation was set to 7.7.
[0031]
The major difference between the laminated strip line filter model of the present invention and the conventional laminated strip line filter model in the present embodiment is the overlap width WB of the first and third one-end open rectangular resonant electrodes. The overlapping width WB of the first and third single-ended open rectangular resonance electrodes for realizing desired filter characteristics is WB = 40 μm in the case of the conventional multilayer strip line filter, and the overlap width WB of the multilayer strip line filter of the present invention is obtained. In this case, WB = 230 μm. WB forms the attenuation pole fr2 in the filter characteristics shown in FIG. Therefore, a comparison was made between the amount of change in the attenuation pole fr2 due to lamination displacement between the laminated strip line filter of the present invention and the conventional laminated strip line filter.
[0032]
8, the horizontal axis represents the amount of lamination deviation (unit: μm) in the width direction (the plane parallel to the paper surface and the horizontal direction), and the vertical axis represents the amount of change (unit: MHz) of the attenuation pole fr2 in FIG. In each characteristic curve, B indicates that the surface having the first resonator 71 and the surface having the third resonator 73 in the laminated strip line filter of the present invention shown in FIGS. The result in the case of displacement is that A is ±± in the width direction with respect to the plane where the first and second resonators exist in the conventional laminated strip line filter shown in FIGS. The result when the stacking displacement is 50 μm is shown.
[0033]
As is clear from the results shown in FIG. 8, according to the laminated strip line filter of the present invention, it is possible to reduce the fluctuation of the attenuation pole of the filter characteristic due to the lamination displacement occurring in the step of laminating a plurality of dielectric layers. it can.
[0034]
For example, when looking at the amount of change in the attenuation pole fr2 when the amount of stacking deviation is −50 μm,
A: Amount of change in attenuation pole fr2: -231 MHz
B: Amount of change in attenuation pole fr2: -126 MHz
It is. The first reason that the variation (A) of the variation of the attenuation pole in the multilayer strip line filter of the present invention can reduce the variation as compared with the variation (A) of the attenuation pole in the conventional multilayer strip line filter is as follows. Since the resonator 71 and the third resonator 73 are arranged with the two layers of the second and third dielectric layers 41 and 42 interposed therebetween, the capacitive element having the same strength as the case where one layer is interposed is provided. In order to secure the electromagnetic field coupling amount, it is necessary to set the overlap width WB of the rectangular resonator electrodes having one end open to the first resonator 71 and the third resonator 73 to be large. In addition, since the overlap width WB of the one-end open rectangular resonance electrode of the third resonator 73 can be sufficiently ensured, the allowable range for the change in the electromagnetic field coupling between the resonance electrodes due to the lamination displacement can be sufficiently ensured. And decay This is because it is possible to reduce the amount of change in fr2.
[0035]
Further, in the conventional laminated strip line filter, the overlapping width of the rectangular resonator electrodes 52 and 53 (53 and 56) with one end open (short-circuited) of the first resonator 71 and the second resonator 72 or the first resonator In the case where one of the overlapping widths of the rectangular resonator electrodes 52, 54 (55, 57) having one end open (short-circuited) of the third resonator must be designed to be narrow, the overlapping strip width of the laminated strip line filter of the present invention. By arranging the narrower electrode side with the second dielectric layer 41 and the third dielectric layer 42 interposed therebetween, a sufficient overlapping width can be ensured, and as a result, a sufficient overlap width between the electrodes can be secured. The overlapping width can be secured at the same time.
[0036]
For example, the width WA in which the first one-end open rectangular resonance electrode 52 and the second one-end open rectangular resonance electrode 53 in FIG. 1 overlap each other with the second dielectric layer 41 interposed therebetween, and the first one-end short-circuit rectangular If the width WC of the shape resonance electrode 55 and the third one-end short-circuited rectangular resonance electrode 56 overlapping each other with the second dielectric layer 41 interposed therebetween cannot be sufficiently ensured, these electrodes are connected to the first end of the above description. The same as the relationship between the open (short-circuit) rectangular resonance electrode 52 (55) and the third one-end open (short-circuit) rectangular resonance electrode 54 (57), the second single-end open rectangular resonance electrode 53 and the third The two single-ended short-circuited rectangular resonance electrodes 56 are disposed with the second dielectric layer 41 and the third dielectric layer 42 interposed therebetween. One end short-circuited rectangular resonance electrode 57 is sandwiched between second dielectric layers 41. No problem even if the.
[0037]
Further, in the laminated strip line filter of the present invention, in the above configuration, the ground connection conductor for electrically connecting the first and second ground electrodes 50 and 51 in the laminating direction and the first to third single-ended short-circuited rectangular resonances are provided. The connection conductor for electrically connecting the short-circuited ends 59 of the electrodes 55 to 57 in the stacking direction is a through conductor formed inside the dielectric layer and / or a side conductor formed on the side surface. With this, it is possible to improve the degree of freedom in designing a laminated strip line filter formed inside a plurality of laminated dielectric layers, and to provide a small and high performance laminated strip line filter.
[0038]
It should be noted that the present invention is not limited to the above-described embodiments, and various changes and improvements may be made without departing from the spirit of the present invention.
[0039]
Further, a width WA in which the first open-ended rectangular resonant electrode 52 and the second open-ended rectangular resonant electrode 53 overlap each other with the second dielectric layer 41 interposed therebetween, and a first open-ended rectangular resonant electrode The width WC at which the 55 and the second one-end short-circuited rectangular resonance electrode 56 overlap each other with the second dielectric layer 41 interposed therebetween, and the first one-end open rectangular resonance electrode 52 and the third one-end open rectangular resonance electrode 54, a width WB overlapping each other with the second dielectric layer 41 and the third dielectric layer 42 interposed therebetween, and a first one-end short-circuited rectangular resonance electrode 55 and a third one-end short-circuited rectangular resonance electrode 57. By adjusting the width WD overlapping each other with the second dielectric layer 41 and the third dielectric layer 42 interposed therebetween, a filter having one attenuation pole on each of the high band side and the low band side with respect to the pass band or , The attenuation pole on the higher side of the pass band Pieces having filters or, it is possible to realize a filter characteristic having two attenuation poles on the lower-frequency side relative to the passband.
[0040]
【The invention's effect】
According to the laminated strip line filter of the present invention, the third one-end open rectangular resonance electrode and the third one-end short-circuit rectangular resonance electrode are disposed with the second and third two dielectric layers interposed therebetween. A width WB at which the first open-ended rectangular resonant electrode 52 and the third open-ended rectangular resonant electrode 54 overlap each other with the second dielectric layer 41 and the third dielectric layer 42 interposed therebetween; The width WD at which the single-ended short-circuited rectangular resonance electrode 55 and the third single-ended short-circuited rectangular resonance electrode 57 overlap each other with the second dielectric layer 41 and the third dielectric layer 42 interposed therebetween can be sufficiently ensured. Therefore, it is possible to sufficiently secure an allowable range for the change in the electromagnetic field coupling between the resonance electrodes due to the stacking deviation, and as a result, it is possible to realize a stacked stripline filter capable of reducing the fluctuation of the attenuation pole of the filter characteristic. Can .
[0041]
Further, according to the laminated strip line filter of the present invention, in the above-described configuration, each ground electrode, or the short-circuited end of each one-end short-circuited rectangular resonance electrode and each ground electrode are formed in the through conductor formed inside the dielectric layer. And / or when electrically connected in the laminating direction by side conductors formed on the side surfaces, the degree of freedom in designing a laminated strip line filter formed inside a plurality of laminated dielectric layers is improved, and the size is reduced. And a high-performance laminated strip line can be provided.
[0042]
As described above, according to the present invention, in a laminated strip line filter, there is provided a laminated strip line filter capable of reducing a variation in an attenuation pole of a filter characteristic due to a lamination shift generated in a step of laminating a plurality of dielectric layers. Could be provided.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an example of an embodiment of a laminated strip line filter of the present invention.
FIG. 2 is a perspective plan view showing an example of an embodiment of the laminated strip line filter of the present invention.
FIG. 3 is a cross-sectional view taken along the line aa ′ in FIG. 2 showing an example of the embodiment of the laminated strip line filter of the present invention.
FIG. 4 is a perspective view showing an example of a conventional laminated strip line filter.
FIG. 5 is a perspective plan view showing an example of a conventional laminated strip line filter.
FIG. 6 is a cross-sectional view taken along the line bb ′ in FIG. 5, illustrating an example of a conventional laminated strip line filter.
FIG. 7 is a diagram showing an example of insertion loss in the laminated strip line filter of the present invention and a conventional laminated strip line filter.
FIG. 8 is a diagram showing an example of a variation amount of an attenuation pole fr2 with respect to a lamination displacement amount in a width direction in a laminated strip line filter of the present invention and a conventional laminated strip line filter.
[Explanation of symbols]
40... First dielectric layer
41 ... second dielectric layer
42... Third dielectric layer
43... Fourth dielectric layer
50: first ground electrode
51... Second ground electrode
52 first rectangular open-ended resonant electrode at one end
53... 2nd open-ended rectangular resonant electrode
54... Third third open-ended rectangular resonant electrode
55... 1st one-end short-circuited rectangular resonance electrode
56... Second short-circuited rectangular resonant electrode at one end
57: third one-end short-circuited rectangular resonance electrode
58 ... open end
59 ・・・ Short-circuit end
60 ... input terminal (output terminal)
61 ・・・ Output terminal (input terminal)
71... First resonator
72... Second resonator
73... Third resonator

Claims

A first dielectric layer, a second dielectric layer laminated on the first dielectric layer, a third dielectric layer laminated on the second dielectric layer, A fourth dielectric layer laminated on the third dielectric layer, a first ground electrode disposed on the lower surface of the first dielectric layer, and the first and second dielectric layers A first open-ended rectangular resonant electrode and a first open-ended rectangular resonant electrode disposed between layers, and a second open-ended rectangular electrode disposed between the second and third dielectric layers. A shape resonance electrode and a second one-end short-circuited rectangular resonance electrode, and a third one-end open rectangular resonance electrode and a third one-end short-circuited rectangular resonance electrode disposed between the third and fourth dielectric layers. And a second ground electrode disposed on the upper surface of the fourth dielectric layer,
The first and second open-ended rectangular resonant electrodes are arranged in parallel so that at least a part of each of the first and second rectangular open-ended resonant electrodes overlaps when viewed from the laminating direction, and the first and second open-ended resonant electrodes are arranged in parallel. The three open-ended rectangular resonant electrodes are arranged in parallel so that at least a part of each of the two resonant electrodes sandwiches the second and third dielectric layers when viewed from the laminating direction.
The first and second one-end short-circuited rectangular resonance electrodes are arranged in parallel so that at least a part of each of the first and second short-circuited rectangular resonance electrodes overlaps when viewed from the laminating direction, with the second dielectric layer interposed therebetween. 3 is arranged in parallel so that at least a part of each of the two short-circuited rectangular resonant electrodes overlaps each other with the second and third dielectric layers interposed therebetween when viewed from the laminating direction.
The first and second ground electrodes are arranged so as to cover the first to third single-ended rectangular resonant electrodes and the first to third single-ended short-circuited rectangular resonant electrodes when viewed from the lamination direction,
An end opposite to the open end of the first one-end open rectangular resonance electrode and an end opposite to the short-circuit end of the first one-end short-circuit rectangular resonance electrode are electrically connected to each other to form a first end. Forming a resonator of
An end of the second one-end open rectangular resonance electrode opposite to the open end and an end of the second one-end short-circuit rectangular resonance electrode opposite to the short-circuit end are electrically connected to form a second end. Forming a resonator of
An end of the third one-end open rectangular resonance electrode opposite to the open end and an end of the third one-end short-circuit rectangular resonance electrode opposite to the short-circuit end are electrically connected to form a third end. Forming a resonator of
An input terminal is electrically connected to the second resonator and an output terminal is electrically connected to the third resonator, or an output terminal is electrically connected to the second resonator and an input terminal is electrically connected to the third resonator. A laminated strip line filter, which is electrically connected.

The respective ground electrodes or the short-circuited ends of the single-ended rectangular resonant electrodes and the respective ground electrodes are laminated by a through conductor formed inside the dielectric layer and / or a side conductor formed on a side surface. 2. The multilayer strip line filter according to claim 1, wherein the filter is electrically connected in the directions.