JP2004364062A

JP2004364062A - Cavity resonator, method for connecting same, and cavity resonator filter

Info

Publication number: JP2004364062A
Application number: JP2003161301A
Authority: JP
Inventors: Hisato Ito; 久人伊藤
Original assignee: SPC Electronics Corp
Current assignee: SPC Electronics Corp
Priority date: 2003-06-05
Filing date: 2003-06-05
Publication date: 2004-12-24
Anticipated expiration: 2023-06-05
Also published as: JP4071162B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cavity resonator for facilitating not only 180° connection but also 90° connection by reducing effect when a plurality of cavity resonators are connected. <P>SOLUTION: The cavity resonator includes connection surface part to be connected to a connection object part. Notched holes 16 communicating with each spot facing part 17 storing the head of a connection screw 3 for connection to the connection object part are arranged in the connection surface part. While the head of each connection screw 3 is stored in each spot facing part 17, the end of the connection screw 3 is guided to the connection object part through each notched hole 16. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、マイクロ波フィルタに使用される空胴共振器、この空胴共振器の結合方法、及びこの空胴共振器を多段接続して構成される空胴共振器フィルタに関する。
【０００２】
【従来の技術】
マイクロ波帯のレーダシステムで使用される低損失のバンド・パス・フィルタとして、ＴＥ_０１ｎモード（ｎは自然数、以下同じ）の円筒空胴共振器フィルタがある。
円筒空胴共振器フィルタの中には、それぞれ同一特性の複数の円筒空胴共振器を多段結合してなるフィルタ、すなわち、それぞれ電磁波が入出力される部分にフランジが形成され、フランジの略中央部に開口部が形成されている複数の円筒空胴共振器が、互いに自己の開口部及び他方の円筒空胴共振器の開口部と、その間に介在する結合板の孔部とを通じて電気的に結合されているものがある。初段の円筒空胴共振器の入力端部には入力用導波管のフランジが、終段の円筒空胴共振器の出力端部には出力用導波管のフランジが、それぞれ孔部が形成された結合板を挟んでビス等によって締結されるようになっている。
【０００３】
図４、５は、従来の２つの円筒空胴共振器を結合してなる円筒空胴共振器フィルタの構造説明図である。
なお本明細書では、円筒空胴共振器の共振周波数を調整する端板あるいは固定端板についてはすべて省略する。また、円筒空胴共振器フィルタの初段の入力側及び最終段の出力側の結合板も省略する。
【０００４】
図４に示す円筒空胴共振器フィルタは、同一特性、形状の２つの円筒空胴共振器１ｄ、１ｅが、結合板２ｃを挟んで連結用ネジ３及び連結用ナット４により結合されて構成されている。各円筒空胴共振器１ｄ、１ｅは、円筒形の空洞が形成された直方体形状の本体５をもち、この本体５には、電磁波が入出力される入力端部６及び出力端部７としての開口部が形成される。入力端部６及び出力端部７が形成される面には、それぞれフランジ８が設けられている。フランジ８の略中央部には、入力端部６及び出力端部７に対応する位置に、電磁波の入出力のための開口窓９が形成されている。
フランジ８は、本体５からはみ出す位置に連結用ネジ３を貫通させるためのネジ孔１０が形成されているために、本体５の互いに平行な面にしか設けることができず、互いに垂直に交わる面には設けることができない。円筒空胴共振器を９０度に結合させることにより、高次モードＴＥ_３１１を疎結合にさせて、ＴＥ_０１１モードフィルタの減衰特性をより良好とすることができるが、フランジ８を用いる構造であるために、この種の円筒空胴共振器を９０度に結合させることは困難である。
【０００５】
結合板２ｃは、フランジ８の形状に対応した長方形の板状であり、結合時に各円筒空胴共振器１ｄ、１ｅのフランジ８に形成されたネジ孔１０に対応する位置にネジ孔１１が形成され、また、結合時に円筒空胴共振器１ｄの出力端部７及び円筒空胴共振器１ｅの入力端部６に対応する位置に開口窓１２ｃが形成されている。
結合板２ｃの開口窓１２ｃは、円筒空胴共振器フィルタの共振器の段数、パスバンド巾、リップル値等の選択によりサセプタンスの値に応じて決定される。
【０００６】
円筒空胴共振器１ｄ、１ｅを結合する際には、円筒空胴共振器１ｄの出力端部７側の面と円筒空胴共振器１ｅの入力端部６側の面を対向させて、その間に結合板２ｃを挟み、連結用ネジ３を、円筒空胴共振器１ｅのフランジ８に形成されたネジ孔１０、結合板２ｃに形成されたネジ孔１１、及び円筒空胴共振器１ｄのフランジ８に形成されたネジ孔１０に貫通させて、連結用ナット４にて締結する。この例では、フランジ８及び結合板２ｃにそれぞれ４つのネジ孔１０、１１が形成されているので、連結用ネジ３及び連結用ナット４により４箇所で締結される。
【０００７】
さらに別の円筒空胴共振器を接続する際には、同様にして、結合板２ｃを挟んで連結用ネジ３及び連結用ナット４で接続することになる。
結合板２ｃの開口窓１２ｃの形状を変えるときには、結合板２ｃを交換する必要があるが、この場合、連結用ネジ３を完全に取り外してから交換を行う。
【０００８】
図５に示す円筒空胴共振器フィルタは、図４に示す円筒空胴共振器フィルタと基本的な構成は同じである。相違点は、円筒空胴共振器１ｆ、１ｇの本体５の形状が円筒形であることと、フランジ８及び結合板２ｄが円板状に形成されていることである。この種の円筒空胴共振器もフランジ８が本体５からはみ出すために、９０度結合に適していない。
【０００９】
円筒空胴共振器フィルタにとって、電磁波の伝播特性に影響を与えずに２つの円筒空胴共振器を結合させることは重要である。そのために、電磁波の伝播特性への影響ができるだけ小さくなるように空胴共振器や導波管を結合させるための、様々な技術が提案されている。
【００１０】
例えば、特開平６−２９１５０２号公報（発明の名称：導波管接続構造）には、結合時にフランジの結合部分の隙間を覆うようにフランジの周囲に電波吸収体を支持した電波吸収構体を設けて、結合部分から電磁波が漏れないようにしている。特開平６−３５０３０１号公報（発明の名称：導波管接続用ゴムガスケットおよびそれを用いた導波管の接続構造）には、導波管の結合に用いる結合板に、導電性の充填材が配合されたゴム製のガスケットを用いて結合部分による電磁波の減衰を防止している。特公平７−３８５２１号公報（発明の名称：導波管とフランジの接合部構造）には、導波管とフランジとを接合する接合部に、接着剤を収容する溝を設けて、導波管とフランジの接合強度を高めるような構成としている。特開平６−１７７６０１号公報（発明の名称：導波管の接続構造）には、２つの導波管のフランジを挟んで密着させる保持板により、導波管の接続作業を簡易にする。
【００１１】
【発明が解決しようとする課題】
以上の各例では、本体にフランジを設けた構成が基本となっており、空胴共振器は、互いのフランジをネジで締結して結合されている。フランジを用いる場合には、フランジを本体に蝋付けなどにより取り付けることになる。また、本体も切削などにより、フランジを取り付け易くするための加工が必要になる。フランジの取り付け加工は、電磁波の伝播特性に影響を与えるために、精度を要求される。さらに、前述の通りフランジを用いることにより、空胴共振器の９０度結合が困難になっている。
【００１２】
そこで本発明は、複数の空胴共振器を結合した際の影響を少なくし、空胴共振器の９０度結合を容易に可能にした、空胴共振器、この空胴共振器の結合方法及び空胴共振器を複数接続した空胴共振器フィルタを提供することを課題とする。
【００１３】
【課題を解決するための手段】
上記課題を解決する本発明の空胴共振器は、結合対象部品との結合面部を有する空胴共振器であって、前記結合面部の所定部位に、前記結合対象部品と結合するための連結用ネジの頭部が収容される座ぐり穴が設けられており、前記座ぐり穴は、前記連結用ネジの頭部が収容された状態で当該連結用ネジの端部を前記結合対象部品へ案内する構造を有することを特徴とする。
【００１４】
本発明の空胴共振器では、連結用ネジの頭部が空胴共振器に設けられた座ぐり穴に収容されて、導波管や他の空胴共振器等の結合対象部品と結合されるようになっているので、結合のためのフランジを必要としない。そのためにフランジを設けることにより生じる様々な困難が解消される。
【００１５】
このような空胴共振器では、例えば前記結合面部に開口部が形成される。この開口部を通じて前記結合対象部品との間で電磁波が入力又は出力される。
空胴共振器は、例えば円筒形の空洞が形成された略直方体形状の本体を有しており、この本体に、前記空洞に連通して前記開口部が設けられる。開口部は、例えば２つの異なる結合面部のそれぞれに設けられ、これら２つの異なる結合面部が、これらの開口部による電磁波の入力方向と出力方向とが９０度をなすように形成されると、この空胴共振器を介して９０度結合が容易になる。
【００１６】
本発明の空胴共振器の結合方法は、結合対象部品との結合面部を有し、前記結合面部の所定部位に、前記結合対象部品と結合するための連結用ネジの頭部が収容される座ぐり穴が設けられるとともに、前記結合対象部品から案内される連結用ネジが螺合されるネジ穴を有する空胴共振器を、同じ構成の他の空胴共振器と結合させる方法であって、前記空胴共振器及び前記他の空胴共振器の各々の前記ネジ穴にそれぞれ連結用ネジの端部を仮止めし、前記空胴共振器に仮止めされた連結用ネジの頭部を前記他の空胴共振器に設けられた座ぐり穴に収容するとともに、前記他の空胴共振器に仮止めされた連結用ネジの頭部を前記空胴共振器に設けられた座ぐり穴に収容し、前記連結用ネジを螺合して、前記空胴共振器及び前記他の空胴共振器を結合する。
【００１７】
本発明の空胴共振器フィルタは、互いに結合面部で結合された複数の空胴共振器を有する空胴共振器フィルタであって、前記複数の空胴共振器の各々の前記結合面部に、ネジ穴が設けられており、前記複数の空胴共振器の各々の前記結合面部の所定部位に、他の空胴共振器と結合するための連結用ネジの頭部が収容される座ぐり穴が設けられており、前記座ぐり穴は、前記連結用ネジの頭部が収容された状態で当該連結用ネジの端部を前記他の空胴共振器へ案内する構造を有し、前記ネジ穴には、前記他の空胴共振器から案内された連結用ネジが螺合される。
【００１８】
本発明の空胴共振器フィルタでは、連結用ネジの頭部が空胴共振器に設けられた座ぐり穴に収容されて、他の空胴共振器と結合されるようになっているので、結合のためのフランジを必要としない。そのために空胴共振器の９０度結合が容易になり、９０度結合された空胴共振器による空胴共振器フィルタを容易に構成できるようになる。また、締結する２つの空胴共振器間の距離が短くなるために、無負荷Ｑが大きくなって、挿入損失が小さくなる。高次モードＴＥ_３１１を疎結合にさせて、ＴＥ_０１１モードフィルタの減衰特性を、より良好にすることができる。
【００１９】
このような空胴共振器フィルタでは、例えば前記結合面部に開口部が形成される。この開口部を通じて前記他の空胴共振器との間で電磁波が入力又は出力されるようになる。
互いに結合される２つの空胴共振器の間には、結合板が設けらるようにしてもよい。この結合板は、例えば、前記２つの空胴共振器の各々の結合面部に形成された前記開口部に対応する位置に、これらの開口部よりも小さい面積の開口窓が設けられており、前記連結用ネジが通る位置に孔部又は切欠部が形成される。
少なくとも一つの空胴共振器は、例えば円筒形の空洞が形成された略直方体形状の本体を有しており、この本体に、前記空洞に連通して前記開口部が設けられる。開口部は、例えば２つの異なる結合面部のそれぞれに設けられ、これら２つの異なる結合面部が、これらの開口部による電磁波の入力方向と出力方向とが９０度をなすように形成されると、空胴共振器が９０度結合された空胴共振器フィルタが容易に構成できる。
空胴共振器の結合を容易にするために、前記結合面部に、他の空胴共振器が結合される位置を合わせるための位置決めピンと、他の空胴共振器の前記位置決めピンが嵌挿される位置決め穴とを設けてもよい。前記他の空胴共振器の位置決め穴に前記位置決めピンが嵌挿されることにより、他の空胴共振器との結合の際の位置決めを容易に行うことができるようになる。
【００２０】
【発明の実施の形態】
以下、本発明の実施形態について、図面を参照しつつ詳細に説明する。
【００２１】
図１は、本実施形態の空胴共振器１の構造説明図である。この空胴共振器は、円筒形の空洞が形成された略直方体（略立方体を含む）形状の本体５をもち、この本体５には、円筒形の側面部にあたる位置に、電磁波が入力又は出力される入力端部６及び出力端部７としての開口部が空洞に連通して形成される、円筒空胴共振器である。入力端部６および出力端部７は、説明の便宜上、区別しているが、これはどちらの開口部が入力端部６（出力端部７）になっても構わない。また、この例では、入力端部６が形成される面及び出力端部７が形成される面が直角に交わっているが、それぞれが平行な面に形成されていてもよい。円筒空胴共振器を結合する場合には、この入力端部６、出力端部７が形成された面が、他の円筒空胴共振器の入力端部６、出力端部７が形成される面との結合面部になる。
【００２２】
入力端部６が形成される面には、結合対象となる入力用導波管や円筒空胴共振器等の結合対象部品からの連結用ネジ３が螺合されるネジ穴１３、結合対象部品との結合位置を決めるための位置決めピン１４、結合対象部品の位置決めピン１４が嵌挿される位置決め穴１５、結合対象部品へ連結用ネジ３の端部を案内するための切欠穴１６が形成される。切欠穴１６は、この面の縁部に形成される。
【００２３】
入力端部６が形成される面に対して、切欠穴１６が形成された縁部で垂直に接する面には、切欠穴１６と一連に座ぐり部１７が形成される。この例では、座ぐり部１７は出力端部７が形成される面に形成されている。座ぐり部１７と切欠穴１６により、連結用ネジ３の頭部が収容された状態で、この連結用ネジ３の端部を結合対象部品へ案内する、座ぐり穴が形成される。
【００２４】
出力端部７が形成される面には、入力端部６が形成される面と同様に、ネジ穴１３、位置決めピン１４、位置決め穴１５、切欠穴１６が形成され、出力端部７が形成される面に対して、切欠穴１６が形成された縁部で垂直に接する面に切欠穴１６と一連に座ぐり部１７が形成されている。
【００２５】
この円筒空胴共振器を結合対象部品と結合させる場合に、連結用ネジ３は、頭部が座ぐり部１７に収容されて、端部が結合対象部品のネジ穴１３に螺合される。ネジ穴１３には、結合対象部品からの連結用ネジ３が螺合される。このようにして円筒空胴共振器は、結合対象部品と結合される。
【００２６】
このような円筒空胴共振器は、フランジを必要としないために、円筒空胴共振器を本体５の形状と同じ略直方体に一体形成できる。本体５の切削やフランジの蝋付けが不要となるために、寸法精度の向上が図れる。また、フランジがないために直列結合だけでなく、９０度結合も容易になる。
【００２７】
この実施形態では、一面にネジ穴１３、位置決めピン１４、位置決め穴１５、切欠穴１６が形成されるようにしているが、これに限らず、ネジ穴１３を切欠穴１６の位置にも設け、位置決め穴１５を位置決めピン１４の位置にも設けるようにしてもよい。つまり、一面に４個のネジ穴１３と２個の位置決め穴１５を形成するようにしてもよい。なお、このような面に結合される結合対象部品は、その結合面に４個の切欠穴１６と２個の位置決めピン１４が形成される。
【００２８】
図２は、３つの円筒空胴共振器１ａ、１ｂ、１ｃをそれぞれ９０度結合させた円筒空胴共振器フィルタの構造説明図である。円筒空胴共振器１ｂと２つの円筒空胴共振器１ａ、１ｃとのそれぞれの結合面には、結合板２ａ、２ｂがそれぞれ挟持されている。
【００２９】
結合板２ａは、円筒空胴共振器１ａ、１ｂの結合面の形状と同じ形状の面を持っており、円筒空胴共振器１ａの出力端部７、円筒空胴共振器１ｂの入力端部６に対応する位置に、開口窓１２ａが設けられる。結合板２ｂは、円筒空胴共振器１ｂ、１ｃの結合面の形状と同じ形状であり、円筒空胴共振器１ｂの出力端部７、円筒空胴共振器１ｃの入力端部６に対応する位置に、開口窓１２ｂが設けられる。結合板２ａ、２ｂのそれぞれの開口窓１２ａ、ｂは、円筒空胴共振器フィルタの共振器段数、パスバンド巾、リップル値に応じたサイズを容易に確保するために、入力端部６、出力端部７の開口部よりも小さく形成される。
結合板２ａ、２ｂの周縁部には、円筒空胴共振器結合時に連結用ネジ３の端部が通る切欠部１８が設けられる。また、位置決めピン１４に対応する位置に孔１９が形成される。
【００３０】
円筒空胴共振器１ａは、略直方体の本体５の、入力端部６が設けられる面には図示しない入力用導波管などが結合され、出力端部７が設けられる面が円筒空胴共振器１ｂに面している。入力用導波管などから入力される電磁波は、入力端部６から入力され、出力端部７から出力されて円筒空胴共振器１ｂに送られる。
【００３１】
入力端部６が設けられる面には、入力用導波管などからの連結用ネジ３が螺合される、連結用ネジ穴１３が形成される。
【００３２】
出力端部７が設けられる面には、円筒空胴共振器１ｂからの連結用ネジ３が螺合される連結用ネジ穴１３と、位置決めピン１４と、円筒空胴共振器１ｂから延びる位置決めピン１４が嵌挿される位置決め穴１５と、座ぐり部１７に頭部が収容された連結用ネジ３の端部を円筒空胴共振器１ｂへ案内するための切欠穴１６と、が面の周縁に沿って設けられる。
【００３３】
円筒空胴共振器１ｂは、図１に示す円筒空胴共振器と同様の形状であり、入力端部６が設けられる面が円筒空胴共振器１ａに面しており、出力端部７が設けられる面が円筒空胴共振器１ｃに面している。円筒空胴共振器１ａから入力される電磁波は、入力端部６から入力され、出力端部７から出力されて円筒空胴共振器１ｃに送られるようになっている。
【００３４】
円筒空胴共振器１ｂの入力端部６が設けられる面には、円筒空胴共振器１ａからの連結用ネジ３が螺合される連結用ネジ穴１３と、位置決めピン１４と、円筒空胴共振器１ａから延びる位置決めピン１４が嵌挿される位置決め穴１５と、頭部が座ぐり部１７に収容された連結用ネジ３の端部を円筒空胴共振器１ａへ案内するための切欠穴１６と、が面の周縁に沿って設けられる。
【００３５】
円筒空胴共振器１ｂの出力端部７が設けられる面には、円筒空胴共振器１ｃからの連結用ネジ３が螺合される連結用ネジ穴１３と、位置決めピン１４と、円筒空胴共振器１ｃから延びる位置決めピン１４が嵌挿される位置決め穴１５と、頭部が座ぐり部１７に収容された連結用ネジ３の端部を円筒空胴共振器１ｃへ案内するための切欠穴１６と、が面の周縁に沿って設けられる。また、この面には、入力端部６に設けられた切欠穴１６と一連の座ぐり部１７が形成される。
【００３６】
円筒空胴共振器１ｃは、略直方体の本体５の、入力端部６が設けられる面が円筒空胴共振器１ｂに面し、出力端部７が設けられる面には図示しない出力用導波管などが接続される。円筒空胴共振器１ｂから入力される電磁波は、入力端部６から入力され、出力端部７から出力されて出力用導波管などに送られる。
【００３７】
入力端部６が設けられる面には、円筒空胴共振器１ｂからの連結用ネジ３が螺合される連結用ネジ穴１３と、位置決めピン１４と、円筒空胴共振器１ｂから延びる位置決めピン１４が嵌挿される位置決め穴１５と、座ぐり部１７に頭部が収容された連結用ネジ３の端部を円筒空胴共振器１ｂへ案内するための切欠穴１６と、が面の周縁に沿って設けられる。
【００３８】
出力端部７が設けられる面には、出力用導波管などからの連結用ネジ３が螺合される連結用ネジ穴１３が形成される。
【００３９】
円筒空胴共振器１ａ、１ｂを結合させる際には、円筒空胴共振器１ａの出力端部７が設けられる面と、円筒空胴共振器１ｂの入力端部６が設けられる面とにより、結合板２ａが挟持されることになる。
円筒空胴共振器１ａの出力端部７が設けられる面と、円筒空胴共振器１ｂの入力端部６が設けられる面とにそれぞれ設けられている位置決めピン１４は、結合板２ａに形成された孔１９を貫通して、それぞれ対向する位置にある位置決め穴１５に嵌挿される。位置決めピン１４により、円筒空胴共振器１ａ、１ｂを正しい位置に設置することができる。
また、円筒空胴共振器１ａ、１ｂのそれぞれからの連結用ネジ３は、結合板２ａの切欠部１８を通って、それぞれ対面する位置にある連結用ネジ穴１３に螺合される。連結用ネジ３により、円筒空胴共振器１ａ、１ｂが結合される。
【００４０】
円筒空胴共振器１ｂ、１ｃを結合させる際には、円筒空胴共振器１ｂの出力端部７が設けられる面と、円筒空胴共振器１ｃの入力端部６が設けられる面とにより、結合板２ｂが挟持されることになる。
円筒空胴共振器１ｂの出力端部７が設けられる面と、円筒空胴共振器１ｃの入力端部６が設けられる面とにそれぞれ設けられている位置決めピン１４は、結合板２ｂに形成された孔１９を貫通して、それぞれ対面する位置にある位置決め穴１５に嵌挿される。位置決めピン１４により、円筒空胴共振器１ｂ、１ｃを正しい位置に設置することができる。
また、円筒空胴共振器１ｂ、１ｃのそれぞれからの連結用ネジ３は、結合板２ｂの切欠部１８を通って、それぞれ対面する位置にある連結用ネジ穴１３に螺合される。連結用ネジ３により、円筒空胴共振器１ｂ、１ｃが結合される。
【００４１】
円筒空胴共振器１ａ、１ｂ、１ｃの結合は、図３で説明する方法で容易に行える。図３は、円筒空胴共振器１ａ、１ｂの結合方法を説明するための図である。
まず、円筒空胴共振器１ａ、１ｂのそれぞれの連結用ネジ穴１３に連結用ネジ３を仮止めしておく。次いで、仮止めした連結用ネジ３の頭部が、連結用ネジ穴１３に対向する位置にある座ぐり部１７に収容されるように、円筒空胴共振器１ａ、１ｂをスライドさせる。座ぐり部１７に連結用ネジ３の頭部を収容後に、連結用ネジ３を締結する。位置決めピン１４及び位置決め穴１５により、円筒空胴共振器１ａ、１ｂをスライドさせて結合するようにしても、位置決めが困難になることはない。
結合板２ａは、連結用ネジ３を完全に取り外すことなく、緩めて円筒空胴共振器１ａ、１ｂを連結時とは逆の方向に互いにスライドさせることで交換が容易に行える。
【００４２】
このように結合された円筒空胴共振器１ａ、１ｂ、１ｃにより構成される円筒空胴共振器フィルタは、例えば、入力用導波管から円筒空胴共振器１ａの入力端部６に供給される電磁波が、円筒空胴共振器１ａの出力端部７から結合板２ａを介して円筒空胴共振器１ｂの入力端部６に供給され、円筒空胴共振器１ｂの出力端部７から結合板２ｂを介して円筒空胴共振器１ｃの入力端部６に供給され、円筒空胴共振器１ｃの出力端部７から出力用導波管へ出力されるようになっている。円筒空胴共振器１ａ、１ｂ、１ｃ及び結合板２ａ、２ｂの特性に応じて電磁波が濾波される。
【００４３】
以上の円筒空胴共振器１ａ、１ｂ、１ｃは、フランジを用いないために、円筒空胴共振器の９０度結合が容易にできるようになる。９０度結合させることにより、高次モードＴＥ_３１１を疎結合にさせ、ＴＥ_０１１モードフィルタの減衰特性をより良好にすることができる。また、フランジを用いないために、円筒空胴共振器同士の距離が短くできるために、無負荷Ｑが大きくなり、挿入損失を小さくすることができる。
また、連結用ネジ３が、座ぐり部１７により容易に締緩ができるようになっている。そのために、２つの連結用ネジ３を外すことにより、結合板２ａ、２ｂを取り外すことができ、結合板２ａ、２ｂの交換が容易に行えるようになる。
【００４４】
なお、円筒空胴共振器１ａ、１ｂ、１ｃの各結合面に形成される切欠穴１６は、連結用ネジ３が貫通すればよいので、切欠ではなく、結合板２ａ、２ｂに形成された切欠部１８の長尺方向と同じ方向に延びて形成された孔であってもよい。
この場合、円筒空胴共振器を結合させる際には、座ぐり部１７に連結用ネジ３の頭部を収容し、この孔を通して対向する位置にある連結用ネジ穴１３に当該連結用ネジ３を仮止めして、円筒空胴共振器をスライドさせることになる。結合板２ａ、２ｂの交換は、連結用ネジ３を緩めて、円筒空胴共振器を連結時とは逆にスライドさせることで行える。
【００４５】
【発明の効果】
以上の説明から明らかなように、本発明によれば、空胴共振器が直列のみでなく９０度結合もできるようになる。９０度結合させることにより、高次モードＴＥ_３１１を疎結合にさせ、ＴＥ_０１１モードフィルタの減衰特性をより良好にすることができる。また、締結する２つの空胴共振器間の距離が短くなるために、無負荷Ｑが大きくなり、挿入損失が小さくなる。
【図面の簡単な説明】
【図１】本実施形態の円筒空胴共振器の構造説明図。
【図２】本実施形態の円筒空胴共振器フィルタの構造説明図。
【図３】円筒空胴共振器１ａ、１ｂの結合方法を説明するための説明図。
【図４】従来の円筒空胴共振器フィルタの構造説明図。
【図５】従来の他の円筒空胴共振器フィルタの構造説明図。
【符号の説明】
１、１ａ、１ｂ、１ｃ、１ｄ、１ｅ、１ｆ、１ｇ円筒空胴共振器
２ａ、２ｂ、２ｃ、２ｄ結合板
３連結用ネジ
４連結用ナット
５本体
６入力端部
７出力端部
８フランジ
９、１２ａ、１２ｂ、１２ｃ、１２ｄ開口窓
１０、１１ネジ孔
１３連結用ネジ穴
１４位置決めピン
１５位置決め穴
１６切欠穴
１７座ぐり部
１８切欠部
１９孔[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a cavity resonator used in a microwave filter, a method of coupling the cavity resonator, and a cavity resonator filter formed by connecting the cavity resonators in multiple stages.
[0002]
[Prior art]
As a low-loss band-pass filter used in a microwave band radar system, there is a TE _01n mode (n is a natural number, the same _applies hereinafter) cylindrical cavity resonator filter.
In the cylindrical cavity resonator filter, a filter formed by multi-stage coupling of a plurality of cylindrical cavity resonators having the same characteristics, that is, a flange is formed at a portion where electromagnetic waves are input / output, and a substantially center of the flange is formed. The plurality of cylindrical cavities each having an opening formed therein are electrically connected to each other through their own opening and the opening of the other cylindrical cavity, and the hole of the coupling plate interposed therebetween. Some are combined. An input waveguide flange is formed at the input end of the first-stage cylindrical cavity resonator, and an output waveguide flange is formed at the output end of the last-stage cylindrical cavity. The fastening plate is fastened by screws or the like with the combined plate interposed therebetween.
[0003]
FIGS. 4 and 5 are explanatory diagrams of the structure of a conventional cylindrical cavity resonator filter formed by coupling two cylindrical cavity resonators.
In this specification, all the end plates or fixed end plates for adjusting the resonance frequency of the cylindrical cavity resonator are omitted. Also, the first stage input side and the last stage output side coupling plate of the cylindrical cavity resonator filter are omitted.
[0004]
The cylindrical cavity resonator filter shown in FIG. 4 is formed by coupling two cylindrical cavity resonators 1d and 1e having the same characteristics and shape with a coupling screw 3 and a coupling nut 4 with a coupling plate 2c interposed therebetween. ing. Each of the cylindrical cavity resonators 1d and 1e has a rectangular parallelepiped main body 5 in which a cylindrical cavity is formed. The main body 5 has an input end 6 and an output end 7 for inputting and outputting electromagnetic waves. An opening is formed. A flange 8 is provided on a surface on which the input end 6 and the output end 7 are formed. An opening window 9 for inputting and outputting electromagnetic waves is formed at a position corresponding to the input end 6 and the output end 7 at a substantially central portion of the flange 8.
Since the screw holes 10 for penetrating the connection screw 3 are formed at positions protruding from the main body 5, the flanges 8 can be provided only on surfaces parallel to each other of the main body 5, and are surfaces perpendicular to each other. Cannot be provided. By coupling the cylindrical cavity resonator at 90 degrees, the higher-order mode TE ₃₁₁ can be loosely coupled to improve the attenuation characteristic of the TE ₀₁₁ mode filter. However, the structure using the flange 8 is adopted. Therefore, it is difficult to couple such a cylindrical cavity resonator at 90 degrees.
[0005]
The coupling plate 2c has a rectangular plate shape corresponding to the shape of the flange 8, and a screw hole 11 is formed at a position corresponding to the screw hole 10 formed in the flange 8 of each of the cylindrical cavity resonators 1d and 1e at the time of coupling. An opening window 12c is formed at a position corresponding to the output end 7 of the cylindrical cavity resonator 1d and the input end 6 of the cylindrical cavity resonator 1e at the time of coupling.
The aperture window 12c of the coupling plate 2c is determined according to the value of the susceptance by selecting the number of resonators, the pass band width, the ripple value, and the like of the cylindrical cavity resonator filter.
[0006]
When coupling the cylindrical cavity resonators 1d and 1e, the surface on the output end 7 side of the cylindrical cavity resonator 1d and the surface on the input end 6 side of the cylindrical cavity resonator 1e face each other. The coupling screw 3 is inserted between the screw hole 10 formed in the flange 8 of the cylindrical cavity resonator 1e, the screw hole 11 formed in the coupling plate 2c, and the flange of the cylindrical cavity resonator 1d. 8 and is fastened by the connecting nut 4. In this example, since four screw holes 10 and 11 are formed in the flange 8 and the coupling plate 2c, respectively, the four holes are fastened by the coupling screw 3 and the coupling nut 4.
[0007]
When another cylindrical cavity resonator is connected, it is connected in the same manner with the connecting screw 3 and the connecting nut 4 with the connecting plate 2c interposed therebetween.
When changing the shape of the opening window 12c of the coupling plate 2c, it is necessary to replace the coupling plate 2c. In this case, the coupling screw 3 is completely removed before replacement.
[0008]
The basic configuration of the cylindrical cavity resonator filter shown in FIG. 5 is the same as that of the cylindrical cavity resonator filter shown in FIG. The difference is that the shape of the main body 5 of the cylindrical cavity resonators 1f and 1g is cylindrical, and the flange 8 and the coupling plate 2d are formed in a disk shape. This type of cylindrical cavity resonator is also not suitable for 90-degree coupling because the flange 8 protrudes from the main body 5.
[0009]
For a cylindrical cavity resonator filter, it is important to couple two cylindrical cavity resonators without affecting the propagation characteristics of the electromagnetic wave. For this purpose, various techniques have been proposed for coupling a cavity resonator and a waveguide such that the influence on the propagation characteristics of electromagnetic waves is minimized.
[0010]
For example, Japanese Unexamined Patent Publication No. 6-291502 (name of the invention: waveguide connection structure) provides a radio wave absorbing structure that supports a radio wave absorber around the flange so as to cover a gap between the coupling portions of the flange during coupling. Thus, the electromagnetic wave is prevented from leaking from the coupling portion. Japanese Patent Application Laid-Open No. 6-350301 (Title of Invention: Rubber gasket for connecting waveguides and connection structure of waveguides using the same) includes a conductive filler in a coupling plate used for coupling waveguides. The use of a rubber gasket in which the electromagnetic wave is attenuated by the joint is prevented. In Japanese Patent Publication No. 7-38521 (title of the invention: structure of a joint between a waveguide and a flange), a groove for accommodating an adhesive is provided at a joint between the waveguide and the flange to guide the waveguide. It is designed to increase the joint strength between the pipe and the flange. JP-A-6-177601 (title of invention: connection structure of waveguides) simplifies the work of connecting waveguides by using a holding plate that is in close contact with a flange of two waveguides.
[0011]
[Problems to be solved by the invention]
In each of the above examples, the basic configuration is that the main body is provided with a flange, and the cavity resonators are coupled by fastening the respective flanges with screws. When a flange is used, the flange is attached to the main body by brazing or the like. In addition, the main body also needs to be machined by cutting or the like so that the flange can be easily attached. The mounting process of the flange requires accuracy in order to affect the propagation characteristics of electromagnetic waves. Furthermore, the use of the flange as described above makes it difficult to couple the cavity resonators at 90 degrees.
[0012]
Accordingly, the present invention provides a cavity resonator, a method of coupling the cavity resonator, and a method of reducing the influence when a plurality of cavity resonators are coupled, and facilitating 90-degree coupling of the cavity resonators. An object of the present invention is to provide a cavity resonator filter in which a plurality of cavity resonators are connected.
[0013]
[Means for Solving the Problems]
A cavity resonator according to the present invention for solving the above-mentioned problem is a cavity resonator having a coupling surface portion with a coupling target component, and a coupling portion for coupling to the coupling target component at a predetermined portion of the coupling surface portion. A counterbore for receiving the head of the screw is provided, and the counterbore guides the end of the connection screw to the part to be connected in a state where the head of the connection screw is stored. Characterized by having a structure that:
[0014]
In the cavity resonator of the present invention, the head of the connection screw is accommodated in the counterbore hole provided in the cavity resonator, and coupled to a coupling target component such as a waveguide or another cavity resonator. So that no flange is required for the connection. Therefore, various difficulties caused by providing the flange are eliminated.
[0015]
In such a cavity resonator, for example, an opening is formed in the coupling surface. Electromagnetic waves are input to or output from the coupling target component through the opening.
The cavity resonator has a substantially rectangular parallelepiped main body in which a cylindrical cavity is formed, for example, and the main body is provided with the opening in communication with the cavity. The opening is provided, for example, in each of two different coupling surfaces, and when these two different coupling surfaces are formed such that the input direction and the output direction of the electromagnetic wave by these openings form 90 degrees, 90 degree coupling is facilitated via the cavity resonator.
[0016]
The method for coupling a cavity resonator according to the present invention has a coupling surface with a component to be coupled, and a head of a coupling screw for coupling to the component to be coupled is accommodated in a predetermined portion of the coupling surface. A method in which a counterbore is provided, and a cavity having a screw hole into which a coupling screw guided from the coupling target component is screwed is coupled to another cavity having the same configuration. An end of a connection screw is temporarily fixed to each of the screw holes of the cavity and the other cavity, and a head of the connection screw temporarily fixed to the cavity is fixed to the cavity. A counterbore provided in the cavity is provided with a head of a connection screw temporarily accommodated in the cavity provided in the cavity. And the connection screws are screwed together to connect the cavity resonator and the other cavity resonator. To.
[0017]
A cavity resonator filter according to the present invention is a cavity resonator filter having a plurality of cavity resonators coupled to each other at a coupling surface portion, wherein a screw is provided on the coupling surface portion of each of the plurality of cavity resonators. A hole is provided, and at a predetermined portion of the coupling surface portion of each of the plurality of cavity resonators, a counterbore hole for accommodating a head of a connection screw for coupling with another cavity resonator is provided. Wherein the counterbore has a structure for guiding an end of the connection screw to the other cavity while the head of the connection screw is housed, and Is connected with a coupling screw guided from the other cavity resonator.
[0018]
In the cavity resonator filter of the present invention, the head of the connection screw is accommodated in a counterbore provided in the cavity, and is coupled to another cavity. No flange is required for the connection. Therefore, 90 ° coupling of the cavity resonators is facilitated, and a cavity resonator filter including the cavity resonators coupled at 90 ° can be easily configured. Further, since the distance between the two cavity resonators to be fastened becomes short, the no-load Q increases, and the insertion loss decreases. By making the higher-order mode TE ₃₁₁ loosely coupled, the attenuation characteristic of the TE ₀₁₁ mode filter can be improved.
[0019]
In such a cavity resonator filter, for example, an opening is formed in the coupling surface. Electromagnetic waves can be input or output to and from the other cavity through the opening.
A coupling plate may be provided between two cavity resonators that are coupled to each other. In the coupling plate, for example, at a position corresponding to the opening formed in the coupling surface of each of the two cavity resonators, an opening window having an area smaller than these openings is provided, A hole or notch is formed at a position where the connecting screw passes.
At least one cavity resonator has a substantially rectangular parallelepiped main body in which, for example, a cylindrical cavity is formed, and the main body is provided with the opening in communication with the cavity. The opening is provided, for example, in each of two different coupling surface portions. When the two different coupling surface portions are formed such that the input direction and the output direction of the electromagnetic wave by these openings form 90 degrees, the opening becomes empty. A cavity resonator filter in which the cavity resonators are coupled at 90 degrees can be easily configured.
In order to facilitate coupling of the cavity resonator, a positioning pin for adjusting a position where another cavity is coupled and the positioning pin of another cavity are fitted into the coupling surface portion. A positioning hole may be provided. The positioning pin is inserted into the positioning hole of the other cavity resonator, so that positioning at the time of coupling with the other cavity resonator can be easily performed.
[0020]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0021]
FIG. 1 is a structural explanatory view of a cavity resonator 1 of the present embodiment. The cavity resonator has a substantially rectangular parallelepiped (including a substantially cubic) main body 5 having a cylindrical cavity formed therein. The main body 5 receives an input or output of an electromagnetic wave at a position corresponding to a cylindrical side surface portion. An opening as an input end 6 and an output end 7 is formed to communicate with the cavity. Although the input end 6 and the output end 7 are distinguished for convenience of explanation, either of the openings may be the input end 6 (output end 7). Further, in this example, the surface on which the input end 6 is formed and the surface on which the output end 7 is formed intersect at a right angle, but they may be formed on parallel surfaces. When the cylindrical cavity resonator is coupled, the surface on which the input end 6 and the output end 7 are formed forms the input end 6 and the output end 7 of another cylindrical cavity. It becomes a bonding surface part with the surface.
[0022]
A screw hole 13 into which a connection screw 3 from a coupling target component such as an input waveguide or a cylindrical cavity resonator to be coupled is screwed, a coupling target component is formed on a surface on which the input end 6 is formed. A positioning pin 14 for deciding the position of connection with the component, a positioning hole 15 into which the positioning pin 14 of the component to be coupled is inserted, and a cutout hole 16 for guiding the end of the connection screw 3 to the component to be coupled are formed. . A notch 16 is formed in the edge of this surface.
[0023]
A notch 16 and a counterbore 17 are formed in series on a surface which is perpendicular to an edge where the notch 16 is formed with respect to the surface on which the input end 6 is formed. In this example, the spot facing portion 17 is formed on the surface on which the output end portion 7 is formed. The counterbore 17 and the cutout hole 16 form a counterbore for guiding the end of the connection screw 3 to the part to be coupled in a state where the head of the connection screw 3 is housed.
[0024]
A screw hole 13, a positioning pin 14, a positioning hole 15, and a notch hole 16 are formed on the surface on which the output end 7 is formed, similarly to the surface on which the input end 6 is formed, and the output end 7 is formed. A notch 16 and a counterbore 17 are formed in series on a surface which is perpendicularly contacted with the edge where the notch 16 is formed.
[0025]
When this cylindrical cavity resonator is to be coupled to a component to be coupled, the connection screw 3 has its head housed in the counterbore portion 17 and its end is screwed into the screw hole 13 of the component to be coupled. The connection screw 3 from the connection target component is screwed into the screw hole 13. In this way, the cylindrical cavity resonator is coupled to the component to be coupled.
[0026]
Since such a cylindrical cavity resonator does not require a flange, the cylindrical cavity resonator can be integrally formed in a substantially rectangular parallelepiped having the same shape as the main body 5. Since the cutting of the main body 5 and the brazing of the flange are not required, the dimensional accuracy can be improved. In addition, since there is no flange, not only serial connection but also 90-degree connection becomes easy.
[0027]
In this embodiment, the screw hole 13, the positioning pin 14, the positioning hole 15, and the notch hole 16 are formed on one surface. However, the present invention is not limited to this, and the screw hole 13 is also provided at the position of the notch hole 16. The positioning hole 15 may be provided also at the position of the positioning pin 14. That is, four screw holes 13 and two positioning holes 15 may be formed on one surface. The part to be coupled to such a surface has four notches 16 and two positioning pins 14 formed on the coupling surface.
[0028]
FIG. 2 is a structural explanatory view of a cylindrical cavity resonator filter in which three cylindrical cavity resonators 1a, 1b, and 1c are respectively coupled by 90 degrees. Coupling plates 2a and 2b are respectively sandwiched between coupling surfaces of the cylindrical cavity resonator 1b and the two cylindrical cavity resonators 1a and 1c.
[0029]
The coupling plate 2a has a surface having the same shape as the coupling surface of the cylindrical cavity resonators 1a and 1b, and has an output end 7 of the cylindrical cavity resonator 1a and an input end of the cylindrical cavity resonator 1b. 6, an opening window 12a is provided. The coupling plate 2b has the same shape as the coupling surface of the cylindrical cavity resonators 1b and 1c, and corresponds to the output end 7 of the cylindrical cavity resonator 1b and the input end 6 of the cylindrical cavity resonator 1c. An opening window 12b is provided at the position. The respective opening windows 12a and 12b of the coupling plates 2a and 2b are provided with an input end 6 and an output terminal 6 in order to easily secure a size corresponding to the number of resonator stages, pass band width, and ripple value of the cylindrical cavity resonator filter. It is formed smaller than the opening at the end 7.
A notch 18 through which the end of the coupling screw 3 passes when the cylindrical cavity resonator is coupled is provided on the peripheral edge of the coupling plates 2a and 2b. Further, a hole 19 is formed at a position corresponding to the positioning pin 14.
[0030]
In the cylindrical cavity resonator 1a, an input waveguide (not shown) or the like (not shown) is coupled to a surface of the substantially rectangular parallelepiped main body 5 on which the input end 6 is provided, and a surface on which the output end 7 is provided has a cylindrical cavity resonance. Facing the container 1b. An electromagnetic wave input from an input waveguide or the like is input from the input end 6, output from the output end 7, and sent to the cylindrical cavity resonator 1 b.
[0031]
A connection screw hole 13 into which the connection screw 3 from the input waveguide or the like is screwed is formed on the surface on which the input end 6 is provided.
[0032]
On the surface on which the output end 7 is provided, a connection screw hole 13 into which the connection screw 3 from the cylindrical cavity resonator 1b is screwed, a positioning pin 14, and a positioning pin extending from the cylindrical cavity resonator 1b. A positioning hole 15 into which the head 14 is inserted and a cutout hole 16 for guiding the end of the connection screw 3 whose head is housed in the counterbore 17 to the cylindrical cavity resonator 1b are provided on the periphery of the surface. It is provided along.
[0033]
The cylindrical cavity resonator 1b has the same shape as the cylindrical cavity resonator shown in FIG. 1, the surface on which the input end 6 is provided faces the cylindrical cavity resonator 1a, and the output end 7 is The surface provided faces the cylindrical cavity resonator 1c. The electromagnetic wave input from the cylindrical cavity resonator 1a is input from the input end 6, output from the output end 7, and sent to the cylindrical cavity resonator 1c.
[0034]
On the surface of the cylindrical cavity resonator 1b where the input end 6 is provided, a connection screw hole 13 into which the connection screw 3 from the cylindrical cavity resonator 1a is screwed, a positioning pin 14, and a cylindrical cavity. A positioning hole 15 into which a positioning pin 14 extending from the resonator 1a is inserted, and a notch hole 16 for guiding the end of the connection screw 3 whose head is accommodated in the counterbore 17 to the cylindrical cavity resonator 1a. And are provided along the periphery of the surface.
[0035]
On the surface of the cylindrical cavity resonator 1b where the output end 7 is provided, a connection screw hole 13 into which the connection screw 3 from the cylindrical cavity resonator 1c is screwed, a positioning pin 14, and a cylindrical cavity. A positioning hole 15 into which a positioning pin 14 extending from the resonator 1c is inserted, and a notch hole 16 for guiding the end of the connection screw 3 whose head is accommodated in the counterbore 17 to the cylindrical cavity resonator 1c. And are provided along the periphery of the surface. In this surface, a notch hole 16 provided in the input end 6 and a series of counterbore portions 17 are formed.
[0036]
The cylindrical cavity resonator 1c has a substantially rectangular parallelepiped main body 5 in which the surface on which the input end 6 is provided faces the cylindrical cavity resonator 1b, and the surface on which the output end 7 is provided has an output waveguide (not shown). A pipe or the like is connected. The electromagnetic wave input from the cylindrical cavity resonator 1b is input from the input end 6, output from the output end 7, and sent to an output waveguide or the like.
[0037]
On the surface on which the input end 6 is provided, a connection screw hole 13 into which the connection screw 3 from the cylindrical cavity resonator 1b is screwed, a positioning pin 14, and a positioning pin extending from the cylindrical cavity resonator 1b. A positioning hole 15 into which the head 14 is inserted and a cutout hole 16 for guiding the end of the connection screw 3 whose head is housed in the counterbore 17 to the cylindrical cavity resonator 1b are provided on the periphery of the surface. It is provided along.
[0038]
A connection screw hole 13 into which the connection screw 3 from the output waveguide or the like is screwed is formed on the surface on which the output end 7 is provided.
[0039]
When coupling the cylindrical cavity resonators 1a and 1b, the surface on which the output end 7 of the cylindrical cavity resonator 1a is provided, and the surface on which the input end 6 of the cylindrical cavity resonator 1b is provided, The coupling plate 2a is sandwiched.
Positioning pins 14 provided on the surface on which the output end 7 of the cylindrical cavity resonator 1a is provided and the surface on which the input end 6 of the cylindrical cavity resonator 1b is provided are formed on the coupling plate 2a. The holes 19 pass through the holes 19 and are inserted into the positioning holes 15 at the positions facing each other. The positioning pins 14 allow the cylindrical cavity resonators 1a and 1b to be installed at correct positions.
The connecting screws 3 from each of the cylindrical cavity resonators 1a and 1b are screwed into the connecting screw holes 13 at positions facing each other through the cutouts 18 of the coupling plate 2a. The coupling cavity 3 couples the cylindrical cavity resonators 1a and 1b.
[0040]
When the cylindrical cavity resonators 1b and 1c are coupled, the surface on which the output end 7 of the cylindrical cavity resonator 1b is provided and the surface on which the input end 6 of the cylindrical cavity resonator 1c is provided, The coupling plate 2b is sandwiched.
The positioning pins 14 provided on the surface of the cylindrical cavity resonator 1b where the output end 7 is provided and the surface of the cylindrical cavity resonator 1c where the input end 6 is provided are formed on the coupling plate 2b. The holes 19 pass through the holes 19 and are inserted into the positioning holes 15 at positions facing each other. The positioning pins 14 allow the cylindrical cavity resonators 1b and 1c to be installed at correct positions.
The connecting screws 3 from each of the cylindrical cavity resonators 1b and 1c pass through the cutouts 18 of the coupling plate 2b and are screwed into the connecting screw holes 13 at positions facing each other. The coupling cavity 3 couples the cylindrical cavity resonators 1b and 1c.
[0041]
Coupling of the cylindrical cavity resonators 1a, 1b, 1c can be easily performed by the method described with reference to FIG. FIG. 3 is a diagram for explaining a method of coupling the cylindrical cavity resonators 1a and 1b.
First, the connection screw 3 is temporarily fixed to the connection screw hole 13 of each of the cylindrical cavity resonators 1a and 1b. Next, the cylindrical cavity resonators 1a and 1b are slid so that the head of the temporarily fixed connection screw 3 is accommodated in the counterbore 17 located at a position facing the connection screw hole 13. After accommodating the head of the connection screw 3 in the spot facing portion 17, the connection screw 3 is fastened. Even if the cylindrical cavity resonators 1a and 1b are slid and coupled by the positioning pins 14 and the positioning holes 15, the positioning does not become difficult.
The coupling plate 2a can be easily exchanged by loosening and sliding the cylindrical cavity resonators 1a and 1b in directions opposite to those of the coupling plate 2a without completely removing the coupling screw 3.
[0042]
The cylindrical cavity resonator filter constituted by the cylindrical cavity resonators 1a, 1b, and 1c thus coupled is supplied from, for example, an input waveguide to the input end 6 of the cylindrical cavity resonator 1a. Electromagnetic wave is supplied from the output end 7 of the cylindrical cavity resonator 1a to the input end 6 of the cylindrical cavity resonator 1b via the coupling plate 2a, and is coupled from the output end 7 of the cylindrical cavity resonator 1b. It is supplied to the input end 6 of the cylindrical cavity resonator 1c via the plate 2b, and is outputted from the output end 7 of the cylindrical cavity resonator 1c to the output waveguide. Electromagnetic waves are filtered according to the characteristics of the cylindrical cavity resonators 1a, 1b, 1c and the coupling plates 2a, 2b.
[0043]
Since the cylindrical cavity resonators 1a, 1b, and 1c do not use a flange, 90-degree coupling of the cylindrical cavity resonators can be easily performed. By coupling 90 degrees, the higher-order mode TE ₃₁₁ can be loosely coupled, and the attenuation characteristic of the TE ₀₁₁ mode filter can be further improved. Further, since no flange is used, the distance between the cylindrical cavity resonators can be shortened, so that the no-load Q increases and the insertion loss can be reduced.
Further, the connecting screw 3 can be easily tightened and loosened by the counterbore 17. Therefore, by removing the two connection screws 3, the coupling plates 2a and 2b can be removed, and the coupling plates 2a and 2b can be easily replaced.
[0044]
The notch 16 formed in each coupling surface of the cylindrical cavity resonators 1a, 1b and 1c is not a notch but a notch formed in the coupling plates 2a and 2b, since the coupling screw 3 only has to penetrate. The hole may extend in the same direction as the longitudinal direction of the portion 18.
In this case, when coupling the cylindrical cavity resonator, the head of the connecting screw 3 is accommodated in the counterbore portion 17 and the connecting screw hole 13 located at an opposite position through this hole. Is temporarily fixed, and the cylindrical cavity resonator is slid. The exchange of the coupling plates 2a and 2b can be performed by loosening the coupling screw 3 and sliding the cylindrical cavity resonator in the opposite direction to the coupling.
[0045]
【The invention's effect】
As is clear from the above description, according to the present invention, the cavity resonator can be coupled not only in series but also at 90 degrees. By coupling 90 degrees, the higher-order mode TE ₃₁₁ can be loosely coupled, and the attenuation characteristic of the TE ₀₁₁ mode filter can be further improved. Further, since the distance between the two cavity resonators to be fastened becomes short, the no-load Q becomes large, and the insertion loss becomes small.
[Brief description of the drawings]
FIG. 1 is a structural explanatory view of a cylindrical cavity resonator of the present embodiment.
FIG. 2 is a structural explanatory view of a cylindrical cavity resonator filter of the present embodiment.
FIG. 3 is an explanatory diagram for explaining a method of coupling the cylindrical cavity resonators 1a and 1b.
FIG. 4 is a structural explanatory view of a conventional cylindrical cavity resonator filter.
FIG. 5 is a structural explanatory view of another conventional cylindrical cavity resonator filter.
[Explanation of symbols]
1, 1a, 1b, 1c, 1d, 1e, 1f, 1g Cylindrical cavity resonators 2a, 2b, 2c, 2d Coupling plate 3 Connection screw 4 Connection nut 5 Main body 6 Input end 7 Output end 8 Flange 9 , 12a, 12b, 12c, 12d Opening windows 10, 11 Screw holes 13 Connecting screw holes 14 Positioning pins 15 Positioning holes 16 Notches 17 Counterbore 18 Notches 19 holes

Claims

A cavity resonator having a coupling surface with a component to be coupled,
A counterbore for accommodating a head of a connection screw for coupling with the component to be coupled is provided at a predetermined portion of the coupling surface portion,
The counterbore hole has a structure for guiding an end of the connection screw to the component to be coupled in a state in which a head of the connection screw is housed,
Cavity resonator.

An opening is formed in the coupling surface portion, and electromagnetic waves are input or output between the coupling target component through the opening.
The cavity resonator according to claim 1.

It has a substantially rectangular parallelepiped main body in which a cylindrical cavity is formed, and the main body is provided with the opening in communication with the cavity,
The cavity resonator according to claim 2.

Each of two different coupling surface portions having said opening;
These two different coupling surfaces are formed such that the input direction and the output direction of the electromagnetic wave by these openings form 90 degrees,
The cavity resonator according to claim 2.

A counterbore for receiving a connection screw head for coupling with the coupling target component is provided at a predetermined portion of the coupling surface portion, the counterpart hole being provided at a predetermined portion of the coupling surface portion; A method of coupling a cavity having a screw hole into which a coupling screw guided from is screwed with another cavity having the same configuration,
The ends of the connecting screws are temporarily fixed to the screw holes of each of the cavity resonator and the other cavity resonator, and the head of the connecting screw temporarily fixed to the cavity is While being accommodated in a counterbore provided in the other cavity, the head of the connecting screw temporarily fixed to the other cavity is inserted into a counterbore provided in the cavity. Receiving, screwing the coupling screw, and coupling the cavity resonator and the other cavity resonator,
A method of coupling cavity resonators.

A cavity resonator filter having a plurality of cavity resonators coupled to each other at a coupling surface portion,
A screw hole is provided in the coupling surface portion of each of the plurality of cavity resonators,
At a predetermined portion of the coupling surface portion of each of the plurality of cavity resonators, a counterbore hole is provided for accommodating a head of a connection screw for coupling with another cavity resonator,
The counterbore has a structure for guiding the end of the connection screw to the other cavity while the head of the connection screw is housed,
A connection screw guided from the other cavity resonator is screwed into the screw hole.
Cavity resonator filter.

An opening is formed in the coupling surface portion, and electromagnetic waves are input or output between the other cavity resonator through the opening.
The cavity resonator filter according to claim 6.

A coupling plate is provided between the two cavity resonators coupled to each other,
The coupling plate is provided with an opening window having an area smaller than those of the two cavity resonators at a position corresponding to the opening formed on the coupling surface of each of the two cavity resonators. A hole or notch is formed at the position where the screw passes,
A cavity resonator filter according to claim 7.

At least one cavity resonator has a substantially rectangular parallelepiped main body in which a cylindrical cavity is formed, and the main body is provided with the opening in communication with the cavity.
A cavity resonator filter according to claim 7.

At least one cavity resonator is formed such that each of two different coupling surfaces has the opening, and an input direction and an output direction of an electromagnetic wave by these coupling surfaces form 90 degrees.
A cavity resonator filter according to claim 7.

The coupling surface portion is provided with a positioning pin for adjusting a position where another cavity resonator is coupled, and a positioning hole into which the positioning pin of another cavity resonator is inserted.
The positioning pin is inserted into the positioning hole of the other cavity resonator to determine a position at the time of coupling with the other cavity resonator.
A cavity resonator filter according to claim 6.