JP3941349B2

JP3941349B2 - Beam scanning antenna

Info

Publication number: JP3941349B2
Application number: JP2000214324A
Authority: JP
Inventors: 正人佐藤; 輝雄古屋; 勉遠藤
Original assignee: Mitsubishi Electric Corp
Current assignee: Mitsubishi Electric Corp
Priority date: 2000-07-14
Filing date: 2000-07-14
Publication date: 2007-07-04
Anticipated expiration: 2020-07-14
Also published as: JP2002033612A

Description

【０００１】
【発明の属する技術分野】
この発明は、無線信号の送信方向もしくは到来波の受信方向を、機械的な駆動装置を用いることなく電気的に変化させることが可能なビーム走査アンテナに関するものである。
【０００２】
【従来の技術】
図１１は従来のビーム走査アンテナを示す外観図であり、図１２は従来のビーム走査アンテナの動作原理を説明する外観図である。これらは特開平８−３２１７１０号公報に記載された例である。
【０００３】
図１１及び図１２において、２６は放物線形反射器、２７は回動可能なミラー、２８は放射器、２９は下部板、３０は上部板、３１は上記下部板２９と上記上部板３０とで構成される平行平板導波管、３２は上記放物線形反射器２６の焦点、３３は上記平行平板導波管３１の内部で上記焦点３２の位置に置かれた給電ホーン、３４は上記回動可能なミラー２７の中央部に配置した回転軸、３５は上記回動可能なミラー２７の裏面の端部に装着されたボール、３６は上記ボール３５に接触するように設けられたカム、３７は上記放射器２８の入力ポート、３８は上記放射器２８の出力開口、３９と４０はそれぞれ上記放射器における一方のポート側部と他方のポート側部、４１は上記一方のポート側部３９から上記他方のポート側部４０へと上記上部板３０上を横切るように且つ上記平行平板導波管３１の管内波長の整数倍の間隔で設けられた複数の矩形開口、４２は上記給電ホーン３３から放射されて放物線形反射器２６に入射するマイクロ波信号の入射光線経路、４３は上記放物線反射器２６で反射されたマイクロ波信号の反射光線経路、４４は反射光線の波面、４５は上記回動可能なミラー２７で反射された反射光線経路、４６は反射光線経路の波面、４７は上記矩形開口４１からの放射マイクロ波の経路、４８は放射マイクロ波の波面である。
【０００４】
次に動作について説明する。マイクロ波信号は、給電ホーン３３によって誘導され、入射光線経路４２を経て、放物線形反射器２６に入射する。入射したマイクロ波信号は反射光線経路４３に沿って照準されたマイクロ波エネルギーとして反射される。放物線形反射器２６の放物線形により、反射された反射光線の波面４４は反射光線経路４３と直交する面に位置する。図１１において、回動可能なミラー２７は４５°の角度に設定される。入射角度αは反射角度βに等しくなくてはならないのでマイクロ波エネルギーは垂直方向の反射光線経路４５に沿って、図中で水平方向になる反射光線の波面４６で再指向される。再指向されたマイクロ波エネルギーは、放射器２８の入力ポート３７へ供給される。さらにマイクロ波エネルギーは放射器２８中を紙面の上方に向かって伝搬し、出力開口３８の矩形開口４１から放射マイクロ波の経路４７の方向に放射される。矩形開口４１は入力ポート３７と平行しているので、放射マイクロ波の波面４８は矩形開口４１と平行している。生成されるビームは放射マイクロ波の波面４８に対して直交しているのでアンテナのビームは紙面に対して垂直な方向を向く。
【０００５】
図１２のように、回動可能なミラー２７を裏面に配置されたカム３６を駆動することによって、元の４５°の位置から角度δ=３．７５°だけ反時計回りに回動する。したがって、入射角度αは４８．７５°になり、反射角度も４８．７５°になる。回動可能なミラー２７の反射によって再指向された反射光線経路４５と反射光線の波面４６は元の位置から７．５°回転する。反射光線の波面４６と放射マイクロ波の波面４８との間の放射マイクロ波の経路４７に沿う経路距離はすべて等しいので、放射マイクロ波の波面４８も７．５°傾斜する。これによって放射器２８から放射されるビームは紙面に対して垂直な方向から７．５°回転した方向を向く。したがって、カム３６の機械的駆動によりビームを走査することができる。
【０００６】
【発明が解決しようとする課題】
従来のビーム走査アンテナは以上のように構成されているため、機械的な駆動装置を具備する必要があり、その耐候性、耐久性、精度、信頼性がアンテナ装置全体に与える影響が大きいという問題があった。また、入力ポートが一つしかないため、一つの開口でビームは一つであり、複数方向のビームを同時に構成するのは困難であるという問題もあった。
【０００７】
この発明は上記のような問題点を解決するためになされたものであり、機械的な駆動を用いることなくアンテナのビーム走査を実現することを目的としている。また、一つの開口で複数方向のビームの同時発生を実現させることも目的としている。
【０００８】
【課題を解決するための手段】
第１の発明のビーム走査アンテナは、第1の導波管部と第２の導波管部を複数個の結合孔で結合した構造のビーム走査アンテナであって、上記第１の導波管部は、ロットマンレンズを有し、上記ロットマンレンズの各アレー給電ポートに対応した複数の結合孔により上記第２の導波管部に形成した複数のスロットを励振するようにしたものである。
【０００９】
また、第２の発明のビーム走査アンテナは、第1の導波管部と第２の導波管部のそれぞれ一方の端部を複数個の結合孔で結合した構造のビーム走査アンテナであって、上記第1の導波管部内部において上記結合孔と反対側の端部に複数個配置された給電部と、上記第１の導波管部の伝搬路に設けられた平行平板導波路及び複数個の導波管からなるロットマンレンズと、上記第２の導波管部の外側に向いた広壁面上で且つ第１の方向（Y軸）に上記結合孔と反対側の短絡終端された導体壁からの距離が概ね半波長である位置から上記結合孔側に概ね１波長間隔で配列された複数個のスロットからなるものである。
【００１０】
第３の発明のビーム走査アンテナは、第２の導波管部内部において、各結合孔の周囲を電磁波の電界面に概ね平行な導体壁で囲み、且つ第１の方向（Y軸）であるスロットが配置されている側に上記導体壁の開口部を設けるものである。
【００１１】
また、第４の発明のビーム走査アンテナは、第２の導波管部内部において、伝搬する電磁波の電界面に概ね平行で且つ第１の方向（Y軸）に沿った導体壁を自由空間波長より小さい間隔で第２の方向（X軸）に複数個配置するものである。
【００１２】
第５の発明のビーム走査アンテナは、第２の導波管部内部において、各結合孔と第１の方向（Y軸）で相対する端部の導体壁に反射波抑圧手段を具備し、且つ上記スロットを第１の方向（Y軸）にビームのチルト角に応じた素子間隔で配列するものである。
【００１３】
また、第６の発明のビーム走査アンテナは、第1の導波管部と第２の導波管部のそれぞれ一方の端部を複数個の結合孔で結合した構造のビーム走査アンテナであって、上記第1の導波管部内部において上記結合孔と反対側の端部に複数個配置された給電部と、上記第１の導波管部の伝搬路に設けられた平行平板導波路及び複数個の導波管からなるロットマンレンズとを備え、さらに第２の導波管部における外側の広壁面上に誘電体を配置し、上記広壁面と相対する上記誘電体における他方の面に複数個の放射導体を形成すると共に、上記第２の導波管部内部と上記放射導体とをプローブで接続するものである。
【００１４】
第７の発明のビーム走査アンテナは、第６の発明の構成に加え、第２の導波管部内部において、伝搬する電磁波の電界面に概ね平行で且つ第１の方向（Y軸）に沿った導体壁を自由空間波長より小さい間隔で第２の方向（X軸）に複数個配置するものである。
【００１５】
また、第８の発明のビーム走査アンテナは、第２の導波管部内部において、各結合孔と第１の方向（Y軸）で相対する端部の導体壁に反射波抑圧手段を具備し、且つ上記プローブ接続の放射導体を第１の方向（Y軸）にビームのチルト角に応じた素子間隔で配列するものである。
【００１６】
第９の発明のビーム走査アンテナは、第１の導波管部及び第２の導波管を誘電体多層基板で構成し、且つ厚さ方向における導体壁をビアホールなどの接続用導体で構成するものである。
【００１７】
【発明の実施の形態】
実施の形態１．
図１はこの実施の形態１におけるビーム走査アンテナを示す上平面透視図（ａ）及び下平面透視図（ｂ）、図２は接続構成を補足する説明図であり、図３は内部構造及びビーム走査状態を説明するためのＡ−Ａ‘断面視図（ａ）及びＢ−Ｂ‘断面視図（ｂ）である。
【００１８】
図において、１は第１の導波管部、２ａ〜２ｃは上記第１の導波管部１の端部に設けられた給電部、３ａ〜３ｃはそれぞれ上記給電部２ａ〜２ｃに接続されたビームポート、４ａ〜４ｃは焦点あるいは焦点近傍に位置する上記ビームポート３ａ〜３ｃに接続されたアレー給電ポート、５ａ〜５ｃはそれぞれ上記アレー給電ポート４ａ〜４ｃに接続された結合孔、６は上記第１の導波管部１の内部で且つ伝搬する電磁波の電界面に概ね平行に設けられた導体壁、７は上記第１の導波管部１内部であって上記導体壁６により上記ビームポート３と上記アレー給電ポート４を通る軌跡で導波路領域を形成した平行平板導波路、８は上記ビームポート３と上記アレー給電ポート４の間での伝搬路を構成する上記平行平板導波路７と上記アレー給電ポート４と上記結合孔５との伝搬路を構成する導波管領域からなるロットマンレンズ、９は上記結合孔５によって上記第１の導波管部１と接続された第２の導波管部、１０は上記第２の導波管部９の外側に向いた広壁面上で且つ第１の方向（Y軸）に概ね１波長間隔で複数個配列されたスロット、１１ａと１１ｂは上記第２の導波管部９の第１の方向（Y軸）と概ね直交する導体壁、１２ａ〜１２ｃはそれぞれ上記ビームポート３ａ〜３ｃに対応し上記第２の導波管部９の内部を伝搬する波面、１３ａ〜１３ｃは上記第１の導波管部１から上記結合孔５を介して上記第２の導波管部９の内部を伝搬する電磁波の伝搬方向、１４ａ〜１４ｃはそれぞれ上記波面１２ａ〜１２ｃに対応し概ねXZ面上に放射するビームである。
【００１９】
次に、このビーム走査アンテナの動作について説明する。給電部２ａに供給されたエネルギーは第１の導波管部１の内部において導体壁６により構成された導波管内を伝搬しビームポート３ａに到達する。ビームポート３ａは平行平板導波路７における焦点あるいは焦点近傍に位置するためビームポート３ａから出た電磁波は平行平板導波路７内を伝搬し、アレー給電ポート４ａ〜４ｃに分配・伝搬される。これらの各アレー給電ポート４ａ〜４ｃに到達した電磁波は物理長あるいは電気長の異なる導波管伝搬路を伝搬し、各結合孔５ａ〜５ｃを介して第２の導波管部９に導かれ、傾斜した波面１２ａの平面波として第２の導波管部９内部を第１の方向（Y軸）に伝搬しながら複数個のスロット１０を励振するため、空間に電磁波として放射される。
【００２０】
ここで、スロット１０は共振スロットであり、且つ短絡終端された導体壁１１ａからの距離ａが管内波長の概ね半波長である位置から結合孔５側に管内波長の概ね１波長の素子間隔Dyで配列されているため、共振型のスロットアレーとして動作する。また、XZ面内においてグレーティングローブを発生させないために第２の方向（X軸）での素子間隔Dxは自由空間波長より小さい値に設定される。したがって、放射されるビーム１４は、概ねXZ面上で且つZ軸からチルトしたビーム１４ａとなる。また、スロット１０は第１の方向（Y軸）に対して４５度傾斜しているため、斜め４５度偏波となる。
【００２１】
これまで、エネルギーが一つの給電部２ａから供給される場合の動作例を述べたが、給電部２ｂ及び２ｃから供給される場合は、第２の導波管部９内での平面波がそれぞれ波面１２ｂと１２ｃとなるため、ビームは各波面１２ｂと１２ｃに対応したビーム１４ｂと１４ｃのように異なった指向方向に放射される。したがって、各給電部２ａ〜２ｃに接続する送信回路もしくは受信回路をRFスイッチで電気的に切り替えれば、概ねXZ面内において電気的にビーム１４を走査することができる。概ねXZ面内とは、例えば波面１２ａと１２ｂでは各スロット１０の励振方向が異なるため、結果として波面１２ａに対応したビーム１４ａの指向方向がXZ面上より若干外れてしまうことを意味する。また、各結合孔５ａ〜５ｃの寸法により結合量を制御できるため、第２の方向（X軸）でのスロット１０に対する励振分布を任意の値に設定できる。さらに、第１の導波管部１と放射部であるスロット１０を有する第２の導波管部９を積み重ねた構成としているのでアンテナを小形化することができる。
【００２２】
実施の形態２．
図４はこの発明の実施の形態２を示すビーム走査アンテナの上平面透視図である。この実施の形態２は、第２の導波管部９内部において、各結合孔５の周囲を電磁波の電界面に概ね平行な導体壁１５で囲み、且つ第１の方向（Y軸）であるスロット１０が配置されている側に上記導体壁１５の開口部を設けるものである。なお、この実施の形態２におけるビーム走査アンテナを示す第１の導波管部１の下平面透視図は図１（ｂ）と同様であり、接続構成を補足する説明図は図２と同様である。また、内部構造及びビーム走査状態を示すＡ−Ａ‘断面視図とＢ−Ｂ‘断面視図はそれぞれ図３（ａ）及び図３（ｂ）と同様である。
【００２３】
以上説明したように、この実施の形態２によるビーム走査アンテナによれば、各結合孔５の周囲を電磁波の電界面に概ね平行な導体壁１５で囲み、且つ第１の方向（Y軸）であるスロット１０が配置されている側に上記導体壁１５の開口部を設けているため、各結合孔５ａ〜５ｃ間でのポート間結合を低減でき、所望の波面１２ａ〜１２ｃを形成できると共に、各結合孔５ａ〜５ｃでのスロット１０に対する第２の方向（X軸）での設定励振分布の劣化を低減できる。ビーム走査については実施の形態１と同様な原理で実現できる。
【００２４】
実施の形態３．
図５はこの発明の実施の形態３を示すビーム走査アンテナの上平面透視図（ａ）及び斜め透視図（ｂ）である。この実施の形態３は、第２の導波管部９内部において、伝搬する電磁波の電界面に概ね平行で且つ第１の方向（Y軸）に沿った導体壁１６を自由空間波長より小さい間隔で第２の方向（X軸）に複数個配置するものである。なお、この実施の形態３におけるビーム走査アンテナを示す第１の導波管部１の下平面透視図は図１（ｂ）と同様であり、接続構成を補足する説明図は図２と同様である。また、内部構造及びビーム走査状態を示すＡ−Ａ‘断面視図とＢ−Ｂ‘断面視図はそれぞれ図３（ａ）及び図３（ｂ）と同様である。
【００２５】
以上説明したように、この実施の形態３によるビーム走査アンテナによれば、導体壁１６を自由空間波長より小さい間隔で第２の方向（X軸）に複数個配置しているため、第１の方向（Y軸）における複数個のスロット１０からなるサブアレー単位で第２の導波管部９内部を電気的に分離することができ、各結合孔５ａ〜５ｃから所望の励振振幅・位相で各サブアレーを励振できる。さらに、各スロット１０への励振方向は指向方向の異なるビーム１４ａ〜１４ｃによらず一定［第１の方向（Y軸）］であるため、XZ面内から指向方向が外れることなくビーム走査できる。ビーム走査については実施の形態１あるいは２のいずれかと同様な原理で実現できる。
【００２６】
実施の形態４．
図６はこの発明の実施の形態４を示すビーム走査アンテナの上平面透視図（ａ）及びＡ−Ａ‘断面視図（ｂ）である。この実施の形態４は、第２の導波管部９における外側の広壁面上に誘電体１９を配置し、上記広壁面と相対する上記誘電体１９における他方の面に複数個の放射導体１７を形成すると共に、上記第２の導波管部９内部と上記放射導体１７とをプローブ１８で接続するものである。なお、この実施の形態４におけるビーム走査アンテナを示す第１の導波管部１の下平面透視図は図１（ｂ）と同様であり、接続構成を補足する説明図は図２と同様である。また、ビーム走査状態を示すＢ−Ｂ‘断面視図は図３（ｂ）と同様である。
【００２７】
以上説明したように、この実施の形態４によるビーム走査アンテナによれば、誘電体１９上に構成した複数の放射導体１７からなる例えばパッチアンテナなどの放射素子への励振を、第２の導波管部９内部に挿入したプローブ１８により励振電力をピックアップするため、プローブ１８の挿入長により励振電力の強さを可変することができる。放射素子としてスロット１０を用いた場合、各スロット１０への励振電力を個々に可変するには斜めスロットを個々に異なった回転角度で配置したり、あるいは非共振スロットを用いて個々のスロット長を異なった長さにすることによって放射抵抗の値を個々に可変しなければならず、前者の場合は交差偏波の発生、後者の場合は進行波給電によるアンテナ効率低下の問題があるが、放射導体１７の偏波方向とプローブ１８の挿入長に依存するピックアップ電力強度は無関係であるため、所望の偏波を有し、且つ交差偏波の発生を回避しつつ第１の方向（Y軸）での励振振幅を効率良く任意に設定可能なビーム走査アンテナを実現できる。ビーム走査については実施の形態１あるいは３のいずれかと同様な原理で実現できる。
【００２８】
実施の形態５．
図７はこの発明の実施の形態５を示すビーム走査アンテナの上平面透視図であり、図８はビームチルト状態を示すＣ―Ｃ‘断面視図である。この実施の形態５は、第２の導波管部９内部において、各結合孔５と第１の方向（Y軸）で相対する端部の導体壁１１ａに反射波抑圧手段である電波吸収体２０を具備し、且つ各スロット１０を上記第１の方向（Y軸）にビーム１４のチルト角θに応じた素子間隔Dyで配列するものである。なお、この実施の形態５におけるビーム走査アンテナを示す第１の導波管部１の下平面透視図は図１（ｂ）と同様であり、接続構成を補足する説明図は図２と同様である。また、ビーム走査状態を示すＢ−Ｂ‘断面視図は図３（ｂ）と同様である。
【００２９】
以上説明したように、この実施の形態５によるビーム走査アンテナによれば、第２の導波管部９内部の導体壁１１ａに電波吸収体２０を具備し、各スロット１０を第１の方向（Y軸）にビーム１４のチルト角θに応じた素子間隔Dyで配列するため、第１の方向（Y軸）において進行波給電のスロットアレーを構成することができ、各給電部２ａ〜２ｃに接続する送信回路もしくは受信回路をRFスイッチで電気的に切り替えることによりXZ面を第１の方向（Y軸の正あるいは負の方向）に傾けた平面内に各ビーム１４ａ〜１４ｃをチルトさせた状態で電気的にビーム走査できる。ビーム走査については実施の形態１から４のいずれかと同様な原理で実現できる。
【００３０】
ここで、上記実施の形態５では、スロット１０を放射素子として用いているが、実施の形態４に示されるようなプローブ１８接続の放射導体１７を放射素子として用いても良い。
【００３１】
また、反射波抑圧手段として電波吸収体２０を用いているが、電波吸収塗料などの電波吸収材を用いても良い。
【００３２】
また、以上の実施の形態１〜４における各結合孔５の代わりに、導波管コーナーや導波管ベンドなどの屈曲導波管を用いて第１の導波管部１と第２の導波管部９を連結する構造としても良い。
【００３３】
実施の形態６．
図９はこの発明の実施の形態６を示すビーム走査アンテナの上平面透視図（ａ）及び下平面透視図（ｂ）であり、図１０はビアホール（インナービア、ブラインドビア、スルーホール）などの接続用導体２３ａと２３ｂによる内部接続状態を示す斜め透視図である。この実施の形態６は、第１の導波管部１及び第２の導波管９を誘電体２５ａ、２５ｂ及び導体板２１，２２，２４からなる多層構造の基板として構成し、且つ厚さ方向における導体壁をビアホールなどの接続用導体２３ａ，２３ｂとするものである。なお、この実施の形態６におけるビーム走査アンテナの接続構成を補足する説明図は図２と同様であり、ビーム走査状態を示すＢ−Ｂ‘断面視図は図３（ｂ）と同様である。
【００３４】
以上説明したように、この実施の形態６によるビーム走査アンテナによれば、第１の導波管部１及び第２の導波管部９を誘電体２５ａと２５ｂを用いた多層基板で構成し、さらに厚さ方向と平行な導体壁を動作周波数における管内波長の概ね半波長以下の間隔で配置したビアホールなどの接続用導体２３ａと２３ｂで構成しているため、接続用導体２３間を電磁波は通過することができず、導体壁と同様な効果を得ることができると共に、量産性に優れた誘電体基板を用いてビーム走査アンテナを構築できる。ビーム走査については実施の形態１から５のいずれかと同様な原理で実現できる。
【００３５】
ここで、上記実施の形態６では、第２の導波管部９の全ての側壁を接続用導体２３で構成しているが、第１の方向（Y軸）での端部に反射波抑圧手段として電波吸収体２０を装着、あるいは端部における誘電体内部に抵抗体を設けて、第１の方向（Y軸）に進行波給電する構成としても良い。
【００３６】
また、以上の実施の形態１〜３、５，６におけるのスロット１０は導波管広壁面に構成した斜めスロットとしているが、これに限らず如何なるスロット１０を用いても良い。
【００３７】
また、以上の実施の形態１〜６におけるビーム走査アンテナは、第１の導波管部と第２の導波管部を積み重ねた構造としているが、共平面構造としても良い。
【００３８】
【発明の効果】
この発明によれば、第１の導波管部に設けたロットマンレンズの各アレー給電ポートに対応した複数個の結合孔により第２の導波管部に形成した複数のスロットを励振するため、ロットマンレンズの各ビームポートに対応した給電部をRFスイッチで電気的に切り替えれることにより、概ねXZ面内において電気的にビームを走査できる効果が得られる。
【００３９】
また、この発明によれば、各結合孔の間を導体壁で遮蔽しているため、各結合孔間でのポート間結合を低減でき、所望の波面を形成できると共に、各結合孔でのスロットに対する第２の方向（X軸）での設定励振分布の劣化を低減できる効果が得られる。
【００４０】
この発明によれば、管壁にスロットが設けられている導波管内部を、その内部を伝搬する電磁波の電界面と平行に導体壁でスロットを一列あるいは複数列毎に仕切ることで第２の方向（X軸）に複数配置したサブアレーでアンテナ開口を構成できるため、各サブアレーを所望の励振振幅・位相で励振できると共に、磁界面方向のスロット間結合を低減できる効果が得られる。さらに、各スロットへの励振方向は指向方向の異なるビームによらず各結合孔で一定［第１の方向（Y軸）］であるため、XZ面内から指向方向が外れることなくビーム走査できる効果も得られる。
【００４１】
また、この発明によれば、第２の導波管部内部と放射導体とをプローブで接続するため、所望の偏波を有し、且つ交差偏波の発生を回避しつつ第１の方向（Y軸）での励振振幅を効率良く任意に設定可能なビーム走査アンテナを実現できる効果が得られる。
【００４２】
この発明によれば、管壁上のスロットを第１の方向（Y軸）において進行波給電のスロットアレーとして動作させるため、マルチビームを形成する第２の方向（X軸）だけでなく、第１の方向（Y軸）へもビームチルトが可能なビーム走査アンテナを実現できる効果が得られる。
【００４３】
また、この発明によれば、導波管を積み重ねた構造の代わりに多層構造の誘電体基板で構成し、さらに厚さ方向と平行な導体壁を動作周波数における管内の半波長以下の間隔で配置した接続用導体で構成するため、多層基板と同様な量産性に優れたビーム走査アンテナを実現することができる効果が得られる。
【図面の簡単な説明】
【図１】この発明によるビーム走査アンテナの実施の形態１を示す上平面透視図及び下平面透視図である。
【図２】接続構成を補足する説明図である。
【図３】内部構造及びビーム走査状態を説明するためのＡ−Ａ‘断面視図及びＢ−Ｂ‘断面視図である。
【図４】この発明によるビーム走査アンテナの実施の形態２を示す上平面透視図である。
【図５】この発明によるビーム走査アンテナの実施の形態３を示す上平面透視図及び斜め透視図である。
【図６】この発明によるビーム走査アンテナの実施の形態４を示す上平面透視図及びＡ−Ａ‘断面視図である。
【図７】この発明によるビーム走査アンテナの実施の形態５を示す上平面透視図である。
【図８】ビームチルト状態を説明するためのＣ―Ｃ‘断面視図である。
【図９】この発明によるビーム走査アンテナの実施の形態６を示す上平面透視図及び下平面透視図である。
【図１０】接続用導体による内部接続状態を示す斜め透視図である。
【図１１】従来のビーム走査アンテナを示す外観図である。
【図１２】従来のビーム走査アンテナの動作原理を示す外観図である。
【符号の説明】
１第１の導波管部、２給電部、３ビームポート、４アレー給電ポート、５結合孔、６導体壁、７平行平板導波路、８ロットマンレンズ、９第２の導波管部、１０スロット、１１導体壁、１２波面、１３伝搬方向、１４ビーム、１５導体壁、１６導体壁、１７放射導体、１８プローブ、１９誘電体、２０電波吸収体、２１導体板、２２導体板、２３接続用導体、２４導体板、２５誘電体。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a beam scanning antenna capable of electrically changing a transmission direction of a radio signal or a reception direction of an incoming wave without using a mechanical driving device.
[0002]
[Prior art]
FIG. 11 is an external view showing a conventional beam scanning antenna, and FIG. 12 is an external view for explaining the operation principle of the conventional beam scanning antenna. These are examples described in JP-A-8-321710.
[0003]
11 and 12, 26 is a parabolic reflector, 27 is a rotatable mirror, 28 is a radiator, 29 is a lower plate, 30 is an upper plate, 31 is the lower plate 29 and the upper plate 30. A parallel plate waveguide 32, 32 is a focal point of the parabolic reflector 26, 33 is a feeding horn placed at the position of the focus 32 inside the parallel plate waveguide 31, and 34 is rotatable. A rotating shaft disposed at the center of the mirror 27, 35 is a ball mounted on the end of the back surface of the rotatable mirror 27, 36 is a cam provided in contact with the ball 35, 37 is the above The input port of the radiator 28, 38 is the output opening of the radiator 28, 39 and 40 are one port side and the other port side of the radiator, and 41 is the one port side 39 to the other Up to port side 40 A plurality of rectangular apertures 42 across the upper plate 30 and at intervals of an integral multiple of the in-tube wavelength of the parallel plate waveguide 31 are radiated from the feeding horn 33 to the parabolic reflector 26. An incident ray path of the incident microwave signal, 43 is a reflected ray path of the microwave signal reflected by the parabolic reflector 26, 44 is a wavefront of the reflected ray, and 45 is a reflection reflected by the rotatable mirror 27. The ray path, 46 is the wavefront of the reflected ray path, 47 is the radiation microwave path from the rectangular opening 41, and 48 is the radiation microwave wavefront.
[0004]
Next, the operation will be described. The microwave signal is guided by the feed horn 33 and enters the parabolic reflector 26 via the incident light path 42. The incident microwave signal is reflected as microwave energy aimed along the reflected ray path 43. Due to the parabolicity of the parabolic reflector 26, the wavefront 44 of the reflected reflected light beam is located in a plane orthogonal to the reflected light beam path 43. In FIG. 11, the rotatable mirror 27 is set at an angle of 45 °. Since the incident angle α must be equal to the reflection angle β, the microwave energy is redirected along the reflected ray path 45 in the vertical direction at the wavefront 46 of the reflected ray, which is horizontal in the figure. The redirected microwave energy is supplied to the input port 37 of the radiator 28. Further, the microwave energy propagates through the radiator 28 toward the upper side of the drawing, and is radiated from the rectangular opening 41 of the output opening 38 in the direction of the radiation microwave path 47. Since the rectangular opening 41 is parallel to the input port 37, the wave front 48 of the radiation microwave is parallel to the rectangular opening 41. Since the generated beam is orthogonal to the wavefront 48 of the radiating microwave, the antenna beam is oriented in a direction perpendicular to the paper surface.
[0005]
As shown in FIG. 12, the rotatable mirror 27 is driven counterclockwise by an angle δ = 3.75 ° from the original 45 ° position by driving the cam 36 disposed on the back surface. Therefore, the incident angle α is 48.75 ° and the reflection angle is 48.75 °. The reflected ray path 45 redirected by the reflection of the rotatable mirror 27 and the wavefront 46 of the reflected ray are rotated 7.5 ° from the original position. Since the path distances along the radiation microwave path 47 between the reflected wavefront 46 and the radiation microwave wavefront 48 are all equal, the radiation microwave wavefront 48 is also tilted by 7.5 °. As a result, the beam emitted from the radiator 28 is directed in a direction rotated by 7.5 ° from the direction perpendicular to the paper surface. Therefore, the beam can be scanned by the mechanical drive of the cam 36.
[0006]
[Problems to be solved by the invention]
Since the conventional beam scanning antenna is configured as described above, it is necessary to provide a mechanical driving device, and the problem is that the weather resistance, durability, accuracy, and reliability have a large influence on the entire antenna device. was there. In addition, since there is only one input port, there is a problem that there is only one beam per aperture, and it is difficult to simultaneously construct beams in a plurality of directions.
[0007]
The present invention has been made to solve the above-described problems, and an object thereof is to realize beam scanning of an antenna without using a mechanical drive. Another object is to realize simultaneous generation of beams in a plurality of directions with one aperture.
[0008]
[Means for Solving the Problems]
A beam scanning antenna according to a first aspect of the present invention is a beam scanning antenna having a structure in which a first waveguide portion and a second waveguide portion are coupled by a plurality of coupling holes. The section has a Rotman lens, and a plurality of slots formed in the second waveguide section are excited by a plurality of coupling holes corresponding to the array power supply ports of the Rotman lens.
[0009]
The beam scanning antenna of the second invention is a beam scanning antenna having a structure in which one end of each of the first waveguide section and the second waveguide section is coupled by a plurality of coupling holes. A plurality of power supply portions arranged at the end opposite to the coupling hole inside the first waveguide portion, a parallel plate waveguide provided in the propagation path of the first waveguide portion, and A Rotman lens composed of a plurality of waveguides and a short-circuit termination on the wide wall facing the outside of the second waveguide section and in the first direction (Y axis) opposite to the coupling hole. It consists of a plurality of slots arranged at intervals of approximately one wavelength from the position where the distance from the conductor wall is approximately half a wavelength to the coupling hole side.
[0010]
A beam scanning antenna according to a third aspect of the present invention is the first direction (Y axis) in the second waveguide section, wherein each coupling hole is surrounded by a conductor wall substantially parallel to the electric field surface of the electromagnetic wave. The opening of the conductor wall is provided on the side where the slot is disposed.
[0011]
According to a fourth aspect of the present invention, there is provided a beam scanning antenna having a free-space wavelength inside a second waveguide portion, the conductor wall being substantially parallel to the electric field surface of the propagating electromagnetic wave and along the first direction (Y-axis). A plurality of them are arranged in the second direction (X axis) at smaller intervals.
[0012]
A beam scanning antenna according to a fifth aspect of the present invention includes reflected wave suppression means on a conductor wall at an end facing each coupling hole in the first direction (Y axis) inside the second waveguide section, and The slots are arranged in the first direction (Y axis) with an element interval corresponding to the tilt angle of the beam.
[0013]
A beam scanning antenna according to a sixth aspect of the present invention is a beam scanning antenna having a structure in which one end of each of the first waveguide section and the second waveguide section is coupled by a plurality of coupling holes. A plurality of power supply portions arranged at the end opposite to the coupling hole inside the first waveguide portion, a parallel plate waveguide provided in the propagation path of the first waveguide portion, and A Rotman lens comprising a plurality of waveguides, a dielectric disposed on the outer wide wall surface of the second waveguide section, and a plurality of dielectrics disposed on the other surface of the dielectric material facing the wide wall surface. A plurality of radiation conductors are formed, and the inside of the second waveguide section and the radiation conductor are connected by a probe.
[0014]
In addition to the configuration of the sixth invention, the beam scanning antenna of the seventh invention is substantially parallel to the electric field surface of the propagating electromagnetic wave and along the first direction (Y axis) in the second waveguide section. A plurality of conductor walls are arranged in the second direction (X axis) at intervals smaller than the free space wavelength.
[0015]
According to an eighth aspect of the present invention, the beam scanning antenna includes reflection wave suppression means on a conductor wall at an end facing each coupling hole in the first direction (Y axis) inside the second waveguide section. In addition, the probe-connected radiation conductors are arranged in the first direction (Y-axis) at an element interval corresponding to the tilt angle of the beam.
[0016]
In the beam scanning antenna of the ninth invention, the first waveguide section and the second waveguide are formed of a dielectric multilayer substrate, and the conductor wall in the thickness direction is formed of a connecting conductor such as a via hole. Is.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
FIG. 1 is an upper plan perspective view (a) and a lower plan perspective view (b) showing the beam scanning antenna in the first embodiment, FIG. 2 is an explanatory diagram supplementing the connection configuration, and FIG. They are AA 'sectional view (a) and BB' sectional view (b) for demonstrating a scanning state.
[0018]
In the figure, 1 is a first waveguide section, 2a to 2c are power supply sections provided at the end of the first waveguide section 1, and 3a to 3c are connected to the power supply sections 2a to 2c, respectively. The beam ports, 4a to 4c are focal points or array feeding ports connected to the beam ports 3a to 3c located near the focal point, 5a to 5c are coupling holes connected to the array feeding ports 4a to 4c, respectively. A conductor wall 7 is provided in the first waveguide portion 1 and substantially parallel to the electric field surface of the propagating electromagnetic wave. The conductor wall 7 is provided in the first waveguide portion 1 by the conductor wall 6. A parallel plate waveguide in which a waveguide region is formed by a trajectory passing through the beam port 3 and the array feed port 4, and 8 is a parallel plate waveguide that forms a propagation path between the beam port 3 and the array feed port 4. 7 and the above array feed port 4 is a Rotman lens comprising a waveguide region that constitutes a propagation path between the coupling hole 5 and the second waveguide part 9 connected to the first waveguide part 1 by the coupling hole 5; Reference numeral 10 denotes a slot arranged on the wide wall surface facing the outside of the second waveguide section 9 and in the first direction (Y-axis) at intervals of approximately one wavelength. Reference numerals 11a and 11b denote the second waveguide section. Conductor walls substantially orthogonal to the first direction (Y-axis) of the waveguide section 9, 12 a to 12 c correspond to the beam ports 3 a to 3 c, respectively, and propagate through the inside of the second waveguide section 9. , 13a to 13c are propagation directions of electromagnetic waves propagating from the first waveguide part 1 through the coupling hole 5 to the inside of the second waveguide part 9, and 14a to 14c are wavefronts 12a to 12c, respectively. This is a beam corresponding to 12c and radiating substantially on the XZ plane.
[0019]
Next, the operation of this beam scanning antenna will be described. The energy supplied to the power feeding unit 2a propagates in the waveguide formed by the conductor wall 6 inside the first waveguide unit 1 and reaches the beam port 3a. Since the beam port 3a is located at or near the focal point of the parallel plate waveguide 7, the electromagnetic wave emitted from the beam port 3a propagates in the parallel plate waveguide 7 and is distributed and propagated to the array feed ports 4a to 4c. The electromagnetic waves reaching these array feed ports 4a to 4c propagate through waveguide propagation paths having different physical lengths or electrical lengths, and are guided to the second waveguide section 9 through the coupling holes 5a to 5c. In order to excite the plurality of slots 10 while propagating through the second waveguide portion 9 in the first direction (Y-axis) as a plane wave of the inclined wavefront 12a, it is radiated as an electromagnetic wave into the space.
[0020]
Here, the slot 10 is a resonance slot, and a distance a from the short-terminated conductor wall 11a is approximately half a wavelength of the tube wavelength from the position of the tube hole to the coupling hole 5 side with an element interval Dy of approximately one wavelength of the tube wavelength. Since they are arranged, they operate as a resonance type slot array. In order not to generate a grating lobe in the XZ plane, the element interval Dx in the second direction (X axis) is set to a value smaller than the free space wavelength. Therefore, the radiated beam 14 becomes a beam 14a tilted substantially on the XZ plane and from the Z axis. Further, since the slot 10 is inclined by 45 degrees with respect to the first direction (Y-axis), it becomes a 45-degree polarized wave.
[0021]
So far, the operation example in the case where the energy is supplied from one power supply unit 2a has been described. 12b and 12c, the beams are radiated in different directivity directions like beams 14b and 14c corresponding to the wavefronts 12b and 12c. Accordingly, if the transmission circuit or the reception circuit connected to each of the power feeding units 2a to 2c is electrically switched by the RF switch, the beam 14 can be scanned electrically in the XZ plane. In general, “in the XZ plane” means that, for example, the wavefronts 12 a and 12 b have different excitation directions of the slots 10, and as a result, the directing direction of the beam 14 a corresponding to the wavefront 12 a slightly deviates from the XZ plane. Further, since the coupling amount can be controlled by the dimensions of the coupling holes 5a to 5c, the excitation distribution for the slot 10 in the second direction (X axis) can be set to an arbitrary value. Further, since the first waveguide section 1 and the second waveguide section 9 having the slot 10 as the radiation section are stacked, the antenna can be miniaturized.
[0022]
Embodiment 2. FIG.
FIG. 4 is a top plan perspective view of the beam scanning antenna according to the second embodiment of the present invention. In the second embodiment, each coupling hole 5 is surrounded by a conductor wall 15 substantially parallel to the electric field surface of the electromagnetic wave in the second waveguide portion 9 and is in the first direction (Y-axis). An opening of the conductor wall 15 is provided on the side where the slot 10 is disposed. In addition, the lower plan perspective view of the first waveguide portion 1 showing the beam scanning antenna in the second embodiment is the same as FIG. 1B, and the explanatory diagram supplementing the connection configuration is the same as FIG. is there. Further, the AA ′ sectional view and the BB ′ sectional view showing the internal structure and the beam scanning state are the same as FIG. 3A and FIG. 3B, respectively.
[0023]
As described above, according to the beam scanning antenna according to the second embodiment, each coupling hole 5 is surrounded by the conductor wall 15 substantially parallel to the electric field surface of the electromagnetic wave, and in the first direction (Y axis). Since the opening of the conductor wall 15 is provided on the side where a certain slot 10 is disposed, the coupling between the ports between the coupling holes 5a to 5c can be reduced, and desired wavefronts 12a to 12c can be formed. It is possible to reduce the deterioration of the set excitation distribution in the second direction (X axis) with respect to the slot 10 in each of the coupling holes 5a to 5c. The beam scanning can be realized by the same principle as in the first embodiment.
[0024]
Embodiment 3 FIG.
5A and 5B are a top plan perspective view (a) and a diagonal perspective view (b) of a beam scanning antenna according to Embodiment 3 of the present invention. In the third embodiment, in the second waveguide portion 9, the conductor wall 16 that is substantially parallel to the electric field surface of the propagating electromagnetic wave and along the first direction (Y-axis) is spaced smaller than the free space wavelength. A plurality are arranged in the second direction (X-axis). In addition, the bottom plan perspective view of the first waveguide section 1 showing the beam scanning antenna in the third embodiment is the same as FIG. 1B, and the explanatory diagram supplementing the connection configuration is the same as FIG. is there. Further, the AA ′ sectional view and the BB ′ sectional view showing the internal structure and the beam scanning state are the same as FIG. 3A and FIG. 3B, respectively.
[0025]
As described above, according to the beam scanning antenna according to the third embodiment, the plurality of conductor walls 16 are arranged in the second direction (X axis) at an interval smaller than the free space wavelength. The inside of the second waveguide section 9 can be electrically separated by a subarray unit composed of a plurality of slots 10 in the direction (Y-axis), and each with a desired excitation amplitude and phase from each coupling hole 5a-5c. The subarray can be excited. Furthermore, since the excitation direction to each slot 10 is constant [first direction (Y axis)] regardless of the beams 14a to 14c having different directivity directions, beam scanning can be performed without deviating the directivity direction from the XZ plane. The beam scanning can be realized by the same principle as in either the first or second embodiment.
[0026]
Embodiment 4 FIG.
6A and 6B are a top plan perspective view (a) and an AA ′ cross-sectional view (b) of the beam scanning antenna according to the fourth embodiment of the present invention. In the fourth embodiment, a dielectric 19 is disposed on the outer wide wall surface of the second waveguide section 9, and a plurality of radiation conductors 17 are provided on the other surface of the dielectric 19 facing the wide wall surface. And the inside of the second waveguide section 9 and the radiation conductor 17 are connected by a probe 18. In addition, the lower plane perspective view of the first waveguide section 1 showing the beam scanning antenna in the fourth embodiment is the same as FIG. 1B, and the explanatory diagram supplementing the connection configuration is the same as FIG. is there. Further, a cross-sectional view taken along the line BB ′ showing the beam scanning state is the same as FIG.
[0027]
As described above, according to the beam scanning antenna according to the fourth embodiment, excitation to a radiating element such as a patch antenna composed of a plurality of radiating conductors 17 formed on the dielectric 19 is performed in the second waveguide. Since the excitation power is picked up by the probe 18 inserted into the tube portion 9, the strength of the excitation power can be varied by the insertion length of the probe 18. When the slot 10 is used as a radiating element, in order to vary the excitation power to each slot 10 individually, oblique slots are individually arranged at different rotation angles, or individual slot lengths are set by using non-resonant slots. The radiation resistance values must be individually varied by using different lengths. In the former case, there is a problem of cross-polarization, and in the latter case, there is a problem of reduced antenna efficiency due to traveling wave feeding. Since the polarization direction of the conductor 17 and the pickup power intensity depending on the insertion length of the probe 18 are irrelevant, the first direction (Y axis) has a desired polarization and avoids the generation of cross polarization. It is possible to realize a beam scanning antenna capable of efficiently and arbitrarily setting the excitation amplitude. The beam scanning can be realized by the same principle as in either the first or third embodiment.
[0028]
Embodiment 5 FIG.
FIG. 7 is a top plan perspective view of a beam scanning antenna according to Embodiment 5 of the present invention, and FIG. 8 is a CC ′ sectional view showing a beam tilt state. In the fifth embodiment, a radio wave absorber that is a reflected wave suppression means on the conductor wall 11a at the end facing each coupling hole 5 in the first direction (Y-axis) inside the second waveguide section 9. 20 and the slots 10 are arranged in the first direction (Y-axis) with an element interval Dy corresponding to the tilt angle θ of the beam 14. The bottom plan perspective view of the first waveguide portion 1 showing the beam scanning antenna in the fifth embodiment is the same as FIG. 1B, and the explanatory diagram supplementing the connection configuration is the same as FIG. is there. Further, a cross-sectional view taken along the line BB ′ showing the beam scanning state is the same as FIG.
[0029]
As described above, according to the beam scanning antenna of the fifth embodiment, the conductor wall 11a in the second waveguide section 9 is provided with the radio wave absorber 20, and each slot 10 is moved in the first direction ( Since the array is arranged on the Y axis) with the element spacing Dy corresponding to the tilt angle θ of the beam 14, a traveling wave power supply slot array can be formed in the first direction (Y axis). A state in which the beams 14a to 14c are tilted in a plane in which the XZ plane is inclined in the first direction (positive or negative direction of the Y axis) by electrically switching a transmitting circuit or a receiving circuit to be connected with an RF switch. The beam can be scanned electrically. The beam scanning can be realized by the same principle as in any of the first to fourth embodiments.
[0030]
Here, in the fifth embodiment, the slot 10 is used as a radiating element. However, the radiating conductor 17 connected to the probe 18 as shown in the fourth embodiment may be used as the radiating element.
[0031]
Further, although the radio wave absorber 20 is used as the reflected wave suppression means, a radio wave absorber such as a radio wave absorbing paint may be used.
[0032]
In addition, instead of each coupling hole 5 in the first to fourth embodiments, a bent waveguide such as a waveguide corner or a waveguide bend is used, and the first waveguide section 1 and the second waveguide are used. It is good also as a structure which connects the wave-tube part 9. FIG.
[0033]
Embodiment 6 FIG.
FIG. 9 is an upper plan perspective view (a) and a lower plan perspective view (b) of the beam scanning antenna according to the sixth embodiment of the present invention, and FIG. 10 shows via holes (inner vias, blind vias, through holes) and the like. It is an oblique perspective figure which shows the internal connection state by the conductors 23a and 23b for connection. In the sixth embodiment, the first waveguide section 1 and the second waveguide 9 are configured as a multilayer substrate composed of dielectrics 25a, 25b and conductor plates 21, 22, 24, and have a thickness. The conductor walls in the direction are connection conductors 23a and 23b such as via holes. An explanatory diagram that supplements the connection configuration of the beam scanning antenna in the sixth embodiment is the same as that in FIG. 2, and a cross-sectional view taken along the line BB ′ showing the beam scanning state is the same as that in FIG.
[0034]
As described above, according to the beam scanning antenna according to the sixth embodiment, the first waveguide section 1 and the second waveguide section 9 are configured by the multilayer substrate using the dielectrics 25a and 25b. Further, since the conductor wall parallel to the thickness direction is composed of the connection conductors 23a and 23b such as via holes in which the inner wall wavelength at the operating frequency is approximately equal to or less than the half wavelength, electromagnetic waves are generated between the connection conductors 23. The beam scanning antenna can be constructed by using a dielectric substrate that cannot pass through and can obtain the same effect as that of the conductor wall and has excellent mass productivity. The beam scanning can be realized by the same principle as in any of the first to fifth embodiments.
[0035]
Here, in the sixth embodiment, all the side walls of the second waveguide section 9 are configured by the connecting conductor 23, but reflected wave suppression is performed at the end in the first direction (Y axis). As a means, a configuration may be adopted in which the radio wave absorber 20 is attached, or a resistor is provided inside the dielectric at the end, and traveling wave power is supplied in the first direction (Y axis).
[0036]
In addition, the slot 10 in the first to third embodiments described above is an oblique slot formed on the wide wall surface of the waveguide, but not limited to this, any slot 10 may be used.
[0037]
In addition, the beam scanning antennas in the first to sixth embodiments described above have a structure in which the first waveguide portion and the second waveguide portion are stacked, but may have a coplanar structure.
[0038]
【The invention's effect】
According to this invention, in order to excite a plurality of slots formed in the second waveguide portion by a plurality of coupling holes corresponding to each array feeding port of the Rotman lens provided in the first waveguide portion, By electrically switching the power feeding unit corresponding to each beam port of the Rotman lens with an RF switch, it is possible to obtain an effect that the beam can be electrically scanned substantially in the XZ plane.
[0039]
Further, according to the present invention, since the gaps between the coupling holes are shielded by the conductor walls, the coupling between the ports between the coupling holes can be reduced, a desired wavefront can be formed, and the slots at the coupling holes can be formed. As a result, it is possible to reduce the deterioration of the set excitation distribution in the second direction (X axis).
[0040]
According to the present invention, the inside of the waveguide provided with the slot on the tube wall is partitioned by the conductor wall in parallel with the electric field surface of the electromagnetic wave propagating through the inside, so that the second or second row of slots is partitioned. Since the antenna aperture can be formed by a plurality of subarrays arranged in the direction (X axis), each subarray can be excited with a desired excitation amplitude and phase, and the effect of reducing the coupling between slots in the magnetic field plane direction can be obtained. Furthermore, the excitation direction to each slot is constant [first direction (Y-axis)] in each coupling hole regardless of the beams having different directivity directions, so that the beam can be scanned without deviating the directivity direction from within the XZ plane. Can also be obtained.
[0041]
According to the present invention, since the inside of the second waveguide section and the radiation conductor are connected by the probe, the first direction (with the desired polarization and avoiding the generation of cross polarization) ( It is possible to realize a beam scanning antenna that can set the excitation amplitude on the Y axis) efficiently and arbitrarily.
[0042]
According to the present invention, since the slot on the tube wall is operated as a traveling wave feeding slot array in the first direction (Y-axis), not only the second direction (X-axis) forming the multi-beam but also the second direction (X-axis). The effect of realizing a beam scanning antenna capable of beam tilting in the direction 1 (Y-axis) can be obtained.
[0043]
Further, according to the present invention, instead of a structure in which waveguides are stacked, a multilayer dielectric substrate is used, and conductor walls parallel to the thickness direction are arranged at intervals of less than a half wavelength in the tube at the operating frequency. Since the connection conductor is used, an effect of realizing a beam scanning antenna having excellent mass productivity similar to that of the multilayer substrate can be obtained.
[Brief description of the drawings]
FIGS. 1A and 1B are an upper plan perspective view and a lower plan perspective view, respectively, showing Embodiment 1 of a beam scanning antenna according to the present invention.
FIG. 2 is an explanatory diagram supplementing a connection configuration.
FIGS. 3A and 3B are an AA ′ sectional view and a BB ′ sectional view for explaining an internal structure and a beam scanning state; FIGS.
FIG. 4 is a top plan perspective view showing a beam scanning antenna according to a second embodiment of the present invention.
FIGS. 5A and 5B are an upper perspective view and an oblique perspective view showing a third embodiment of the beam scanning antenna according to the present invention. FIGS.
FIGS. 6A and 6B are an upper plan perspective view and an AA ′ sectional view showing a beam scanning antenna according to a fourth embodiment of the present invention. FIGS.
FIG. 7 is a top plan perspective view showing a beam scanning antenna according to a fifth embodiment of the present invention.
FIG. 8 is a cross-sectional view taken along the line CC ′ for explaining a beam tilt state.
FIGS. 9A and 9B are an upper plane perspective view and a lower plane perspective view showing Embodiment 6 of the beam scanning antenna according to the present invention. FIGS.
FIG. 10 is an oblique perspective view showing an internal connection state by a connection conductor.
FIG. 11 is an external view showing a conventional beam scanning antenna.
FIG. 12 is an external view showing the operating principle of a conventional beam scanning antenna.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st waveguide part, 2 Feeding part, 3 Beam port, 4 Array feeding port, 5 Coupling hole, 6 Conductor wall, 7 Parallel plate waveguide, 8 Rotman lens, 9 2nd waveguide part, 10 Slot, 11 Conductor wall, 12 Wavefront, 13 Propagation direction, 14 Beam, 15 Conductor wall, 16 Conductor wall, 17 Radiation conductor, 18 Probe, 19 Dielectric, 20 Wave absorber, 21 Conductor plate, 22 Conductor plate, 23 Connection Conductor, 24 conductor plate, 25 dielectric.

Claims

A beam scanning antenna having a structure in which one end of each of the first and second waveguide portions having a waveguide formed therein is vertically fed by a plurality of coupling holes,
The first and second waveguide portions are partitioned by an insole conductor wall provided with the coupling hole and are stacked on each other,
The first waveguide section is provided in the electromagnetic wave propagation path, and a plurality of power feeding sections arranged around the end opposite to the coupling hole on the surface facing the inner bottom conductor wall inside. A parallel plate waveguide and a plurality of waveguides , each of which is connected to each of the feeding portions via a plurality of array feeding ports and a waveguide respectively connected to the coupling holes via the waveguide. A Rotman lens having a plurality of beam ports;
It said second waveguide section, with aligned plurality along a first direction generally parallel to the electric field plane of the propagating electromagnetic wave (Y-axis) orthogonal to the coupling hole in a first direction (Y-axis) a plurality of slots in a plurality of rows arranged is formed toward the second direction being the sequence (X-axis),
Provided inside the second waveguide section is a conductor wall that is substantially parallel to the electric field surface of the electromagnetic wave that propagates around each coupling hole and around each slot arranged along the first direction (Y-axis), And the conductor walls are arranged in a plurality of rows in the second direction (X axis),
The slots arranged in each row in the second direction are excited through the waveguide by the respective coupling holes corresponding to the respective array feeding ports of the Rotman lens,
A beam scanning antenna, wherein each of the power feeding units is electrically switched between a transmission circuit and a reception circuit.

The plurality of slots are distances from a conductor wall that is short-circuit terminated on the wide wall surface facing the outside of the second waveguide portion and in the first direction (Y-axis) opposite to the coupling hole. 2. The beam scanning antenna according to claim 1, wherein the beam scanning antennas are arranged at an interval of approximately one wavelength from a position where is substantially a half wavelength toward the coupling hole.

Inside the second waveguide section, the conductor wall that is substantially parallel to the electric field surface of the propagating electromagnetic wave and along the first direction (Y-axis) is separated in the second direction (X-axis) by an interval smaller than the free space wavelength. A plurality of beam scanning antennas according to claim 1 or 2, wherein a plurality of the beam scanning antennas are arranged in (1).

Inside the second waveguide section, a reflection wave suppression means is provided on the conductor wall at the end facing each coupling hole in the first direction (Y-axis), and the slot is formed in the first direction (Y The beam scanning antenna according to any one of claims 1 to 3, wherein the beam scanning antenna is arranged at an element interval corresponding to a beam tilt angle.

A beam scanning antenna having a structure in which one end of each of the first and second waveguide portions having a waveguide formed therein is vertically fed by a plurality of coupling holes,
The first and second waveguide portions are partitioned by an insole conductor wall provided with the coupling hole and are stacked on each other,
The first waveguide section is provided in the electromagnetic wave propagation path, and a plurality of power feeding sections arranged around the end opposite to the coupling hole on the surface facing the inner bottom conductor wall inside. A parallel plate waveguide and a plurality of waveguides , each of which is connected to each of the feeding portions via a plurality of array feeding ports and a waveguide respectively connected to the coupling holes via the waveguide. A Rotman lens having a plurality of beam ports;
The second waveguide portion includes a dielectric disposed on an outer wide wall surface, and a plurality of radiation conductors are formed on the other surface of the dielectric facing the wide wall surface. Connect the inside of the waveguide section and the radiation conductor with a probe,
The probes are excited through the waveguides by the respective coupling holes corresponding to the array feed ports of the Rotman lens, and are along a first direction (Y axis) substantially parallel to the electric field surface of the propagating electromagnetic wave. converting mechanism are arranged a plurality, a plurality of rows arranged towards the second direction are arranged in the first direction perpendicular to the coupling hole (Y-axis) (X axis),
Provided inside the second waveguide section is a conductor wall that is substantially parallel to the electric field surface of the electromagnetic wave that surrounds and propagates around each coupling hole and around each probe arranged in the first direction (Y-axis), And the conductor walls are arranged in a plurality of rows in the second direction (X axis),
A beam scanning antenna, wherein each of the power feeding units is electrically switched between a transmission circuit and a reception circuit.

Inside the second waveguide section, the conductor wall that is substantially parallel to the electric field surface of the propagating electromagnetic wave and along the first direction (Y-axis) is separated in the second direction (X-axis) by an interval smaller than the free space wavelength. 6. The beam scanning antenna according to claim 5, wherein a plurality of the beam scanning antennas are arranged in the structure.

Inside the second waveguide section, a reflection wave suppression means is provided on the conductor wall at the end facing each coupling hole in the first direction (Y-axis), and the slot is formed in the first direction (Y 7. The beam scanning antenna according to claim 5, wherein the beam scanning antenna is arranged at an element interval corresponding to a beam tilt angle.