JP3683422B2 - Microstrip antenna and microstrip antenna substrate - Google Patents

Description

【００２７】
図３はこの発明の実施の形態１によるマイクロストリップアンテナの地導体２と無給電導体７との間の等価回路を示す説明図である。図において、１０は空気層である。そして、この場合の等価誘電率は静電近似を用いれば下記式２で概算できる。ここでは、それぞれの基板定数をε_r1，ｔ₁ ，ε_r2，ｔ₂ ，ε_r3，ｔ₃ ，としている。
【００２８】
【数２】

【００２９】
そして、この実施の形態１では、現存する誘電体材料の中に１．６１や１．３８程度の誘電率を有する材料はないので、上記第一誘電板１と第二誘電板６とに異なる誘電率を有する誘電性材料を用いている。ちなみに、発泡材やハニカム等は誘電率が１．１程度であり、テフロン系の基板では誘電率が２程度であり、これらを組み合わせている。更に具体的には、この基板材料としてシアネート系レジンやＢＴレジン（ビスマレイミドートリアジン樹脂）、低温焼結セラミックスなどを組み合わせて使用している。なお、壁状部材５としては、例えばフッ素樹脂、ＰＰＯ（ポリフェニレンオキサイド）、セラミック等を使用しており、この壁状部材５の誘電体定数、厚さ、形状、体積などは所定の方向において良好な軸比が選られるように最適な寸法に決定されている。
【００３０】
なお、ＢＴレジンは耐熱性、耐放射線性、機械的特性に優れ、宇宙空間のように温度変化が大きく環境条件の厳しい場所においての使用が可能になる。他方、低温焼成セラミックは比較的高誘電率であり、寸法精度が優れており、高周波数帯において所望の寸法精度を得るためには低誘電率基板では難しいような場合、、特にミリ波帯のように寸法精度が要求される場合には有効である。また、低温焼成セラミックは焼成温度を約９００℃に下げることができ，低抵抗の銅，銀を用いることができるため特に高周波数帯においても低損失化を図ることができ、基板厚の精度が確保できるため、バラツキが小さい。
【００３１】
次に動作について説明する。
給電用配線４から給電導体３と地導体２との間に所定の電圧を印加すると、これに応じて給電導体３と地導体２との間および無給電導体７と地導体２との間において交番電界が生成され、この電界の変化に応じて給電導体３および無給電導体７から円偏波の電波が放出される。この場合、給電導体３からの電波よりも無給電導体７からの電波の方が強い。また、この電波の放射特性は、無給電導体７と給電導体３との間には導体間空間部とともに誘電性材料からなる壁状部材５を配設することで等価誘電率を所望のものに調整しているので、円偏波のＥ面放射特性とＨ面放射特性とを概略一致させて高角度において好適な軸比となっており、しかも、無給電導体７を用いているので広帯域特性である。
【００３２】
図４はこの発明の実施の形態１による空気層１０の厚さｔ_２と軸比や帯域幅との関係の一例を示す特性図である（（ａ）は壁状部材５付きの場合、（ｂ）は壁状部材５無しの場合）。図において、λ_０は自由空間の波長であり、また、これらの図は誘電体基板としてガラスセラミックを用いてビーム走査角が６０度となる方向における特性図である。これらの図を比較すれば明らかなように、壁状部材５を使用しない場合（同図（ｂ）の場合）には軸比を最小にするためには空気層５の厚さｔ_２を０．０２波長程度に設定しなければならないが、壁状部材５を使用する場合（同図（ａ）の場合）には軸比を最小にするためには空気層５の厚さｔ_２を０．０４波長程度以上に設定することができる。しかも、このような軸比においては壁状部材５を使用しない場合よりも良好な帯域幅を同時に確保することができ、壁状部材５を使用することにより従来では得ることができなかった軸比と帯域幅との良好なバランスを得ることができることが解る。
なお、同図はアンテナに対する整合が取れた状態での空気層１０の厚さに対する軸比や帯域幅について示しているが、実際には同図（ｂ）において空気層５の厚さｔ_２を０．０２波長程度に設定してしまうとアンテナの入力インピーダンスが小さくなるため、整合を得ることが難しい。
【００３３】
また、導体間空間部の周囲に形成されるフリンジング部（無給電導体７と地導体２との間の電界が形成される部位）に誘電性材料からなる壁状部材５を設けているので、この壁状部材５を含めてアンテナの送受信波を共振させることができ、表面波の発生自体を抑制してその伝播に起因するエネルギーロスを抑制しつつ、等価誘電率の低下を効果的に抑制することができる。なお、フリンジング部は無給電導体７の周囲から送受信波の１／４波長の距離以内に形成されるものであり、この範囲内のいずれかの位置に壁状部材５を設ければ上記効果を得ることができる。また、壁状部材５の厚さを送受信波の１／２波長よりも薄く形成しても十分に効果が得られる。更に、導体間空間部内は空気層１０であるので、これによっても広帯域特性が改善されている。
【００３４】
以上のように、この実施の形態１によれば、地導体２と、当該地導体２と離間して配設された無給電導体７と、上記地導体２と上記無給電導体７との間に配設され、上記地導体２との間に所定の電圧が印加される給電導体３と、上記無給電導体７の周縁と上記給電導体３の周縁とを結んで仕切られる導体間空間部の周囲に配設され、誘電性材料からなる壁状部材５とを備えたので、無給電導体７と給電導体３との間には導体間空間部とともに誘電性材料からなる壁状部材５が配設されることになり、空気層１０を厚くした場合の等価誘電率の低下を抑制することができる。特に、この実施の形態では、導体間空間部の周囲に形成されるフリンジング部に誘電性材料からなる壁状部材５を設けているので、この壁状部材５を含めてアンテナの送受信波を共振させることができるので、表面波の発生自体を抑制してその伝播に起因するエネルギーロスを抑制しつつ、等価誘電率の低下を効果的に抑制することができる。
【００３５】
従って、導体間空間部の厚さをアンテナで送受信する電波の１／２０波長程度以上の厚さに設定して広帯域特性を得つつも、それによる等価誘電率の低下を抑制することができ、しかも、その分、第一誘電板１や第二誘電板６の厚さを厚くしたりする必要がなくなるので、これらを厚くした場合に発生する表面波伝播による損失の増大を抑制することができる。つまり、高角度における軸比、広帯域、低損失を、従来では得ることができなかった高度なレベルにてバランスさせることができる効果がある。
【００３６】
この実施の形態１によれば、壁状部材５により第一誘電板１と第二誘電板６とを一体化させることができるので、給電導体３と無給電導体７とを精度良く配設することができ、高角度における軸比、広帯域特性、低損失のバランスを設計どおりに実現することができる効果がある。
【００３７】
この実施の形態１によれば、第二誘電板６は第一誘電板１とは異なる誘電率を有する誘電性材料にて形成されているので、高角度における軸比が選られるような等価誘電率に設定することができ、広帯域を図る効果がある。
【００３８】
そして、近年、衛星搭載用アンテナにおいては、電子的にビームを走査するフェーズドアレー技術や、マルチビーム技術が多く用いられるようになってきて、広角度における軸比が良いものが要求されるようになってきているが、この実施の形態１に係るマイクロストリップアンテナ基板を用いることにより、従来用いられていた鏡面アンテナでは得られなかった高角度軸比および広帯域特性を得ることができるので、機械的走査をすることなく複数の送受信波を同時に、異なる角度に対して円偏波信号を送受信することが可能となる。なお、この実施の形態１によるマイクロストリップアンテナ基板を複数個配列したフェーズドアレーの特性は、素子間結合が生じるためマイクロストリップアンテナ基板単体の特性とは異なるが同様の傾向の特性を示す。
【００３９】
なお、ここでは給電導体３や無給電導体７として円形のものを使用したが、方形、三角形、楕円などの形状であってもこの発明は有効である。
【００４０】
また、給電方式としてマイクロストリップ線路で給電する方式を示したが，給電ピンで背面から給電する方式、トリプレート線路による給電、あるいは地導体にスロットを設け、スロットを介して電磁的に給電する電磁結合方式、あるいはマイクロストリップ線路と放射導体（３）とを近接させて給電する近接給電方式など他の給電方法でもこの発明は有効である。
【００４１】
次に、円偏波励振のための切欠部８，９の形状も限定されるものでなく、また、無給電導体７のみに設けてもよい．
【００４２】
更に、壁状部材５として円形リング状のものを例示したが、正方形，長方形，台形，菱形リングなどの他の形状であっても同様の効果を奏する。また、リング状以外のものとしても格子状あるいは棒状などのものでもよく、無給電導体７の周囲全体ではなく、特定の方向にのみ障壁を設けてもよい。
【００４３】
実施の形態２．
図５はこの発明の実施の形態２によるマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。図において、１１は地導体２の裏面に形成された第三誘電板、１２は第三誘電板１１裏面に形成された給電用配線、１３は給電用配線１２裏面に形成された第四誘電板、１４は第四誘電板１３裏面に形成された第二地導体、１５は第二地導体１４裏面に形成された第五誘電板である。そして、これらは地導体２とともにトリプレート線路を構成している。
【００４４】
また、１６は一端が給電用配線１２に接続され、他端が２つに分岐されたマッチング回路、１７はそれぞれ当該各他端を給電導体３に接続する給電プローブである。そして、このマッチング回路１６は給電電圧に基づいて互いに位相が９０°ずれた２つの励振電圧に分岐し、各給電プローブ１７，１７は各励振電圧を給電導体３の９０°ずれた位置に供給する。これにより、給電導体３および無給電導体７から円偏波の電波が放出される。なお、マッチング回路１６としては例えばブランチライン型ハイブリッド回路、ウィルキンソン型分配回路、Ｔ分岐回路、ラットレース回路などがある。
【００４５】
更に、１８は第一誘電板１の表面であって給電導体３の周囲である位置に形成され、給電導体３の外形よりも大きい内径を有し、送受信波の１／２０波長以上の厚さを有する略円筒形状の導電性材料からなる壁状部材である。これ以外の構成は実施の形態１と同様であり同一の符号を付して説明を省略する。
【００４６】
次に動作について説明する。
給電用配線１２から給電導体３と地導体２との間に所定の電圧を印加すると、これに応じて給電導体３と地導体２との間および無給電導体７と地導体２との間において交番電界が生成され、この電界の変化に応じて給電導体３および無給電導体７から円偏波の電波が放出される。この場合、給電導体３からの電波よりも無給電導体７からの電波の方が強い。また、この電波の放射特性は、第一誘電板１や第二誘電板６の誘電率や厚さを調整することにより等価誘電率を所望のものに調整しているので、円偏波のＥ面放射特性とＨ面放射特性とを概略一致させて高角度において好適な軸比となっており、しかも、無給電導体７を用いているので広帯域特性である。
【００４７】
また、導体間空間部の周囲に導電性材料からなる壁状部材１８を設けているので、この壁状部材１８により空気層における表面波の伝播を阻止することができ、複数の基板を配列した場合に発生するアンテナ素子間の結合を防止して、その伝播に起因するエネルギーロスを抑制することができる。なお、この効果は壁状部材１８の厚さを０．１ｍｍ程度に薄くしても得られるものである。
【００４８】
次に、この実施の形態２のように２点給電方式にてマイクロストリップアンテナを円偏波励振した場合には、１点給電方式で励振した場合に比べて、比較的軸比の周波数特性が比較的広帯域となる。他方、１点給電方式は放射導体（給電導体３，無給電導体７）に切欠部８，９等の変形を設け直交したモードの縮退を解くため，構造が簡単であるというメリットがある。
【００４９】
更に、給電用配線１２を多層基板としてアンテナと一体に形成しているので、数百から数千のアンテナを配列する場合であったとしても、これら給電用配線１２とアンテナとを後から積層した場合における層間接続のずれ、はがれなどの問題を生ずることなく、電気的特性の劣化も生ずることがない。
【００５０】
以上のように、この実施の形態２によれば、地導体２と、上記地導体２と離間して配設された無給電導体７と、上記地導体２と上記無給電導体７との間に配設され、上記地導体２との間に所定の電圧が印加される給電導体３と、上記無給電導体７の周縁と上記給電導体３の周縁とを結んで仕切られる導体間空間部の周囲に配設され、導電性材料からなる壁状部材１８とを備えたので、無給電導体７と給電導体３との間の導体間空間部の周囲には導電性材料からなる壁状部材１８が配設されることになる。従って、第一誘電板１や第二誘電板６の厚さを厚くしたりしたとしても、空気層における表面波の伝播を阻止することができ、表面波伝播に起因するエネルギーロスを抑制しつつ、等価誘電率の低下を効果的に抑制することができる。つまり、高角度における軸比、広帯域、低損失を、従来では得ることができなかった高度なレベルにてバランスさせることができる効果がある。また、誘電性材料にて壁状部材５を形成する場合に比べて、薄い壁厚にて上記従来に無い効果を得ることができる効果がある。
【００５１】
実施の形態３．
図６はこの発明の実施の形態３によるマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。図において、１９は第一誘電板１の表面にあって給電導体３の周囲である位置に形成され、給電導体３の外形よりも大きい断面略楕円形状の内径を有し、送受信波の１／２０波長以上の厚さを有する略円筒形状の誘電性材料からなる壁状部材である。これ以外の構成は実施の形態１と同様であり同一の符号を付して説明を省略する。
【００５２】
次に動作について説明する。
給電用配線４から給電導体３と地導体２との間に所定の電圧を印加すると、これに応じて給電導体３と地導体２との間および無給電導体７と地導体２との間において交番電界が生成され、この電界の変化に応じて給電導体３および無給電導体７から円偏波の電波が放出される。この場合、給電導体３からの電波よりも無給電導体７からの電波の方が強い。また、この電波の放射特性は、第一誘電板１や第二誘電板６の誘電率や厚さを調整することにより等価誘電率を所望のものに調整しているので、円偏波のＥ面放射特性とＨ面放射特性とを概略一致させて高角度において好適な軸比となっており、しかも、無給電導体７を用いているので広帯域特性である。
【００５３】
また、導体間空間部の周囲に断面略楕円形状の壁状部材１９を設けているので、楕円の長軸と短軸とで異なる共振状態とすることができるので、単に表面波の発生自体を抑制して、その伝播に起因するエネルギーロスを抑制しつつ、等価誘電率の低下を効果的に抑制することができるだけでなく、高角度における軸比を矯正して、更に高角度まで好適な軸比を得ることができる。
【００５４】
以上のように、この実施の形態３によれば、給電導体３および無給電導体７は円板形状に形成され、導体間空間部の周囲全体に渡って設けられる壁状部材１９には、当該導体間空間部よりも大きい断面略楕円形状の開口部が開設されているので、この開口部の軸方向を調整することにより送受信波の高角度における軸比を改善することができる効果がある。
【００５５】
なお、この実施の形態３では誘電性材料からなる壁状部材１９を前提として断面略楕円形状の場合の例を説明したが、導電性材料からなる壁状部材において断面略楕円形状としても同様の効果を得ることができる。
【００５６】
実施の形態４．
図７はこの発明の実施の形態４によるマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。図において、２０はそれぞれ地導体２に電気的に接続されたスルーホール（導電性シールド）、２１はそれぞれ地導体２に電気的に接続され、当該スルーホール２０とは異なる高さのビアホール（導電性シールド）であり、これらは給電導体３と同心円上において、アンテナの送受信波の波長よりも狭い間隔毎に配列されている。
【００５７】
また、２２は地導体２の裏面に形成された第三誘電板、２３は第三誘電板１１裏面に、給電導体３と電気的に接続される給電用配線、２４は給電導体３の中心に対応する位置において、給電用配線２３と直行する向きに延在させて地導体２に開設された略長方体形状のスロットである。これ以外の構成は実施の形態１と同様であり同一の符号を付して説明を省略する。
【００５８】
次に動作について説明する。
給電用配線２３から給電導体３と地導体２との間に所定の電圧を印加すると、電磁界的にスロット２４を介して給電導体３に交番電圧が励振され、これに応じて給電導体３と地導体２との間および無給電導体７と地導体２との間において交番電界が生成され、この電界の変化に応じて給電導体３および無給電導体７から円偏波の電波が放出される。この場合、給電導体３からの電波よりも無給電導体７からの電波の方が強い。また、この電波の放射特性は、無給電導体７と給電導体３との間には導体間空間部とともに誘電性材料からなる壁状部材５を配設することで等価誘電率を所望のものに調整しているので、円偏波のＥ面放射特性とＨ面放射特性とを概略一致させて高角度において好適な軸比となっており、しかも、無給電導体７を用いているので広帯域特性である。
【００５９】
また、導体間空間部の周囲に形成されるフリンジング部に誘電性材料からなる壁状部材５を設けているので、この壁状部材５を含めてアンテナの送受信波を共振させることができるので、表面波の発生自体を抑制してその伝播に起因するエネルギーロスを抑制しつつ、等価誘電率の低下を効果的に抑制することができる。
【００６０】
更に、壁状部材５の内部に、アンテナの送受信波の波長よりも狭い間隔毎にスルーホール２０およびビアホール２１を配列しているので、導体間空間部の周囲に導電性材料からなる壁状部材を設けた場合と同様に空気層における表面波の伝播を阻止することができ、複数の基板を隣接して配置してもその伝播に起因するエネルギーロスを抑制することができる。
【００６１】
最後に、導体間空間部の周囲に高さの異なる２種類のスルーホール２０およびビアホール２１を設けているので、一方向とそれと９０度の方向とで異なる共振状態とすることができ、単に表面波の発生自体を抑制して、その伝播に起因するエネルギーロスを抑制しつつ、等価誘電率の低下を効果的に抑制することができるだけでなく、高角度における軸比を矯正して更に高角度まで好適な軸比を得ることができる。
【００６２】
以上のように、この実施の形態４によれば、誘電性材料からなる壁状部材５の内部に、給電導体３から無給電導体７へ向かう方向に沿って延在する複数個のスルーホール２０およびビアホール２１が、アンテナの送受信波の波長よりも狭い間隔毎に配列されているので、誘電性材料による壁状部材５による効果とともに導電性材料による壁状部材の効果を併せ持つことができる。従って、誘電性材料のみで壁状部材５を形成する場合よりも薄い壁厚にしてもそれと同等のバランスを得ることができる効果がある。
【００６３】
この実施の形態４によれば、スルーホール２０とともにビアホール２１を用いているので、この長さの配列を調整することにより送受信波の高角度における軸比を改善することができる効果がある。
【００６４】
実施の形態５．
図８はこの発明の実施の形態５によるマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。図において、２５はそれぞれ第一誘電板１の表面に形成され、地導体２との間に所定の電圧が印加される略直方板形状の給電導体、２６はそれぞれ給電導体２５の配列方向において給電導体２５の配設間隔と同じ配設間隔に配列され、送受信波の１／２０波長以上の厚さを有する略長方体形状の誘電性材料からなる壁状部材であり、２７は第二誘電板６の表面であって給電導体２５と対応する位置に形成され、給電導体２５よりも小さい略直方板形状の無給電導体である。
【００６５】
また、２８はそれぞれ、地導体２の周縁部に接続され、その下端２８ａから先端までの長さＬがアンテナの送受信波の波長の１／４の長さに形成されるとともに、その先端部が互いにショートされているチョークである。これ以外は図２と同様であり同一の符号を付して説明を省略する。
【００６６】
次に動作について説明する。
図示外の給電用配線から給電導体２５と地導体２との間に９０°位相がずれた２つの電圧を印加すると、給電導体２５に交番電圧が励振され、これに応じて給電導体２５と地導体２との間および無給電導体２７と地導体２との間において交番電界が生成され、この電界の変化に応じて給電導体２５および無給電導体２７から円偏波の電波が放出される。この場合、給電導体２５からの電波よりも無給電導体２７からの電波の方が強い。また、この電波の放射特性は、無給電導体２７と給電導体２５との間には導体間空間部とともに誘電性材料からなる壁状部材２６を配設することで等価誘電率を所望のものに調整しているので、円偏波のＥ面放射特性とＨ面放射特性とを概略一致させて高角度において好適な軸比となっており、しかも、無給電導体２７を用いているので広帯域特性である。
【００６７】
以上のように、この実施の形態５によれば、地導体２の周縁部にはアンテナの送受信波の波長の１／４の長さの多数のチョーク２８が配列され、且つ、この複数のチョーク２８の先端部が互いにショートされているので、地導体２の大きさを小さくしても、地導体２裏面への放射を抑制することができる。特に、地導体２の大きさを小さくした場合、広角度においてはこの地導体２裏面への放射が顕著に発生し、その裏面の構造体の影響を受けて放射特性が変化し、その結果、軸比の変動、利得低下、裏側に配接された送受信機への電波漏れ込みによるアイソレーション劣化などの問題が発生してしまうが、本発明のように、地導体２の周囲に終端が互いにショートされたチョーク２８を設けることにより、地導体２端部の電界成分を「０」とすることができるので、これらの問題点を防止することができる効果がある。
【００６８】
実施の形態６．
図９はこの発明の実施の形態６によるマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。図において、２９は格子形状に形成された誘電性材料からなるスペーサであり、このスペーサ２９には各導体間空間部よりも大きい断面略四角形状の複数の開口部が開設されている。これ以外の構成は図５および図８と同様の構成なので同一の符号を付して説明を省略する。
【００６９】
次に動作について説明する。
給電用配線１２から給電導体２５と地導体２との間に９０°位相がずれた２つの電圧を印加すると、給電導体２５に交番電圧が励振され、これに応じて給電導体２５と地導体２との間および無給電導体２７と地導体２との間において交番電界が生成され、この電界の変化に応じて給電導体２５および無給電導体２７から円偏波の電波が放出される。この場合、給電導体２５からの電波よりも無給電導体２７からの電波の方が強い。また、この電波の放射特性は、無給電導体２７と給電導体２５との間には導体間空間部とともに誘電性材料からなる壁状部材２９を配設することで等価誘電率を所望のものに調整しているので、円偏波のＥ面放射特性とＨ面放射特性とを概略一致させて高角度において好適な軸比となっており、しかも、無給電導体２７を用いているので広帯域特性である。
【００７０】
なお、ここでは４つのアンテナを四角配列としたが、三角配列であってもよく、また、２個、１６個などのようにアンテナの素子数に制限はない。また、軸比の改善を図るために基板内でシーケンシャルアレーとしてもよい。次に、ここでは円偏波励振用給電回路とアンテナとを一体化する構成を示したが、送受信機をも含めて一体化してもよい。そして、このように多層基板を用いてアレーアンテナ及びサブアレーを構成することで製作が容易になり、量産性が優れる効果がある。
【００７１】
以上のように、この実施の形態６によれば、誘電性材料からなる第一誘電板１と、当該第一誘電板１の裏面に形成された地導体２と、上記第一誘電板１の表面に形成され、上記地導体板２との間に所定の電圧が印加される複数個の給電導体２５と、上記第一誘電板１の表面に形成され、上記複数個の給電導体２５と同様の相互配設間隔にて複数個の開口部が開設された誘電性材料からなるスペーサ２９と、当該スペーサ２９の表面に形成され、誘電性材料からなる第二誘電板６と、当該第二誘電板６の表面あるいは裏面であって上記各給電導体２５と対応する位置に形成された複数個の無給電導体２７とを備えたので、無給電導体２７と給電導体２５との間には導体間空間部とともに誘電性材料からなるスペーサ２９が配設されることになり、空気層を厚くした場合の等価誘電率の低下を抑制することができる。特に、この実施の形態６では、導体間空間部の周囲に形成されるフリンジング部に誘電性材料からなるスペーサ２９を設けているので、このスペーサ２９を含めてアンテナの送受信波を共振させることができ、表面波の発生自体を抑制してその伝播に起因するエネルギーロスを抑制しつつ、等価誘電率の低下を効果的に抑制することができる。
【００７２】
従って、導体間空間部の厚さをアンテナで送受信する電波の１／２０波長程度以上の厚さに設定して広帯域特性を得つつも、それによる等価誘電率の低下を抑制することができ、しかも、その分第一誘電板１や第二誘電板６の厚さを厚くしたりする必要がなくなるので、表面波伝播による損失の増大を抑制することができる。つまり、高角度における軸比、広帯域、低損失を従来では得ることができなかった高度なレベルにてバランスさせることができる効果がある。
【００７３】
また、スペーサ２９により第一誘電板１と第二誘電板６とを一体化させることができるので、給電導体２５と無給電導体２７とを精度良く配設することができ、各アンテナの特性を高角度における軸比、広帯域特性、低損失のバランスを設計どおりに、且つ、同等の特性に実現することができる効果がある。
【００７４】
この実施の形態６によれば、スペーサ２９はその各開口部が、各無給電導体２７の周縁と各給電導体２５の周縁とを結んで仕切られる各導体間空間部に対応する位置となるように配設されているので、最も広帯域な特性を得ることができる効果がある。
【００７５】
この実施の形態６によれば、第三誘電板１１上に給電導体２５と電気的に接続される給電用配線１２を形成したので、給電回路自体も一体化させ、それを含めて高角度における軸比、広帯域、低損失を従来では得ることができなかった高度なレベルにてバランスさせることができるので、給電方法に起因するこれらの特性劣化を防止することができる効果がある。
【００７６】
実施の形態７．
図１０はこの発明の実施の形態７によるマイクロストリップアンテナ基板の１つのアンテナの構造を示す部分分解斜視図および断面図である。図において、３０は格子形状に形成され、各交叉位置が給電導体３と無給電導体７の中心部と重なるように配設された誘電性材料からなるスペーサであり、３１はこのスペーサ３０の各交叉位置に開設された中空のスルーホール、３２はこのスルーホール３１を介して地導体２と無給電導体７の中心部とを接続する接地導体である。
【００７７】
なお、円偏波を得るためには直交したモードの縮退を解く必要があるので、２つの誘電体棒３０ａ（各格子を構成する誘電体のこと）を給電位置に対して斜め４５°方向にそれぞれ挿入し，両者の幅をそれぞれ適当に変えている。これにより直交したモードの共振周波数が変化し円偏波を励振することができる。また、２本の誘電体棒３０ａを給電位置から斜め４５°方向から各々ずらしてその角度を変えることでも直交したモードの縮退を解くことができる。
【００７８】
次に動作について説明する。
給電用配線４から給電導体３と地導体２との間に所定の電圧を印加すると、これに応じて給電導体３と地導体２との間および無給電導体７と地導体２との間において交番電界が生成され、この電界の変化に応じて給電導体３および無給電導体７から円偏波の電波が放出される。この場合、給電導体３からの電波よりも無給電導体７からの電波の方が強い。また、この電波の放射特性は、無給電導体７と給電導体３との間には導体間空間部とともに誘電性材料からなるスペーサ３０を配設することで等価誘電率を所望のものに調整しているので、円偏波のＥ面放射特性とＨ面放射特性とを概略一致させて高角度において好適な軸比となっており、しかも、無給電導体７を用いているので広帯域特性である。
【００７９】
また、導体間空間部をスペーサ３０で微小区間毎に区切っているので、このスペーサ３０により空気層における表面波の伝播を阻止することができ、その伝播に起因するエネルギーロスを抑制することができる。
【００８０】
更に、無給電導体７をその電界成分が０である中心部において地導体２に接地しているので、無給電導体７の放射特性を損なうことなく、この無給電導体７が帯電してしまうことを防止することができる。
【００８１】
以上のように、この実施の形態７によれば、スペーサ３０は各無給電導体７の中心部には各開口部が対応しないように配設されるとともに当該中心部に対応する位置にスルーホール３１が形成され、当該スルーホール３１を介して各無給電導体７が地導体２と電気的に接続されているので、無給電導体７からの放射特性に悪影響を及ぼすことなくこの無給電導体７の帯電を防止することができ、放電や落雷などによって無給電導体７に高電圧が印加されてしまうことを防止することができる効果がある。
【００８２】
実施の形態８．
図１１はこの発明の実施の形態８による複数のマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。図において、３３は第五誘電板１５裏面に形成された第二の給電用配線、３４はこの第二の給電用配線３３裏側に配設された第六誘電板であり、３５は多層基板であり、第一誘電板１からこの第六誘電板３４までの厚さＬがアンテナの送受信波の１／４波長と等しくなるようにこの多層基板３５は形成されている。
【００８３】
また、３６は多層基板３５側面全面に蒸着された側面メタライズ部（被覆膜）、３７は第一誘電板１表面周縁部全体に蒸着された上面メタライズ部（被覆膜）、３８は第六誘電板３４裏面全体に渡って蒸着された下面メタライズ部（被覆膜）であり、３９はそれぞれこれらメタライズ部３６，３７，３８を上記上面の第一誘電板１および下面の第六誘電板３４において地導体２に電気的に接続するスルーホールである。これ以外の構成は図５および図９と同様なので同一の符号を付して説明を省略する。
【００８４】
次に動作について説明する。
給電用配線１２や第二の給電用配線３３から給電導体２５と地導体２との間に９０°位相がずれた２つの電圧を印加すると、給電導体２５に交番電圧が励振され、これに応じて給電導体２５と地導体２との間および無給電導体２７と地導体２との間において交番電界が生成され、この電界の変化に応じて給電導体２５および無給電導体２７から円偏波の電波が放出される。この場合、給電導体２５からの電波よりも無給電導体２７からの電波の方が強い。また、この電波の放射特性は、無給電導体２７と給電導体２５との間には導体間空間部とともに誘電性材料からなる壁状部材を配設することで等価誘電率を所望のものに調整しているので、円偏波のＥ面放射特性とＨ面放射特性とを概略一致させて高角度において好適な軸比となっており、しかも、無給電導体２７を用いているので広帯域特性である。
【００８５】
また、多層基板３５の側面に１／４波長の長さの側面メタライズ部３６を設けるとともに、その両端部に連続して上面メタライズ部３７および下面メタライズ部３８を設けた構造となっているので、複数の多層基板３５を近接して配置することにより、送受信波の周波数においては側面メタライズ部３６の両端部をオープン状態とすることができ、これら複数の多層基板３５，３５の間から当該送受信波が裏側に回り込みにくくすることができる。
【００８６】
また、このように複数の多層基板３５，３５を近接して配置して基板間の隙間にてチョークを構成しているので、実施の形態５に比べて簡易に、且つ、多層基板３５と一体化させてチョークを構成することができ、しかも、複数の多層基板３５，３５を高密度に配列することができる。
【００８７】
以上のように、この実施の形態８によれば、側面の長さがアンテナの送受信波の波長の１／４の長さとなるように多層基板３５を形成するとともに、少なくともその多層基板３５の側面、表面１周縁部および裏面３４周縁部を導電性材料からなる被覆膜であるメタライズ部３６，３７，３８にて被覆し、更に、地導体２の周縁部と上記表面周縁部の上面メタライズ部３７および裏面周縁部の下面メタライズ部３８の被覆膜とを複数のスルーホール３９を用いて電気的に接続するので、複数の多層基板３５，３５を高密度に隣接して配置することで当該被覆膜である側面メタライズ部３６の上面側端縁や下面側端縁において上記アンテナの送受信波に関してはオープン状態とすることができるので、これら多層基板３５，３５の間から裏面に上記アンテナの送受信波が回り込むことを防止することができ、軸比の変動、利得低下、裏側に配接された送受信機への電波漏れ込みによるアイソレーション劣化などの問題を防止することができる効果がある。
【００８８】
【発明の効果】
この発明によれば、地導体と、当該地導体と離間して配設された無給電導体と、上記地導体と上記無給電導体との間に配設され、上記地導体との間に所定の電圧が印加される給電導体と、上記無給電導体の周縁と上記給電導体の周縁とを結んで仕切られる導体間空間部の周囲に配設され、送受信波の波長の１／２０以上の厚さを有する略円筒形状の誘電性材料からなる壁状部材とを備えるように構成したので、無給電導体と給電導体との間の導体間空間部の厚さをアンテナで送受信する電波の１／２０波長以上の厚さに設定することができて広帯域特性を得ることができると共に、上述のような略円筒形状の壁状部材を含めてアンテナの送受信波を共振させることができることにより、表面波の発生自体を抑制してその伝播に起因するエネルギーロスを抑制しつつ、等価誘電率の低下を効果的に抑制することができる。
【００８９】
従って、導体間空間部の厚さをアンテナで送受信する電波の１／２０波長程度以上の厚さに設定して広帯域特性を得つつも、それによる等価誘電率の低下を抑制することができ、しかも、その分第一誘電板や第二誘電板の厚さを厚くしたりする必要がなくなるので、表面波伝播による損失の増大を抑制することができる。つまり、高角度における軸比、広帯域、低損失を従来では得ることができなかった高度なレベルにてバランスさせることができる効果がある。
【００９１】
この発明によれば、給電導体および無給電導体が円板形状に形成され、壁状部材には、導体間空間部よりも大きい断面略楕円形状の開口部が開設されているので、この開口部の軸方向を調整することにより送受信波の高角度における軸比を改善することができる効果がある。
【００９２】
この発明によれば、壁状部材の内部あるいは表面には、給電導体から無給電導体へ向かう方向に沿って導電性シールドが複数延在し、その導電性シールドは、送受信波の波長よりも狭い間隔毎に配列されているので、誘電性材料による壁状部材による効果とともに導電性材料による壁状部材による効果を得ることができる。従って、誘電性材料のみで壁状部材を形成する場合よりも薄い壁厚にしてもそれと同等のバランスが得られる効果がある。
【００９３】
この発明によれば、壁状部材の内部あるいは表面には、給電導体から無給電導体へ向かう方向の長さが異なる複数種類の導電性シールドが延在しているので、この長さの配列を調整することにより送受信波の高角度における軸比を改善することができる効果がある。
【００９４】
この発明によれば、地導体の周縁部には送受信波の波長の１／４の長さの多数のチョークが配列され、且つ、この複数のチョークの先端部が互いにショートされているので、地導体の大きさを小さくしても、地導体裏面への放射を抑制することができる。特に、地導体の大きさを小さくした場合、広角度においてはこの地導体裏面への放射が顕著に発生し、その裏面の構造体の影響を受けて放射特性が変化し、その結果、軸比の変動、利得低下、裏側に配接された送受信機への電波漏れ込みによるアイソレーション劣化などの問題が発生してしまうが、本発明のように、地導体の周囲に終端が互いにショートされたチョークを設けることにより、地導体端部の電界成分を「０」とすることができるので、これらの問題点を防止することができる。
【００９５】
この発明によれば、誘電性材料からなる第一誘電板と、当該第一誘電板の裏面に形成された地導体と、上記第一誘電板の表面に形成され、上記地導体板との間に所定の電圧が印加される給電導体と、上記第一誘電板の表面であって上記給電導体の周囲である位置に形成され、誘電性材料からなる壁状部材と、当該壁状部材の表面に形成され、誘電性材料からなる第二誘電板と、当該第二誘電板の表面あるいは裏面であって上記給電導体と対応する位置に形成された無給電導体とを備えたので、無給電導体と給電導体との間には導体間空間部とともに誘電性材料からなる壁状部材が配設されることになり、空気層を厚くした場合の等価誘電率の低下を抑制することができる。特に、この発明では、導体間空間部の周囲に形成されるフリンジング部に誘電性材料からなる壁状部材を設けているので、この壁状部材を含めてアンテナの送受信波を共振させることができ、表面波の発生自体を抑制してその伝播に起因するエネルギーロスを抑制しつつ、等価誘電率の低下を効果的に抑制することができる。
【００９６】
従って、導体間空間部の厚さをアンテナで送受信する電波の１／２０波長程度以上の厚さに設定して広帯域特性を得つつも、それによる等価誘電率の低下を抑制することができ、しかも、その分第一誘電板や第二誘電板の厚さを厚くしたりする必要がなくなるので、表面波伝播による損失の増大を抑制することができる。つまり、高角度における軸比、広帯域、低損失を従来では得ることができなかった高度なレベルにてバランスさせることができる効果がある。
【００９７】
また、壁状部材により第一誘電板と第二誘電板とを一体化させることができるので、給電導体と無給電導体とを精度良く配設することができ、高角度における軸比、広帯域特性、低損失のバランスを設計どおりに実現することができる効果がある。
【０１０３】
この発明によれば、第一誘電板上あるいは地導体の裏側に形成した第三誘電板の裏側に、給電導体と電気的に接続される給電用配線を形成したので、給電回路自体も一体化させ、それを含めて高角度における軸比、広帯域、低損失を従来では得ることができなかった高度なレベルにてバランスさせることができるので、給電方法に起因するこれらの特性劣化を防止することができる効果がある。
【０１０４】
この発明によれば、誘電性材料からなる壁状部材には送受信波の波長よりも狭い間隔毎にスルーホールおよび／またはビアホールを複数個開設し、上記スルーホールあるいはビアホール内にはそれぞれ導電性シールドが形成されているので、誘電性材料による壁状部材による効果とともに導電性材料による壁状部材による効果を得ることができる。従って、誘電性材料のみで壁状部材を形成する場合よりも薄い壁厚にしてもそれと同等のバランスが得られる効果がある。
【０１０５】
この発明によれば、第二誘電板は第一誘電板とは異なる誘電率を有する誘電性材料にて形成されているので、高角度における軸比が選られるような等価誘電率に設定することができる効果がある。
【０１０６】
この発明によれば、第一誘電板の給電導体と反対側に形成された第一誘電板を含む多層基板の側面の長さを送受信波の波長の１／４の長さとし、少なくともその多層基板の側面、表面周縁部および裏面周縁部を導電性材料からなる被覆膜にて被覆し、更に、地導体の周縁部と上記表面周縁部および裏面周縁部の被覆膜とを複数のスルーホールあるいはビアホールを用いて電気的に接続するので、多数の基板を高密度に隣接して配置することで当該被覆膜の上面側端縁や下面側端縁において、上記アンテナの送受信波に関してはオープン状態とすることができるので、これら基板の間から裏面に上記アンテナの送受信波が回り込むことを防止することができ、軸比の変動、利得低下、裏側に配接された送受信機への電波漏れ込みによるアイソレーション劣化などの問題を防止することができる効果がある。
【図面の簡単な説明】
【図１】 この発明の実施の形態１によるマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。
【図２】 この発明の実施の形態１によるマイクロストリップアンテナにおいて、円形マイクロストリップアンテナの基本モードの場合に、軸比が「１」となる角度（放射方向）と地導体２と無給電導体７との間の誘電率との関係を示す特性図である。
【図３】 この発明の実施の形態１によるマイクロストリップアンテナの地導体２と無給電導体７との間の等価回路を示す説明図である。
【図４】 この発明の実施の形態１による空気層１０の厚さｔ_２と軸比や帯域幅との関係の一例を示す特性図である（（ａ）は壁状部材５付きの場合、（ｂ）は壁状部材５無しの場合）。
【図５】 この発明の実施の形態２によるマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。
【図６】 この発明の実施の形態３によるマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。
【図７】 この発明の実施の形態４によるマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。
【図８】 この発明の実施の形態５によるマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。
【図９】 この発明の実施の形態６によるマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。
【図１０】 この発明の実施の形態７によるマイクロストリップアンテナ基板の１つのアンテナの構造を示す部分分解斜視図および断面図である。
【図１１】 この発明の実施の形態８による複数のマイクロストリップアンテナ基板の構造を示す部分分解斜視図および断面図である。
【図１２】 従来のマイクロストリップアンテナ基板を示す断面図である。
【符号の説明】
１ 第一誘電板、２ 地導体、３，２５ 給電導体、４，１２，２３，３３ 給電用配線、５，１８，１９，２６ 壁状部材、６ 第二誘電板、７，２７ 無給電導体、２０ スルーホール（導電性シールド）、２１ ビアホール（導電性シールド）、２８ チョーク、２９，３０ スペーサ、３１ スルーホール、３６ 側面メタライズ部（被覆膜）、３７ 上面メタライズ部（被覆膜）、３８ 下面メタライズ部（被覆膜）、３９ スルーホール。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a microstrip antenna and a microstrip antenna substrate for transmitting and receiving radio waves, and in particular, has a parasitic conductor and highly balances the axial ratio, wideband, and low loss at a high angle, and circularly polarized waves in satellites and the like. The present invention relates to a microstrip antenna and a microstrip antenna substrate suitable for scanning radio waves.
[0002]
[Prior art]
12 shows a “broadband coplanar circularly polarized microstrip array antenna” (Hori, Nakajima, IEICE Transactions (B) Vol. J68-B No. 4, pp. 515-522, published in April 1985). 1 is a cross-sectional view illustrating a conventional microstrip antenna substrate disclosed in FIG. In the figure, 1 is a first dielectric plate made of a dielectric material, 2 is a ground conductor formed on the back surface of the first dielectric plate 1, and 3 is a surface formed on the surface of the first dielectric plate 1 and between the ground conductor 2. A substantially disc-shaped power supply conductor to which a predetermined voltage is applied to 4, 4 is formed on the surface of the first dielectric plate 1 and connected to the power supply conductor 3, and 40 is connected to the surface of the first dielectric plate 1. A foamed member made of foamed polystyrene, foamed urethane, or the like, 6 is a second dielectric plate formed on the surface of the foamed member 40 and made of a dielectric material, and 7 is a surface of the second dielectric plate 6, It is a substantially disk-shaped non-feeding conductor formed at a corresponding position and having a slightly smaller radius than the feeding conductor 3. Reference numeral 8 denotes a feed conductor cutout formed at a position 90 degrees apart from the feed wiring connection position of the feed conductor 3.
[0003]
Next, the operation will be described.
When a predetermined voltage is applied between the power supply wiring 4 and the power supply conductor 3 and the ground conductor 2, between the power supply conductor 3 and the ground conductor 2 and between the parasitic conductor 7 and the ground conductor 2 accordingly. An alternating electric field is generated, and circularly polarized radio waves are emitted from the feeding conductor 3 and the parasitic conductor 7 in accordance with the change in the electric field.
[0004]
Since this conventional microstrip antenna substrate uses the parasitic conductor 7 and becomes the main radiating conductor, it is possible to obtain broadband characteristics as compared with those not using the parasitic conductor 7, and it is simple. A circularly polarized wave can be excited by a simple feeding method. Other antennas that can excite circularly polarized waves include helical antennas, spiral antennas, and crossed dipoles, but microstrip antennas are easier to manufacture than these, and are more reliable. Is expensive.
[0005]
[Problems to be solved by the invention]
Since the conventional microstrip antenna substrate is configured as described above, when attempting to obtain broadband characteristics by reducing the height of Q, the thickness of the foamed member 40 containing air is transmitted and received by the antenna. It is necessary to set the thickness to about 1/20 wavelength or more of the radio wave to be transmitted. For this reason, the equivalent dielectric constant between the parasitic conductor 7 as the main radiation conductor and the ground conductor 2 becomes too small, and the radiation on the E plane The directivity becomes sharper than the radiation directivity of the H-plane, and “a circularly polarized microstrip antenna with a wide angle and good axial ratio” (Naohisa Goto, IEICE Technical Report A. P81-39, 81) There is a problem that it is not possible to obtain an equivalent dielectric constant (about 1.7 to 1.3) at which a good axial ratio at a wide angle as shown in (Issue) is obtained.
[0006]
Further, in order to improve the axial ratio at a wide angle while obtaining broadband characteristics, the thickness of the first dielectric plate 1 and the second dielectric plate 6 is increased corresponding to the thickness of the foamed member 40 containing air. If a dielectric material having a high dielectric constant is used, the surface wave component propagating in each layer 1, 40, 6 between the ground conductor 2 and the parasitic conductor 7 is increased. As a result, another problem of increased energy loss in the antenna occurs.
[0007]
The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a microstrip antenna and a microstrip antenna substrate capable of highly balancing the axial ratio, wideband, and low loss at a high angle. To do.
[0008]
[Means for Solving the Problems]
A microstrip antenna according to the present invention is provided between a ground conductor, a parasitic conductor spaced apart from the ground conductor, and between the ground conductor and the parasitic conductor. A power supply conductor to which a predetermined voltage is applied, and a periphery of the inter-conductor space section partitioned by connecting the periphery of the parasitic conductor and the periphery of the power supply conductor; A substantially cylindrical shape having a thickness of 1/20 or more of the wavelength of the transmission / reception wave And a wall-shaped member made of a dielectric material.
[0010]
A microstrip antenna according to the present invention includes a feeding conductor and a parasitic conductor But Formed in a disk shape, The wall-shaped member has a space between conductors. An opening having a substantially elliptical cross section larger than that is opened.
[0011]
The microstrip antenna according to the present invention is Wall member Inside or on the surface of the wire along the direction from the feed conductor to the parasitic conductor A plurality of conductive shields extend, and the conductive shields Are arranged at intervals that are narrower than the wavelength.
[0012]
The microstrip antenna according to the present invention is On the inside or surface of the wall member, Multiple types of conductive shields with different lengths from the feed conductor to the parasitic conductor Is extended Is.
[0013]
The microstrip antenna according to the present invention is provided on the peripheral edge of the ground conductor. Transmission / reception wave A large number of chokes having a length of ¼ of the wavelength are arranged, and the tip portions of the plurality of chokes are short-circuited to each other.
[0014]
The microstrip antenna substrate according to the present invention includes a first dielectric plate made of a dielectric material, a ground conductor formed on the back surface of the first dielectric plate, and a surface of the first dielectric plate. A power supply conductor to which a predetermined voltage is applied between the plate, a wall-like member made of a dielectric material formed on a surface of the first dielectric plate and around the power supply conductor, and the wall Comprising a second dielectric plate made of a dielectric material and a parasitic conductor formed on the front or back surface of the second dielectric plate at a position corresponding to the feeder conductor. It is.
[0018]
The microstrip antenna substrate according to the present invention is a third dielectric plate formed on the first dielectric plate or on the back side of the ground conductor. Back of Further, a power supply wiring electrically connected to the power supply conductor is formed.
[0019]
The microstrip antenna substrate according to the present invention is made of a dielectric material. Transmitting and receiving waves on wall-like members A plurality of through holes and / or via holes are opened at intervals shorter than the wavelength of the above, and a conductive shield is formed in each of the through holes or via holes.
[0020]
In the microstrip antenna substrate according to the present invention, the second dielectric plate is formed of a dielectric material having a dielectric constant different from that of the first dielectric plate.
[0021]
A microstrip antenna substrate according to the present invention includes: The length of the side surface of the multilayer substrate including the first dielectric plate formed on the side opposite to the feeding conductor of the first dielectric plate is ¼ of the wavelength of the transmission / reception wave, At least that Multilayer board The side surface, the front surface peripheral portion, and the back surface peripheral portion are coated with a coating film made of a conductive material, and the peripheral edge portion of the ground conductor and the coating film on the front surface peripheral portion and the back surface peripheral portion are formed into a plurality of through holes. Alternatively, they are electrically connected using via holes.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below.
Embodiment 1 FIG.
1 is a partially exploded perspective view and a sectional view showing a structure of a microstrip antenna substrate according to Embodiment 1 of the present invention. In the figure, 1 is a first dielectric plate made of a dielectric material, 2 is a ground conductor formed on the back surface of the first dielectric plate 1, and 3 is a surface formed on the surface of the first dielectric plate 1 and between the ground conductor 2. A substantially disc-shaped power supply conductor to which a predetermined voltage is applied to 4, 4 is formed on the surface of the first dielectric plate 1, and a power supply wiring connected to the power supply conductor 3, 5 is a surface of the first dielectric plate 1. A wall made of a substantially cylindrical dielectric material that is formed at a position around the power supply conductor 3, has an inner diameter larger than the outer shape of the power supply conductor 3, and has a thickness of 1/20 wavelength or more of transmission / reception waves. 6 is formed on the surface of the wall-shaped member 5, and the second dielectric plate 7 made of a dielectric material is formed on the surface of the second dielectric plate 6 at a position corresponding to the power supply conductor 3. 3 is a substantially disk-shaped parasitic conductor having a radius slightly smaller than 3.
[0023]
Reference numeral 8 denotes a feed conductor cutout portion formed at a position 90 degrees apart from the feed wiring connection position of the feed conductor 3, and reference numeral 9 denotes a blank formed at a position corresponding to each feed conductor cutout portion 8. It is a feed conductor cutout. These cut-out portions 8 and 9 can solve the orthogonal mode degeneration, generate circularly polarized electromagnetic waves from the feed conductor 3 in spite of the single point feed, and the parasitic conductor 7 in the same manner. Circularly polarized electromagnetic waves are generated.
[0024]
FIG. 2 shows the microstrip antenna according to Embodiment 1 of the present invention, in the case of the fundamental mode of the circular microstrip antenna, the angle (radiation direction) at which the axial ratio is “1”, the ground conductor 2 and the parasitic conductor 7. It is a characteristic view which shows the relationship with the dielectric constant between. In the figure, the horizontal axis represents an angle in a predetermined radiation direction with respect to the normal direction of the microstrip antenna, and the vertical axis represents the dielectric constant. From this figure, for example, it is necessary to set the relative dielectric constant to 1.61 when it is desired to secure 30 ° as θd, and to be 1.38 when it is desired to ensure 60 ° as θd. .
[0025]
The axial ratio (AR) in the basic mode of the circular microstrip antenna can be calculated by the following equation 1. Where a is the radius of the circular microstrip antenna (parasitic conductor 7), ε _r Is the relative dielectric constant of the substrate, J ₀ , J ₂ Is a 0th-order and 2nd-order Bessel function, and this expression is obtained when the frequency is limited to a specific frequency. In order to improve the axial ratio, the directivities of the E plane and the H plane need only be matched. Here, the directivity of the E plane is almost determined, so the directivity of the E plane is controlled. . As can be seen from Equation 1, the directivity is the dielectric constant ε of the substrate. _r The dielectric constant ε of the substrate _r It can be seen that the axial ratio can be improved by appropriately selecting.
[0026]
[Expression 1]

[0027]
FIG. 3 is an explanatory diagram showing an equivalent circuit between the ground conductor 2 and the parasitic conductor 7 of the microstrip antenna according to the first embodiment of the present invention. In the figure, 10 is an air layer. In this case, the equivalent dielectric constant can be approximated by the following formula 2 using electrostatic approximation. Here, each substrate constant is expressed as ε _r1 , T ₁ , Ε _r2 , T ₂ , Ε _r3 , T _Three , And.
[0028]
[Expression 2]

[0029]
In the first embodiment, there is no material having a dielectric constant of about 1.61 or 1.38 among the existing dielectric materials, so the first dielectric plate 1 and the second dielectric plate 6 are different. A dielectric material having a dielectric constant is used. Incidentally, the dielectric constant of foam material, honeycomb, etc. is about 1.1, and the dielectric constant of Teflon-based substrates is about 2, and these are combined. More specifically, a cyanate resin, a BT resin (bismaleimide-triazine resin), a low-temperature sintered ceramic, or the like is used in combination as the substrate material. For example, a fluororesin, PPO (polyphenylene oxide), ceramic, or the like is used as the wall member 5, and the dielectric constant, thickness, shape, volume, etc. of the wall member 5 are good in a predetermined direction. The optimum dimension is determined so that a proper axial ratio can be selected.
[0030]
The BT resin is excellent in heat resistance, radiation resistance and mechanical properties, and can be used in places where the temperature is large and the environmental conditions are severe, such as in space. On the other hand, low-temperature fired ceramics have a relatively high dielectric constant and excellent dimensional accuracy, and it is difficult to obtain a desired dimensional accuracy in a high frequency band, especially in the millimeter wave band. This is effective when dimensional accuracy is required. The low-temperature fired ceramic can lower the firing temperature to about 900 ° C., and can use low resistance copper and silver. Therefore, the loss can be reduced especially in a high frequency band, and the accuracy of the substrate thickness can be improved. Because it can be secured, the variation is small.
[0031]
Next, the operation will be described.
When a predetermined voltage is applied between the power supply wiring 4 and the power supply conductor 3 and the ground conductor 2, between the power supply conductor 3 and the ground conductor 2 and between the parasitic conductor 7 and the ground conductor 2 accordingly. An alternating electric field is generated, and circularly polarized radio waves are emitted from the feeding conductor 3 and the parasitic conductor 7 in accordance with the change in the electric field. In this case, the radio wave from the parasitic conductor 7 is stronger than the radio wave from the feed conductor 3. In addition, the radio wave radiation characteristic is obtained by providing a wall-like member 5 made of a dielectric material together with a space between conductors between the parasitic conductor 7 and the feeder conductor 3 to achieve a desired equivalent dielectric constant. Since the adjustment is made, the E-plane radiation characteristic and the H-plane radiation characteristic of circular polarization are approximately matched to provide a suitable axial ratio at a high angle, and since the parasitic conductor 7 is used, the broadband characteristic is obtained. It is.
[0032]
FIG. 4 shows the thickness t of the air layer 10 according to the first embodiment of the present invention. ₂ FIG. 6 is a characteristic diagram showing an example of the relationship between the axis ratio and the bandwidth (when (a) is with the wall-shaped member 5 and (b) is without the wall-shaped member 5). In the figure, λ ₀ Is a wavelength in free space, and these figures are characteristic diagrams in a direction in which a glass ceramic is used as a dielectric substrate and a beam scanning angle is 60 degrees. As is clear from comparison of these figures, the thickness t of the air layer 5 is minimized in order to minimize the axial ratio when the wall-like member 5 is not used (in the case of FIG. 5B). ₂ Must be set to about 0.02 wavelength. However, when the wall-like member 5 is used (in the case of FIG. 5A), the thickness t of the air layer 5 is minimized in order to minimize the axial ratio. ₂ Can be set to about 0.04 wavelength or more. Moreover, in such an axial ratio, a better bandwidth can be ensured at the same time than when the wall-shaped member 5 is not used, and an axial ratio that could not be obtained conventionally by using the wall-shaped member 5. It can be seen that a good balance between bandwidth and bandwidth can be obtained.
Although the figure shows the axial ratio and bandwidth with respect to the thickness of the air layer 10 in a state where the antenna is matched, the thickness t of the air layer 5 is actually shown in FIG. ₂ Is set to about 0.02 wavelength, the input impedance of the antenna becomes small, and it is difficult to obtain matching.
[0033]
Moreover, since the wall-like member 5 made of a dielectric material is provided in the fringing part (the part where the electric field between the parasitic conductor 7 and the ground conductor 2 is formed) formed around the inter-conductor space part. The transmission / reception wave of the antenna including this wall-shaped member 5 can be resonated, and the generation of surface wave itself is suppressed to effectively suppress the energy loss caused by the propagation while effectively reducing the equivalent dielectric constant. Can be suppressed. The fringing portion is formed within a distance of ¼ wavelength of the transmission / reception wave from the periphery of the parasitic conductor 7, and if the wall-like member 5 is provided at any position within this range, the above effect is obtained. Can be obtained. Further, even if the thickness of the wall-like member 5 is made thinner than a half wavelength of the transmission / reception wave, a sufficient effect can be obtained. Furthermore, since the space between the conductors is the air layer 10, this also improves the broadband characteristics.
[0034]
As described above, according to the first embodiment, the ground conductor 2, the parasitic conductor 7 disposed away from the ground conductor 2, and the ground conductor 2 and the parasitic conductor 7 are interposed. A power supply conductor 3 to which a predetermined voltage is applied between the ground conductor 2 and an inter-conductor space section that connects and partitions the periphery of the parasitic conductor 7 and the periphery of the power supply conductor 3. Since the wall-like member 5 made of a dielectric material is disposed around the wall-like member 5, the wall-like member 5 made of a dielectric material is disposed between the parasitic conductor 7 and the power feed conductor 3 together with the inter-conductor space portion. Therefore, it is possible to suppress a decrease in equivalent dielectric constant when the air layer 10 is thickened. In particular, in this embodiment, since the wall-shaped member 5 made of a dielectric material is provided in the fringing portion formed around the inter-conductor space portion, the transmission / reception wave of the antenna including the wall-shaped member 5 is transmitted. Since it is possible to resonate, it is possible to effectively suppress the reduction of the equivalent dielectric constant while suppressing the generation of the surface wave itself and the energy loss caused by the propagation.
[0035]
Therefore, while setting the thickness of the space between the conductors to a thickness of about 1/20 wavelength or more of the radio wave transmitted and received by the antenna, it is possible to suppress a reduction in equivalent dielectric constant while obtaining broadband characteristics, In addition, since it is not necessary to increase the thickness of the first dielectric plate 1 and the second dielectric plate 6 accordingly, an increase in loss due to surface wave propagation that occurs when the thickness is increased can be suppressed. . That is, there is an effect that the axial ratio, the wide band, and the low loss at a high angle can be balanced at a high level that could not be obtained conventionally.
[0036]
According to the first embodiment, since the first dielectric plate 1 and the second dielectric plate 6 can be integrated by the wall-like member 5, the feeding conductor 3 and the parasitic conductor 7 are arranged with high accuracy. It is possible to achieve the balance of high axial ratio, wideband characteristics, and low loss as designed.
[0037]
According to the first embodiment, since the second dielectric plate 6 is formed of a dielectric material having a dielectric constant different from that of the first dielectric plate 1, an equivalent dielectric that can select an axial ratio at a high angle. The rate can be set, and there is an effect of widening the bandwidth.
[0038]
In recent years, phased array technology that electronically scans beams and multi-beam technology are often used for satellite-mounted antennas, so that antennas with good axial ratios at wide angles are required. However, by using the microstrip antenna substrate according to the first embodiment, it is possible to obtain a high angle axial ratio and a wideband characteristic that cannot be obtained with a conventionally used mirror antenna. It becomes possible to transmit and receive a circularly polarized wave signal with respect to different angles at the same time without scanning. The characteristics of the phased array in which a plurality of microstrip antenna substrates according to the first embodiment are arranged are different from the characteristics of the microstrip antenna substrate alone because of the coupling between elements, but exhibit the same tendency.
[0039]
Here, circular conductors are used as the feeding conductor 3 and the parasitic conductor 7, but the present invention is effective even in a rectangular, triangular, or elliptical shape.
[0040]
In addition, as a power supply method, the method of supplying power through the microstrip line has been shown. The present invention is also effective in other feeding methods such as a coupling method or a proximity feeding method in which the microstrip line and the radiation conductor (3) are placed close to each other.
[0041]
Next, the shape of the notches 8 and 9 for circularly polarized wave excitation is not limited, and may be provided only on the parasitic conductor 7.
[0042]
Furthermore, although the circular ring-shaped thing was illustrated as the wall-shaped member 5, even if it is other shapes, such as a square, a rectangle, a trapezoid, and a rhombus ring, there exists the same effect. In addition to the ring shape, a lattice shape or a rod shape may be used, and a barrier may be provided only in a specific direction instead of the entire periphery of the parasitic conductor 7.
[0043]
Embodiment 2. FIG.
FIG. 5 is a partially exploded perspective view and a sectional view showing a structure of a microstrip antenna substrate according to Embodiment 2 of the present invention. In the figure, 11 is a third dielectric plate formed on the back surface of the ground conductor 2, 12 is a power supply wiring formed on the back surface of the third dielectric plate 11, and 13 is a fourth dielectric plate formed on the back surface of the power supply wiring 12. , 14 is a second ground conductor formed on the back surface of the fourth dielectric plate 13, and 15 is a fifth dielectric plate formed on the back surface of the second ground conductor 14. These constitute a triplate line together with the ground conductor 2.
[0044]
Reference numeral 16 denotes a matching circuit having one end connected to the power supply wiring 12 and the other end branched into two. Reference numeral 17 denotes a power supply probe that connects the other end to the power supply conductor 3. The matching circuit 16 branches into two excitation voltages whose phases are shifted by 90 ° based on the power supply voltage, and the power supply probes 17 and 17 supply the excitation voltages to positions of the power supply conductor 3 that are shifted by 90 °. . As a result, circularly polarized radio waves are emitted from the feed conductor 3 and the non-feed conductor 7. Examples of the matching circuit 16 include a branch line type hybrid circuit, a Wilkinson type distribution circuit, a T branch circuit, and a rat race circuit.
[0045]
Further, 18 is a surface of the first dielectric plate 1 and is formed at a position around the power supply conductor 3, has an inner diameter larger than the outer shape of the power supply conductor 3, and has a thickness of 1/20 wavelength or more of transmission / reception waves. It is a wall-shaped member which consists of a substantially cylindrical conductive material which has. Other configurations are the same as those of the first embodiment, and the same reference numerals are given and the description thereof is omitted.
[0046]
Next, the operation will be described.
When a predetermined voltage is applied between the power supply wiring 12 and the power supply conductor 3 and the ground conductor 2, between the power supply conductor 3 and the ground conductor 2 and between the parasitic conductor 7 and the ground conductor 2 accordingly. An alternating electric field is generated, and circularly polarized radio waves are emitted from the feeding conductor 3 and the parasitic conductor 7 in accordance with the change in the electric field. In this case, the radio wave from the parasitic conductor 7 is stronger than the radio wave from the feed conductor 3. In addition, since the equivalent dielectric constant is adjusted to a desired value by adjusting the dielectric constant and the thickness of the first dielectric plate 1 and the second dielectric plate 6, the radiation characteristics of the radio wave are adjusted so that E The surface radiation characteristic and the H-plane radiation characteristic are approximately matched to provide a suitable axial ratio at a high angle, and since the parasitic conductor 7 is used, it is a wideband characteristic.
[0047]
Further, since the wall-shaped member 18 made of a conductive material is provided around the space between the conductors, the wall-shaped member 18 can prevent the propagation of surface waves in the air layer, and a plurality of substrates are arranged. It is possible to prevent coupling between antenna elements that occurs in some cases, and to suppress energy loss due to the propagation. This effect can be obtained even if the thickness of the wall-shaped member 18 is reduced to about 0.1 mm.
[0048]
Next, when the microstrip antenna is subjected to circular polarization excitation by the two-point feeding method as in the second embodiment, the frequency characteristic of the relative axial ratio is relatively high compared to the case of exciting by the one-point feeding method. A relatively wide band. On the other hand, the one-point feeding method has an advantage that the structure is simple because the radiating conductor (feeding conductor 3, non-feeding conductor 7) is provided with deformations such as the notches 8 and 9 and the degeneration of the orthogonal modes is solved.
[0049]
Furthermore, since the power supply wiring 12 is integrally formed with the antenna as a multilayer substrate, even if hundreds to thousands of antennas are arranged, the power supply wiring 12 and the antenna are laminated later. In this case, there is no problem such as deviation of interlayer connection or peeling, and electrical characteristics are not deteriorated.
[0050]
As described above, according to the second embodiment, the ground conductor 2, the parasitic conductor 7 disposed away from the ground conductor 2, and the ground conductor 2 and the parasitic conductor 7 are interposed. A power supply conductor 3 to which a predetermined voltage is applied between the ground conductor 2 and an inter-conductor space section that connects and partitions the periphery of the parasitic conductor 7 and the periphery of the power supply conductor 3. The wall-shaped member 18 made of a conductive material is provided around the space between the conductors 7 and the power supply conductor 3. Will be disposed. Therefore, even if the thickness of the first dielectric plate 1 or the second dielectric plate 6 is increased, the propagation of the surface wave in the air layer can be prevented, and the energy loss caused by the surface wave propagation is suppressed. Therefore, it is possible to effectively suppress a decrease in equivalent dielectric constant. That is, there is an effect that the axial ratio, the wide band, and the low loss at a high angle can be balanced at a high level that could not be obtained conventionally. In addition, compared with the case where the wall-shaped member 5 is formed of a dielectric material, there is an effect that the above-described effect that is not conventionally obtained can be obtained with a thin wall thickness.
[0051]
Embodiment 3 FIG.
6 is a partially exploded perspective view and a sectional view showing the structure of a microstrip antenna substrate according to Embodiment 3 of the present invention. In the figure, 19 is formed at a position on the surface of the first dielectric plate 1 and around the power supply conductor 3, has an inner diameter with a substantially elliptical cross section larger than the outer shape of the power supply conductor 3, and is 1 / It is a wall-shaped member made of a substantially cylindrical dielectric material having a thickness of 20 wavelengths or more. Other configurations are the same as those of the first embodiment, and the same reference numerals are given and the description thereof is omitted.
[0052]
Next, the operation will be described.
When a predetermined voltage is applied between the power supply wiring 4 and the power supply conductor 3 and the ground conductor 2, between the power supply conductor 3 and the ground conductor 2 and between the parasitic conductor 7 and the ground conductor 2 accordingly. An alternating electric field is generated, and circularly polarized radio waves are emitted from the feeding conductor 3 and the parasitic conductor 7 in accordance with the change in the electric field. In this case, the radio wave from the parasitic conductor 7 is stronger than the radio wave from the feed conductor 3. In addition, since the equivalent dielectric constant is adjusted to a desired value by adjusting the dielectric constant and the thickness of the first dielectric plate 1 and the second dielectric plate 6, the radiation characteristics of the radio wave are adjusted so that E The surface radiation characteristic and the H-plane radiation characteristic are approximately matched to provide a suitable axial ratio at a high angle, and since the parasitic conductor 7 is used, it is a wideband characteristic.
[0053]
In addition, since the wall-shaped member 19 having a substantially elliptical cross section is provided around the space between the conductors, the resonance state can be different between the major axis and the minor axis of the ellipse. In addition to suppressing the energy loss due to the propagation and effectively suppressing the reduction of the equivalent dielectric constant, the axis ratio at a high angle is corrected to a suitable axis up to a higher angle. A ratio can be obtained.
[0054]
As described above, according to the third embodiment, the feeding conductor 3 and the parasitic conductor 7 are formed in a disk shape, and the wall-shaped member 19 provided over the entire periphery of the inter-conductor space portion includes Since an opening having a substantially elliptical cross section larger than the space between the conductors is opened, adjusting the axial direction of the opening has an effect of improving the axial ratio of the transmitted and received waves at a high angle.
[0055]
In the third embodiment, an example in which the wall-shaped member 19 made of a dielectric material is assumed to have a substantially elliptical cross section has been described. However, a wall-shaped member made of a conductive material may have a substantially elliptical cross section. An effect can be obtained.
[0056]
Embodiment 4 FIG.
7 is a partially exploded perspective view and a sectional view showing a structure of a microstrip antenna substrate according to Embodiment 4 of the present invention. In the figure, 20 is a through hole (conductive shield) electrically connected to the ground conductor 2, and 21 is a via hole (conductive) which is electrically connected to the ground conductor 2 and has a height different from that of the through hole 20. These are arranged at intervals narrower than the wavelength of the transmission / reception wave of the antenna on the concentric circle with the feeding conductor 3.
[0057]
Reference numeral 22 denotes a third dielectric plate formed on the back surface of the ground conductor 2, 23 denotes a back surface of the third dielectric plate 11, power supply wiring electrically connected to the power supply conductor 3, and 24 denotes a center of the power supply conductor 3. In the corresponding position, a slot having a substantially rectangular parallelepiped shape opened in the ground conductor 2 extending in a direction perpendicular to the power supply wiring 23. Other configurations are the same as those of the first embodiment, and the same reference numerals are given and the description thereof is omitted.
[0058]
Next, the operation will be described.
When a predetermined voltage is applied from the power supply wiring 23 between the power supply conductor 3 and the ground conductor 2, an alternating voltage is excited in the power supply conductor 3 via the slot 24 electromagnetically, and the power supply conductor 3 An alternating electric field is generated between the ground conductor 2 and between the parasitic conductor 7 and the ground conductor 2, and circularly polarized radio waves are emitted from the feeder conductor 3 and the parasitic conductor 7 in accordance with the change in the electric field. . In this case, the radio wave from the parasitic conductor 7 is stronger than the radio wave from the feed conductor 3. In addition, the radio wave radiation characteristic is obtained by providing a wall-like member 5 made of a dielectric material together with a space between conductors between the parasitic conductor 7 and the feeder conductor 3 to achieve a desired equivalent dielectric constant. Since the adjustment is made, the E-plane radiation characteristic and the H-plane radiation characteristic of circular polarization are approximately matched to provide a suitable axial ratio at a high angle, and since the parasitic conductor 7 is used, the broadband characteristic is obtained. It is.
[0059]
Further, since the wall-like member 5 made of a dielectric material is provided in the fringing portion formed around the inter-conductor space portion, the transmission / reception wave of the antenna including the wall-like member 5 can be resonated. In addition, it is possible to effectively suppress a decrease in equivalent dielectric constant while suppressing the generation of surface waves and suppressing energy loss due to the propagation.
[0060]
Further, since the through holes 20 and the via holes 21 are arranged in the wall member 5 at intervals smaller than the wavelength of the transmission / reception wave of the antenna, the wall member made of a conductive material around the space between the conductors. As in the case of providing the surface wave, the propagation of the surface wave in the air layer can be prevented, and even if a plurality of substrates are arranged adjacent to each other, the energy loss due to the propagation can be suppressed.
[0061]
Finally, since two types of through-holes 20 and via-holes 21 having different heights are provided around the space between the conductors, the resonance state can be made different in one direction and the direction of 90 degrees. Not only can the generation of the wave itself be suppressed and energy loss due to its propagation can be suppressed, but the equivalent dielectric constant can be effectively suppressed from decreasing, and the axial ratio at a high angle can be corrected to achieve a higher angle. A suitable axial ratio can be obtained.
[0062]
As described above, according to the fourth embodiment, the plurality of through holes 20 extending along the direction from the power supply conductor 3 to the parasitic conductor 7 inside the wall member 5 made of a dielectric material. Since the via holes 21 are arranged at intervals that are narrower than the wavelength of the transmission / reception wave of the antenna, it is possible to have the effect of the wall member made of the conductive material as well as the effect of the wall member 5 made of the dielectric material. Therefore, even if the wall thickness is thinner than that in the case where the wall-shaped member 5 is formed only of the dielectric material, there is an effect that the same balance can be obtained.
[0063]
According to the fourth embodiment, since the via hole 21 is used together with the through hole 20, there is an effect that the axial ratio at a high angle of the transmitted / received wave can be improved by adjusting the arrangement of the lengths.
[0064]
Embodiment 5 FIG.
8 is a partially exploded perspective view and a sectional view showing the structure of a microstrip antenna substrate according to Embodiment 5 of the present invention. In the figure, 25 is formed on the surface of the first dielectric plate 1, and a substantially rectangular plate-shaped power supply conductor to which a predetermined voltage is applied to the ground conductor 2. 26 is a power supply in the arrangement direction of the power supply conductors 25. A wall-like member made of a dielectric material having a substantially rectangular shape and having a thickness of 1/20 wavelength or more of transmission / reception waves, arranged at the same arrangement interval as that of the conductor 25, 27 is a second dielectric. The non-feeding conductor is formed in a position corresponding to the power supply conductor 25 on the surface of the plate 6 and has a substantially rectangular plate shape smaller than the power supply conductor 25.
[0065]
Each 28 is connected to the peripheral edge of the ground conductor 2, and the length L from the lower end 28a to the tip is formed to be ¼ of the wavelength of the transmission / reception wave of the antenna, and the tip is Chokes that are shorted together. Except this, it is the same as that of FIG.
[0066]
Next, the operation will be described.
When two voltages whose phases are shifted by 90 ° are applied between the power supply conductor 25 and the ground conductor 2 from a power supply wiring (not shown), an alternating voltage is excited in the power supply conductor 25, and accordingly, the power supply conductor 25 and the ground conductor are grounded. An alternating electric field is generated between the conductor 2 and between the parasitic conductor 27 and the ground conductor 2, and circularly polarized radio waves are emitted from the feeder conductor 25 and the parasitic conductor 27 in accordance with changes in the electric field. In this case, the radio wave from the parasitic conductor 27 is stronger than the radio wave from the feed conductor 25. Further, the radiation characteristic of this radio wave is such that the equivalent dielectric constant is set to a desired value by disposing a wall-shaped member 26 made of a dielectric material together with a space portion between the parasitic conductor 27 and the feeder conductor 25 together with the interconductor space portion. Since the adjustment is made, the E-plane radiation characteristic and the H-plane radiation characteristic of circular polarization are approximately matched to obtain a suitable axial ratio at a high angle, and since the parasitic conductor 27 is used, the broadband characteristic is obtained. It is.
[0067]
As described above, according to the fifth embodiment, a large number of chokes 28 having a length ¼ of the wavelength of the transmission / reception wave of the antenna are arranged at the periphery of the ground conductor 2, and the plurality of chokes Since the tip portions of 28 are short-circuited with each other, even when the size of the ground conductor 2 is reduced, radiation to the back surface of the ground conductor 2 can be suppressed. In particular, when the size of the ground conductor 2 is reduced, radiation to the back surface of the ground conductor 2 occurs remarkably at a wide angle, and the radiation characteristics change under the influence of the structure on the back surface. Problems such as fluctuations in the axial ratio, gain reduction, and deterioration of isolation due to leakage of radio waves to the transmitter / receiver installed on the back side occur. However, as in the present invention, terminations are mutually connected around the ground conductor 2. By providing the shorted choke 28, the electric field component at the end of the ground conductor 2 can be set to “0”, which has an effect of preventing these problems.
[0068]
Embodiment 6 FIG.
FIG. 9 is a partially exploded perspective view and a sectional view showing the structure of a microstrip antenna substrate according to Embodiment 6 of the present invention. In the figure, reference numeral 29 denotes a spacer made of a dielectric material formed in a lattice shape, and the spacer 29 has a plurality of openings having a substantially rectangular cross section larger than the space between the conductors. Since the other configuration is the same as that shown in FIGS. 5 and 8, the same reference numerals are given and the description thereof is omitted.
[0069]
Next, the operation will be described.
When two voltages having a phase difference of 90 ° are applied between the power supply wiring 12 and the power supply conductor 25 and the ground conductor 2, an alternating voltage is excited in the power supply conductor 25, and the power supply conductor 25 and the ground conductor 2 are correspondingly excited. And between the parasitic conductor 27 and the ground conductor 2, an alternating electric field is generated, and circularly polarized radio waves are emitted from the feeder conductor 25 and the parasitic conductor 27 in accordance with changes in the electric field. In this case, the radio wave from the parasitic conductor 27 is stronger than the radio wave from the feed conductor 25. In addition, the radio wave radiation characteristic is obtained by providing a wall-like member 29 made of a dielectric material together with a space between conductors between the parasitic conductor 27 and the feeder conductor 25 to achieve a desired equivalent dielectric constant. Since the adjustment is made, the E-plane radiation characteristic and the H-plane radiation characteristic of circular polarization are approximately matched to obtain a suitable axial ratio at a high angle, and since the parasitic conductor 27 is used, the broadband characteristic is obtained. It is.
[0070]
Here, the four antennas are arranged in a quadrangular array, but may be in a triangular array, and there are no restrictions on the number of antenna elements such as two or sixteen. In order to improve the axial ratio, a sequential array may be used in the substrate. Next, although the configuration in which the circularly polarized wave excitation feeding circuit and the antenna are integrated is shown here, the antenna including the transceiver may be integrated. In addition, since the array antenna and the subarray are configured using the multilayer substrate as described above, the manufacturing becomes easy and the mass productivity is excellent.
[0071]
As described above, according to the sixth embodiment, the first dielectric plate 1 made of a dielectric material, the ground conductor 2 formed on the back surface of the first dielectric plate 1, and the first dielectric plate 1 A plurality of power supply conductors 25 formed on the surface and applied with a predetermined voltage between the ground conductor plate 2 and formed on the surface of the first dielectric plate 1 and similar to the plurality of power supply conductors 25 The spacer 29 made of a dielectric material having a plurality of openings opened at intervals of each other, the second dielectric plate 6 made of a dielectric material formed on the surface of the spacer 29, and the second dielectric Since the plurality of parasitic conductors 27 formed on the front surface or the rear surface of the plate 6 at positions corresponding to the respective feeding conductors 25 are provided, a gap between the parasitic conductors 27 and the feeding conductors 25 is provided between the conductors. A spacer 29 made of a dielectric material is disposed along with the space. It is possible to suppress the reduction of the equivalent dielectric constant in the case of thick air layer. In particular, in the sixth embodiment, since the spacer 29 made of a dielectric material is provided in the fringing portion formed around the inter-conductor space portion, the transmission / reception wave of the antenna including the spacer 29 is resonated. It is possible to suppress the reduction of the equivalent dielectric constant while suppressing the generation of the surface wave itself and the energy loss due to the propagation.
[0072]
Therefore, while setting the thickness of the space between the conductors to a thickness of about 1/20 wavelength or more of the radio wave transmitted and received by the antenna, it is possible to suppress a reduction in equivalent dielectric constant while obtaining broadband characteristics, In addition, since it is not necessary to increase the thickness of the first dielectric plate 1 and the second dielectric plate 6 accordingly, an increase in loss due to surface wave propagation can be suppressed. That is, there is an effect that the axial ratio, the wide band, and the low loss at a high angle can be balanced at a high level that cannot be obtained conventionally.
[0073]
Further, since the first dielectric plate 1 and the second dielectric plate 6 can be integrated by the spacer 29, the feeding conductor 25 and the parasitic conductor 27 can be arranged with high accuracy, and the characteristics of each antenna can be improved. There is an effect that it is possible to realize the balance between the axial ratio at a high angle, the wide band characteristics, and the low loss as designed and with the same characteristics.
[0074]
According to the sixth embodiment, each opening of the spacer 29 is located at a position corresponding to each inter-conductor space portion that is partitioned by connecting the periphery of each parasitic conductor 27 and the periphery of each power supply conductor 25. Therefore, it is possible to obtain the widest band characteristics.
[0075]
According to the sixth embodiment, since the power supply wiring 12 that is electrically connected to the power supply conductor 25 is formed on the third dielectric plate 11, the power supply circuit itself is also integrated and included at a high angle. Since the axial ratio, wide band, and low loss can be balanced at a high level that could not be obtained in the past, there is an effect that it is possible to prevent these characteristic deteriorations caused by the power feeding method.
[0076]
Embodiment 7 FIG.
FIG. 10 is a partially exploded perspective view and a sectional view showing the structure of one antenna of the microstrip antenna substrate according to the seventh embodiment of the present invention. In the figure, reference numeral 30 denotes a lattice-shaped spacer, and each crossing position is a spacer made of a dielectric material disposed so as to overlap the central portion of the feeding conductor 3 and the parasitic conductor 7, and 31 denotes each of the spacers 30. A hollow through hole 32 opened at the crossing position is a grounding conductor that connects the ground conductor 2 and the central portion of the parasitic conductor 7 through the through hole 31.
[0077]
In order to obtain circularly polarized waves, it is necessary to solve the degeneration of the orthogonal modes, so that the two dielectric rods 30a (dielectrics constituting each lattice) are inclined at 45 ° with respect to the feeding position. Each is inserted and the width of both is changed appropriately. As a result, the resonance frequency of the orthogonal modes changes, and circularly polarized waves can be excited. Also, the degeneration of the orthogonal modes can be solved by shifting the two dielectric rods 30a from the feeding position obliquely from the 45 ° direction and changing their angles.
[0078]
Next, the operation will be described.
When a predetermined voltage is applied between the power supply wiring 4 and the power supply conductor 3 and the ground conductor 2, between the power supply conductor 3 and the ground conductor 2 and between the parasitic conductor 7 and the ground conductor 2 accordingly. An alternating electric field is generated, and circularly polarized radio waves are emitted from the feeding conductor 3 and the parasitic conductor 7 in accordance with the change in the electric field. In this case, the radio wave from the parasitic conductor 7 is stronger than the radio wave from the feed conductor 3. Further, the radiation characteristic of the radio wave is adjusted to a desired equivalent dielectric constant by arranging a spacer 30 made of a dielectric material together with a space between conductors between the parasitic conductor 7 and the feeder conductor 3. Therefore, the E-plane radiation characteristic and the H-plane radiation characteristic of circular polarization are approximately matched to provide a suitable axial ratio at a high angle, and since the parasitic conductor 7 is used, the characteristics are wideband. .
[0079]
Further, since the inter-conductor space is divided by the spacer 30 for every minute section, the propagation of surface waves in the air layer can be prevented by the spacer 30, and energy loss caused by the propagation can be suppressed. .
[0080]
Further, since the parasitic conductor 7 is grounded to the ground conductor 2 in the center where the electric field component is zero, the parasitic conductor 7 is charged without impairing the radiation characteristics of the parasitic conductor 7. Can be prevented.
[0081]
As described above, according to the seventh embodiment, the spacer 30 is disposed so that each opening does not correspond to the central portion of each parasitic conductor 7, and a through hole is provided at a position corresponding to the central portion. 31 is formed, and each parasitic conductor 7 is electrically connected to the ground conductor 2 through the through-hole 31, so that the parasitic conductor 7 is not adversely affected on the radiation characteristics from the parasitic conductor 7. There is an effect that the high voltage can be prevented from being applied to the parasitic conductor 7 due to discharge or lightning strike.
[0082]
Embodiment 8 FIG.
FIG. 11 is a partially exploded perspective view and a sectional view showing the structure of a plurality of microstrip antenna substrates according to Embodiment 8 of the present invention. In the figure, 33 is a second power supply wiring formed on the back surface of the fifth dielectric plate 15, 34 is a sixth dielectric plate disposed on the back side of the second power supply wiring 33, and 35 is a multilayer substrate. The multilayer substrate 35 is formed so that the thickness L from the first dielectric plate 1 to the sixth dielectric plate 34 is equal to the quarter wavelength of the transmission / reception wave of the antenna.
[0083]
Further, 36 is a side metallized portion (coating film) deposited on the entire side surface of the multilayer substrate 35, 37 is an upper surface metallized portion (coating film) deposited on the entire peripheral surface of the first dielectric plate 1, and 38 is a sixth. The lower metallized portion (coating film) is deposited over the entire back surface of the dielectric plate 34, and 39 denotes the metallized portions 36, 37, and 38, respectively, the first dielectric plate 1 on the upper surface and the sixth dielectric plate 34 on the lower surface. The through hole is electrically connected to the ground conductor 2 in FIG. Since other configurations are the same as those in FIGS. 5 and 9, the same reference numerals are given and the description thereof is omitted.
[0084]
Next, the operation will be described.
When two voltages with a phase difference of 90 ° are applied between the power supply wiring 12 and the second power supply wiring 33 between the power supply conductor 25 and the ground conductor 2, an alternating voltage is excited in the power supply conductor 25, and accordingly Thus, an alternating electric field is generated between the feed conductor 25 and the ground conductor 2 and between the parasitic conductor 27 and the ground conductor 2, and circularly polarized waves are generated from the feed conductor 25 and the parasitic conductor 27 according to the change in the electric field. Radio waves are emitted. In this case, the radio wave from the parasitic conductor 27 is stronger than the radio wave from the feed conductor 25. In addition, the radiation characteristic of this radio wave is adjusted to a desired equivalent dielectric constant by arranging a wall-shaped member made of a dielectric material together with a space portion between the parasitic conductor 27 and the feeder conductor 25 together with a space between the conductors. Therefore, the E-plane radiation characteristic and the H-plane radiation characteristic of circular polarization are approximately matched to provide a suitable axial ratio at a high angle, and since the parasitic conductor 27 is used, the broadband characteristic is obtained. is there.
[0085]
In addition, the side surface metallized portion 36 having a length of ¼ wavelength is provided on the side surface of the multilayer substrate 35, and the upper surface metallized portion 37 and the lower surface metallized portion 38 are provided continuously at both ends thereof. By arranging a plurality of multilayer substrates 35 close to each other, both end portions of the side surface metallized portion 36 can be opened at the frequency of the transmission / reception wave, and the transmission / reception waves can be transmitted between the plurality of multilayer substrates 35, 35. Can be difficult to wrap around to the back side.
[0086]
In addition, since the plurality of multilayer substrates 35 and 35 are arranged close to each other to form a choke in the gap between the substrates, the multilayer substrate 35 is simpler and integrated with the multilayer substrate 35 than in the fifth embodiment. Thus, a choke can be formed, and a plurality of multilayer substrates 35 and 35 can be arranged with high density.
[0087]
As described above, according to the eighth embodiment, the multilayer substrate 35 is formed so that the length of the side surface is 1/4 of the wavelength of the transmission / reception wave of the antenna, and at least the side surface of the multilayer substrate 35 is formed. The peripheral portion of the front surface 1 and the peripheral portion of the back surface 34 are covered with metallized portions 36, 37, 38 which are coating films made of a conductive material, and the peripheral portion of the ground conductor 2 and the upper surface metallized portion of the front peripheral portion. 37 and the coating film of the lower-surface metallized portion 38 on the peripheral edge of the back surface are electrically connected using a plurality of through-holes 39, so that the plurality of multilayer substrates 35 and 35 are arranged adjacent to each other at high density. Since the transmission / reception wave of the antenna can be opened at the upper surface side edge and the lower surface side edge of the side surface metallized portion 36 which is a coating film, the upper surface of the side metallized portion 36 is placed between the multilayer substrates 35 and 35 on the back surface. It is possible to prevent the transmission / reception wave of the antenna from wrapping around, and to prevent problems such as fluctuations in the axial ratio, gain reduction, and isolation degradation due to leakage of radio waves to the transmitter / receiver installed on the back side. is there.
[0088]
【The invention's effect】
According to the present invention, the ground conductor, the parasitic conductor disposed away from the ground conductor, and the ground conductor and the parasitic conductor are disposed between the ground conductor and the ground conductor. Is provided around the space between the conductors that are partitioned by connecting the power supply conductor to which the voltage is applied, the periphery of the parasitic conductor and the periphery of the power supply conductor, A substantially cylindrical shape having a thickness of 1/20 or more of the wavelength of the transmission / reception wave A wall-shaped member made of a dielectric material Configured to Therefore, between the parasitic conductor and the feeding conductor of Space between conductors Can be set to a thickness of 1/20 wavelength or more of radio waves transmitted / received by an antenna to obtain a wide band characteristic, and has a substantially cylindrical shape as described above. Can resonate the transmitted and received waves of the antenna including the wall-shaped member By It is possible to effectively suppress the decrease in equivalent dielectric constant while suppressing the generation of surface waves and suppressing energy loss due to the propagation.
[0089]
Therefore, while setting the thickness of the space between the conductors to a thickness of about 1/20 wavelength or more of the radio wave transmitted and received by the antenna, it is possible to suppress a reduction in equivalent dielectric constant while obtaining broadband characteristics, In addition, since it is not necessary to increase the thickness of the first dielectric plate and the second dielectric plate accordingly, an increase in loss due to surface wave propagation can be suppressed. That is, there is an effect that the axial ratio, the wide band, and the low loss at a high angle can be balanced at a high level that cannot be obtained conventionally.
[0091]
According to the present invention, the feeding conductor and the parasitic conductor But Formed in a disk shape, The wall-shaped member has a space between conductors. Since an opening having a substantially elliptical cross section larger than that is opened, adjusting the axial direction of the opening has an effect of improving the axial ratio of the transmitted and received waves at a high angle.
[0092]
According to this invention, Wall member Inside or on the surface of the wire along the direction from the feed conductor to the parasitic conductor A plurality of conductive shields extend, and the conductive shields Therefore, the effect of the wall member made of the conductive material can be obtained together with the effect of the wall member made of the dielectric material. Therefore, even if the wall thickness is thinner than that in the case where the wall-shaped member is formed only of the dielectric material, there is an effect that the same balance can be obtained.
[0093]
According to this invention, On the inside or surface of the wall member, Multiple types of conductive shields with different lengths from the feed conductor to the parasitic conductor Is extended Therefore, there is an effect that the axial ratio at a high angle of the transmission / reception wave can be improved by adjusting the arrangement of the lengths.
[0094]
According to this invention, the peripheral portion of the ground conductor Transmission / reception wave A large number of chokes having a length ¼ of the wavelength is arranged, and the tip portions of the plurality of chokes are short-circuited to each other, so even if the size of the ground conductor is reduced, Radiation can be suppressed. In particular, when the size of the ground conductor is reduced, radiation to the back surface of the ground conductor is noticeably generated at a wide angle, and the radiation characteristics change due to the influence of the structure on the back surface. Fluctuations, gain reduction, isolation degradation due to leakage of radio waves to the transmitter / receiver installed on the back side, but the terminations are short-circuited around the ground conductor as in the present invention By providing the choke, the electric field component at the end portion of the ground conductor can be set to “0”, so that these problems can be prevented.
[0095]
According to this invention, the first dielectric plate made of a dielectric material, the ground conductor formed on the back surface of the first dielectric plate, and the surface of the first dielectric plate between the ground conductor plate A power supply conductor to which a predetermined voltage is applied, a wall-shaped member formed on the surface of the first dielectric plate at a position around the power supply conductor, and made of a dielectric material, and a surface of the wall-shaped member A second dielectric plate made of a dielectric material and a parasitic conductor formed on the front or back surface of the second dielectric plate at a position corresponding to the feeder conductor. A wall-like member made of a dielectric material is disposed between the conductor and the power supply conductor together with the inter-conductor space, and a reduction in equivalent dielectric constant when the air layer is thickened can be suppressed. In particular, in this invention, since the wall-like member made of a dielectric material is provided in the fringing portion formed around the inter-conductor space portion, it is possible to resonate the transmission / reception wave of the antenna including this wall-like member. In addition, it is possible to effectively suppress the reduction of the equivalent dielectric constant while suppressing the generation of the surface wave itself and suppressing the energy loss due to the propagation.
[0096]
Therefore, while setting the thickness of the space between the conductors to a thickness of about 1/20 wavelength or more of the radio wave transmitted and received by the antenna, it is possible to suppress a reduction in equivalent dielectric constant while obtaining broadband characteristics, In addition, since it is not necessary to increase the thickness of the first dielectric plate and the second dielectric plate accordingly, an increase in loss due to surface wave propagation can be suppressed. That is, there is an effect that the axial ratio, the wide band, and the low loss at a high angle can be balanced at a high level that cannot be obtained conventionally.
[0097]
In addition, since the first dielectric plate and the second dielectric plate can be integrated by the wall-like member, the feeding conductor and the parasitic conductor can be arranged with high precision, and the axial ratio at high angles and the wideband characteristics. There is an effect that a balance of low loss can be realized as designed.
[0103]
According to this invention, the third dielectric plate formed on the first dielectric plate or on the back side of the ground conductor. Back of In addition, since the power supply wiring that is electrically connected to the power supply conductor is formed, the power supply circuit itself is also integrated, and it has not been possible to obtain a high angle axial ratio, wide band, and low loss. Since the balance can be achieved at a high level, there is an effect that it is possible to prevent deterioration of these characteristics due to the power feeding method.
[0104]
According to this invention, it consists of a dielectric material. Transmitting and receiving waves on wall-like members A plurality of through-holes and / or via holes are opened at intervals shorter than the wavelength of each, and conductive shields are formed in the through-holes or via-holes, respectively. The effect by the wall-shaped member by a property material can be acquired. Therefore, even if the wall thickness is thinner than that in the case where the wall-shaped member is formed only of the dielectric material, there is an effect that the same balance can be obtained.
[0105]
According to the present invention, since the second dielectric plate is formed of a dielectric material having a different dielectric constant from that of the first dielectric plate, the second dielectric plate is set to an equivalent dielectric constant so that an axial ratio at a high angle can be selected. There is an effect that can.
[0106]
According to this invention, The length of the side surface of the multilayer substrate including the first dielectric plate formed on the side opposite to the feeding conductor of the first dielectric plate is ¼ of the wavelength of the transmission / reception wave, At least that Multilayer board The side surface, the front surface peripheral portion, and the back surface peripheral portion are coated with a coating film made of a conductive material, and the peripheral edge portion of the ground conductor and the coating film on the front surface peripheral portion and the back surface peripheral portion are formed into a plurality of through holes. Alternatively, since electrical connection is made using via holes, a large number of substrates are arranged adjacent to each other at high density, so that the transmission and reception waves of the antenna are open at the upper and lower edges of the coating film. Therefore, it is possible to prevent the transmission / reception wave of the antenna from wrapping around between these substrates to the back side, fluctuation of the axial ratio, gain reduction, and leakage of radio waves to the transmitter / receiver installed on the back side. There is an effect that it is possible to prevent problems such as isolation deterioration due to the inclusion of the
[Brief description of the drawings]
FIGS. 1A and 1B are a partially exploded perspective view and a sectional view showing a structure of a microstrip antenna substrate according to a first embodiment of the invention. FIGS.
FIG. 2 shows a microstrip antenna according to Embodiment 1 of the present invention, in the case of a fundamental mode of a circular microstrip antenna, an angle (radiation direction) at which the axial ratio becomes “1”, a ground conductor 2 and a parasitic conductor 7. It is a characteristic view which shows the relationship with the dielectric constant between.
FIG. 3 is an explanatory diagram showing an equivalent circuit between a ground conductor 2 and a parasitic conductor 7 of the microstrip antenna according to the first embodiment of the present invention.
FIG. 4 shows the thickness t of the air layer 10 according to the first embodiment of the present invention. ₂ FIG. 6 is a characteristic diagram showing an example of the relationship between the axis ratio and the bandwidth (when (a) is with the wall-shaped member 5 and (b) is without the wall-shaped member 5).
FIGS. 5A and 5B are a partially exploded perspective view and a sectional view showing a structure of a microstrip antenna substrate according to a second embodiment of the present invention. FIGS.
FIGS. 6A and 6B are a partially exploded perspective view and a sectional view showing a structure of a microstrip antenna substrate according to a third embodiment of the present invention. FIGS.
FIGS. 7A and 7B are a partially exploded perspective view and a sectional view showing a structure of a microstrip antenna substrate according to a fourth embodiment of the present invention. FIGS.
FIGS. 8A and 8B are a partially exploded perspective view and a sectional view showing a structure of a microstrip antenna substrate according to a fifth embodiment of the present invention. FIGS.
FIGS. 9A and 9B are a partially exploded perspective view and a sectional view showing a structure of a microstrip antenna substrate according to a sixth embodiment of the present invention. FIGS.
FIGS. 10A and 10B are a partially exploded perspective view and a sectional view showing a structure of one antenna of a microstrip antenna substrate according to a seventh embodiment of the present invention. FIGS.
FIGS. 11A and 11B are a partially exploded perspective view and a sectional view showing a structure of a plurality of microstrip antenna substrates according to an eighth embodiment of the invention. FIGS.
FIG. 12 is a cross-sectional view showing a conventional microstrip antenna substrate.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 1st dielectric plate, 2 Ground conductor, 3,25 Feeding conductor, 4, 12, 23, 33 Feeding wiring, 5, 18, 19, 26 Wall-shaped member, 6 Second dielectric plate, 7, 27 Parasitic conductor , 20 Through hole (conductive shield), 21 Via hole (conductive shield), 28 Choke, 29, 30 Spacer, 31 Through hole, 36 Side metallized part (coating film), 37 Upper surface metallized part (coating film), 38 bottom metallized part (coating film), 39 through hole.

Claims (10)

  A ground conductor, a parasitic conductor disposed away from the ground conductor, and the ground conductor and the parasitic conductor are disposed between the ground conductor and a predetermined voltage is applied between the ground conductor. A substantially cylindrical shape having a thickness of 1/20 or more of the wavelength of a transmission / reception wave, disposed around a space between conductors that connects and partitions the feeder conductor, the periphery of the parasitic conductor, and the periphery of the feeder conductor A microstrip antenna comprising a wall member made of a dielectric material. A ground conductor, a parasitic conductor disposed away from the ground conductor, and the ground conductor and the parasitic conductor are disposed between the ground conductor and a predetermined voltage is applied between the ground conductor. A dielectric material having a thickness of 1/20 or more of the wavelength of the transmission / reception wave, disposed around the space between the conductors, which is partitioned by connecting the feeder conductor, the periphery of the parasitic conductor, and the periphery of the feeder conductor In the microstrip antenna provided with a wall-shaped member, the feeding conductor and the parasitic conductor are formed in a disk shape, and the wall-shaped member has an opening having a substantially elliptical cross section larger than the space between the conductors. A microstrip antenna characterized by the fact that the department has been established. Inside or on the surface of the wall member, a plurality of conductive shields extend along the direction from the feeding conductor to the non-feeding conductor, and the conductive shields are arranged at intervals that are narrower than the wavelength of the transmission / reception wave. The microstrip antenna according to claim 1 or 2, wherein the microstrip antenna is provided. 4. The microstrip antenna according to claim 3, wherein a plurality of types of conductive shields extending in a direction from the feeding conductor to the non-feeding conductor extend inside or on the surface of the wall member . 2. A plurality of chokes having a length of ¼ of a wavelength of a transmission / reception wave are arranged on a peripheral portion of the ground conductor, and tips of the plurality of chokes are short-circuited to each other. The microstrip antenna according to claim 4.   A predetermined voltage is applied between the first dielectric plate made of a dielectric material, the ground conductor formed on the back surface of the first dielectric plate, and the surface of the first dielectric plate. And a substantially cylindrical dielectric material having a thickness of 1/20 or more of the wavelength of the transmission / reception wave, which is formed on the surface of the first dielectric plate and around the power supply conductor. A wall-like member, a second dielectric plate formed on the surface of the wall-like member, made of a dielectric material, and a non-duct formed on the front or back surface of the second dielectric plate at a position corresponding to the feeding conductor. A microstrip antenna substrate having a feeding conductor. On the back side of the third dielectric plate formed on the back side of the first dielectric plate or on the ground conductor, the microstrip antenna substrate according to claim 6, wherein the forming the feed conductor electrically connected to the power feeding wiring . A wall-shaped member made of a dielectric material is provided with a plurality of through holes and / or via holes at intervals narrower than the wavelength of the transmitted / received wave , and a conductive shield is formed in each of the through holes or via holes. The microstrip antenna substrate according to claim 6 . 7. The microstrip antenna substrate according to claim 6, wherein the second dielectric plate is made of a dielectric material having a dielectric constant different from that of the first dielectric plate. The length of the side surface of the multilayer substrate including the first dielectric plate formed on the side opposite to the feeding conductor of the first dielectric plate is ¼ of the wavelength of the transmission / reception wave, and at least the side surface of the multilayer substrate and the surface peripheral portion In addition, the periphery of the back surface is covered with a coating film made of a conductive material, and the periphery of the ground conductor and the coating film of the surface periphery and the back surface periphery are electrically connected using a plurality of through holes or via holes. The microstrip antenna substrate according to claim 6 , wherein the microstrip antenna substrate is connected.

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