JP4259760B2 - One plane dual strip antenna - Google Patents

Description

上記の例実施形態では、１オンス銅は、第１および第２のストリップ４０４および４０８を構成するために使用され、０．０７８７４ｃｍ（０．０３１インチ）厚さのＦＲ４（周知の商用プリント回路板（ＰＣＢ）材料）は絶縁基板４１２として使用された。さらに、同じ平面にある導波管４１６の正端子は、アンテナ４００の閉じられた端部から０．８３８２ｃｍ（０．３３０）インチの距離で第１のストリップ４０４に接続されている。
【００６１】
図１０は、セルラ周波数バンドにわたって作動するようなサイズにされたアンテナ４００の一実施形態の測定周波数応答を示している。図１０は、アンテナが８２５ＭＨｚで−１５．０１ｄＢ周波数応答および８９５．０ＭＨｚで−１８．３８ｄＢ周波数応答を有することを示している。したがって、アンテナは８．１４パーセント帯域幅を有する。
【００６２】
本発明の他の実例実施形態では、アンテナ４００は、ＰＣＢ周波数バンド、すなわち１．８５〜１．９９ＧＨｚにわたって作動するような大きさにされる。ＰＣＢ周波数バンドに対するアンテナ４００の寸法は下記の表２に示されている。
【００６３】
【表２】

上記実例実施形態では、１オンス銅は、再度第１および第２のストリップ４０４および４０８を構成するために使用され、０．０７８７４ｃｍ（０．０３１インチ）の厚いＦＲ４（ＰＣＢ材料）は絶縁基板４１２として使用された。さらに、同じ平面にある導波管４１６の正端子は、アンテナ４００の閉じられた端部から０．５０８ｃｍ（０．２インチ）の距離で第１のストリップ４０４に接続された。
【００６４】
図１１は、ＰＣＢ周波数バンドにわたって作動するようなサイズにされるアンテナ４００の一実施形態の測定周波数応答を示している。図１１は、アンテナが１．７９ＧＨｚで−９．９２ｄＢ応答および２．１６ＧＨｚで−１０．１８ｄＢ応答を有することを示している。したがって、本実施形態では、アンテナ４００は１８．８パーセント帯域幅を有する。
【００６５】
図１２および図１３は、ＰＣＢ周波数バンドにわたって作動するアンテナ４００の一実施形態の測定電界パターンを示している。特に、アジマス平面の電界パターンの大きさのプロットを示しているのに対して、図１３は、俯角平面の電界パターンの大きさのプロットを示している。図１２および図１３の両方は、デュアル・ストリップ・アンテナがほぼ全方向性放射パターンを有し、それによってパーソナル通信装置での使用に適するようにすることを示している。
【００６６】
一実施形態は、「Ｄ」状放射器ストリップ装置を使用して開発された。第２のストリップは、第１のストリップよりも非常に長く、所望のようにそれ自体の中に後方に一様に折り畳まれる第１のストリップの「内部」および第１のストリップから離れた所に延ばすように通常折り畳まれる。アンテナ１４００が基板１４１２上に置かれるかあるいは配置されているストリップ１４０４および１４０８を使用して形成されるこのアンテナ構造が、図１４に示されている。アンテナの上部は、「Ｃ」形状にわずかに湾曲される（あるいはＤの前縁）ものとして示されている第１の導電性ストリップ１４０４によって形成される。この湾曲は、湾曲側壁を有する装置ハウジングの側面におよびこのハウジングの側面に隣接してアンテナ１４００を配置することを可能にするために使用される。第２のストリップは、前述のように、第１のストリップよりも幅広く、帯域幅を改善する。
【００６７】
アンテナが置かれたクラムシェル型(clamshell type)無線電話のフリップトップ(flip-top)部の内部寸法に概略相当する約３７．５９ｍｍ（Ｙ）×５１．８９ｍｍ（Ｘ）の全寸法を有するこのようなアンテナのモデルが構成され、試験される。
【００６８】
アンテナ１４００は、フィード部１４１６を使用して無線装置内の適切なトランシーバ回路に接続される。要素１４２０は、いかにいろいろの公知の回路部品あるいは装置が基板１４１２上にも取り付けることができるかあるいはそれとは別にいろいろな部品あるいはケーブルが所望のように延びる通路あるいは穴１４２２を形成できるかを示している。
【００６９】
好ましい実施形態も、Ｄ状放射器ストリップ装置を使用して開発された。第２のストリップは、第１のストリップよりも非常に長く、幅広く、通常第１のストリップの周りを包むように延びている。アンテナ１５００が基板１５１２上に置かれるかあるいは配置されるストリップ１５０４および１５０８を使用して形成されるこのようなアンテナが図１５に示されている。さらに、第２のストリップによって形成されるようなアンテナ１５００の上部は、無線装置へのアンテナ１５００の改善された配置を可能にするようにわずかに曲げられたものとして示されている。
【００７０】
この種のアンテナは、信号を供給するために使用される導体を有する結合構造として形成できる。同軸フィード構造は、アンテナを形成する導体と同じ可撓性基板（１５１２）上に形成できる。マイラ、キャプトン、あるいはテフロンの薄いシートに基づく材料、全ては当該技術で周知の材料である。いかにこれを行うことができるかの例は、「同じ平面にある導波管」の形の長い可撓性信号フィード構造あるいはセクション１５２０が示されている図１５に示されている。導波管１５２０は、一端で終端し、一端を同じ平面にある導波管のアース部の一部を形成する負のフィードストリップに接続する。フィードストリップ１５２４は、フィードストリップ１５２８が第２のストリップ１５０８に接続される接続素子１５０６に接続するかあるいは結合される。正フィードストリップ１５２２あるいはフィード構造１５２０の中心は第１のストリップ１５０４に直接接続される。このフィードストリップのための接続点とストリップ１５２８との間の分離は、使用される周波数および公知であるような導電性材料１５０６の長さおよび他の寸法に従って所定のインピーダンスを提供するように選択される。
【００７１】
材料１５１２に沿って短距離終端する正フィード１５２２が示され、導体１５２４および１５２８と同様な第３の中心導体１５２６に通常接続あるいは結合されるかあるいは導体１５２４および１５２８と同様な第３の中心導体１５２６になるように広がる。導体１５２６は、材料１５１２の長さに沿ってコネクタ端１５３０に延び、同じ平面にある導波管の中心部あるいは正の部分を形成する。
【００７２】
しかしながら、１つあるいはそれ以上のフィードストリップ導体を基板上の対向する側に配置することを含む他の形状を使用できる。例えば、正フィード導体は、材料１５１２の一方の側上に形成でき、負フィード導体は材料１５１２の他方の側上に形成できる。したがって、導電性バイアは、適切な場合に信号を材料を通して伝達するために使用される。導体およびバイアの他の組み合わせは、公知であるような信号伝達を実現するために使用されてもよい。
【００７３】
したがって、アンテナ１５００は、これらの導体（１５２２、１５２４、１５２８）とともに単一のモノリシック構造として形成でき、コストにおける増加された効率、信頼性、および製造効率をもたらす。フィード部１５２０上の導体（１５２４、１５２６、１５２８）は、一般的には、アンテナが結合される回路板上のいろいろのばね動作あるいはばね荷重コネクタを接続するために使用される導電性パッドあるいは小さいコネクタ１５３２で終端する。
【００７４】
図１５に使用される導波管あるいはフィード部１５２０および基板１５１２のための形状あるいは全形状は、例示だけの目的のためであり、図示されるような無線装置１００内に最も効果的に適合するためである。しかしながら、当業者は、他の形状が役に立ち得る、本発明の教示内にあるということを容易に分かる。例えば、約４５°の角度である導波管１５２０の長さに沿う角のある曲げを使用する代わりに、一連の９０°の曲げ、折り畳みあるいは回転が導体のために使用できる。このような折り畳みおよび回転は、導体のパス長を最少にするために使用されると同時に基板あるいはアンテナに加えられた物理的制約を受け入れる。さらに、導体１５２４、１５２６および１５２８は、一般的には、導波管１５２０に沿って１つあるいはそれ以上の地点で幅が狭くされ、これらの位置も特定の用途に従って変えてもよい。導体１５２４および１５２８を電気的に接合する図１５に示された小さい空気ブリッジは役に立つが、本発明には必要ない。
【００７５】
無線電話１００のような無線装置内に置かれた場合、フィード構造あるいは導波管１５２０は、無線装置内で使用されるアンテナ１００といろいろの受信素子および送信素子ならびに部品との間での有効な信号の伝達を可能にする。アンテナおよび同じ平面にある導波管を共通であるが薄くて可撓性の絶縁基板上に形成することによって、アンテナは、非常に小さい空間を占め、スピーカのような多数の他の個別部品の周りに形成できるので、アンテナは、装置の多数の構成部分内に取り付けることができる。フィード導体は、多数の無線装置（電話、コンピュータ）にあるような可撓性の回転あるいは折り畳みできる接合部分の周りに接続できる。
【００７６】
一方、ミニ同軸線は、同じ結果を得るために導波管(waveguide)（フィード）１５２０の代わりに使用できる。例えば、０．８ｍｍあるいは１．２ｍｍの直径を有する公知の型式の同軸線あるいはケーブルは、所望のように、アンテナ１５００と対応する回路あるいは適切な回路との間で信号を伝達する際に役に立ち得ることを示している。他の方式および型式の導体は、既知であるような信号伝達特性に応じて所定の用途のために使用されてもよい。
【００７７】
図１６および図１７は、図１の電話内に取り付けられた本発明の一実施形態の側面図および後部カットアウェイ(cutaway)図をそれぞれ示している。このような電話は、必要とされるかあるいは望まれるいろいろの機能を実行する１つあるいはそれ以上の回路板上に通常支持されるいろいろの内部部品を有する。回路板１６０２は、集積回路あるいはチップ１６０４のようないろいろの部品、抵抗器およびキャパシタのような個別部品およびいろいろのコネクタ１６０８を支持する、図１６および図１７のハウジングの内部に示されている。パネルディスプレイおよびキーボードは、一般的には電池あるいは外部電源、スピーカ、マイクロホン、あるいは回路板１６０２上の回路の他の同様な周知の素子と同様ないろいろの他の部品とインタフェースするワイヤ、導体、コネクタ（図示せず）で電話ハウジング１０２の前部を面する回路板１６０２の裏側に取り付けられる。
【００７８】
本実施形態では、スライドインあるいはプラグイン型式のコネクタ１６１０は、電話の前部の近くの回路板の下側に取り付けられ、アンテナ１５００のためのフィーダ部１５２０の接続端を受け入れるように構成される。一方、１つあるいはそれ以上の公知のばね接点あるいはクリップは、導電性パッドを端部１５３０上に接触させるために使用でき、アンテナ１５００を回路板１６０２に電気的に結合あるいは接続する。このようなばね接点あるいはクリップは、半田付けあるいは導電性接着剤のような周知の技術を使用して回路板１６０２上に取り付けられ、信号を所望の送受信回路へおよびこの送受信回路から伝達するように適切な導体に電気的に接続されている。しかしながら、半田の使用あるいは小型同軸コネクタ（小さいケーブルが使用される場合）の使用を含む他の型式の接続技術が役に立つものであることも公知である。所望のように、周知のように、フィード構造と相互接続するために無線装置内で使用される回路に専用インピーダンスマッチング素子もあり得る。
【００７９】
図１７の側面図では、回路板１６０２は、当該技術分野で多層回路板あるいはプリント回路板と呼ばれるものを形成するために一緒に接着される導電性材料および絶縁材料の多層を含むものとして示されている。このような回路板は、周知であり、当該技術分野で理解されている。これは、金属導体層１６１８を支持するかあるいは金属導体層１６１８に隣接して配置されている絶縁材料層１６１６に隣接して配置されている金属導体層１６１４に隣接して配置された絶縁材料層１６１２として示されている。導電性バイア（図示せず）は、異なる層あるいはレベルのいろいろな導体を外部表面上の部品と相互接続するために使用される。任意の所与の層上のエッチングされたパターンはこの層のための相互接続パターンを決定する。この形状では、層１６１４あるいは１６１８のいずれかは、当該技術分野で周知であるように、回路板１６０２のために普通に呼ばれているようなアース層あるいはアース平面を形成できる。
【００８０】
一般的には、一連の支持ポスト、スタンド、あるいはリッジ(ridges)１６２０は、ハウジング内に回路板あるいは他の部品を取り付けるために使用される。これらは、射出成形プラスティックによって形成される場合のようにハウジングの一部として形成できるし、あるいは特に例えば、接着剤あるいは他の周知の機構を使用することによって所定の場所に固定できる。さらに、一般的には、ハウジング１０２の取り外し可能カバーのような構成部分を互いに固定するように締め金具を収容するために使用される１つあるいはそれ以上の固定ポスト１６２２がある。
【００８１】
前述されるように、アンテナ１５００は、例えば、この機能に役に立つことが知られている接着剤、にかわ、テープ、注封材料、あるいは結合材料等の使用であるがこれに限定されないいくつかの公知の技術を使用してハウジング１０２の構成部分内に固定できる。例えば、アンテナ１５００は、基板１５１２に接着された接着剤層あるいはストリップ１６３０を使用して無線装置の側壁あるいは他の構成部分あるいは要素に対して支持できる。このアンテナは、一般にハウジングの側面に対して、好ましくは絶縁材料の上に、あるいは支え金具、ねじ、あるいは同様な固定要素を使用して所定の場所に取り付けることができる支え金具アセンブリに対して固定される。
【００８２】
所定の場所にアンテナを取り付けるかあるいは固定する他の機構は当該技術分野で公知である。例えば、ハウジングを製造するために使用される材料に形成されるリッジ、溝等は、基板を所定の場所に物理的に固定するために使用できる。一連の突起あるいは隆起も、アンテナを支持するために使用でき、所望の用途に適切であるようないろいろの形状を有することができる。
【００８３】
図１７で分かるように、基板１５１２は、ハウジングの形状にぴったりと合うようにあるいは無線装置内の他の素子、機能あるいは部品に適合するように湾曲あるいは特に曲げることができる。図において、スピーカの一部の周りに「包まれた」アンテナ放射器あるいはストリップに対して配置されたスピーカ１６３２が示されている。
【００８４】
この基板は、湾曲されるかあるいは折り畳まれた形状で製造あるいは設置中に変形できる。薄い基板を使用することによって、基板は、設置される場合、時々締め金具を必要としないで通常基板を所定の場所に固定するように曲げられた隣接表面に対して張力あるいは圧力を与えることができる。したがって、ある形式の捕獲は、隣接装置、部品、あるいは回路板および所定の場所に固定されるハウジングのカバーあるいは構成部分を装備することによって単に得られる。しかしながら、本発明が適切に機能するために製造中あるいは設置中のいずれか基板を変形あるいは湾曲する条件は全然ない。
【００８５】
図１８は、本発明が、例えば、携帯コンピュータ、モデム、データ端末、ファクシミリ機、あるいは同様な携帯電子装置であるがこれに限定されない、本発明が使用できる付加的な無線装置を示している。図１８において、上部コーナー部１８０４を有する主ハウジングあるいは本体１８０２を有する無線装置１８００を使用する無線装置が示されている。図１８のカットアウェイ図において、アンテナ５００は、上部コーナー１８０４の所定の場所に固定され、ケーブルあるいは導体セット１８０８は、アンテナフィード５１６を無線装置内の適切な回路に接続するために使用される。当業者は、他の形状および向きが本発明の教示内のアンテナに対して可能であることを容易に分かる。
【００８６】
本発明のいろいろの実施形態が上記に説明されているが、この実施形態が例としてだけ示されていて、これに限定されないことを理解すべきである。したがって、本発明の広がりおよび範囲は、前述の典型的な実施形態のいずれかによって検定されるべきでなく、上記の特許請求の範囲およびその均等物によってのみ規定されるべきである。
【図面の簡単な説明】
本発明は、同じ参照番号が通常同一で、機能的に同じ要素、および／または構造的に同じ要素を示す添付図面を参照して説明され、要素が最初に生じるこの図面は参照番号において最も左の数字で示される。
【図１Ａおよび１Ｂ】 ホイップアンテナおよび外部ヘリカルアンテナを有する携帯電話を示している。
【図２】 従来のマイクロストリップ・パッチアンテナを示している。
【図３】 図２のマイクロストリップ・パッチアンテナの側面図を示している。
【図４】 本発明の一実施形態による一平面デュアル・ストリップ・アンテナを示している。
【図５Ａ〜５Ｇ】 ストリップ・を接続するために正方形遷移を使用する本発明のいくつかの他の実施形態の平面図を示している。
【図６Ａ〜６Ｃ】 ストリップ・を接続するために湾曲遷移を使用する本発明のいくつかの他の実施形態の平面図を示している。
【図７Ａ〜７Ｅ】 ストリップ・を接続するためにＶ状曲遷移を使用する本発明の他のいくつかの他の実施形態の平面図を示している。
【図８Ａ〜８Ｇ】 湾曲ストリップ・形状、角のあるストリップ・形状、および複合ストリップ・形状を使用する本発明の付加的な他の実施形態の平面図を示している。
【図９Ａ〜９Ｂ】 ある他の用途で役に立つ本発明のいくつかの他の実施形態の斜視図である。
【図１０】 セルラ電話で使用するのに適している本発明の一実施形態の測定周波数応答を示している。
【図１１】 ＰＣＳ無線電話で使用するのに適している本発明の他の実施形態の測定周波数応答を示している。
【図１２および１３】 本発明の一実施形態のための測定電界パターンを示している。
【図１４】 図１の電話で使用するための本発明の一実施形態の平面図を示している。
【図１５】 本発明の他の実施形態および図１の電話で使用するための信号フィード構造の平面図を示している。
【図１６】 図１の電話内に取り付けられた本発明の一実施形態の底部平面図および側面断面図を示している。
【図１７】 図１の電話内に取り付けられた本発明の一実施形態の底部平面図および側面断面図を示している。
【図１８】 本発明が使用されてもよい付加的無線装置を示している。
【符号の説明】
１００…ヘリカルアンテナ，１０２…ハウジング，１０４…ホイップアンテナ、１１０…スピーカ、１１２…ディスプレイパネル、１１４…キーパッド、１１６…マイクロホン，１１８…外部電源コネクタ，１２０…電池、４００…一平面デュアル・ストリップ・アンテナ，４０４…第１のストリップ，４０６…閉じられた端部，４０８…第２のストリップ，４１２…絶縁基板，４１６…導波管，４２０…正端子，４２４…負端子，４２８…負端子，５０６…遷移ストリップ，６０６…遷移ストリップ，８０６…遷移ストリップ，[0001]
BACKGROUND OF THE INVENTION
The present invention relates generally to antennas, and more particularly to a uniplanar dual strip multiple frequency antenna. The invention further relates to an internal antenna for wireless devices, in particular with improved bandwidth and radiation characteristics.
[0002]
[Prior art]
An antenna is an important component of wireless communication and wireless communication systems. Although antennas are available in many different shapes and sizes, each antenna operates according to the same basic electromagnetic principles. This antenna has a structure related to the region of transition between the guide wave and the free space wave and vice versa. As a general principle, a guided wave moving along a spreading transmission line radiates free space waves, also known as electromagnetic waves.
[0003]
In recent years, with the increasing use of personal wireless communication devices such as mobile and mobile cellular and personal communication service (PCS) phones, the demand for small antennas suitable for such communication devices has increased. Recent developments in integrated circuit and battery technology have allowed the size and weight of such communication devices to be significantly reduced over the past few years. One area where size reduction is still desirable is communication device antennas. This is due to the fact that the size of the antenna can play an important role in reducing the size of the device. Furthermore, the antenna size and shape affects the device aesthetics and manufacturing costs.
[0004]
One important factor to consider when designing an antenna for a wireless communication device is the antenna radiation pattern. In typical applications, the communication device must be able to communicate with other such devices or base stations, hubs, or satellites that can be placed in any number of directions from the device. Therefore, it is very important that such a communication device antenna has an almost omnidirectional radiation pattern.
[0005]
Another important factor considered when designing an antenna for a wireless communication device is the bandwidth of the antenna. For example, wireless devices such as telephones used in conjunction with PCS communication systems operate between the frequency bands of 1.85 to 1.99 GHz and thus require 7.29 percent of the effective bandwidth. A telephone for use with a typical cellular communication system operates between the 824-894 MHz frequency band, which requires 8.14 percent of the bandwidth. Therefore, antennas for use with these types of wireless communication devices must be designed to meet the appropriate bandwidth requirements, or the communication signal is severely attenuated.
[0006]
One type of antenna commonly used in wireless communication devices is a whip antenna that is easily retracted into the device when not in use. However, there are several drawbacks associated with whip antennas. Often, whip antennas are damaged by hitting objects, people or surfaces when extended for use or even when retracted. Even when the whip antenna is designed so that it can be retracted to prevent such damage, the whip antenna can extend over the entire dimensions of the device, and can provide higher functionality and in some parts of the device. Impedes circuit placement. Whip antennas may also require a minimum device housing dimension that is larger than desired when retracted. This antenna can be configured with additional fitting sections to reduce size when retracted, but this antenna is generally less aesthetic by consumers, more fragile, unstable and less functional It is recognized that it does not fulfill.
[0007]
Furthermore, the whip antenna has a radiation pattern that is annular, ie donut-shaped, with a null in the center in effect. If a cellular telephone or other wireless device using such an antenna is held with an antenna perpendicular to the ground at an angle of 90 ° to the ground or local horizontal plane, this null is also tilted at an angle of 90 °. Has a central axis. This does not prevent signal reception because the incoming signal is not constrained to arrive at an angle of 90 ° to the antenna. However, telephone users often tilt their cellular telephone during use, and in addition tilt any associated whip antenna. It is noted that cellular phone users typically tilt their phones at an angle of about 30 ° (60 ° from the vertical) with respect to the local horizontal plane and tilt the whip antenna at an angle of 30 °. . This results in a null central axis that is also oriented at a 30 ° angle. At this angle, the null prevents reception of incoming signals that arrive at an angle of 30 °. Unfortunately, incoming signals in cellular communication systems often arrive within a range of about 30 ° or 30 °, increasing the likelihood that a wrong-oriented null will prevent some signals.
[0008]
Another type of antenna that appears to be suitable for use in a wireless communication device is a conformal antenna. Typically, conformal antennas follow the shape of the surface to which they are attached and usually exhibit a very low profile. There are several different types of regular antennas such as patch antennas, microstrip antennas and strip line antennas. In particular, microstrip antennas have recently been used in personal communication devices.
[0009]
As the term suggests, a microstrip antenna includes a patch or microstrip element, commonly referred to as a radiator patch. The length of the microstrip element is selected to match the relevant frequency, such as 800 MHz or 1900 MHz.₀Wavelength λ related to₀Set for. The length of a commonly used microstrip element is 1/2 wavelength (λ₀/ 2) and 1/4 wavelength (λ₀/ 4). Although some types of microstrip antennas have recently been used in wireless communication devices, other improvements are desired in some areas. One such area where other improvements are desired is a reduction in overall size. Another area that requires significant improvement is the bandwidth area. Modern patch antenna or microstrip antenna designs appear to achieve the desired 7.29-8.14 percent bandwidth characteristics or more desired for use in practical size modern communications systems. Absent.
[0010]
[Problems to be solved by the invention]
Therefore, new antenna structures and techniques for manufacturing antennas need to obtain a corresponding bandwidth according to the latest communication system requirements. In addition, the antenna structure should be conductive to the internal mounting device to provide a more versatile component that locates within the wireless device with greatly improved aesthetics and reduced antenna damage.
[0011]
[Means for Solving the Problems]
The present invention is directed to a single planar dual strip antenna having a two-dimensional structure. The single planar dual strip antenna includes first and second metal strips each printed on a thin planar substrate. The first and second strips are separated by a predetermined gap or region of non-conductive material. According to the invention, the first and second strips are used as conductors for a two-wire transmission line. Air or other insulating material deposited on the substrate between the strips serves as an insulating medium between the first and second strips. In one embodiment of the invention, the length of the first strip is less than the length of the second strip, and the width of the first strip is less than the width of the second strip.
[0012]
Waveguides in the same plane are coupled to a single plane dual strip antenna. Waveguides in the same plane are constructed by etching metal or depositing metal on a substrate. The positive terminal of the waveguide is electrically connected to the first strip. The negative terminal of the waveguide is connected to both the first and second strips. On the other hand, coaxial cables can be used as feeds instead of waveguides in the same plane.
[0013]
In one embodiment of the invention, a waveguide in the same plane has two negative terminals and a positive terminal. The positive terminal is connected to the first strip. The negative terminal is connected to the second strip, while the other negative terminal is connected to the first strip. The negative terminals are electrically interconnected at a convenient location.
[0014]
In one embodiment of the present invention, a single planar dual strip antenna is formed by printing a metal strip on a thin flexible substrate and etching the metal strip or depositing the metal strip on a thin potential substrate. Composed. Waveguides in the same plane are also etched or deposited on a flexible substrate. In other embodiments of the present invention, a single planar dual strip antenna is constructed by etching a metal strip or depositing it on a printed circuit (PC) board. This greatly simplifies the manufacture of the dual strip antenna.
[0015]
In one embodiment of the invention, the first and second strips are substantially parallel to each other. In other embodiments of the present invention, the first and second strips are electrically connected to a waveguide in the same plane so that the first and second strips provide improved impedance matching with air or free space. Flares out outward at the open end to stretch away from where they are connected. In another embodiment of the invention, the first and second strips are substantially bent. Various other shapes can also be used for the first and second strips.
[0016]
The one-plane dual strip antenna according to the present invention provides increased bandwidth over typical quarter-wave or half-wave patch antennas. Experimental results have shown that a single planar dual strip antenna has a bandwidth of approximately 8-20%, which is very advantageous for PCS and cellular phones.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
1. Summary and discussion of the invention
While conventional microstrip antennas have several characteristics that make them suitable for use in personal communication devices, further improvements in other areas of microstrip antennas include cellular phones and PCS phones. It is further desirable to make it more suitable for use in a wireless communication device. One such area where other improvements are desired is its bandwidth. PCS phones and cellular phones typically require about 8 percent bandwidth to operate satisfactorily. Since the bandwidth of currently available microstrip antennas is in the range of approximately 1-2 percent, an increase in that bandwidth is desired to be more suitable for use with PCS and cellular phones.
[0018]
Another area where other improvements are desired is the size of microstrip antennas. For example, the reduction in the size of the microstrip makes the wireless communication device in which the microstrip antenna is used more compact and more aesthetic. In fact, this can uniformly determine whether such an antenna can be used in a wireless communication device anyway or not at all. In the past, reducing the size of conventional microstrip antennas has been made possible by reducing the thickness of any insulating substrate used or increasing the dielectric constant. However, this has the undesirable effect of reducing the antenna bandwidth, thereby making it less suitable for wireless communication devices.
[0019]
Furthermore, the field pattern of conventional microstrip antennas such as patch radiators is generally directional. Most patch radiators radiate only in the upper hemisphere relative to the local horizontal plane for the antenna. As described above, this pattern can move or rotate with the movement of the device, creating undesirable nulls in the coverage. Therefore, microstrip antennas have been less desirable for use in many wireless communication devices based on their radiation patterns.
[0020]
The present invention provides a solution to these and other problems. The present invention is directed to a one-plane dual strip antenna having a two-dimensional structure and operating as an open-ended parallel plate waveguide but with asymmetric conductor termination.
[0021]
Single plane dual strip antennas provide increased bandwidth and size reduction over other antenna designs while retaining other characteristics that are desirable for use in wireless communication devices.
[0022]
Since the one-plane dual strip antenna has a two-dimensional structure, can this antenna be glued to various surfaces such as cellular telephones or other radio equipment plastic housings so that they can be adapted? Alternatively, it can be supported by this surface. The one-plane antenna may be formed near the upper surface or the lower surface of a wireless communication device such as a mobile phone, or other such as a speaker, an earphone, an I / O circuit, a keypad, etc. of the wireless communication device. It may be attached near or behind the element. Uniplanar antennas can also be formed on or in the surface of an automobile where a wireless communication device may be used.
[0023]
Unlike either whip antennas or external helical antennas, single plane dual strip antennas are less susceptible to damage from hitting objects or surfaces. In addition, a single plane dual strip antenna can be formed near or along the top surface of the wireless communication device, so this antenna does not use up the internal space required for advanced functions and circuitry, Also, there is no need for large housing dimensions to accommodate when retracted. The antenna of the present invention can be manufactured using an automated process that reduces the labor and cost associated with the antenna and increases reliability. In addition, a single planar dual strip antenna radiates a nearly omnidirectional pattern that makes it suitable for many wireless communication devices.
[0024]
2. Example environment
Before describing the present invention in detail, it is helpful to describe a typical environment in which the present invention can be implemented. In a broad sense, the present invention can be implemented in any wireless device such as a personal communication device, wireless telephone, wireless modem, facsimile device, personal computer, pager, message broadcast receiver, and the like. One such environment is a portable or handheld wireless telephone, such as a telephone used for cellular, PCS or other commercial communication services. A variety of such radiotelephones with corresponding different housing shapes and types are known in the art.
[0025]
1A and 1B show a typical radiotelephone 100 used in a wireless communication system such as the cellular and PCS systems described above. The radiotelephone shown in FIG. 1 (1A, 1B) has a “clam shell” foldable body or a flip-type phone shape for compactness. Other wireless devices and phones use more common “bar” housings or shapes.
[0026]
The telephone shown in FIG. 1 includes a whip antenna 104 protruding from a housing 102 and a helical antenna 100 concentric with the whip. Shown is the front of the housing that supports the speaker 110, display panel or screen 112, keypad 114, microphone or microphone access hole 116, external power connector 118, and battery 120, which are typical radiotelephone components known in the art. It is. In FIG. 1B, the antenna 104 is shown in an extended position that is typically seen during use, whereas in FIG. 1A, a retracted antenna 104 is shown (not visible due to viewing angle). ). Because there are various wireless devices and telephones with which the present invention may be used, and associated physical shapes, the telephone is used for illustration purposes only.
[0027]
As mentioned above, the antenna 104 has several drawbacks. One is that when the antenna is extended during use, it is sometimes damaged by retraction when hitting other objects or surfaces. This antenna also uses up the interior space of the phone to place components for advanced functions and circuits, including power supplies such as batteries. Further, the antenna 104 may require a large minimum housing dimension that is unacceptable when retracted. The antenna 106 also has the disadvantage of hitting other items or surfaces during use and cannot be retracted into the telephone housing 102.
[0028]
The present invention will be described with respect to this example environment. Explanation of these terms is for purposes of clarity and convenience only. The present invention is not intended to be limited to use in this example environment. After reading the following description, it will become apparent to one skilled in the art how to implement the invention in other environments. In fact, as will be described later, the present invention is, for example, a portable facsimile machine or a portable computer having a wireless communication function, but it is obvious that the present invention can be used in any wireless communication apparatus that is not limited to this.
[0029]
FIG. 2 shows a conventional microstrip patch antenna 200. The antenna 200 includes a microstrip element 204, an insulating substrate 208, a ground plane 212, and a feed point 216. Microstrip element 204 (commonly referred to as a radiator patch) and ground plane 212 are each made from a layer of conductive material, such as a copper plate.
[0030]
The most commonly used microstrip elements and associated ground planes consist of rectangular elements, although associated ground planes having other shapes such as microstrip elements and circles are also used. The microstrip element can be manufactured using a variety of known techniques, including photographic etching on one side of the printed circuit board, whereas the ground plane is the other side of the printed circuit board or the other Photoetched into layers. Various other methods by which microstrip elements and ground planes can be constructed, such as by selectively depositing a conductive material on a substrate and bonding the plate to a dielectric or coating a plastic with a conductive material There is.
[0031]
FIG. 3 shows a side view of a conventional microstrip antenna 200. A coaxial cable having a center conductor 220 and an outer conductor 224 is connected to the antenna 200. The central conductor (positive terminal) 220 is connected to the microstrip element 204 at a feed point 216. The external connector (negative terminal) 224 is connected to the ground plane 212. The length L of the microstrip element 204 is usually equal to 1/2 or 1/4 wavelength at the relevant frequency on the insulating substrate 208 (Antenna Technology Handbook by Richard C. Johnson and Henry Jasik, Second Edition). (See Chapter 7, page 7-2), indicated by the following relationship:
[0032]
L = 0.5λ_d= 0.5λ₀/ √ε_rOr
L = 0.25λ_d= 0.25λ₀/ √ε_r
Where L = length of microstrip element 204,
ε_r= Relative dielectric constant of insulating substrate 208,
λ₀= Free space wavelength
λ_d= Wavelength in insulating substrate 208.
[0033]
Since variations in dielectric constant and feed inductance make it difficult to predict the exact dimensions, test elements are usually formed to determine the exact length. The thickness t is typically about 0.01λ to minimize or prevent lateral currents or modes.₀Is usually much smaller than the wavelength of. The selected value of t is further detailed below based on the bandwidth over which the antenna must operate.
[0034]
Since the width “w” of the microstrip element 204 must be less than the wavelength in the insulating substrate material, ie, λd, higher order modes are not excited. An exception to this is when a multi-signal feed is used to remove higher order modes.
[0035]
A commonly used second microstrip antenna is a quarter wave microstrip antenna. The ground plane of a quarter wave microstrip antenna usually has a much larger area than the ground plane of a microstrip element. The length of the microstrip element is approximately ¼ wavelength at the relevant frequency in the substrate material. The length of the ground plane is approximately ½ wavelength at the relevant frequency in the substrate material.
[0036]
  The bandwidth of a quarter wavelength microstrip antenna is determined by the thickness of the insulating substrate. As previously mentioned, PCS and cellular radiotelephone operations require approximately 8 percent bandwidth. In order for the quarter-wave microstrip antenna to meet the 8 percent bandwidth requirement, the thickness of the insulating substrate 208 is approximately in the cellular frequency band (824-894 MHz).3.175cm (1.25 inches)And PCS frequency band1.27cm (0.5 inch)Must. This large thickness is almost0.635cm (0.25 inch)Alternatively, it is clearly undesirable in a small wireless device or personal communication device where a smaller thickness is desired. An antenna with a greater thickness generally cannot fit within the usable volume of most communication devices.
[0037]
3. The present invention
A one-plane dual strip antenna 400 constructed and operative in accordance with one embodiment of the present invention is shown in FIG. In FIG. 4, a one-plane dual strip antenna 400 includes a first strip 404, a second strip 408, an insulating substrate 412, and a waveguide 416 in the same plane. The first strip 404 is electrically connected to the second strip 408 at one end or adjacent thereto. This end is referred to as the “closed end” 406 for the antenna 400.
The first and second strips 404 and 408 are each printed on an insulating substrate 412 and etched or deposited, each affected by known impedance and current characteristics, eg, copper, brass Made of conductive material such as aluminum, silver, gold or other known conductive material. The first and second strips 404 and 408 are separated from each other by a predetermined gap t that can be filled with an insulating material (usually air) such as a known foam for such use as desired. In one embodiment of the present invention, the first and second strips 404 and 408 are placed substantially parallel to each other on their respective lengths. In other embodiments (see, eg, FIGS. 5A-5C and 9B), the first and second strips are morning glory outward at the open end to provide a better impedance that matches air or free space. Spread in shape.
[0038]
A coplanar waveguide having a positive terminal 420 and two negative terminals 424 and 428 is coupled to the first and second strips 404 and 408. In one embodiment of the invention, the positive and negative terminals 420, 424 and 428 are formed by three parallel metal strips. The center strip is shown as a positive terminal 420 and is electrically connected to the first strip 404. One outer strip is shown as negative terminal 424 and the other outer strip is shown as negative terminal 428. Negative terminal 424 is electrically connected to first strip 404 and negative terminal 428 is electrically connected to second strip 408. In one embodiment of the present invention, the waveguide 416 in the same plane is constructed by printing metal on the insulating substrate 412 and etching the metal or depositing the metal on the insulating substrate 412. The waveguide 416 in the same plane is made from a conductive material such as copper, silver, gold, aluminum or other known conductive material. On the other hand, coaxial cables are used as feeds instead of waveguides in the same plane.
[0039]
The single plane dual strip antenna 400 has a two-dimensional structure. Thus, the antenna can be glued so that it can be adapted to multiple surfaces, such as a plastic telephone plastic housing. In one embodiment of the invention, the antenna 400 is etched and can serve as an insulating substrate or medium such as Mylar, Kapton, or other known flexible insulating materials. Can be printed on or attached to a flexible sheet. It is advantageous that the dual strip antenna can be mounted on a thin part of the wireless device, such as a flip type, clam shell or folding part of a wireless mobile phone, as will be described later. .
[0040]
The lengths of the first and second strips 404 and 408 mainly determine the resonant frequency of the one-plane dual strip antenna 400. The lengths of the first and second strips 404 and 408 are sized appropriately to serve as a two-wire transmission line that can receive and transmit signals having a preselected desired frequency. Methods for selecting appropriate lengths for the first and second strips 404 and 408 to operate as a two-wire transmission line at a desired frequency are well known in the art. Briefly, in order for the first and second strips 404 and 408 to serve as two-wire transmission lines, each must have a length of approximately λ / 4. Here, λ is a wavelength at a frequency related to the electromagnetic wave. Next, the resulting antenna bandwidth formed by the two-wire transmission line is increased. This simultaneously decreases the length and width of the first strip while increasing the length and width of the second strip until the desired bandwidth is obtained.
[0041]
A waveguide 416 in the same plane couples a signal device (not shown) to the dual strip antenna 400. Note that this signaling device is used here to indicate the functionality provided by the signal source and / or signal receiver. Whether the signaling device provides one or both of these functionalities depends on how the antenna 400 is configured to operate. The antenna 400 can be configured to operate, for example, simply as a transmission element, in which case the signal device operates as a signal source. On the other hand, the signaling device operates as a signal receiver when the antenna 400 is configured to operate only as a receiving element. This signaling device provides both functionality in the form of a transceiver when the antenna 400 is configured to operate as both a transceiver element.
[0042]
The antennas or strips are, for example, 1/4 circle, semicircle, semi-elliptical, parabolic, square, circular and square C-shaped, L-shaped, U-shaped and V-shaped. It can be formed in various other shapes not limited to the above. V-shaped structures can vary from angles less than 90 ° to almost 180 °. The curved structure can use a relatively small radius or a large radius. The width of the conductor, i.e. the first and second strips, varies along the length so that the conductor tapers, curves and otherwise gradually changes towards the outer end (non-feed). Can do. As will be clearly understood by those skilled in the art, some of these effects or shapes can be combined in a single antenna structure.
[0043]
Some plan views of other embodiments or shapes for the strips of the present invention show that the last digit of the reference number indicates whether the breakdown is the first strip or the second strip, ie 4 or 8, respectively. 5A-5G, FIGS. 6A-6C, FIGS. 7A-7E and FIGS. 8A-8F. The first number and last letter indicate a diagram in which elements are displayed as in 504A for FIG. 5A, 708B for FIG. 7B, and so on. For purposes of clarity in the drawings, the widths for the strips used in these figures should not be scaled and are usually the same. However, as noted above, as will be readily apparent, these two strips usually have different widths to obtain the desired bandwidth.
[0044]
The antenna embodiments shown in FIGS. 5A-5G illustrate other shapes for the present invention that use rectangular or square transitions to connect the strips together. That is, for the closed end of the antenna of the embodiment shown in FIGS. 5A-5G, the first and second strips have substantially straight conductive connecting elements or transition strips 506 (506A-506G). Used together or joined together. Furthermore, further changes in direction for the strips relative to each other are made at approximately square corners. Each change in direction requires positioning a new portion of each strip that is approximately perpendicular to the previous portion, ie, at an angle of 90 °. Of course, these angles need not be accurate for most applications, and other angles can be used with curved or chamfered corners as desired.
[0045]
FIG. 5B shows that in order to accommodate a longer second strip, this strip can be folded to retain the entire desired length for the antenna structure. FIG. 5C shows that the crease may be either towards the plane with the first strip or away from this plane. FIG. 5D shows that the second strip can be folded back either partially or completely around the first strip. On the other hand, FIG. 5E also shows the extension of the first strip through the folded architecture. FIG. 5F shows the change of direction for the first and second strips performed in smaller steps. On the other hand, the end of each strip can be bent or oriented at an angle as shown in FIG. 5G to form an all-Y shape. In general, the separation angle is a 90 ° angle, although it is not required as if a duller Y-shaped end structure is acceptable.
[0046]
The antenna embodiments shown in FIGS. 6A-6C illustrate other shapes for the present invention that use curved or curved transitions to connect strips together. That is, in the embodiment shown in FIGS. 6A-6C, the first and second strips are connected or joined together at a closed end using a curved conductive connecting element or transition strip 606. Is done. The strip 606 can have a variety of shapes including, but not limited to, a quarter circle, a semicircle, a semi-ellipse, or a parabola or combination thereof. The curved structure can use a relatively small radius or a large radius as desired for a particular application. Further, each of the strips can be folded to retain the entire desired length for the antenna structure, as shown in FIGS. FIG. 6A shows a curve transition of a normal semicircle, FIG. 6B shows a transition of a normal quarter circle, or an ellipse, and a curve. FIG. 6C shows a transition of a normal parabolic curve. These types of transitions can also be used in combination.
[0047]
The antenna embodiment shown in FIGS. 7A-7E shows another shape for the present invention that uses V-shaped transitions to connect the strips together. That is, in the embodiment shown in FIGS. 7A-7E, the first and second strips were closed without using separate conductive connection elements or transition strips, or by using very small strips. Connected or joined together at the ends. Instead, the first and second strips extend from a common joint in the shape of outward separation or a flared shape. Further, as described above, each of the strips can be folded to retain the entire desired length for the antenna structure, as shown in FIGS. 5A-5H.
[0048]
7A and 7B show a normal straight V-shaped or acute angle transition where the strips join together. In FIG. 7B, the two strips are bent again to form a generally parallel strip or to provide a reduced angular tilt relative to each other. 7C-7E, at least one of the two strips is curved after the initial V-shaped joint. In FIG. 7C, both strips are curved to follow a logarithmic or parabolic curve function. In FIG. 7D, only one strip is curved, and in FIG. 7E, both strips are curved but can be folded upright. As mentioned above, these types of transitions can be used in any combination as desired for a particular application.
[0049]
8A-8G illustrate some other embodiments or shapes for strips of the present invention that use curved strips, angular strips, and composite strips. Here, the strips are placed almost parallel to each other over their respective lengths, but the strips are connected together at the closed ends using conductive connecting elements or transition strips 806 (806A-806F). In the case of a circular, serpentine or V-shaped path extending outward from a circular, serpentine or V-shaped path to be joined or joined, or in the case of the circular or elliptical of FIG. 8G No connection strip is used. The use of a composite shape allows the formation of an antenna structure on a support substrate that also supports circuitry or discrete components or devices, or allows clearance paths around other devices in the target wireless device.
[0050]
On the other hand, this antenna structure is a two-dimensional structure in a single plane, and is a structure that can be adapted or adapted so that the plane does not need to be flat. That is, the shape of the one-plane antenna can be effectively changed in three dimensions by bending or forming the support substrate. A pair of strips appearing as a flat surface in two dimensions can be bent along an arc or can be bent at an angle (here z) which is three dimensional. Some embodiments of the present invention in which a pair of strips are curved or bent in the z-direction are shown in FIGS. These embodiments are very useful when it is desired to place the antenna in a predetermined space of a wireless device that requires the antenna to be “fit” around a predetermined part or structure within the wireless device.
[0051]
FIG. 9A shows the first and second strips as can be seen in FIG. 4 which are also curved along their respective lengths in three dimensions using a simple curve. FIG. 9B shows the first and second strips as seen in FIG. 7A, connected together in a V-shaped or acute angle transition, but observed in three dimensions with a V-shaped offset. More complex curves or fold sets are used to form the plane where the strip is in FIG. 9C.
[0052]
The dual strip antenna 400 is formed at one end by etching a metal strip or attaching it to two opposing sides of an insulating substrate and using one or more plated through vias, jumpers, connectors or wires. It can also be configured by electrically connecting metal strips together. In this form, the antenna 400 utilizes some of the substrate material as a dielectric placed between the two strips. This takes into account only bandwidth and other characteristics as is well known when designing an antenna. The dual strip antenna 400 is formed of a plastic or other known insulating material or dielectric material to form a support structure having a desired shape (U-shaped, V-shaped, C-shaped, curved, rectangular, etc.) It can then also be constructed by plating or coating a suitable portion of a plastic having a conductive material including a liquid conductive material using known methods.
[0053]
The insulating substrate is secured within the components of the wireless device housing using posts, ridges, channels formed from the materials used to manufacture the housing. That is, such a support is molded or, particularly when manufactured, for example, by injection molding, in the wall of the device housing. Thus, these support elements hold the substrate in place when inserted over or into these support elements during telephone assembly. Other techniques include using a layer of adhesive material that secures the assembly within the device housing, or some type of fastener or retainer that interacts with holes or edges in the substrate.
[0054]
  As described above, according to the present invention, the first and second strips 404 and 408 (504, 508; 604, 608; 704, 708; 804, 808, etc.) function as two-wire transmission lines. . One advantage of a two-wire transmission line is that the two-wire transmission line does not require a ground plane. This allows the antenna 400 to be a two-dimensional structure with negligible thickness. Most of the thickness of the antenna 400 is determined by the thickness of the insulating substrate. For example,0.00127cm (0.0005 inch)~0.00508cm (0.002 inch)A thin sheet of mylar or capton having a thickness in the range of may be used as an insulating substrate. In contrast, traditional microstrip antennas designed for cellular frequency bands are3.175cm (1.25 inches)The microstrip designed for the PCS frequency band, whereas an insulating substrate with a thickness of1.27cm (0.5 inch)Insulating substrate having a thickness of 1 mm is required. Thus, the present invention allows a substantial reduction in the overall thickness of the antenna, thereby making it more desirable for personal communication devices such as PCS or cellular telephones. However, those skilled in the art will recognize that other thicknesses, including thicker materials, may be used to maintain the desired structural integrity for the antenna, either during use of the wireless device or during installation or during service. Can easily be used.
[0055]
The single planar dual strip antenna 400 according to the present invention provides increased bandwidth over typical quarter wavelength or half wavelength patch antennas. Experimental results show that antenna 400 has a width of about 8-20 percent, which is highly desirable for PCS and cellular phones. As previously mentioned, conventional microstrip antennas have a very narrow bandwidth that makes them less desirable for use in personal communication devices.
[0056]
In the present invention, increased bandwidth is mainly enabled by operating antenna 400 as a two-wire transmission line rather than as a conventional microstrip patch antenna. Unlike a conventional microstrip patch antenna with a radiator patch and a ground plane, in the antenna 400, both the first and second strips 404 and 408 serve as active radiators. In other words, the length and width of the first and second strips are carefully sized such that both the first and second strips 404 and 408 serve as active radiators at the relevant wavelength or frequency. The During operation of the antenna 400, a surface current is induced in the first strip as well as the second strip. Initially, the inventor selected appropriate dimensions that were the length and width of the first and second strips by using analysis methods and EM simulation software well known in the art. Thereafter, the inventor verified the simulation result by an experimental method known in the art.
[0057]
To increase the bandwidth of the radiator or antenna, the dimensions of each strip in the preferred embodiment are selected to produce different center frequencies that are related to each other in a preselected manner. For example, f₀Is the desired center frequency of the antenna. A shorter strip length has a center frequency f₀+ △ f or f₀The length of the longer strip is chosen so that its center frequency is f₀-△ f or f₀It is selected to be in the -Δf round. This is about 3Δf / f on the antenna₀~ 4Δf / f₀Gives a wide bandwidth. That is, f₀On the other hand, the use of a +/− frequency offset results in a scheme that increases the antenna radiator bandwidth. In this configuration, Δf is f₀(△ f << f₀) The resonant frequency of the two strips is small. Δf is f₀It is believed that the antenna does not perform well when selected to be around. In other words, it is intended to be used as a dual band antenna, each strip acting as a separate antenna radiator.
[0058]
In the present invention, the increase in bandwidth is obtained without a corresponding increase in the size of the antenna. This is contrary to the teachings of conventional patch antennas where the bandwidth is greatly increased by increasing the thickness of the patch antenna, thereby resulting in a larger overall size of the patch antenna.
[0059]
In an exemplary embodiment of the invention, antenna 400 is sized appropriately for the cellular frequency band, i.e., 824-894 MHz. The dimensions of antenna 400 for the cellular frequency band are shown in Table 1 below.
[0060]
[Table 1]

In the example embodiment above, 1 oz copper is used to construct the first and second strips 404 and 408;0.07874cm (0.031 inch)A thickness of FR4 (a well-known commercial printed circuit board (PCB) material) was used as the insulating substrate 412. In addition, the positive terminal of the waveguide 416 in the same plane is routed from the closed end of the antenna 400.0.8382cm (0.330)Connected to the first strip 404 at an inch distance.
[0061]
FIG. 10 shows the measured frequency response of one embodiment of an antenna 400 sized to operate over the cellular frequency band. FIG. 10 shows that the antenna has a -15.01 dB frequency response at 825 MHz and a -18.38 dB frequency response at 895.0 MHz. Thus, the antenna has an 8.14 percent bandwidth.
[0062]
In another illustrative embodiment of the invention, antenna 400 is sized to operate over the PCB frequency band, ie 1.85 to 1.99 GHz. The dimensions of antenna 400 for the PCB frequency band are shown in Table 2 below.
[0063]
[Table 2]

In the example embodiment, 1 oz copper is again used to construct the first and second strips 404 and 408,0.07874cm (0.031 inch)Thick FR4 (PCB material) was used as the insulating substrate 412. In addition, the positive terminal of the waveguide 416 in the same plane is routed from the closed end of the antenna 400.0.508cm (0.2 inch)Connected to the first strip 404 at a distance of.
[0064]
FIG. 11 shows the measured frequency response of one embodiment of an antenna 400 sized to operate over the PCB frequency band. FIG. 11 shows that the antenna has a −9.92 dB response at 1.79 GHz and a −10.18 dB response at 2.16 GHz. Thus, in this embodiment, antenna 400 has a 18.8 percent bandwidth.
[0065]
12 and 13 show the measured electric field pattern of one embodiment of antenna 400 operating over the PCB frequency band. In particular, while a plot of the electric field pattern magnitude on the azimuth plane is shown, FIG. 13 shows a plot of the electric field pattern magnitude on the depression plane. Both FIG. 12 and FIG. 13 show that a dual strip antenna has a nearly omnidirectional radiation pattern, thereby making it suitable for use in a personal communication device.
[0066]
One embodiment was developed using a “D” -shaped radiator strip device. The second strip is much longer than the first strip and is “inside” the first strip and folded away back into itself as desired and away from the first strip. Usually folded to extend. This antenna structure formed using strips 1404 and 1408 on which antenna 1400 is placed or placed on substrate 1412 is shown in FIG. The top of the antenna is formed by a first conductive strip 1404 that is shown as being slightly curved into a “C” shape (or the leading edge of D). This curvature is used to allow the antenna 1400 to be placed on and adjacent to the side of the device housing with curved sidewalls. The second strip is wider than the first strip and improves bandwidth as described above.
[0067]
This has an overall dimension of approximately 37.59 mm (Y) x 51.89 mm (X), which roughly corresponds to the internal dimensions of the flip-top portion of the clamshell type radiotelephone with the antenna. A model of such an antenna is constructed and tested.
[0068]
The antenna 1400 is connected to a suitable transceiver circuit in the wireless device using the feed 1416. Element 1420 shows how various known circuit components or devices can be mounted on the substrate 1412 or otherwise various components or cables can form passages or holes 1422 that extend as desired. Yes.
[0069]
A preferred embodiment has also been developed using a D-shaped radiator strip device. The second strip is much longer and wider than the first strip, and usually extends to wrap around the first strip. Such an antenna formed using strips 1504 and 1508 on which antenna 1500 is placed or placed on substrate 1512 is shown in FIG. Furthermore, the top of the antenna 1500 as formed by the second strip is shown as being slightly bent to allow improved placement of the antenna 1500 in the wireless device.
[0070]
This type of antenna can be formed as a coupling structure with conductors used to supply signals. The coaxial feed structure can be formed on the same flexible substrate (1512) as the conductor forming the antenna. Materials based on Mylar, Capton, or a thin sheet of Teflon are all materials well known in the art. An example of how this can be done is shown in FIG. 15, where a long flexible signal feed structure or section 1520 in the form of a “waveguide in the same plane” is shown. The waveguide 1520 terminates at one end and connects one end to a negative feed strip that forms part of the waveguide ground in the same plane. Feed strip 1524 is connected to or coupled to a connecting element 1506 where feed strip 1528 is connected to second strip 1508. The center of the positive feed strip 1522 or feed structure 1520 is directly connected to the first strip 1504. The separation between the connection point for this feed strip and the strip 1528 is selected to provide a predetermined impedance according to the frequency used and the length and other dimensions of the conductive material 1506 as is known. The
[0071]
A positive feed 1522 is shown that terminates a short distance along the material 1512 and is usually connected or coupled to a third central conductor 1526 similar to conductors 1524 and 1528 or a third central conductor similar to conductors 1524 and 1528. It spreads to 1526. The conductor 1526 extends along the length of the material 1512 to the connector end 1530 and forms the central or positive portion of the waveguide in the same plane.
[0072]
However, other shapes can be used including placing one or more feed strip conductors on opposite sides of the substrate. For example, a positive feed conductor can be formed on one side of material 1512 and a negative feed conductor can be formed on the other side of material 1512. Thus, conductive vias are used to transmit signals through the material when appropriate. Other combinations of conductors and vias may be used to achieve signal transmission as is known.
[0073]
Thus, the antenna 1500 can be formed as a single monolithic structure with these conductors (1522, 1524, 1528), resulting in increased efficiency, reliability, and manufacturing efficiency in cost. The conductors (1524, 1526, 1528) on the feed portion 1520 are generally conductive pads or small ones used to connect various spring-action or spring-loaded connectors on the circuit board to which the antenna is coupled. Terminate at connector 1532.
[0074]
The shape or overall shape for the waveguide or feed 1520 and substrate 1512 used in FIG. 15 is for illustrative purposes only and fits most effectively within the wireless device 100 as shown. Because. However, one of ordinary skill in the art will readily appreciate that other shapes are within the teachings of the invention that may be useful. For example, instead of using an angular bend along the length of the waveguide 1520 that is approximately 45 °, a series of 90 ° bends, folds, or rotations can be used for the conductor. Such folding and rotation is used to minimize the path length of the conductor while at the same time accepting physical constraints placed on the substrate or antenna. In addition, conductors 1524, 1526, and 1528 are typically reduced in width at one or more points along waveguide 1520, and their positions may also vary according to the particular application. The small air bridge shown in FIG. 15 that electrically joins the conductors 1524 and 1528 is useful but not necessary for the present invention.
[0075]
When placed in a wireless device, such as the wireless telephone 100, the feed structure or waveguide 1520 is effective between the antenna 100 used in the wireless device and the various receiving and transmitting elements and components. Enable signal transmission. By forming the antenna and a waveguide in the same plane on a common but thin and flexible insulating substrate, the antenna occupies a very small space and is free of many other individual components such as speakers. Since it can be formed around, the antenna can be mounted in a number of components of the device. The feed conductor can be connected around a flexible rotatable or foldable joint such as in many wireless devices (phones, computers).
[0076]
On the other hand, a mini-coaxial line can be used instead of a waveguide (feed) 1520 to achieve the same result. For example, a known type of coaxial line or cable having a diameter of 0.8 mm or 1.2 mm can be useful in transmitting signals between the antenna 1500 and a corresponding or appropriate circuit, as desired. It is shown that. Other types and types of conductors may be used for a given application depending on the signal transfer characteristics as is known.
[0077]
16 and 17 show a side view and a rear cutaway view, respectively, of one embodiment of the present invention installed in the telephone of FIG. Such telephones have various internal components that are typically supported on one or more circuit boards that perform various functions as required or desired. A circuit board 1602 is shown inside the housing of FIGS. 16 and 17 that supports various components such as an integrated circuit or chip 1604, discrete components such as resistors and capacitors, and various connectors 1608. Panel displays and keyboards are typically wires, conductors, connectors that interface with a battery or external power source, speakers, microphones, or other similar components of the circuit on the circuit board 1602 as well as various other components. (Not shown) attached to the back side of the circuit board 1602 facing the front of the telephone housing 102.
[0078]
In this embodiment, a slide-in or plug-in type connector 1610 is attached to the underside of the circuit board near the front of the phone and is configured to receive the connection end of the feeder portion 1520 for the antenna 1500. . On the other hand, one or more known spring contacts or clips can be used to contact the conductive pads on the end 1530 to electrically couple or connect the antenna 1500 to the circuit board 1602. Such spring contacts or clips are mounted on circuit board 1602 using well known techniques such as soldering or conductive adhesive so as to transmit signals to and from the desired transceiver circuit. It is electrically connected to a suitable conductor. However, other types of connection techniques are also known to be useful, including the use of solder or the use of small coaxial connectors (when small cables are used). As desired, there may also be a dedicated impedance matching element in the circuitry used in the wireless device to interconnect with the feed structure, as is well known.
[0079]
In the side view of FIG. 17, circuit board 1602 is shown as including multiple layers of conductive and insulating materials that are bonded together to form what is referred to in the art as a multilayer circuit board or printed circuit board. ing. Such circuit boards are well known and understood in the art. This is because the insulating material layer disposed adjacent to the metal conductor layer 1614 that supports the metal conductor layer 1618 or is disposed adjacent to the insulating material layer 1616 disposed adjacent to the metal conductor layer 1618. It is shown as 1612. Conductive vias (not shown) are used to interconnect various conductors of different layers or levels with components on the outer surface. The etched pattern on any given layer determines the interconnect pattern for this layer. In this configuration, either layer 1614 or 1618 can form a ground layer or ground plane as commonly referred to for circuit board 1602, as is well known in the art.
[0080]
In general, a series of support posts, stands, or ridges 1620 are used to mount circuit boards or other components within the housing. These can be formed as part of the housing, such as when formed by an injection molded plastic, or in particular can be secured in place, for example, by using an adhesive or other well-known mechanism. In addition, there are typically one or more securing posts 1622 that are used to receive fasteners to secure components such as removable covers of the housing 102 together.
[0081]
As described above, the antenna 1500 may include some known but not limited to the use of adhesives, glues, tapes, potting materials, or bonding materials that are known to be useful for this function. Can be secured within a component of the housing 102 using this technique. For example, the antenna 1500 can be supported against the sidewalls or other components or elements of the wireless device using an adhesive layer or strip 1630 bonded to the substrate 1512. The antenna is generally fixed to the side of the housing, preferably on an insulating material, or to a brace assembly that can be mounted in place using braces, screws, or similar fastening elements. Is done.
[0082]
Other mechanisms for attaching or securing an antenna in place are known in the art. For example, ridges, grooves, etc. formed in the material used to manufacture the housing can be used to physically secure the substrate in place. A series of protrusions or ridges can also be used to support the antenna and can have a variety of shapes as appropriate to the desired application.
[0083]
As can be seen in FIG. 17, the substrate 1512 can be curved or specifically bent to fit the shape of the housing or to fit other elements, functions or components within the wireless device. In the figure, a speaker 1632 is shown disposed with respect to an antenna radiator or strip "wrapped" around a portion of the speaker.
[0084]
This substrate can be deformed during manufacture or installation in a curved or folded shape. By using a thin substrate, the substrate, when installed, can apply tension or pressure against adjacent surfaces that are usually bent to secure the substrate in place without the need for fasteners from time to time. it can. Thus, some type of capture is simply obtained by equipping adjacent devices, components, or circuit boards and housing covers or components that are fixed in place. However, in order for the present invention to function properly, there are no conditions to deform or curve either the substrate during manufacture or installation.
[0085]
FIG. 18 illustrates additional wireless devices in which the present invention can be used, such as, but not limited to, portable computers, modems, data terminals, facsimile machines, or similar portable electronic devices. In FIG. 18, a wireless device using a wireless device 1800 having a main housing or body 1802 having an upper corner 1804 is shown. In the cut-away diagram of FIG. 18, the antenna 500 is fixed in place in the upper corner 1804 and a cable or conductor set 1808 is used to connect the antenna feed 516 to the appropriate circuitry in the wireless device. Those skilled in the art will readily appreciate that other shapes and orientations are possible for the antennas within the teachings of the present invention.
[0086]
While various embodiments of the present invention have been described above, it should be understood that this embodiment is shown by way of example only and not limitation. Accordingly, the breadth and scope of the present invention should not be examined by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims and their equivalents.
[Brief description of the drawings]
The present invention will be described with reference to the accompanying drawings, wherein like reference numerals are usually identical, functionally similar elements, and / or structurally the same elements, where the elements first appear in the reference numerals. It is indicated by the number.
FIGS. 1A and 1B show a mobile phone having a whip antenna and an external helical antenna.
FIG. 2 shows a conventional microstrip patch antenna.
FIG. 3 shows a side view of the microstrip patch antenna of FIG.
FIG. 4 illustrates a single planar dual strip antenna according to an embodiment of the present invention.
Figures 5A-5G show plan views of several other embodiments of the present invention that use square transitions to connect strips.
Figures 6A-6C show top views of several other embodiments of the present invention that use curved transitions to connect strips.
Figures 7A-7E show plan views of several other other embodiments of the present invention that use V-shaped transitions to connect strips.
FIGS. 8A-8G show plan views of additional alternative embodiments of the present invention using curved strip shapes, angular strip shapes, and composite strip shapes.
FIGS. 9A-9B are perspective views of some other embodiments of the present invention useful in certain other applications. FIGS.
FIG. 10 shows the measured frequency response of one embodiment of the present invention suitable for use with a cellular telephone.
FIG. 11 shows the measured frequency response of another embodiment of the present invention suitable for use with a PCS radiotelephone.
12 and 13 show measured electric field patterns for one embodiment of the present invention.
FIG. 14 shows a top view of one embodiment of the present invention for use with the telephone of FIG.
15 shows a top view of a signal feed structure for use with another embodiment of the present invention and the telephone of FIG. 1. FIG.
16 shows a bottom plan view and a side cross-sectional view of one embodiment of the present invention installed in the telephone of FIG. 1. FIG.
FIG. 17 shows a bottom plan view and a side cross-sectional view of one embodiment of the present invention installed in the telephone of FIG.
FIG. 18 shows an additional wireless device in which the present invention may be used.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 100 ... Helical antenna, 102 ... Housing, 104 ... Whip antenna, 110 ... Speaker, 112 ... Display panel, 114 ... Keypad, 116 ... Microphone, 118 ... External power connector, 120 ... Battery, 400 ... One plane dual strip Antenna, 404 ... first strip, 406 ... closed end, 408 ... second strip, 412 ... insulating substrate, 416 ... waveguide, 420 ... positive terminal, 424 ... negative terminal, 428 ... negative terminal, 506 ... Transition strip, 606 ... Transition strip, 806 ... Transition strip,

Claims (13)

A one-plane dual strip antenna comprising a first conductive metal strip and a second conductive metal strip mounted on a first surface of an insulating substrate,
The first and second strips are separated from each other by a selected constant gap;
The length and width of the first and second strips are selected to form a two-wire transmission line that receives and transmits electromagnetic energy;
And a waveguide in the same plane having positive and negative terminals , the waveguide in the same plane being formed by disposing metal on the substrate, the positive terminal being electrically connected to the first strip. The negative terminal is electrically connected to the first and second strips;
A surface current is formed on the first and second strips when the one-plane dual strip antenna is energized by an electrical signal through a waveguide in the same plane .
The one-plane dual strip antenna.   The single planar dual strip antenna of claim 1, wherein the first and second strips comprise metal strips printed on the same side of the insulating substrate.   The single planar dual strip antenna of claim 1, wherein the first and second strips comprise metal strips deposited on the same surface of the insulating substrate.   The single planar dual strip antenna of claim 1, wherein the first strip is substantially parallel to the second strip.   The single planar dual strip antenna of claim 1, wherein a length of the first strip is shorter than a length of the second strip.   The single planar dual strip antenna of claim 1, wherein a length of the first strip is equal to a length of the second strip.   The single planar dual strip antenna of claim 1, wherein the width of the first strip is smaller than the width of the second strip.   The single planar dual strip antenna of claim 1, wherein the width of the first strip is equal to the width of the second strip.   The single planar dual strip antenna of claim 1, wherein the insulating substrate is a flexible sheet that can act as an insulating medium.   The length and width of the first and second strips are sized such that the one-plane dual strip antenna can receive and transmit signals having a frequency range of 1.85 to 1.99 GHz. Item 2. The one-plane dual strip antenna according to item 1.   The length and width of the first and second strips are sized such that the single planar dual strip antenna can receive and transmit signals having a frequency range of 824-894 MHz. One plane dual strip antenna. A one-plane dual strip antenna comprising a first conductive metal strip and a second conductive metal strip mounted on an insulating substrate,
The first and second strips are separated from each other by a selected constant gap;
The length and width of said first and second strips are selected so as to form a two-wire transmission line for receiving the electromagnetic energy and transmits,
The one-plane dual strip antenna. A one-plane dual strip antenna comprising a first conductive metal strip and a second conductive metal strip mounted on an insulating substrate,
The first and second strips are separated from each other by a selected constant gap;
The length and width of the first and second strips are selected to form a two-wire transmission line that receives and transmits electromagnetic energy;
And a waveguide in the same plane having positive and negative terminals, wherein the waveguide in the same plane is formed by disposing metal on the same surface of the substrate, and the positive terminal is the first terminal. Electrically connected to the strip, and the negative terminal is electrically connected to the first and second strips;
A surface current is formed on the first and second strips when the one-plane dual strip antenna is energized by an electrical signal through a waveguide in the same plane .
The one-plane dual strip antenna.

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