M429184 五、新型說明： 【新型所屬之技術領域】 本新型是有關於一種圓極化天線，特別是指一種縮小化之 圓極化天線。 【先前技術】 隨著無線射頻辨識系統技術(RFID)應用的逐漸普及，使得 物件辨識更快速也更安全。且為方便使用者攜帶或使用，輕薄M429184 V. New description: [New technical field] The present invention relates to a circularly polarized antenna, in particular to a reduced circularly polarized antenna. [Prior Art] With the increasing popularity of Radio Frequency Identification System (RFID) applications, object recognition is faster and safer. And for the convenience of users to carry or use, thin and light
短小成為電子產品的主要設計趨勢’耻極化天線應用在 該等電子產品上時，天_尺核小縣設計天_的重要考 量之一。 -般圓極化平面天線的設計可分為單饋人與雙饋入兩種 =式單饋入之圓極化天線可利用截肖、挖槽孔或植入窄槽縫 等微擾方式，使縣正交的娜激發出兩鱗減且相位差 90度的相_直模態。但此種天線雖然只需單層基板即可， 但其缺點是操作織非常狹f，通料超過躲性極化輕射頻 寬的三分之―，且設雜制條件較多，不容易機天線圓極化 特性及阻抗匹配’所以設計困難。 通常是使用Wilkinson功率分配 至於雙饋入之圓極化天線則 器或支路輕合器(branch-line C〇u_級供振幅相等且相位相差9〇度的激發電流 ，且兩個 饋入點需分別位於互_直财向。_天線料較單饋入之 天線頻寬大且糊極化雛__，但由於需要使用兩 3 層以上的基板，以致天線體積變得過於龐大。 【新型内容】 因此’本新型之目的，係在提供-種在不影響天線輕射效 能情況下有效縮小天線尺寸的圓極化天線。 於是，本新型之圓極化天線’包括一基板、一環形輻射部、 一微帶輻射部及一接地面。該基板具有相反之一第一面及一第 二面。該環形輻射部設於該基板之第一面。該微帶輻射部設於 該環形輕射部所圍繞的空間中’並包括一第一線段及一第二線 #又，該二線段的一端相鄰近以饋入訊號，另一端相遠離且分別 連接該環形輻射部。該接地面，設於該基板之第二面。 較佳地，該圓極化天線更包括一用以平均分配饋入訊號功 率的饋入單元，其包含設於該環形輻射部所圍繞的空間中的一 饋入部及一電阻，該饋入部包含一饋入線段及二由該饋入線段 一端向外延伸之轉阻線段，該二轉阻線段分別終止於該第一線 段及第二線段相鄰近的一端並各別連接該第一線段及第二線 段’且該電阻兩端連接該二轉阻線段之鄰近該第一線段及第二 線段的一端β 較佳地，其中該饋入線段的另一端更設有一貫穿該基板的 第面和第二面的貫孔，供一 SMA接頭連接以饋入訊號，以 使該SMA接頭的t心饋入線與該饋入線段電連接，並使該 SMA接頭的一接地端經由該貫孔與設於基板第二面的接地面 電連接。 可替換地，該饋入單元可以是一功率分配器，其連接該第 一線段及弟一線段相鄰近的一端，用以分配饋入訊號功率使平 均饋入該第一線段及第二線段。 較佳地，該環形輕射部可以是圓環形、方環形、三角環形 或橢圓環形之環形結構金屬線。 較佳地’該第一線段及第二線段可以是L形彎折或圓弧形 之金屬線’且第一線段及第二線段係概呈垂直地以其相遠離 之另一端各別連接該環形輻射部。 較佳地，該第一線段與第二線段的總長相差四分之一波 長。 較佳地，該接地面可以是一矩形、圓形、三角形或與該基 板近似形狀的金屬平面。 較佳地，該饋入線段可以是長條形、L形或圓盤形之金屬 線段。 較佳地’該轉阻線段可以是圓弧形、矩形或L形彎折之金 屬線段。 較佳地，該基板可以是玻璃纖維基板或陶瓷基板。 較佳地’該基板可以是矩形或圓盤形。 本新型之圓極化天線具有結構簡單、尺寸短小、圓極化轴 比頻寬大、收發角度廣且增益高等優點，因此十分適合應用於 M429184 無線通訊系統之天線設計上’尤其適合輕薄短小之電子通訊產 品，具有極高的產業價值。 【實施方式】 有關本新型之前述及其他技術内容、特點與功效，在以下 配合參考圖式之一較佳實施例的詳細說明中，將可清楚的呈 現0 參見圖1及圖2，是本新型圓極化天線的一較佳實施例， 本實施例之圓極化天線1應用在920 MHz之操作頻率，其包 括一基板11、一接地面12、一環形輻射部13、一微帶輕射部 14及一饋入單元15。 基板11具有相反的一第一面111及一第二面112,在本實 施例中’基板11是一矩形的玻璃纖維板(FR4)，其尺寸為95 X 95 mm2,環形輻射部13及微帶輻射面η設於基板丨丨的第一 面111 ’接地面12設於基板11的第二面112。接地面η在本 實施例中是一設於基板11第二面112中央的矩形金屬平面， 其尺寸為64 X 64 mm2。 值得一提的是，本實施例之基板10並不以矩形為限，它 也可以是圓盤形或其它相似形狀，且其材質除了玻璃纖維板 (FR4)外，也可以使用陶瓷基板或其它可用的介質材料。而接 地面12亦不以矩形為限，它也可以是圓形、三角形或與基板 10近似形狀的金屬平面。 6 M429184 環形輻射部13是-封閉路徑金屬線段，在本實施例中， 該封閉路彳2金屬線段為-環繞基板11面⑴周邊的方環 形金屬線段’其内環邊長為76mm ’外環邊長為95mm。然環 形輻射部B並不以方環形為限，它也可以是圓環形、三角環 形、橢圓形或其它相似之環形結構。 微帶輻射部14設於環形輻射部13所環繞的空間中，並包 括-第-線段141及-第二線段142 ’且兩線段⑷、142的 總長相差四分之一波長，在本實施例中，該二線段141、M2 為一呈L形彎折的金屬線段’其一端143、ι44相鄰近以饋入 訊號’另一端相运離且概呈互相垂直地分別連接於環形輻射部 13相鄰的兩邊13卜132的内環邊長中點，第一線段14ι的總 長為59mm，第二線段142的總長為104mm。且第一線段141 及第二線段142除了 L形彎折結構外，也可以是圓弧形之金屬 線段。 饋入單元15設在環形輻射部13所環繞的空間中，其包括 一饋入部151及一電阻152。 饋入部151包含一饋入線段153及二轉阻線段154、155。 饋入線段153位於第一線段141及第二線段142所圈圍的空間 中’是一長度為10.3mm，寬度為3mm的長條形金屬線段，其 一端150設有一貫穿基板η第一面ill和第二面112的貫孔 156 ’其孔徑直徑為umm，供一 SMA接頭(圖未示)連接以饋 7 入訊號，使SMA接頭的中心饋入線與饋入線段153 一端15〇 電連接，而SMA接頭的接地端則經由貫孔156與第二面112 的接地面12電連接。 該二轉阻線段154、155由饋入線段153的另一端向外延 伸且分別终止於第―線段H1及第二線段142柳近的—端 143、144並分别連接該端143、144，在本實施例中，該二轉 阻線段154、155 S-狐長為48.G7mm、寬為1.6mm的圓弧形 金屬線段。 電阻152的兩端連接在該二轉阻線段154、155之連接第 —線段141及第二線段142的一端之間，其阻抗值為1〇〇歐姆。 上述饋入單元15的作用在於使饋入訊號的輸入功率可以 平均分配給第一線段141及第二線段142。其中饋入線段153 除了長條形外，也可以是L形或圓盤形之金屬線段，而轉阻線 段154、155除了圓弧形外，也可以是矩形、[形彎折或其它 相似形狀之金屬線段。當然饋入單元15並不限於使用上述微 帶線結構，它也可以用其它可將饋入訊號能量平均分配成多個 輸出的習知功率分配器來實現。 參見圖3至圖8 ’為本實施例圓極化天線1之實作量測結 果，由圖3之反射損失結果可得到天線的阻抗頻寬，即以γ 轴10dB為準橫切過去，對應曲線所得之頻寬為 762〜1175MHz ’ 即 1175-762=413MHz。 圖4所示為本實施例圓極化天線之史密斯圖的實驗結 果’圖5及圖6為天線在操作頻率920MHZ的輕射場型量測結 果，在漣波約在0〜3Db的情況下，圓極化天線1接收的半功 率波束角度可達90度。圖7則為操作頻帶内之圖極化天線軸 比的實驗結果’本實施例之圓極化天線1之轴比頻寬以γ軸 3dB為準横切過去，對應曲線所得之頻寬為866〜982ΜΉζ，即 982-866=116ΜΗζ。圖8則為操作頻帶内之圓極化天線i的増 益實驗量測結果’本實施例之圓極化天線1在操作頻帶内的增 益在4.5~6.2dBi之間。 由上述說明可知，本實施例之圓極化天線丨的結構十分簡 早，其由一正方形的玻璃纖維板當作基板ίο，並於此基板η 的第一面111上設置一環形輻射部13、一微帶輻射部14及— 饋入單元15，且在第二面112設置一接地面12，並將微帶輻 射部14及饋入單元15設於環形輻射單13中，由饋入單元15 將饋入訊號之輸入功率平均分配為等振幅且相位相差9〇度的 兩個輸出能量’並經由微帶輻射部14之總長相差四分之一波 長的苐一線段141及第一線段142以概呈相互垂直方式連接至 環形輕射部13，以激發出天線的圓極化特性，並作電磁波輻 射與接收，而且藉由改變第一線段141或第二線段142在環形 輻射部13中的連接位置，可以輕易地改變天線圓極化波的特 性，亦即當第一線段141連接環形輻射部13的左邊，第二線 M429184 段142連接環形輕射部13的下邊時，可得到一右旋圓極化波 (RHCP) ’反之若將第-線段⑷連接環形輻射部13的右邊， 第二線段142連接環形輻射部13的下邊時，可得到一左旋圓 極化波(LHCP)。 綜上所述，本實施例之圓極化天線1具有結構簡單、尺寸 短小、圓極化轴比頻寬大、收發角度廣且增益高等優點，因此 十分適合應用於無線通訊系統之天線設計上，尤其適合輕薄短 小之電子通訊產品，具有極高的產業價值。 惟以上所述者，鶴本新型之雛實施_已，當不能以 此限定本新型實施之範圍，即大凡依本新型申請專利範圍及新 型祝明内容所作之簡單料效變化與料，皆仍屬本新型專利 涵盖之範圍内。 【圖式簡單說明】 圖1為本新型圓極化天線之—較佳實施例之立體圖。 圖2為本實施例圓極化天線之平面圖； 圖3為本實施例®極化天線的反射損失實測數據圖； 圖4為本實施例圓極化天線的實驗結果史密斯圖； 圖5為本實施姻極化天線在Χ·ζ平面的輻射場型實驗 結果； 圖6為本實施例圓極化天線在Υ_ζ平面的輻射場型實驗结 果； 10 M429184 圖7為本實施例圓極化天線在操作頻帶内之天線轴比實 驗結果；及 圖8為本實施例圓極化天線在操作頻帶内之天線增益實 驗結果。 【主要元件符號說明】 1 圓極化天線 11基板 12 接地面 B環形輻射部 14 微帶輻射部 15饋入單元 111 第一面 112第二面 131 、132 邊 141第一線段 142 第二線段 143、144、15〇 端 151 饋入部 152電阻 153 156 饋入線段 貫孔 154、155轉阻線段Short-term becomes the main design trend of electronic products. When the shame-polarized antenna is applied to these electronic products, it is one of the important considerations for the design of Tianxian County. The design of the general circularly polarized planar antenna can be divided into single-input and double-input two-input single-input circularly polarized antennas, which can be used to intercept, dig, or implant narrow slots. The phase orthogonal to the county is excited by a phase-to-straight mode with two scales reduced by 90 degrees. However, although such an antenna only needs a single-layer substrate, the disadvantage is that the operation woven is very narrow, and the material exceeds the three-points of the evasive polarization and the light-radio-width, and the miscellaneous conditions are more, which is not easy. The antenna circular polarization characteristics and impedance matching are difficult to design. Usually using Wilkinson power distribution to the dual-input circularly polarized antenna or branch light combiner (branch-line C〇u_ stage for equal amplitude and phase difference of 9 的 excitation current, and two feeds The points need to be located in the mutual _ direct financial direction. _ The antenna material has a larger bandwidth than the single-feed antenna and the ambiguous polarization __, but the antenna volume becomes too large due to the need to use two or more layers of the substrate. Therefore, the purpose of the present invention is to provide a circularly polarized antenna that effectively reduces the size of the antenna without affecting the light-emitting efficiency of the antenna. Thus, the circularly polarized antenna of the present invention includes a substrate and a ring-shaped radiation. a microstrip radiation portion and a ground plane. The substrate has an opposite first surface and a second surface. The annular radiation portion is disposed on the first surface of the substrate. The microstrip radiation portion is disposed on the annular light The space surrounded by the shot portion 'and includes a first line segment and a second line # again, one end of the two line segments are adjacent to each other to feed the signal, and the other end is away from and connected to the annular radiation portion. Provided on the second side of the substrate Preferably, the circularly polarized antenna further includes a feed unit for equally distributing the power of the feed signal, and includes a feed portion disposed in a space surrounded by the annular radiating portion and a resistor, the feed portion The invention includes a feed line segment and a transimpedance line segment extending outward from one end of the feed line segment, wherein the two transimpedance line segments respectively terminate at adjacent ends of the first line segment and the second line segment and are respectively connected to the first line Preferably, the two ends of the feed line segment are connected to the end of the second line segment and the second line segment β of the second line segment, wherein the other end of the feed line segment is further provided with a through-substrate a through hole of the first surface and the second surface, for connecting an SMA connector to feed the signal, so that the t-heart feed line of the SMA connector is electrically connected to the feed line segment, and a ground end of the SMA connector is connected thereto The hole is electrically connected to the grounding surface disposed on the second surface of the substrate. Alternatively, the feeding unit may be a power distributor connected to the adjacent end of the first line segment and the first line segment for distributing the signal power. Feeding the average into the first line segment and Preferably, the annular light-emitting portion may be a circular, square, triangular or elliptical annular metal wire. Preferably, the first line and the second line may be L-shaped. a bent or arc-shaped metal wire' and the first line segment and the second line segment are vertically connected to each other at a distance from the other end thereof. Preferably, the first line segment and the first line segment The total length of the two segments is a quarter of a wavelength. Preferably, the ground plane may be a rectangle, a circle, a triangle or a metal plane having an approximate shape to the substrate. Preferably, the feed line segment may be a long strip. Preferably, the translucent line segment may be a circular arc, a rectangular or an L-shaped bent metal segment. Preferably, the substrate may be a fiberglass substrate or a ceramic substrate. Preferably, the substrate may be rectangular or disc shaped. The novel circularly polarized antenna has the advantages of simple structure, short size, large circular polarization axis, wide transmission angle, wide transmission angle and high gain, so it is very suitable for the antenna design of the M429184 wireless communication system, especially suitable for light and short electronic Communication products have a very high industrial value. [Embodiment] The foregoing and other technical contents, features and effects of the present invention will be clearly shown in the following detailed description of a preferred embodiment with reference to the drawings. Referring to FIG. 1 and FIG. A preferred embodiment of the novel circularly polarized antenna, the circularly polarized antenna 1 of the present embodiment is applied to an operating frequency of 920 MHz, and includes a substrate 11, a ground plane 12, an annular radiating portion 13, and a microstrip light. The shooting unit 14 and a feeding unit 15 are provided. The substrate 11 has an opposite first surface 111 and a second surface 112. In the present embodiment, the substrate 11 is a rectangular glass fiber board (FR4) having a size of 95 X 95 mm2, the annular radiation portion 13 and the microstrip. The radiation surface η is disposed on the first surface 111 of the substrate ' The ground plane 12 is disposed on the second surface 112 of the substrate 11 . In this embodiment, the ground plane η is a rectangular metal plane disposed at the center of the second surface 112 of the substrate 11, and has a size of 64 X 64 mm 2 . It should be noted that the substrate 10 of the embodiment is not limited to a rectangular shape, and may also be a disc shape or the like, and the material thereof may be a ceramic substrate or other materials besides the fiberglass board (FR4). Medium material. The ground 12 is not limited to a rectangle, and it may be a circle, a triangle or a metal plane similar to the substrate 10. 6 M429184 The annular radiating portion 13 is a closed-path metal wire segment. In the embodiment, the closed-turn 彳 2 metal wire segment is a square annular metal wire segment surrounding the surface of the substrate 11 (1), and the inner ring-side length is 76 mm. The side length is 95mm. However, the annular radiating portion B is not limited to a square ring, and it may be a circular ring, a triangular ring shape, an elliptical shape or the like. The microstrip radiation portion 14 is disposed in a space surrounded by the annular radiation portion 13, and includes a -------------------- The two line segments 141 and M2 are an L-shaped bent metal wire segment. The one ends 143 and ι44 are adjacent to each other to feed the signal, and the other end phase is transported away from each other and is perpendicularly connected to the annular radiating portion 13 respectively. The inner side of the adjacent sides 13 132 has a long midpoint, the total length of the first line 14 i is 59 mm, and the total length of the second line 142 is 104 mm. The first line segment 141 and the second line segment 142 may be arc-shaped metal segments in addition to the L-shaped bent structure. The feed unit 15 is disposed in a space surrounded by the annular radiating portion 13, and includes a feed portion 151 and a resistor 152. The feeding portion 151 includes a feeding line segment 153 and two transimpedance line segments 154, 155. The feeding line segment 153 is located in a space surrounded by the first line segment 141 and the second line segment 142. It is an elongated metal wire segment having a length of 10.3 mm and a width of 3 mm, and one end 150 is provided with a first surface penetrating through the substrate η. The through hole 156' of the ill and the second surface 112 has an aperture diameter of umm, and is connected by an SMA connector (not shown) for feeding a signal, so that the center feeding line of the SMA connector is electrically connected to one end 15〇 of the feeding line segment 153. The ground end of the SMA connector is electrically connected to the ground plane 12 of the second surface 112 via the through hole 156. The two transposed line segments 154, 155 extend outwardly from the other end of the feeding line segment 153 and terminate at the ends 143, 144 of the first line segment H1 and the second line segment 142, respectively, and are connected to the ends 143, 144, respectively. In this embodiment, the two transposed line segments 154, 155 S-the fox length is a circular arc-shaped metal wire segment of 48.G7 mm and a width of 1.6 mm. The two ends of the resistor 152 are connected between the connecting first line segment 141 and the second line segment 142 of the two transposed line segments 154, 155, and have an impedance value of 1 〇〇 ohm. The function of the feed unit 15 is that the input power of the feed signal can be equally distributed to the first line segment 141 and the second line segment 142. The feed line segment 153 may be an L-shaped or disc-shaped metal wire segment in addition to the elongated shape, and the resistance-resisting wire segments 154 and 155 may be rectangular, [shaped, or other similar shapes in addition to the circular arc shape. Metal wire segment. Of course, the feed unit 15 is not limited to the use of the above microstrip line structure, but it can also be implemented by other conventional power dividers that can evenly distribute the feed signal energy into a plurality of outputs. Referring to FIG. 3 to FIG. 8 'the implementation measurement result of the circularly polarized antenna 1 of the present embodiment, the impedance bandwidth of the antenna can be obtained from the reflection loss result of FIG. 3, that is, the γ axis is 10 dB as the standard, and the corresponding The resulting bandwidth of the curve is 762~1175MHz', ie 1175-762=413MHz. 4 shows the experimental results of the Smith chart of the circularly polarized antenna of the present embodiment. FIG. 5 and FIG. 6 show the light field type measurement results of the antenna at the operating frequency of 920 MHz, and the chopping is about 0 to 3 Db. The circularly polarized antenna 1 receives a half power beam angle of up to 90 degrees. 7 is an experimental result of the axial ratio of the polarized antenna in the operating frequency band. The axial specific bandwidth of the circularly polarized antenna 1 of this embodiment is transversely cut by 3 dB on the γ axis, and the bandwidth obtained by the corresponding curve is 866. ~982ΜΉζ, ie 982-866=116ΜΗζ. Fig. 8 is a result of the experimental measurement of the circularly polarized antenna i in the operating band. The gain of the circularly polarized antenna 1 of the present embodiment in the operating band is between 4.5 and 6.2 dBi. It can be seen from the above description that the structure of the circularly polarized antenna 本 of the present embodiment is very simple, and a square fiberglass board is used as the substrate ίο, and an annular radiating portion 13 is disposed on the first surface 111 of the substrate η. a microstrip radiating portion 14 and a feeding unit 15, and a ground plane 12 is disposed on the second surface 112, and the microstrip radiating portion 14 and the feeding unit 15 are disposed in the annular radiating unit 13 by the feeding unit 15 The input power of the feed signal is evenly distributed into two output energies of equal amplitude and phase difference of 9 ' degrees and the first line segment 141 and the first line segment 142 which are separated by a quarter wavelength of the total length of the microstrip radiation portion 14 The circular light-emitting portion 13 is connected to the annular light-emitting portion 13 in an approximately vertical manner to excite the circular polarization characteristic of the antenna, and to radiate and receive electromagnetic waves, and to change the first line segment 141 or the second line segment 142 at the annular radiation portion 13 In the connection position, the characteristic of the circularly polarized wave of the antenna can be easily changed, that is, when the first line segment 141 is connected to the left side of the annular radiating portion 13, and the second line M429184 segment 142 is connected to the lower side of the annular light projecting portion 13, Obtain a right-hand circularly polarized wave ( RHCP) On the contrary, if the first line segment (4) is connected to the right side of the annular radiating portion 13, and the second line portion 142 is connected to the lower side of the annular radiating portion 13, a left circular polarized wave (LHCP) is obtained. In summary, the circularly polarized antenna 1 of the present embodiment has the advantages of simple structure, short size, large circular polarization axis ratio, wide transmission and reception angle, and high gain, and is therefore suitable for antenna design of a wireless communication system. Especially suitable for light and short electronic communication products, with high industrial value. However, the above-mentioned ones, the implementation of the new version of the crane, have not been limited to the scope of the implementation of the new model, that is, the simple material effect changes and materials made by the new patent application scope and the new type of wishing content are still This new patent covers the scope. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a preferred embodiment of a circularly polarized antenna. 2 is a plan view of a circularly polarized antenna of the present embodiment; FIG. 3 is a measured data of reflection loss of a polarized antenna of the present embodiment; FIG. 4 is a Smith chart of the experimental result of the circularly polarized antenna of the present embodiment; The experimental results of the radiation pattern of the polarization antenna in the Χ·ζ plane are implemented; FIG. 6 is the experimental result of the radiation pattern of the circularly polarized antenna in the Υ_ζ plane of the present embodiment; 10 M429184 FIG. 7 is a circularly polarized antenna of the present embodiment. The antenna axis ratio in the operating band is compared with the experimental result; and FIG. 8 is an experimental result of the antenna gain of the circularly polarized antenna in the operating band of the present embodiment. [Description of main component symbols] 1 circularly polarized antenna 11 substrate 12 ground plane B annular radiating portion 14 microstrip radiating portion 15 feeding unit 111 first surface 112 second surface 131, 132 side 141 first line segment 142 second line segment 143, 144, 15 〇 151 feed 152 resistance 153 156 feed line segment through holes 154, 155 resistance line segment