1364875 九、發明說明： 【發明所屬之技術領域】 本發明係提供一種小型化共面波導饋入式之不對稱 單極天線，尤指一種可多頻帶或寬頻帶操作之小型化共面 波導饋入不對稱τ型單極天線。 【先前技術】1364875 IX. Description of the Invention: [Technical Field] The present invention provides a miniaturized coplanar waveguide feed-type asymmetric monopole antenna, and more particularly to a miniaturized coplanar waveguide feed capable of multi-band or wide-band operation Into an asymmetric τ-type monopole antenna. [Prior Art]
無線通訊在生活中已是不可或缺，如PDA、筆記型 電腦、3G手機等。而無線通訊的運作都需利用天線負責 訊號的傳輸與接收。 現今的無線通訊系統中有GSM、藍芽、WiFi及Wireless communication is indispensable in life, such as PDAs, notebook computers, 3G mobile phones, etc. The operation of wireless communication requires the use of an antenna to transmit and receive signals. Today's wireless communication systems include GSM, Bluetooth, WiFi and
WiMAX等；其中WiFi系統係使用2.4-2.5GHz的ISM全 球共通頻段，而國際間的WiMAX頻段大都劃在3.4至 3.7GHz之間。又為達到無線傳輸的需求，通訊頻段必需 多頻和寬頻，且依專家估計，未來WIMAX通訊協定將會 普及。 為增加通訊頻段和頻寬，在習用技術上通常必須 天線的數目或以寬頻天線來涵蓋操作頻段，此外，在天線 設計上’習用大部分的天線體積偏大，佔了電路中很大的 面積’對現今輕薄短小的無線通訊產品來說，無疑漸不太 3常:ί:寬頻天線中因含蓋的頻率很大’在習用技術 、σ人濾波11來抑制掉不需要的操作頻段，導致 成本提向與製造不便。 是以，應該有需要-種可多頻帶和寬頻帶操作以及體 5 1364875 積小並可降低成本的天線產生。 【發明内容】 本發明人有鑑於此，乃悉心從事設計，於今有本發明 產生。緣此，本發明之主要目的在提供一種適用於無線通 訊的小型化共面波導饋入式之不對稱單極天線，藉以提供 更寬的操作頻帶並可涵蓋更多的無線通訊應用，而且該天 線具有低姿勢、質量輕、製造容易、成本低等優點。 依據本發明一實施例構成的小型化共面波導饋入式 之不對稱單極天線，係包含一微波基板、印製在該微波基 板上的一輕射金屬面、印製在該微波基板上的一金屬接地 面及可用以產生寬頻帶操作的二缺口；該輻射金屬面具有 一由微帶線構成的饋入部，而該金屬接地面包含位在饋入 部兩側的第一接地片及一第二接地片，又該二缺口係個別 設在該第一接地片與該饋入部之間以及該第二接地片與 該饋入部之間，藉以形成一個寬頻操作的天線。 在一實施例中，係進一步在輻射金屬面上設有可用以 抑制頻帶的溝槽，該溝槽概呈倒L型，其包含一縱向的第 一槽縫及自該第一槽縫尾端橫向延伸的第二槽縫，藉以形 成一個三頻操作的天線。 在一實施例中，該第一接地片及第二接地片的尺寸不 相等且相對該饋入部為不對稱，而該饋入部的尾端係形成 一梯型的饋入端，該梯型饋入端後側有一概呈T型的金屬 輻射貼片，該T型金屬輻射貼片包含一縱向下部及一橫向 6 丄364875 上部’該橫向上部在寬度方向有延伸出該縱向下部的 凸部及一短凸部。 隹一 貫施例中，該第 '^ ^ 1日啤即日硪贫屬輻射面之縱向 :部的底端垂直延伸至橫向上部，而該第二槽縫係在該金 屬輻射面之寬度方向上由短凸部向長凸部延伸。 在一實施例中，該缺口 13的長寬為5 5x2mm。WiMAX, etc.; the WiFi system uses the 2.4-2.5 GHz ISM global common band, while the international WiMAX band is mostly between 3.4 and 3.7 GHz. In order to meet the demand of wireless transmission, the communication frequency band must be multi-frequency and wide-band, and according to experts' estimates, the future WIMAX communication protocol will become popular. In order to increase the communication frequency band and bandwidth, it is usually necessary to use the number of antennas or wide-band antennas to cover the operating frequency band in the conventional technology. In addition, most of the antennas used in the antenna design are bulky, occupying a large area in the circuit. 'For today's light and short wireless communication products, it is undoubtedly less common: ί: The wide frequency antenna has a large frequency due to the cover. In the conventional technology, σ human filter 11 to suppress the unnecessary operating frequency band, resulting in Cost increase and manufacturing inconvenience. Therefore, there should be a need for multi-band and wide-band operation and antenna generation with a small size and reduced cost. SUMMARY OF THE INVENTION The present inventors have made it in mind that the present invention has been made in view of the above. Accordingly, it is a primary object of the present invention to provide a miniaturized coplanar waveguide feed-type asymmetric monopole antenna suitable for wireless communication, thereby providing a wider operating band and covering more wireless communication applications, and The antenna has the advantages of low posture, light weight, easy manufacture, and low cost. A miniaturized coplanar waveguide feed-type asymmetric monopole antenna constructed according to an embodiment of the present invention includes a microwave substrate, a light-emitting metal surface printed on the microwave substrate, and printed on the microwave substrate a metal ground plane and a second gap that can be used to generate a broadband operation; the radiation metal mask has a feed portion formed by a microstrip line, and the metal ground plane includes a first ground plane on both sides of the feed portion and a The second grounding strip is further disposed between the first grounding strip and the feeding portion and between the second grounding strip and the feeding portion to form a broadband operating antenna. In one embodiment, a trench is further provided on the radiant metal surface for suppressing a frequency band, the trench being substantially inverted L-shaped, including a longitudinal first slot and from the first slot end A second slot extending laterally to form a three-frequency operated antenna. In an embodiment, the first grounding strip and the second grounding strip are unequal in size and asymmetric with respect to the feeding portion, and the trailing end of the feeding portion forms a ladder type feeding end, and the ladder type feeding The rear side of the inlet has a T-shaped metal radiation patch, and the T-shaped metal radiation patch comprises a longitudinal lower portion and a lateral portion 6 丄 364875. The upper portion has a convex portion extending in the width direction from the longitudinal lower portion and A short convex part.隹 In the consistent example, the '^^1 day beer is the longitudinal direction of the sun-drenched radiation surface: the bottom end of the portion extends vertically to the lateral upper portion, and the second slot is in the width direction of the metal radiation surface The short convex portion extends toward the long convex portion. In one embodiment, the gap 13 has a length to width of 5 5 x 2 mm.
曰該第一槽縫與第二槽縫的長度最好固定為16mm，以 得低頻抑制頻帶為2.72到3.26GHz。 關於本發明之其他目的、優點及特徵，將可由以下較 佳實施例的詳細說明並參照所附圖式來了解。 【實施方式】 有關本發明的構造設計，將經由僅為例子但非用以限 制的實施例並參照所附圖式作進一步說明： 參閱第一圖，顯示依據本發明第一實施例構成的小型 • 化共面波導饋入式之不對稱單極天線卜該天線包括一微 波基板10、印製在微波基板1〇 一側面上的一輻射金屬面 u、印製在微波基板1〇上的一金屬接地面12以及用以產 生寬頻帶操作的缺口 13。 在本實施例中，該微波基板1〇係一厚度為〇 8mm、 相對介電常數（er)為44、損耗正切常數（〖⑽5)為 0·〇245及面積為28mmx 26 4 mm的FR4玻璃纖維板。 該輻射金屬面11概呈平面區域，其一端係由微帶線 構成的饋入部111，在本實施例中，該饋入部ln的微帶 7 1364875 線寬度Wf為2.4mm，並有50歐姆的共面波導饋入線從 天線主體中央沿著Z軸筆直的饋入（未圖示）；又該饋入 部111的尾端係一梯型的饋入端112’其底寬τι可用來 調整阻抗匹配，在本實施例中，饋入端112的底寬T1設 定為9mm時，可達成寬頻特性；在梯型饋入端112後側 並有一概呈T型的金屬輻射貼片，該丁型金屬輻射貼片 包含一縱向下部113及一橫向上部114,該橫向上部Π4 在寬度方向有延伸出該縱向下部113的一長凸部115及一 短凸部116，該二凸部之寬度W1、W3係不相等，可用來 達到寬頻的匹配。 金屬接地面12包含位在饋入部lu兩側的第一接地 片121及第二接地片122,該二接地片的尺寸不相等且相 對饋入部ill為不對稱’其中第一接地片121的寬度Wgl 也是一個可用來調整阻抗的參數，在本實施例中，第一接 地片121與第二接地片122的寬度值分別設為1〇與 13.6mm，又接地面12與饋入部ln之間的間距G為〇 2mm ，以形成一共面波導天線。 該用以產生寬頻帶操作的缺口 13係設在該接地面12 與該輻射金屬面11之間，在本實施例中，係在第一接地 片121與饋入部in之間以及在第二接地片122與饋入部 1Π之間個別設有一缺口 13，該二缺口 13最好形成對稱 ，在本實施例中，各缺口 13的長寬（L4xW4)分別為 5.5x2mm，經實驗顯示其具有可升高或降低阻抗頻寬之起 始頻率的作用，以形成一可供寬頻操作的天線。 8 1364875 依據本發明第一實施例構成的天線1之主要特徵在 於接地面12上設有二對稱的矩形缺口 13用以產生寬頻帶 操作的效用，配合選擇一個適當的尺寸，就會激發一個接 近於天線主共振模態附近的新共振模態。當兩個共振模態 拉近在一起而產生一個最近新的寬頻操作後，再經由調整 50歐姆的共面波導饋入線長度即可達到良好的阻抗匹配 ，而形成一個寬頻操作的天線。如第二圖所示，係為該第 一圖之寬頻天線之返射損失圖，其頻段含蓋2 43〜6个gHz 〇 參閱第二圖，顯示依據本發明第二實施例構成的共面 波導饋入天線1，該天線包括一微波基板1〇'印製在微波 基板10上的一輻射金屬面u、印製在微波基板1〇上的 一金屬接地面12、用以產生寬頻帶操作的缺口 13及用以 抑制頻帶的溝槽14。該實施例中的微波基板1()、輕射金 屬面11、金屬接地面12及缺口 13係與第一實施例說明 者相同，因而只附上同一標號，不再贅述。 該第二實施例的天線1特徵係在輻射金屬面u上設 有可用以抑制頻帶的溝槽14，在本實施例中，該溝槽Μ 係概呈倒L型’其包含—縱向的第—槽縫⑷及自該第一 槽縫141尾端橫向延伸的第二槽縫142 :在本實施例中， 該第槽縫141係自該金屬輻射面之縱向下部113的底端 ，直延伸至橫向上部114，其寬度為G 5_，長度si-設 ^為m時可用以抑制掉高頻（〜GHz )的頻段；而該第 一槽縫142係在該金屬輻射面之寬度方向上由短凸部116 9 Γ364875 向長凸部115延伸’其寬度為〇.5mm，長度S2設定為7mm 時可用以抑制掉低頻（〜GHz)的頻段，再者，經實驗顯 示，若調整溝槽14的長度係可任意使兩個抑制頻帶往高 頻或低頻移動’又當第一槽縫141與第二槽縫142的長度 固定在16mm時，係可得低頻抑制頻帶為2.72到3.26GHz ，中心頻率為2.99GHz在3.5dB左右。是以，藉由該倒L 型溝槽14產生雙頻抑制的特性’使得適用於WiMAX標 準的三頻天線成功設計出。 參看第四圖’係為該第三圖之三頻平面區域或矩形共 面波導式天線的返射損失圖，其中實線代表實驗量測的結 果，顯示有符合WIMAX技術之操作頻段的三個頻段（ 2.25〜2.97, 3.25〜3.92, 5.12〜6 f GHz);參看第五圖至第七 圖，分別為三個頻段天線增益圖，圖中顯示三個頻段的天 線最大增益值分別為3.07,2.65及5.56dBi，满足WiMAX 系統高增益的須求。 參看第八圖至第十圖，分別為操作頻率在2.5GHz、 3.6GHz和5.5GHz時，寬頻和三頻在X-Y平面和γ_ζ平 面上的同極化（co-pol)及交叉極化（cross-pol)遠場輻射場 型實驗量測結果；從這些輻射場型的結果中顯示依據本發 明構成的天線具有良好的主極化輻射，且為常用的垂向輕 射（broadside radiation );又由該等輻射場型量測圖並可 發現植入的槽縫對天線的輻射場型影響不大，即使在高頻 中，寬頻和三頻都具有著良好的全向性輻射的特性。 依據本發明構成的共面波導饋入天線，藉由在接地面 1.364875 12設置缺口 13可以產生寬頻帶操作，且藉由整體_ 不對稱性可以產生單溝槽雙抑制的特性，達成可任：：計 成為寬頻或三頻操作，又當三頻操作時，該倒L 槽 14可為電路設計省下滤波器的成本，再者，本發明應^ 於WIMAX規格的小型化二頻天線體積僅有 28x26.4x0.8mm3 ’故本發明的天線具有小型化的體積、重 量輕、低姿態（low profile)、低成本、良好的輻射特性、 全向性的輻射場輻圖及容易與射頻電路系統做整合等優 點。 前述是對本發明之構造作較佳實施例的說明，而依本 發明的設計精神是可作多種變化或修改的實施例。是以， 對於熟悉此項技藝人士可作之明顯替換與修飾，仍將併入 於本發明所主張的專利範圍之内。 【圖式簡單說明】 第一圖：係依據本發明第一實施例構成的天線之幾何 結構圖。 第二圖：係第一圖之寬頻天線之返射損失圖。 第三圖：係依據本發明第二實施例構成的天線之幾何 結構圖。 第四圖：係第三圖之三頻天線之返射損失圖。 第五圖：係本發明天線在2.25〜2.97GHz頻段的增益圖 〇 第六圖：係本發明天線在3.25〜3.92GHz頻段的增益圖 1364875 第七圖：係本發明天線在5.12〜6 ΐ GHz頻段的增益圖 〇 第八圖：係本發明天線在操作頻率為2.5GHz時，寬頻 和三頻在X-Y平面與Y-Z平面上的同極化 (co-pol)及交叉極化（cross-pol)之輕射場型圖 〇 第九圖：係本發明天線在操作頻率為3.6GHz時，寬頻 鲁 和三頻在X-Y平面與Y-Z平面上的同極化 (co-pol)及交叉極化（cross-pol)之輻射場型圖 〇 第十圖：係本發明天線在操作頻率為5.5GHz時，寬頻 和三頻在X-Y平面與Y-Z平面上的同極化 (co-pol)及交叉極化（cross-pol)之輻射場型圖 〇 12 1364875 【主要元件符號說明】 (1)天線 (10)微波基板 (11)輻射金屬面 (111)饋入部 (112)饋入端 (113)下部 (114)上部 (115)長凸部 (116)短凸部 (12)接地面 (121)第一接地片 (122)第二接地片 (13)缺口 (141)第一槽縫 (14)溝槽 (142)第二槽縫 13Preferably, the length of the first slot and the second slot is fixed to 16 mm so that the low frequency suppression band is 2.72 to 3.26 GHz. Other objects, advantages and features of the present invention will become apparent from the Detailed Description of the <RTIgt; [Embodiment] The structural design of the present invention will be further described by way of example only, but not by way of limitation, and reference to the accompanying drawings. Referring to the first figure, showing a small structure according to the first embodiment of the present invention • A coplanar waveguide feed-type asymmetric monopole antenna comprising a microwave substrate 10, a radiating metal surface u printed on one side of the microwave substrate 1 , and a printed on the microwave substrate 1 Metal ground plane 12 and a notch 13 for generating broadband operation. In the present embodiment, the microwave substrate 1 is a FR4 glass having a thickness of 〇8 mm, a relative dielectric constant (er) of 44, a loss tangent constant ((10)5) of 0·〇245, and an area of 28 mm×26 4 mm. Fiberboard. The radiating metal surface 11 is a planar area, and one end thereof is a feeding portion 111 composed of a microstrip line. In the embodiment, the microstrip 7 1364875 of the feeding portion ln has a line width Wf of 2.4 mm and 50 ohms. The coplanar waveguide feed line is fed straight from the center of the antenna body along the Z axis (not shown); the end of the feed portion 111 is a ladder type feed end 112' whose bottom width τι can be used to adjust the impedance matching In this embodiment, when the bottom width T1 of the feeding end 112 is set to 9 mm, the broadband characteristic can be achieved; on the rear side of the ladder type feeding end 112, there is a T-shaped metal radiation patch, the butt metal The radiation patch comprises a longitudinal lower portion 113 and a lateral upper portion 114. The lateral upper portion 4 has a long convex portion 115 and a short convex portion 116 extending in the width direction from the longitudinal lower portion 113. The widths of the two convex portions are W1 and W3. They are not equal and can be used to achieve wideband matching. The metal ground plane 12 includes a first grounding strip 121 and a second grounding strip 122 on both sides of the feeding portion lu. The two grounding strips are unequal in size and asymmetric with respect to the feeding portion ill, wherein the width of the first grounding strip 121 is Wgl is also a parameter that can be used to adjust the impedance. In this embodiment, the width values of the first grounding strip 121 and the second grounding strip 122 are set to 1 〇 and 13.6 mm, respectively, and between the ground plane 12 and the feeding portion ln. The pitch G is 〇2 mm to form a coplanar waveguide antenna. The notch 13 for generating a broadband operation is disposed between the ground plane 12 and the radiating metal surface 11, in the embodiment, between the first grounding strip 121 and the feeding portion in and at the second ground. A notch 13 is formed between the piece 122 and the feeding portion 1 , and the two notches 13 are preferably symmetric. In the embodiment, the length and width (L4xW4) of each notch 13 are 5.5×2 mm, respectively, which has been experimentally shown to be capable of rising. The effect of increasing or decreasing the initial frequency of the impedance bandwidth to form an antenna for wideband operation. 8 1364875 The main feature of the antenna 1 constructed according to the first embodiment of the present invention is that the ground plane 12 is provided with two symmetric rectangular notches 13 for generating the effect of wide-band operation, and selecting an appropriate size will inspire an approach. A new resonant mode near the main resonant mode of the antenna. When the two resonant modes are brought together to produce a recent new wideband operation, good impedance matching can be achieved by adjusting the 50 ohm coplanar waveguide feed line length to form a broadband operating antenna. As shown in the second figure, it is a return loss map of the broadband antenna of the first figure, and the frequency band includes a cover 2 43 to 6 gHz. Referring to the second figure, the coplanar composition according to the second embodiment of the present invention is shown. The waveguide is fed into the antenna 1. The antenna includes a microwave substrate 1 'a radiating metal surface u printed on the microwave substrate 10 and a metal ground plane 12 printed on the microwave substrate 1 for generating a broadband operation. The notch 13 and the trench 14 for suppressing the frequency band. The microwave substrate 1 (), the light-emitting metal surface 11, the metal ground plane 12, and the notch 13 in this embodiment are the same as those described in the first embodiment, and therefore, the same reference numerals will be given, and the description thereof will not be repeated. The antenna 1 of the second embodiment is characterized in that a groove 14 for suppressing a frequency band is provided on the radiating metal surface u. In the present embodiment, the groove is substantially inverted L-shaped, which includes - longitudinal a slot (4) and a second slot 142 extending laterally from the rear end of the first slot 141: in the embodiment, the slot 141 extends straight from the bottom end of the longitudinal lower portion 113 of the metal radiating surface To the lateral upper portion 114, the width is G 5_, and the length si- is m to suppress the high frequency (~GHz) frequency band; and the first slot 142 is in the width direction of the metal radiation surface The short convex portion 116 9 Γ 364875 extends toward the long convex portion 115 whose width is 〇.5 mm, and when the length S2 is set to 7 mm, the frequency band of the low frequency (~GHz) can be suppressed, and further, experimentally, if the groove 14 is adjusted The length of the two suppression bands can be arbitrarily moved to the high frequency or low frequency. When the lengths of the first slot 141 and the second slot 142 are fixed at 16 mm, the low frequency suppression band is 2.72 to 3.26 GHz. The frequency is around 2.99 GHz at around 3.5 dB. Therefore, the characteristics of the dual-frequency rejection by the inverted L-shaped trenches 14 enable the tri-band antenna suitable for the WiMAX standard to be successfully designed. See Fig. 4' for the return loss map of the third-frequency planar region or rectangular coplanar waveguide antenna of the third graph, where the solid line represents the experimental measurement results, showing three operating frequency bands in accordance with WIMAX technology. The frequency bands ( 2.25~2.97, 3.25~3.92, 5.12~6 f GHz); see the fifth to seventh figures, respectively, for the three-band antenna gain map, which shows that the maximum gain values of the three bands are 3.07, respectively. 2.65 and 5.56dBi, which meet the high gain requirements of WiMAX systems. Referring to the eighth to tenth figures, the co-pol and cross-polarization of the broadband and tri-band in the XY plane and the γ_ζ plane at operating frequencies of 2.5 GHz, 3.6 GHz, and 5.5 GHz, respectively. -pol) far field radiation field type experimental measurement results; from the results of these radiation patterns, it is shown that the antenna constructed according to the present invention has good main polarization radiation and is a commonly used broadside radiation; From these radiation pattern measurements, it can be found that the implanted slot has little effect on the radiation pattern of the antenna, and even in high frequencies, both broadband and tri-band have good omnidirectional radiation characteristics. According to the coplanar waveguide feeding antenna constructed by the present invention, wide-band operation can be generated by providing the notch 13 on the ground plane 1.364875 12, and the single-channel double suppression characteristic can be generated by the overall_asymmetry, and the following can be achieved: : The meter becomes broadband or tri-band operation, and when tri-band operation, the inverted L-slot 14 can save the cost of the filter for the circuit design. Furthermore, the present invention should be used for the miniaturized two-band antenna of the WIMAX specification. There are 28x26.4x0.8mm3 'The antenna of the present invention has miniaturized volume, light weight, low profile, low cost, good radiation characteristics, omnidirectional radiation field radiation and easy with RF circuitry Do integration and other advantages. The foregoing is a description of the preferred embodiments of the present invention, and the embodiments of the invention may be modified or modified. Therefore, obvious substitutions and modifications may be made by those skilled in the art, which are still within the scope of the claimed invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a geometrical view of an antenna constructed in accordance with a first embodiment of the present invention. Second picture: the return loss map of the broadband antenna of the first figure. Fig. 3 is a geometrical view of an antenna constructed in accordance with a second embodiment of the present invention. The fourth picture is the return loss map of the three-frequency antenna of the third figure. Figure 5 is a gain diagram of the antenna of the present invention in the 2.25~2.97 GHz band. Figure 6 is a gain diagram of the antenna of the present invention in the 3.25~3.92 GHz band. 1364875. Figure 7 is an antenna of the present invention at 5.12~6 ΐ GHz. Gain map of the band 〇 Figure 8: Co-pol and cross-pol of the broadband and tri-band in the XY plane and the YZ plane at an operating frequency of 2.5 GHz. Light field type diagram 〇 ninth diagram: Co-pol and cross-polarization of cross-band Lu and tri-band in XY plane and YZ plane at an operating frequency of 3.6 GHz (cross- Radiation pattern of pol) Figure 10: Co-pol and cross-polarization of wideband and tri-band in XY plane and YZ plane at an operating frequency of 5.5 GHz -pol) Radiation pattern 〇12 1364875 [Explanation of main component symbols] (1) Antenna (10) Microwave substrate (11) Radiation metal surface (111) Feeding part (112) Feeding end (113) Lower part (114) Upper portion (115) long convex portion (116) short convex portion (12) ground surface (121) first ground piece (122) second ground piece (13) notch (141) Slot (14) a groove (142) of the second slot 13