200913384 九、發明說明： 【發明所屬之技術領域】 種平面雙頻天 本發明關於一種雙頻天線，特別關於 線。 【先前技術】 無線傳輸廣泛地應用於電子產品，而為滿足消 求’現今許多電子產品大多具有無線傳輪的功能。在無ς 傳輪糸統中，天線是用來發射與接收電磁波能量的重要元 件丄若是沒有了天線，則無線傳輪系統將會無法發射 收貧料。因此’天線的角色在無線傳輸來說，是不可或缺 的一環。 、 選用適當的天線除了有助於搭配產品的外型以及提 升傳輸品質外，還可以更進—步降低產品成本。目前在各 種不同的制產品巾’較關域設収法鄕作材質 也不盡相同’另外’針對每—個國家對所需要的使用頻帶 不同因此在设计天線時亦需要加入許多因素的考量。 —請參照圖1所示，-種平面單頻天線i包含一辕射單 疋11、-接地單12及-饋人單^ 13。平面單頻天線i =置於一電路板14。接地單元12自輻射單元丨丨之一端部 突設’讀人單幻3自韓射單元u之-處突設，且接地單 疋12„與饋入單元13位於輕射單元11之同一側。其中， 接地單元12用以接地，饋入單元Μ用以饋入訊號。 平面單頻天線1藉由輻射單元u可操作於一頻段， 200913384 例如為符合電機電子工程師學會（Insiitute 〇f Ekctrical and200913384 IX. DESCRIPTION OF THE INVENTION: TECHNICAL FIELD OF THE INVENTION The present invention relates to a dual frequency antenna, and more particularly to a line. [Prior Art] Wireless transmission is widely used in electronic products to satisfy the demand. Many of today's electronic products mostly have wireless transmission functions. In the flawless transmission system, the antenna is an important component for transmitting and receiving electromagnetic wave energy. If there is no antenna, the wireless transmission system will not be able to transmit the poor material. Therefore, the role of the antenna is an indispensable part of wireless transmission. In addition to helping to match the appearance of the product and improving the transmission quality, the selection of an appropriate antenna can further reduce the cost of the product. At present, the materials used in different types of products are not the same. 'Alternatively' For each country, the required frequency bands are different. Therefore, many factors need to be added when designing the antenna. - Referring to Figure 1, the planar single-frequency antenna i includes a single shot 疋11, a grounding single 12, and a feed single. The planar single frequency antenna i = is placed on a circuit board 14. The grounding unit 12 protrudes from one end of the radiation unit ', and the grounding unit 12 is located on the same side of the light-emitting unit 11 as the feeding unit 13 . The grounding unit 12 is used for grounding, and the feeding unit Μ is used for feeding signals. The planar single-frequency antenna 1 can be operated in a frequency band by the radiating unit u, 200913384, for example, in accordance with the Institute of Electrical and Electronics Engineers (Insiitute 〇f Ekctrical and
Electronic Engineers，IEEE) 802.1 lb/g 規範之 2.4GHz，或 符合IEEE 802.11a規範之5GHz等等。然而，對於目前多 頻丰又的應用，平面单頻天線1之單一頻段已不敷使用。 因此，如何提供一種平面雙頻天線，能夠操作於雙頻 段，進而提升效能，實為當前重要課題之一。 【發明内容】 有鑑於上述課題，本發明之目的為提供一種能夠操作 於雙頻段的平面雙頻天線。 緣是，為達上述目的，依本發明之一種平面雙頻天線 包含一輻射單元、一接地單元以及—饋入單元。接地單元 之一端與輻射單70連接，而其另一端接地，且接地單元具 有一寬度漸變段。輻射單元被接地單元區分為一第一輻射 部及一第二輻射部。饋入單元連接於第一輻射部與第二輻 射部的連接處’並電性連接韓射單元與接地單元。 承上所述，因依本發明之-種平面雙頻天線可藉由調 整饋入單元的相對位置及接地單元的設置，使得第一轄射 部及接地單元可操作於H段，第二輻射部及接^單 元可操作於-第二頻段。此外’本發明藉由寬度漸變段可 調整阻抗，進而增加操作頻寬。故本發明之平面雙頻天線 可操作於雙頻段並具有較大頻寬，進而提升整體效能。' 【實施方式】 200913384 以下將參照相關圖式，說明依本發明較佳實施例之一 種平面雙頻天線，其中相同的元件將以相同的參照符號加 以說明。 請參照圖2所示，本發明較佳實施例之一種平面雙頻 天線2包含一輻射單元21、一接地單元22及一饋入單元 23。在本實施例中，輻射單元21、接地單元22及饋入單 元23為一體成型。 輻射單元21可具有至少一彎折211，彎折211可讓輻 射單元21之長度不致太長，有助於天線小型化設計。輻 射單元21在無彎折211時可呈長條型；在具有彎折211 時，可呈L型。當然，輻射單元21亦可為其他形狀，於 此並不限制。 接地單元22之一端與輻射單元21連接，另一端係與 一接地面24連接而接地。在本實施例中，接地單元22與 輻射單元21之間具有一角度，角度可為銳角或鈍角。接 地單元2 2可具有至少一彎折，在此其具有二彎折2 21、2 2 2。 另外，接地單元22具有一寬度漸變段223，即接地單 元22的寬度可逐漸增加或縮減，以調整阻抗來增加操作 頻寬。於此，寬度漸變段223係設置於接地單元22靠近 輻射單元21的位置，且其寬度漸縮。此外，輻射單元21 被接地單元22區分為一第一輻射部212及一第二輻射部 213 ° 饋入單元23連接於第一輻射部212與第二輻射部213 的連接處，並電性連接於輻射單元21與接地單元22。饋 200913384 入單元23與接地單元22位於輻射單元21的同一側。在 本實施例中，輻射單元21與饋入單元23呈T型。此外， 饋入單元23與輻射單元21的連接處鄰近接地單元22與 ' 輻射單元21的連接處。本實施例之平面雙頻天線2藉由 - 調整饋入單元23與接地單元22的相對位置而能操作於雙 頻。 平面雙頻天線2更包含一基板25，輻射單元21、接 地單元22、饋入單元23及接地面24皆設置於基板25上。 基板25可為一印刷電路板。 請再參照圖3所示，平面雙頻天線2更包含一導電單 元26，例如但不限於一同軸傳輸線。導電單元26具有一 導電體261及一接地導體262。其中，導電體261與饋入 單元23電性連接，而接地導體262接地。於此接地導體 262係與接地面24連接而接地。導電單元26更具有一第 一絕緣層263及一第二絕緣層264，其中第一絕緣層263 設置在導電體261與接地導體262之間以隔離兩者之間的 電氣訊號，而第二絕緣層264設置於導電單元26之最外 層以作為絕緣及保護作用。當然，除了導電單元26之外， 亦可藉由基板25上的走線提供訊號饋入。 r 在本實施例中，第一輻射部212及接地單元22操作 於一第一頻段，第二輻射部213及接地單元22操作於一 第二頻段。其中，第一頻段例如為符合IEEE 802.11b/g規 範之頻段，其約在2.4GHz至2.5GHz之間；而第二頻段例 如為符合符合IEEE 802.11a規範之頻段，其約在5.2GHz 8 200913384 至5.8GHz之間。於此需注意者，熟悉天線技術領域者皆 知道天線之操作頻段與其尺寸有關，且尺寸可依所需要之 操作頻段作調整’例如依據各頻段之共振路徑長度為操作 頻段之波長的四分之一（雙偶極天線）或二分之一（片狀天 線）之原則來調整天線之尺寸。 … ^ τ 平田代表返回損失（Returnloss) 的大小’單位為而橫軸代表頻率。以—般業者對於 返回損失低於·1_即可接受的定義，可峨察到本發明 較佳實施狀錢2可分卿作於2 4GHz至MHz 2及5.2GHz至5.8邮之間。另外，請再參照圖5A至 ^ C及圖6A至圖6C所不，其為平面雙頻天線2操作於 • Hz及5.8GHz的李畐射場型圖。其中，圖μ至圖π分 =平面雙頻天線操作於2.4啦時之χγ平面、χζ平面 天線操作於5鳥時:至：物^ 輕射場型圖。子之灯千面、紅平面及ΥΖ平面的 入單：依據本發明之平面雙頻天線係藉由調整饋 元可摔ίΓΓΓ對位置，使得第一輻射部及接地單 於zti了二頻段’而第二輻射部及接地單元可操作 抗，進而辩 此外，本發明藉由寬度漸變段可調整阻 本發例=非為心=何未脫離 而對其進行之等效修改或變更，均 200913384 應包含於後附之申請專利範圍中。 【圖式簡單說明】 】1::種習知平面單頻天線之一示意圖； -示意圖 發_佳實_之—種平面雙頻天線之 之一種平面雙頻天線之 圖3為依據本發明較佳實施例 另一示意圖； 。圖4為依據本發明較佳實施狀平面雙頻天線之返回 損失之一量測圖； 圖5A至圖5C分別為依據本發明較佳實施例之平面 雙頻天線操作於2.4GHz時之χγ平面、χζ平面及γζ平 面的輻射場形圖；以及 圖6Α至圖6C分別為依據本發明較佳實施例之平面 雙頻天線操作於5.8GHz時之ΧΥ平面、χζ平面及γζ平 面的輻射場形圖。 【主要元件符號說明】 1 :平面單頻天線 11、 21 :輻射單元 12、 22 :接地單元 13、 23 :饋入單元 14 :電路板 2:平面雙頻天線 200913384 211 212 213 223 24 ： 25 ： 26 ： 261 262 263 264 、221、222 :彎折 .第一輪射部 .苐二輕射部 :寬度漸變段 接地面 基板 導電單元 :導電體 :接地導體 :第一絕緣層 :第二絕緣層Electronic Engineers, IEEE) 2.4 GHz for the 802.1 lb/g specification, or 5 GHz for the IEEE 802.11a specification, and so on. However, for the current multi-frequency application, the single frequency band of the planar single-frequency antenna 1 is no longer sufficient. Therefore, how to provide a planar dual-band antenna that can operate in dual-band segments and improve performance is one of the current important topics. SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a planar dual-frequency antenna that can operate in a dual band. In the meantime, in order to achieve the above object, a planar dual-frequency antenna according to the present invention comprises a radiating element, a grounding unit and a feeding unit. One end of the grounding unit is connected to the radiation unit 70, and the other end is grounded, and the grounding unit has a width gradient section. The radiating unit is divided into a first radiating portion and a second radiating portion by the grounding unit. The feeding unit is connected to the junction of the first radiating portion and the second radiating portion and electrically connected to the Korean unit and the ground unit. According to the above aspect, the planar dual-band antenna according to the present invention can adjust the relative position of the feeding unit and the setting of the grounding unit, so that the first illuminating portion and the grounding unit can operate in the H segment, the second radiation The unit and the unit can operate in the second frequency band. In addition, the present invention can adjust the impedance by the width transition section, thereby increasing the operation bandwidth. Therefore, the planar dual-band antenna of the present invention can operate in dual frequency bands and has a large bandwidth, thereby improving overall performance. [Embodiment] 200913384 A planar dual-frequency antenna according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings, wherein the same elements will be denoted by the same reference numerals. Referring to FIG. 2, a planar dual-frequency antenna 2 according to a preferred embodiment of the present invention includes a radiating element 21, a grounding unit 22, and a feeding unit 23. In the present embodiment, the radiating unit 21, the grounding unit 22, and the feeding unit 23 are integrally formed. The radiating element 21 can have at least one bend 211 which allows the length of the radiating element 21 to be not too long, contributing to the miniaturization of the antenna. The radiation unit 21 may be elongated when there is no bend 211, and may be L-shaped when it has the bend 211. Of course, the radiation unit 21 may have other shapes, and is not limited thereto. One end of the grounding unit 22 is connected to the radiating unit 21, and the other end is connected to a grounding surface 24 to be grounded. In the present embodiment, the grounding unit 22 has an angle with the radiating element 21, and the angle may be an acute angle or an obtuse angle. The ground unit 22 can have at least one bend, here having two bends 2 21, 2 2 2 . In addition, the grounding unit 22 has a width transition section 223, i.e., the width of the grounding unit 22 can be gradually increased or decreased to adjust the impedance to increase the operating bandwidth. Here, the width gradation section 223 is disposed at a position where the ground unit 22 is close to the radiation unit 21, and its width is tapered. In addition, the radiating unit 21 is divided into a first radiating portion 212 and a second radiating portion 213 by the grounding unit 22. The feeding unit 23 is connected to the junction of the first radiating portion 212 and the second radiating portion 213, and is electrically connected. The radiation unit 21 and the ground unit 22. The feed unit 23 and the ground unit 22 are located on the same side of the radiating unit 21. In the present embodiment, the radiating unit 21 and the feeding unit 23 are T-shaped. Further, the junction of the feeding unit 23 and the radiating unit 21 is adjacent to the junction of the grounding unit 22 and the 'radiation unit 21. The planar dual-frequency antenna 2 of the present embodiment can operate on the dual frequency by adjusting the relative position of the feed unit 23 and the ground unit 22. The planar dual-frequency antenna 2 further includes a substrate 25, and the radiating unit 21, the grounding unit 22, the feeding unit 23, and the grounding surface 24 are all disposed on the substrate 25. The substrate 25 can be a printed circuit board. Referring again to FIG. 3, the planar dual frequency antenna 2 further includes a conductive unit 26 such as, but not limited to, a coaxial transmission line. The conductive unit 26 has a conductor 261 and a ground conductor 262. The conductor 261 is electrically connected to the feed unit 23, and the ground conductor 262 is grounded. The ground conductor 262 is connected to the ground plane 24 to be grounded. The conductive unit 26 further has a first insulating layer 263 and a second insulating layer 264, wherein the first insulating layer 263 is disposed between the conductor 261 and the ground conductor 262 to isolate an electrical signal therebetween, and the second insulation Layer 264 is disposed on the outermost layer of conductive unit 26 for insulation and protection. Of course, in addition to the conductive unit 26, signal feeding can be provided by the traces on the substrate 25. In this embodiment, the first radiating portion 212 and the grounding unit 22 operate in a first frequency band, and the second radiating portion 213 and the grounding unit 22 operate in a second frequency band. The first frequency band is, for example, a frequency band conforming to the IEEE 802.11b/g specification, which is between 2.4 GHz and 2.5 GHz, and the second frequency band is, for example, a frequency band conforming to the IEEE 802.11a specification, which is about 5.2 GHz 8 200913384 To 5.8GHz. It should be noted that those skilled in the art of antenna technology know that the operating frequency band of the antenna is related to its size, and the size can be adjusted according to the required operating frequency band. For example, according to the resonant path length of each frequency band, the wavelength of the operating frequency band is four quarters. The principle of one (double dipole antenna) or one half (chip antenna) to adjust the size of the antenna. ... ^ τ Pingtian represents the size of the return loss (the unit of the return loss) and the horizontal axis represents the frequency. It is obvious that the preferred embodiment of the present invention can be used between 24 GHz to MHz 2 and 5.2 GHz to 5.8 pm for the definition that the return loss is less than 1 _. In addition, please refer to FIG. 5A to FIG. 5C and FIG. 6A to FIG. 6C, which are diagrams of the plane dual-frequency antenna 2 operating at • Hz and 5.8 GHz. Among them, Fig. μ to Fig. π = Planar dual-frequency antenna operates at 2.4 时 χ γ plane, χζ plane Antenna operates at 5 birds: to: object ^ light field pattern. The input of the sub-light, the red plane and the rake plane: the planar dual-frequency antenna according to the present invention can adjust the position of the feed element so that the first radiating portion and the grounding single are in the z-band The second radiating portion and the grounding unit are operable to resist, and further, the present invention can be adjusted by the width grading section to adjust the resistance of the example = non-heart = no separation, and equivalent modification or change thereof, all of which are 200913384 It is included in the scope of the patent application attached below. [Simple description of the diagram] 】 1:: A schematic diagram of a conventional planar single-frequency antenna; - Schematic _ _ _ _ ─ ─ a kind of planar dual-frequency antenna of a planar dual-frequency antenna Figure 3 is based on the present invention Another schematic diagram of a preferred embodiment; 4 is a measurement diagram of return loss of a planar dual-frequency antenna according to a preferred embodiment of the present invention; FIGS. 5A to 5C are diagrams showing a χ γ plane of a planar dual-frequency antenna operating at 2.4 GHz according to a preferred embodiment of the present invention; Radiation pattern of the pupil plane and the gamma plane; and FIGS. 6A to 6C are radiation field shapes of the plane, the χζ plane and the ζ ζ plane of the planar dual-frequency antenna operating at 5.8 GHz according to the preferred embodiment of the present invention, respectively. Figure. [Description of main component symbols] 1 : Planar single-frequency antenna 11, 21: radiating elements 12, 22: grounding unit 13, 23: feeding unit 14: circuit board 2: planar dual-frequency antenna 200913384 211 212 213 223 24 : 25 : 26 : 261 262 263 264 , 221 , 222 : Bending . First round shot . 苐 2 light shot : width gradient section ground plane substrate Conductive unit : Conductor : Ground conductor : First insulation layer : Second insulation layer