201104961 六、發明說明： 【發明所屬之技術領域】 本發明相關於一種天線，尤指一種應用於多頻系統之天 線。 【先前技術】 隨著無線通訊科技的日益發展，行動電話、筆記型電 腦、個人數位助理（personal digitalassistant，PDA)或藍牙 耳機等可攜式電子產品皆能透過内建天線來收發無線訊 號’因此能連結至無線廣域網路（Wireless Wide Area Network, WWAN)以進行資料交換，讓使用者能夠隨時瀏覽網頁或收 發電子郵件。天線種類眾多，最簡單且普及的是雙極天線 (dipole antenna)和單極天線（monopole antenna) ’ 設計良 好的天線可提升無線通訊系統的效率、靈敏度及可靠度。 請參考第1圖’第1圖為先前技術中一雙極天線30之 示意圖。雙極天線30包含兩金屬輻射元件31和32，分別指 向相反方向’極性相反的電流由中間流入（出），可與電磁波 產生共振而提供一特定電磁波共振帶。金屬輻射元件31和 32之長度L係對應於電磁波共振帶内之中心共振頻率，且 201104961 等於中心共振頻率波長；I的四分之一（L=；l/4)，亦即雙極 天線30之總長度約為；1/2,故雙極天線所需的長度為單極天 線之兩倍，以致佔據較大的空間。 請參考第2圖，第2圖為先前技術中一單極天線40之 示意圖。單極天線40包含一金屬輻射元件42，可與電磁波 產生共振而提供一特定電磁波共振帶。金屬輻射元件42之 總長度L係對應於電磁波共振帶内之中心共振頻率，且等於 _ 中心共振頻率波長又的四分之一（L= λ /4 )，亦即單極天線 40之總長度約為λ/4，因此所需共振長度較雙偶極天線小， 結構簡單。一般而言，單極天線40僅使用一組金屬輻射元 件42與訊號源之輸出/輸入端的正訊號相連接，訊號源之負 端通常連接電路板或機殼之接地端。 【發明内容】 * 本發明提供一種用於多頻系統之天線，其包含一第一輻射元 件，其包含一接地端，用來提供一第一共振頻帶；一第二輻射元 件，用來提供一第二共振頻帶，該第二輻射元件包含：一饋 入端；以及一漸寬區域，其寬度由該饋入端起逐漸增加，用 來提供不同長度之共振路徑，並達到較大的共振頻寬。 【實施方式】 201104961 在不同無線通訊系統中，各種無線通訊網路的操作頻率 亦會有所不同，然而隨著時間與通訊技術的演進，新一代電 子產在在需能涵盍更多元化的糸統應用，故一種可多頻操 作之天線方能滿足此一需求。現今與下一世代的通訊系統有 國際電#聯盟（ITU )制定的第二代流動通訊技術（Third generation，3G)、全球行動通訊系統(Global System for201104961 VI. Description of the Invention: [Technical Field] The present invention relates to an antenna, and more particularly to an antenna applied to a multi-frequency system. [Prior Art] With the development of wireless communication technology, portable electronic products such as mobile phones, notebook computers, personal digital assistants (PDAs) or Bluetooth headsets can transmit and receive wireless signals through built-in antennas. It can be connected to the Wireless Wide Area Network (WWAN) for data exchange, allowing users to browse the web or send and receive emails at any time. There are many types of antennas, the simplest and most popular are dipole antennas and monopole antennas. A well-designed antenna enhances the efficiency, sensitivity and reliability of wireless communication systems. Please refer to FIG. 1 'FIG. 1 is a schematic diagram of a dipole antenna 30 in the prior art. The dipole antenna 30 includes two metal radiating elements 31 and 32, respectively pointing in opposite directions. The opposite polarity current flows in from the middle, and can resonate with the electromagnetic waves to provide a specific electromagnetic wave resonance band. The length L of the metal radiating elements 31 and 32 corresponds to the central resonant frequency within the electromagnetic wave resonance band, and 201104961 is equal to the central resonant frequency wavelength; one quarter of I (L=; l/4), that is, the dipole antenna 30 The total length is about 1/2, so the required length of the dipole antenna is twice that of the monopole antenna, so that it takes up a large space. Please refer to FIG. 2, which is a schematic diagram of a monopole antenna 40 in the prior art. The monopole antenna 40 includes a metal radiating element 42 that resonates with electromagnetic waves to provide a specific electromagnetic wave resonance band. The total length L of the metal radiating element 42 corresponds to the central resonant frequency within the electromagnetic wave resonance band and is equal to a quarter of the wavelength of the central resonant frequency (L = λ /4 ), that is, the total length of the monopole antenna 40 It is about λ/4, so the required resonance length is smaller than that of the double dipole antenna, and the structure is simple. In general, the monopole antenna 40 is connected to the positive signal of the output/input of the signal source using only a set of metal radiating elements 42. The negative terminal of the signal source is typically connected to the ground of the circuit board or the chassis. SUMMARY OF THE INVENTION The present invention provides an antenna for a multi-frequency system including a first radiating element including a ground for providing a first resonant frequency band and a second radiating element for providing a a second resonant frequency band, the second radiating element comprising: a feeding end; and a widening region whose width is gradually increased from the feeding end to provide a resonant path of different lengths and to achieve a large resonant frequency width. [Embodiment] 201104961 In different wireless communication systems, the operating frequencies of various wireless communication networks will also be different. However, with the evolution of time and communication technologies, the new generation of electronic products can be more diversified. SiS applications, so a multi-frequency antenna can meet this need. Today's and next-generation communication systems include the second generation of mobile communication technology (Third generation, 3G) and the Global System for Globalization (ITU).
Mobile Communication，GSM)、進階行動電話服務系統 (Advanced Mobile Phone System，AMPS)、數位通信系統 (Digital Communication System，DCS )、個人通信系統 (Personal Communication System，PCS )、全球行動通信系統 (Universal Mobile Telecommunications System，UMTS )、全 球衛星定位系統（Global Positioning System，GPS )、無線保 真度網路（Wireless Fidelity, Wi-Fi)、全球互通微波存取網 路（Worldwide Interoperability for Microwave Access， WiMAX)、寬帶分碼多工存取（Wideband Code Division Multiple Access, WCDMA) ’ 與長期演進技術（LongTermMobile Communication, GSM), Advanced Mobile Phone System (AMPS), Digital Communication System (DCS), Personal Communication System (PCS), Global Mobile System (Universal Mobile) Telecommunications System (UMTS), Global Positioning System (GPS), Wireless Fidelity (Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Wideband Code Division Multiple Access (WCDMA) and Long Term Evolution (LongTerm)
Evolution，LTE)等。因此’為了讓使用者能更方便地存取不同 的無線通訊網路且不增加產品的成本、複雜度與體積，一種 能涵蓋不同無線通訊系統頻段之天線便可滿足此一需求。另 外’以單支多頻天線取代傳統多支天線的設計亦可順應可攜 式電子產品微型化的趨勢使其輕薄化。 201104961 請參考第3圖，第3圖為本發明第一實施例中一多頻天 線10之上視圖。多頻天線10包含一第一輻射元件11、一第 二輻射元件12，和一基座14。第一輻射元件11設置於基座 14之側邊，可與.電磁波產生共振以提供一第一電磁波共振帶 BL。第二輻射元件12設置於基座14之表面，且不和第一輻 射元件11互相接觸。第二輻射元件12可與電磁波產生共振 以提供複數個電磁波共振帶Bhi〜Βηπ。 • 在本發明第一實施例中，第一輻射元件11包含一接地 端F1，可為一 L型金屬片，設置於基座14之兩相鄰側邊（例 如第3圖中之左側和上側），第一輻射元件11之總長度L 係對應於第一電磁波共振帶BL内之中心共振頻率，且等於 中心共振頻率FL波長的四分之一或四分之一的奇數倍。第 二輕射元件12可為一五邊型金屬片，包含一饋入端F2和一 漸寬區域，饋入端F2位於五邊型之一端點，而漸寬區域之 • 寬度由饋入端F2起逐漸增加。由於本發明第一實施例之第 二輻射元件12包含漸寬區域，因此能提供不同長度的共振 路徑（由第3圖中的虛線箭頭來表示），進而與電磁波產生 共振以提供複數個電磁波共振帶BH1〜BHn。 請參考第4圖，第4圖為本發明第二實施例中一多頻天 線20之上視圖。本發明第二實施例和第一實施例結構類似， 不同之處在於多頻天線20另包含一接地元件26和一同軸纜 線28。接地元件26設置於基座14之另一側邊（例如第4 201104961 圖中之下側），其可連至電路板或機殼之接地端或獨立之金 屬導體面（未顯示於圖内），因此能對第一輻射元件11和 第二輻射元件12提供參考接地電位。同軸纜線28包含一導 電層、一絕緣層和一接地層，導電層連接至第一輕射元件12 之饋入端F2，而接地層連接至接地元件26。因此，多頻天 線20能透過同軸纜線28將電流饋入第二輻射元件12。 請參考第5圖，第5圖為本發明第三實施例中一多頻天 線.30之上視圖。本發明第三實施例和第一實施例結構類似， 不同之處在於多頻天線30之第二輻射元件12另包含一調頻 區域。調頻區域為第二輻射元件12之延伸結構，位於饋入 端F2之對向側（第5圖中之上侧），其作用在於增加共振 路徑的長度，因此能調整電磁波共振帶BH1〜BHn中特定電 磁波共振帶之中心頻率。 請參考第6a〜6c圖，第6a〜6c圖為本發明第一至第三 實施例中第一輻射元件11之示意圖。第一輻射元件11可為 一 L型金屬片，設置於基座14之兩相鄰侧邊，如第6a圖所 示；第一輻射元件11可為一门型金屬片，設置於基座14之 三相鄰側邊，如第6b所示；第一輻射元件11可為一勾狀金 屬片，設置於基座14之三相鄰側邊，如第6c所示。在第6a 〜6c圖所示之實施例中，第一輻射元件11之總長度L皆為 中心共振頻率FL波長的四分之一或四分之一的奇數倍。第 201104961 6a〜6c圖所示僅為本發明之實施例，並不限定本發明之範 疇。 請參考第7a〜7d圖，第7a〜7d圖為本發明第一和第二 實施例中第二輻射元件12之示意圖。本發明第一和第二實 施例之第二輻射元件12可採用各種包含漸寬區域之形狀， 例如五邊形（第73圖）、半圓形（第71)圖）、三角形（第 7c圖）、或梯形（第7d圖）等。第7a〜7d圖所示僅為本發 明之實施例，並不限定本發明之範疇。 請參考第8a〜8d圖，第8a〜8d圖為本發明第三實施例 中第二輻射元件12之示意圖。本發明第三實施例之第二輻 射元件12包含-調頻區域，其為第二輻射元件12主體之延 伸結構。第二輻射元件12之主體可採用各種包含漸寬區域 之形狀，例如五邊形（第_)、半圓形（第扑圖）、三 角形（第8c圖）、或梯形（第8(1圖）等。第圖所 不僅為本發明之實施例，並不限定本發明之範疇。 本發明可使用許多方絲將第—㈣元件u和第二輕 射元件12設置於基座14上，此處以本發明第一實施例之多 ，天線Π)來做說明。請參考第9a圖和第外圖，第如圖為 :發明第-實施例中多頻天線1〇之爆炸圖，而第外圖為多 頻天線H)在組裝完成後之示意圖。如第％圖所示，第一輻 射轉η另包含孔洞42，第二輻射元件12另包含—固定區 201104961 域16，而基座14另包含卡榫44和一凹槽46。孔洞42矛卡 榫44之數目、位置與形狀彼此相關，使得第一輻射元件 能夠卡合於基座14上，如第9b圖所示。另一方面， 射元件12之固定區域16和其五邊形主體形成一勾狀結構 因此能夠穩固地設置於基座14之凹槽46内，且不會和第 輻射元件11互相接觸，如第9b圖所示。第9a圖釦笛 _ 昂9b圖 所示僅為本發明之實施例，並不限定本發明之範赛。 第10圖和第11圖說明了本發明多頻天線之運作，第 10圖顯示了本發明多頻天線在特定應用時之電壓駐波比 (Voltage Standing Wave Ratio, VSWR)圖，而第 u 圖顯示 了本發明多頻天線在特定應用時之運作效率。在第1〇圖中， 縱軸代表阻抗匹配，橫軸代表頻率，本發明透過第一輻射元 件11來提供了操作頻率介於824〜960MHz的低頻電磁波共 振帶BL ’同時透過第二輻射元件12提供了操作頻率介於 1710〜2170MHz、2300〜2700MHz、3300〜3800MHz 和 5150 〜5850MHz的高頻電磁波共振帶Bhi〜Bh4。另一方面，本 發明之多頻天線在各頻率運作時之輻射效率如第U圖所示。 本發明透過第—輻射元件11和第二輻射元件12來提供 了不同操作頻率之電磁波共振帶，因此能應用在包含多個無 線通訊網路之多頻系統。另一方面，本發明之天線體積極 小，因此能符合可攜式電子產品微型化的趨勢。 201104961 以上所述僅為本發明之較佳實施例，凡依本發明申請專 利範圍所做之均等變化與修飾，皆應屬本發明之涵蓋範圍。 【圖式簡單說明】 第1圖為先前技術中一雙極天線之示意圖。 第2圖為先前技術中一單極天線之示意圖。 ® 第3圖為本發明第一實施例中一多頻天線之上視圖。 第4圖為本發明第二實施例中一多頻天線之上視圖。 第5圖為本發明第三實施例中一多頻天線之上視圖。 第6a〜6c圖為本發明第一至第三實施例中第一輻射元件之 示意圖。 第7a〜7d圖為本發明第一和第二實施例中第二輻射元件之 示意圖。 • 第8a〜8d圖為本發明第一和第二實施例中第二輻射元件之 示意圖。 第9a圖為本發明第一實施例中多頻天線之爆炸圖。 第9b圖為本發明第一實施例中多頻天線在組裝完成後之示 意圖。 第10圖顯示了本發明多頻天線在特定應用時之電壓駐波比 圖。 第11圖顯示了本發明多頻天線在特定應用時之輻射效率。 201104961 【主要元件符號說明】 14 基座 16 固定區域 42 孔洞 26 接地元件 44 卡榫 28 同軸變線 F1 接地端 F2 饋入端 46 凹槽 10、 20 ' 30 ' 40 天線 11、 12 、 31 、 32 、 42 輻射元件 12Evolution, LTE), etc. Therefore, in order to make it easier for users to access different wireless communication networks without increasing the cost, complexity and volume of the product, an antenna that can cover different frequency bands of the wireless communication system can meet this requirement. In addition, the design of replacing a conventional multi-drop antenna with a single multi-frequency antenna can also be made lighter and thinner in accordance with the trend of miniaturization of portable electronic products. 201104961 Please refer to FIG. 3, which is a top view of a multi-frequency antenna 10 in the first embodiment of the present invention. The multi-frequency antenna 10 includes a first radiating element 11, a second radiating element 12, and a susceptor 14. The first radiating element 11 is disposed on the side of the susceptor 14 to resonate with the electromagnetic wave to provide a first electromagnetic wave resonant band BL. The second radiating element 12 is disposed on the surface of the susceptor 14 and is not in contact with the first radiating element 11. The second radiating element 12 can resonate with electromagnetic waves to provide a plurality of electromagnetic wave resonance bands Bhi~Βηπ. In the first embodiment of the present invention, the first radiating element 11 includes a grounding end F1, which may be an L-shaped metal piece disposed on two adjacent sides of the base 14 (for example, the left side and the upper side in FIG. 3) The total length L of the first radiating element 11 corresponds to the central resonant frequency within the first electromagnetic wave resonance band BL and is equal to an odd multiple of one quarter or one quarter of the wavelength of the central resonant frequency FL. The second light-emitting element 12 can be a five-sided metal piece, including a feeding end F2 and a widening area, the feeding end F2 is located at one end of the pentagon type, and the width of the widening area is fed by the feeding end. F2 gradually increased. Since the second radiating element 12 of the first embodiment of the present invention includes a widened region, resonant paths of different lengths (represented by dashed arrows in FIG. 3) can be provided to resonate with electromagnetic waves to provide a plurality of electromagnetic wave resonances. With BH1 ~ BHn. Please refer to FIG. 4, which is a top view of a multi-frequency antenna 20 in a second embodiment of the present invention. The second embodiment of the present invention is similar in structure to the first embodiment except that the multi-frequency antenna 20 further includes a grounding member 26 and a coaxial cable 28. The grounding element 26 is disposed on the other side of the base 14 (for example, the lower side of the fourth 201104961 figure), and can be connected to the ground end of the circuit board or the casing or a separate metal conductor surface (not shown) Therefore, the reference ground potential can be supplied to the first radiating element 11 and the second radiating element 12. The coaxial cable 28 includes a conductive layer, an insulating layer and a ground layer, the conductive layer being connected to the feed end F2 of the first light projecting element 12, and the ground layer being connected to the ground element 26. Therefore, the multi-frequency antenna 20 can feed current into the second radiating element 12 through the coaxial cable 28. Please refer to Fig. 5. Fig. 5 is a top view of a multi-frequency antenna.30 in the third embodiment of the present invention. The third embodiment of the present invention is similar in structure to the first embodiment except that the second radiating element 12 of the multi-frequency antenna 30 further includes a frequency modulation region. The frequency modulation region is an extension structure of the second radiating element 12, and is located on the opposite side of the feeding end F2 (the upper side in FIG. 5), and its function is to increase the length of the resonant path, so that the electromagnetic wave resonance bands BH1 to BHn can be adjusted. The center frequency of the specific electromagnetic wave resonance band. Please refer to Figures 6a to 6c, and Figures 6a to 6c are schematic views of the first radiating element 11 in the first to third embodiments of the present invention. The first radiating element 11 can be an L-shaped metal piece disposed on two adjacent sides of the base 14 as shown in FIG. 6a; the first radiating element 11 can be a gate type metal piece disposed on the base 14 The three adjacent sides, as shown in FIG. 6b; the first radiating element 11 may be a hook-shaped metal piece disposed on three adjacent sides of the base 14, as shown in FIG. 6c. In the embodiment shown in Figs. 6a to 6c, the total length L of the first radiating element 11 is an odd multiple of a quarter or a quarter of the wavelength of the center resonant frequency FL. The figures 201104961 6a to 6c are only examples of the present invention and do not limit the scope of the present invention. Referring to Figures 7a to 7d, Figs. 7a to 7d are schematic views of the second radiating element 12 in the first and second embodiments of the present invention. The second radiating element 12 of the first and second embodiments of the present invention may adopt various shapes including a widened area, such as a pentagon (Fig. 73), a semicircular (71) picture, and a triangle (Fig. 7c). ), or trapezoidal (Fig. 7d), etc. The figures 7a to 7d are only examples of the present invention and do not limit the scope of the present invention. Please refer to Figs. 8a to 8d, and Figs. 8a to 8d are schematic views of the second radiating element 12 in the third embodiment of the present invention. The second radiating element 12 of the third embodiment of the present invention comprises a frequency-modulating region which is an elongated structure of the body of the second radiating element 12. The body of the second radiating element 12 may adopt various shapes including a widened area, such as a pentagon (#), a semicircle (pump), a triangle (8c), or a trapezoid (8th (1) The drawings are not only examples of the invention, but are not intended to limit the scope of the invention. The invention can use a plurality of square wires to place the fourth (four) element u and the second light projecting element 12 on the base 14, which The antenna according to the first embodiment of the present invention will be described. Please refer to Fig. 9a and the external diagram. The figure is as follows: the explosion diagram of the multi-frequency antenna 1〇 in the first embodiment of the invention, and the external diagram is the schematic diagram of the multi-frequency antenna H) after the assembly is completed. As shown in the % diagram, the first radiation turn η further includes a hole 42, the second radiating element 12 further includes a fixed area 201104961 field 16, and the base 14 further includes a cassette 44 and a recess 46. The number, position and shape of the holes 42 are related to each other such that the first radiating element can be engaged with the base 14, as shown in Figure 9b. On the other hand, the fixing region 16 of the projecting element 12 and its pentagonal body form a hook-like structure and thus can be stably disposed in the recess 46 of the base 14 without coming into contact with the radiating element 11 as in the first Figure 9b shows. Fig. 9a shows the flute _ 昂 9b diagram is only an embodiment of the present invention, and does not limit the fan of the present invention. 10 and 11 illustrate the operation of the multi-frequency antenna of the present invention, and FIG. 10 shows the voltage standing wave ratio (VSWR) diagram of the multi-frequency antenna of the present invention in a specific application, and FIG. The operational efficiency of the multi-frequency antenna of the present invention in a particular application is shown. In the first diagram, the vertical axis represents impedance matching, and the horizontal axis represents frequency. The present invention provides a low frequency electromagnetic wave resonance band BL' having an operating frequency of 824 to 960 MHz through the first radiating element 11 while transmitting through the second radiating element 12 A high frequency electromagnetic wave resonance band Bhi~Bh4 having an operating frequency of 1710 to 2170 MHz, 2300 to 2700 MHz, 3300 to 3800 MHz, and 5150 to 5850 MHz is provided. On the other hand, the radiation efficiency of the multi-frequency antenna of the present invention operating at each frequency is as shown in Fig. The present invention provides electromagnetic wave resonance bands of different operating frequencies through the first radiating element 11 and the second radiating element 12, and thus can be applied to a multi-frequency system including a plurality of wireless communication networks. On the other hand, the antenna body of the present invention is actively small, and thus can conform to the trend of miniaturization of portable electronic products. The above description is only the preferred embodiment of the present invention, and all changes and modifications made to the patent scope of the present invention are intended to be within the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of a bipolar antenna in the prior art. Figure 2 is a schematic diagram of a monopole antenna in the prior art. ® Fig. 3 is a top view of a multi-frequency antenna in the first embodiment of the present invention. Figure 4 is a top view of a multi-frequency antenna in a second embodiment of the present invention. Figure 5 is a top view of a multi-frequency antenna in a third embodiment of the present invention. 6a to 6c are schematic views of the first radiating element in the first to third embodiments of the present invention. 7a to 7d are schematic views of the second radiating element in the first and second embodiments of the present invention. • Figures 8a to 8d are schematic views of the second radiating element in the first and second embodiments of the present invention. Fig. 9a is an exploded view of the multi-frequency antenna in the first embodiment of the present invention. Fig. 9b is a schematic view of the multi-frequency antenna in the first embodiment of the present invention after assembly is completed. Figure 10 is a graph showing the voltage standing wave ratio of the multi-frequency antenna of the present invention in a specific application. Figure 11 shows the radiation efficiency of the multi-frequency antenna of the present invention in a particular application. 201104961 [Description of main component symbols] 14 Base 16 Fixed area 42 Hole 26 Grounding element 44 Card 28 Coaxial line F1 Grounding point F2 Feeding end 46 Groove 10, 20 ' 30 ' 40 Antennas 11, 12, 31, 32 , 42 radiating elements 12