201017979 六、發明說明： 【發明所屬之技術領域】 種雙頻天線及 本發明係關於一種天線，尤其是關於一 其設計方法。 【先前技術】 ' 在汽車電子市場持續成長的過程中，對於車用無線通 ^訊的需求日漸高漲，未來勢必走向多種通訊介面共^的局 ©面：整合的腳步早已刻不容緩。雖然以今日成熟的積體電 路製程技術而言，要將數位電路做得小巧精緻並非難事， 多種通訊功能可輕易地整合於一機，然而，唯獨無線通訊 系統必備的天線整合不易，同時受限於天線尺寸的大小也 使得產品難以微型化，汽車遙控器即是一例。 早期的汽車防盜遙控器功能單一化，其天線僅需要工 作於單一頻率下，設計天線並非沒有太大的困難度。但是， ⑩隨著汽車電子技術的發達，很多的功能控制，均需要透過 無線方式達成，使用者必須利用各種不同的遙控器進行不 同功能（例如無線車鑰、無線防盜控制）的遙控，甚為不便。 配合使用者的需求，雖然已經有一些整合型的遙控器已經 開么’但是，在設計這些整合型的遙控器之天線時，經常 遇到因為適用於不同頻率範圍的天線因為所接收訊號之波 長差異太大’而適用的天線尺寸不同導致設計困難。而且 對於接收長波長（低頻，如125KHZ)電磁波之天線，現行作 »1 /主要以漆包線進行高匝數的精密繞製、再搭配兩顆正交 配置的高磁性材料製成的電感器，形成三維X、Y、z低頻 3 201017979 磁場感應區域，但低頻天線電感繞線精密、製作不易且耗 工費時（成本高且製程複雜），且低頻天線實體尺寸也非 常龐大。若以125ΚΗζ之低頻天線再搭配相對高頻的天線（例 如：433MHz)，進行雙頻天線模組之設計時，因為二者的 適用波長尺寸相差3500倍，整合設計相當不易。 【發明内容】 ❾ 為了解決前述雙頻天線於整合時，因為低頻天線尺寸 龐大且與高頻天線適用波長差距甚遠，導致整合設計困難 的技術問題，本發明係運用慢波效應（s|〇w wave effect)來 達成天線尺寸微型化，讓不同頻帶之高、低頻天線整合於 同一電路板上，達到一體且簡化設計的技術效果。 配合解決前述的技術問題以及所欲達成的技術效果， 本發明提供-種雙頻微型化天線，其包含-電路板以及形 成於該電路板表面且相互隔離之一導電圖形以及一接地 面，該導電圖形為—具有複數個f折的導線線段且工作於 一第一頻率，該導電圖形包含一 導電圖形之一自由端，該導電圖 饋入點，該饋入點設於該 形以及該接地面之間以一 電谷電感電路連接，遠趙^分帝—雨4 、 連接該電谷電感電路之後的該導電圖 形及該接地面共同提供另―ταμ#& β J圾供另不同於該第一頻率所屬頻帶之 八#頻率八中，該共振頻率與該電容電感電路之等效 電抗值成反比關係。 其中，該導電圖形為繞設 線’该饋入點設於該螺旋線外 置對應於該饋入點，且該接地 匝數為奇數之一螺旋（spiral) 圍之自由端，該接地面之位 面為一大於該螺旋線面積之 201017979 導電板。 其中，該螺旋線可繞設為矩形、圓形、六角形或其它 形狀，本發明係以矩形為例，該矩形螺旋線之外徑總寬度 為30mm、外徑總高度為10mm、線寬為〇 5mm、線距為 1mm以及位於中央之線段線寬為1mm ’該接地面之尺寸 為40mm*30mm之矩形導電板體。 本發明再提供一種雙頻微型化天線設計方法，其步驟 包含： 〇 设计及佈局第一頻率天線，係依據一天線之操作頻 率，其中至少包含一高頻頻率以及一低頻頻率，以其中該 高頻頻率或該低頻頻率之任一者作為一第一頻率，以計算 導電圖形以及一接地面之佈局模擬，並依據模擬或量測 結果取得該導電圖形之該第一頻率天線等效電容電感值； 計算共振頻率天線補償值，依據該第一頻率計算其等效之 一第一頻率電容電感值，並以該第一頻率電容電感值與該 共振頻率天線等效電容電感值計算一電抗補償電容電感 值，再以具有該電抗補償電容電感值之一電容電感電路連 接該導電圖形及該接地面。 其中’所述之雙頻微型化天線設計方法中，該導電圖 形之佈局模擬係以螺旋線段之形式佈局模擬。 本發明又提供一種内儲用於設計雙頻微型化天線之電 腦程式產品，當電腦載入該電腦程式並執行後，可完成所 述之該雙頻微型化天線設計方法。藉此，本發明所提供的 天線其設計方法以及程式’可以讓天線設計完整逐一考量 天線的操作頻率需求之設計，先以螺旋繞線之形狀及長度 201017979 ^成一第—頻率之天線設計後，再以慢波理論計算出另-而求，、振頻率之共振電抗值，大為簡化雙頻天線設計的整 合困難度，以及解決習用技術整合困難的問題。 【實施方式】 "月 > 考第一圖，為本發明之雙頻微型化天線設計方法 的較佳實施例，其步驟包含：設計及佈局第一頻率天線 (1 〇)、計算共振頻率天線補償值㈣以及形成雙頻天線 (30);此外，請參見第人圖所示之RF各頻帶所包含頻率範 圍及波長對照圖’其中本較佳實施例係應用於Key|ess天 線系統’該第-頻率較佳的為315MHZ或433MHZ，而其 相對應之共振頻率較佳的為mKHZ或125KHZ，因此該第 一頻率之所屬頻帶較佳的為UHF，而該共振頻率所屬頻帶 較佳的為LF，然此僅為本發明之較佳實施例，並非用以揭 限该第一頻率及該共振頻率之可應用頻帶範圍。 ❹ 該設計及佈局第-頻率天線（1〇)步驟中，依據使用範 嘴之需求’先確定天線之操作頻率。本較佳實施例係運用 需要工作於兩個以及兩個以上操作頻率的天線，因此，天 線的操作頻率至少包含一高頻頻率以及—低頻頻率，盆中 該向頻頻率以及該低頻頻率係較佳 '、 與也,一 M ± 狂的各自屬於不同頻帶。 舉列“，本較佳實施例所設計之天線，其 125KHZ以及433MHz，以此例而言 為201017979 VI. Description of the Invention: [Technical Field of the Invention] A dual-frequency antenna and the present invention relate to an antenna, and more particularly to a design method thereof. [Prior Art] In the process of continuous growth of the automotive electronics market, the demand for wireless communication for vehicles is increasing, and the future is bound to move toward a variety of communication interfaces. Face: The pace of integration has long been urgent. Although it is not difficult to make the digital circuit compact and exquisite in today's mature integrated circuit processing technology, a variety of communication functions can be easily integrated into one machine. However, the necessary antenna integration of the wireless communication system is not easy, and at the same time Limited to the size of the antenna also makes the product difficult to miniaturize, and the car remote control is an example. The early car anti-theft remote control function was singular, and the antenna only needed to work at a single frequency. It is not too difficult to design the antenna. However, with the development of automotive electronics technology, many functional controls need to be achieved wirelessly. Users must use different remote controllers to perform different functions (such as wireless key and wireless anti-theft control). inconvenient. In line with the needs of users, although some integrated remote controls have been opened, 'but when designing the antennas of these integrated remote controls, they often encounter antennas that are suitable for different frequency ranges because of the wavelength of the received signals. The difference is too large' and the different antenna sizes used make design difficult. Moreover, for antennas that receive long-wavelength (low-frequency, such as 125KHZ) electromagnetic waves, the current work is «1 / mainly with high-turn precision winding of enameled wire, and then with two orthogonally arranged inductors made of high-magnetic material, forming Three-dimensional X, Y, z low frequency 3 201017979 Magnetic field sensing area, but the low frequency antenna inductor winding is precise, difficult to manufacture and time consuming (high cost and complicated process), and the low frequency antenna physical size is also very large. If a low-frequency antenna of 125 再 is used with a relatively high-frequency antenna (for example, 433 MHz), when designing a dual-frequency antenna module, since the applicable wavelength sizes of the two are 3,500 times different, the integrated design is quite difficult. SUMMARY OF THE INVENTION In order to solve the technical problem that the above-mentioned dual-frequency antenna is integrated, because the size of the low-frequency antenna is large and the wavelength of the high-frequency antenna is far away, which leads to integration design difficulties, the present invention uses the slow wave effect (s|〇w) Wave effect) to achieve miniaturization of the antenna size, allowing high-frequency and low-frequency antennas of different frequency bands to be integrated on the same circuit board, achieving integration and simplifying the technical effect of the design. In order to solve the foregoing technical problems and the technical effects to be achieved, the present invention provides a dual-frequency miniaturized antenna including a circuit board and a conductive pattern formed on the surface of the circuit board and isolated from each other and a ground plane. The conductive pattern is a wire segment having a plurality of f-folds and operating at a first frequency, the conductive pattern comprising a free end of a conductive pattern, the conductive pattern feeding a point, the feeding point being disposed at the shape and the connection The ground is connected by an electric valley inductive circuit, far away from the emperor - rain 4, the conductive pattern connected to the electric valley inductive circuit and the ground plane together provide another "ταμ#& β J garbage for another difference In the eighth frequency of the frequency band to which the first frequency belongs, the resonant frequency is inversely proportional to the equivalent reactance value of the capacitive and inductive circuit. Wherein, the conductive pattern is a winding line, the feeding point is disposed outside the spiral line corresponding to the feeding point, and the grounding number is an odd end of a spiral, and the grounding surface is The plane is a 201017979 conductive plate that is larger than the spiral area. Wherein, the spiral can be wound into a rectangle, a circle, a hexagon or other shapes. The present invention is exemplified by a rectangle having a total outer diameter of 30 mm, a total outer diameter of 10 mm, and a line width of 〇 5mm, line spacing is 1mm and the line width at the center is 1mm. The grounding surface is a rectangular conductive plate with a size of 40mm*30mm. The present invention further provides a dual-frequency miniaturized antenna design method, the steps comprising: 〇 designing and arranging a first frequency antenna according to an operating frequency of an antenna, wherein at least one high frequency and one low frequency are included, wherein the height is The frequency frequency or the low frequency is used as a first frequency to calculate a layout of the conductive pattern and a ground plane, and obtain an equivalent capacitance inductance value of the first frequency antenna of the conductive pattern according to the simulation or the measurement result. Calculating the resonance frequency antenna compensation value, calculating one of the equivalent first frequency capacitance inductance values according to the first frequency, and calculating a reactance compensation capacitance by using the first frequency capacitance inductance value and the resonance frequency antenna equivalent capacitance inductance value The inductance value is connected to the conductive pattern and the ground plane by a capacitor inductance circuit having the inductance of the reactance compensation capacitor. In the method for designing the dual-frequency miniaturized antenna, the layout simulation of the conductive pattern is simulated in the form of a spiral segment. The invention further provides a computer program product for designing a dual-frequency miniaturized antenna. After the computer is loaded into the computer program and executed, the dual-frequency miniaturized antenna design method can be completed. Therefore, the design method and the program of the antenna provided by the invention can make the antenna design completely consider the design of the operating frequency requirement of the antenna one by one, and firstly design the antenna with the shape and length of the spiral winding 201017979 ^ into a first-frequency antenna. Then, the slow wave theory is used to calculate the resonance reactance value of the vibration frequency, which greatly simplifies the integration difficulty of the dual-frequency antenna design and solves the problem of difficult integration of the conventional technology. [Embodiment] "Month> The first figure is a preferred embodiment of the dual frequency miniaturized antenna design method of the present invention, and the steps include: designing and arranging the first frequency antenna (1 〇), calculating the resonance frequency The antenna compensation value (4) and the formation of the dual-frequency antenna (30); in addition, please refer to the frequency range and wavelength comparison diagram of the RF bands shown in the figure, wherein the preferred embodiment is applied to the Key|ess antenna system. Preferably, the first frequency is 315 MHz or 433 MHz, and the corresponding resonant frequency is preferably mKHZ or 125 kHz. Therefore, the frequency band of the first frequency is preferably UHF, and the frequency band of the resonant frequency is preferably. It is LF, which is only a preferred embodiment of the present invention, and is not intended to limit the applicable frequency band range of the first frequency and the resonant frequency. ❹ In the design and layout of the first-frequency antenna (1〇) step, determine the operating frequency of the antenna according to the requirements of the use of the nozzle. The preferred embodiment uses an antenna that needs to operate at two or more operating frequencies. Therefore, the operating frequency of the antenna includes at least a high frequency and a low frequency, and the frequency in the basin and the low frequency are compared. Good', and also, one M ± mad, each belonging to a different frequency band. As an example, the antenna designed in the preferred embodiment has a 125 kHz and a 433 MHz, which is, for example,
« Uwp at - ^ b —頻率係分屬 LF =之，圍’波長差異極大，因此較適以4_ :為第一頻率二在：例中該第一頻率即為高頻頻率，但因 μ不同天線之δ又计需求，亦存在將第_ 〜 项手*又疋為低頻頻 6 201017979 率之可能。當操作頻率決定之後，依據所決定之第—頻率 汁昇其對應之波長（c=f · λ η」，並可推知該第一頻率工作 之天線長度（λ 433/4)。 凊參考第二圖，該天線可以利用微導線技術，於一電 路板（51)上佈局形成—導電圖形（52)以及—接地面（53)，該 導電圖形（52)通常為螺旋狀之導線圖形，可為圓形、六角 形或其它形狀之螺旋狀或為如第二圖所示的直角矩形螺旋 圖形，其中，該導電圖形（52)包含一饋入點（522)設於該導 電圖形（52)外圍之自由端。該接地面（53)則設於鄰近該導電 圖形（52)之位置但與該導電圖形（52)形成隔絕。由於天線實 際操作頻率以及其特性（天線的輻射場形·.等）與圖形的佈局 方式有關，因此，該導電圖形（52)之繞線方式可以利用各 種電腦輔助模擬設計軟體（HFSS、Maxwe丨丨…）執行設計，確 保該導電圖形（52)可以工作於所欲之操作頻率。如本較佳 實施例所示，該導電圖形（52)係為具有複數個彎折的矩形 螺旋線段，其尺寸為：外徑總寬度3〇mm、外徑總高度 1〇mm、線寬〇.5mm、線距1mm、中央線寬1mm。該接地 面（53)之尺寸為40mm*30mm之矩形導電板體。當完成佈 局之後，可以先於該導電圖形（52)之操作頻率，單獨對該 導電圖形（52)之單極天線進行量測，以鑑別所完成的導電 圖形（52)作為第一頻率天線時之輻射效能、第一頻率天線 等效電容電感值（L、C)、操作頻率以及阻抗匹配特性（如第 三圖）等。 請參考第四A、B圖所示，設計該導電圖形（52)時，除 了以線見、尺寸及間距來改變天線的特性之外，該導電圖 201017979 形（52)的匝數以及奇、偶繞線數也會影響天線的工作表現， 例如，第四A圖（具有奇數之繞線數）的方式則比第四巳圖（具 有偶數之繞線數）的繞線方式為佳（箭頭標示為電流方向）。 當導電圖形（52)之輻射表現及操作頻率及特性之量測不佳 時，可以重新模擬或對於繞線佈局之方式進行調整，例如 調整間距、繞線外型（改為圓形、六角形…等），重複進行繞 線佈局、量測等步驟’直至滿足天線工作效能需求為止。 該計算共振頻率天線補償值（2〇)步驟中，完成該導電« Uwp at - ^ b — The frequency system belongs to LF =, and the wavelength difference is very large. Therefore, it is more suitable to use 4_: for the first frequency. In the example, the first frequency is the high frequency, but the difference is due to μ. The δ of the antenna is also calculated, and there is also the possibility that the _~ item* will be reduced to the low frequency 6 201017979 rate. After the operating frequency is determined, the corresponding wavelength (c=f · λ η) is raised according to the determined first-frequency juice, and the antenna length (λ 433/4) of the first frequency operation can be inferred. The antenna can be formed on a circuit board (51) by using microwire technology to form a conductive pattern (52) and a ground plane (53). The conductive pattern (52) is usually a spiral conductor pattern, which can be A circular, hexagonal or other shape spiral or a rectangular rectangular spiral pattern as shown in the second figure, wherein the conductive pattern (52) includes a feed point (522) disposed on the periphery of the conductive pattern (52) The free end. The ground plane (53) is disposed adjacent to the conductive pattern (52) but is isolated from the conductive pattern (52). Due to the actual operating frequency of the antenna and its characteristics (radiation field shape of the antenna, etc. ) is related to the layout of the graphic. Therefore, the winding pattern of the conductive pattern (52) can be performed by using various computer-aided analog design softwares (HFSS, Maxwe...) to ensure that the conductive pattern (52) can work in the same manner. Operation As shown in the preferred embodiment, the conductive pattern (52) is a rectangular spiral segment having a plurality of bends, and the dimensions are: total outer diameter of 3 〇 mm, total outer diameter of 1 〇 mm, and line. The width is 5 mm, the line spacing is 1 mm, and the center line width is 1 mm. The size of the ground plane (53) is a rectangular conductive plate of 40 mm * 30 mm. After the layout is completed, the operating frequency of the conductive pattern (52) may be prior to The monopole antenna of the conductive pattern (52) is separately measured to identify the radiation performance of the completed conductive pattern (52) as the first frequency antenna, and the equivalent capacitance inductance value (L, C) of the first frequency antenna. , operating frequency and impedance matching characteristics (such as the third figure), etc. Please refer to the fourth A, B figure, when designing the conductive pattern (52), in addition to changing the characteristics of the antenna by line, size and spacing The number of turns of the conductive pattern 201017979 (52) and the number of odd and even windings also affect the performance of the antenna. For example, the fourth A picture (the number of odd-numbered windings) is better than the fourth picture ( The winding method with an even number of windings is better (arrows are marked Current direction). When the radiation pattern of the conductive pattern (52) and the measurement of the operating frequency and characteristics are not good, you can re-simulate or adjust the way of the winding layout, such as adjusting the pitch and winding shape (to change the circle) Shape, hexagon, etc.), repeat the steps of winding layout, measurement, etc. until the antenna performance requirement is met. In the calculation of the resonance frequency antenna compensation value (2〇) step, the conduction is completed.
圖形（52)設計、製作及量測以確定其效果之後利用一慢 波效應（s丨ow wave effect)計算該導電圖形（52)於該共振二 率（如前述的1 25KHZ)產生諧振（共振）所需的一共振頻率電 容電感值（L，、C’）’並依據該共振頻率電容電感值（l，、c,) 及該第一頻率天線（10)等效電容電感值（L、c)，計算得到 一電抗補償電容電感值（Ls、Cs)，即Ls=L，_L& Cs=c，_c。 其中，所謂之慢波效應，係指電磁波的相速度（phase veiocity，Vp)可以透過増加天線共振之電感與電容值而達 成降低的效果，相速度與電感電容值之關係為：Vp=i//Lc， 其中，VP為相位速度，L為電感值，c $電容值。相速 度和波長的關係、Vp=f.又，其中f為共振頻率，入為共振 頻率的波長，❸X在相同的共振頻率下，降低相速度即可 降低共振波長，即表示天線尺寸得以大幅地縮小。 該形成雙頻天線（30)步驟中，係將前述步驟計算而得 知電抗補償電容電感（Ls、Cs)選擇以實體電容或電感之元件 組成之-電容電感電路（以並聯或串聯的方式）連接於該 導電圖形（52)之饋入點（522)以及接地面（53)之間連接後 8 201017979 之等效電路可如苐五圖所示。 5月參考第六圖’係利用本發明設計操作頻率為 125KHz、433MHz之-車用防盜及無錄（key丨ess)遙控系 統的雙頻天線設計流程，該雙頻天線的反射損失（s彳彳）如第 七圖所示，可證貫依據本較佳實施步驟，確實可以完成效 果良好的雙頻天線。 其中第六圖係依照第一圖之設計流程所完成之較佳設 計範例，此例中選定高頻433 92Mhz作為第一頻率，計算 後得出適當的天線長度約為1 73mm，此後在空間大小為 30mm 1 〇mm的面積上繞設螺旋形之第一頻率天線，利用 頻谱分析儀（Network Analyzer，NA)的 Smith Chart 量測功 能完成第一頻率天線等效電容電感值（L=：a、c = b)的量測， 並確認第一頻率天線效能符合需求後，再利用慢波效應計 算另一低頻共振頻率為124.97KHZ，計算後可再得到最佳 的電抗補償值（Ls = L，-L=4.9_a、Cs = C，-C = 331-b)，最後依 照所選定之最佳饋入點位置將補償電抗與第一頻率天線連 接至接地面’完成雙頻微型化天線的設計。 進一步地，該形成雙頻天線（30)步驟中，若實際量測 的結果未如預期，可回到步驟（1〇)重新模擬或對於改變該 導電圖形（52)及該接地面（53)的尺寸、位置關係。 【圖式簡單說明】 第一圖為本發明較佳實施例之流程圖。 第二圖為本發明較佳實施例之一導電圖形及一接地面 之示意圖。 9 201017979 第二圖為本發明較佳實施例之導電圖形其阻抗匹配特 性圓。 第四A、B圖為本發明較佳實施例之導電圖形的電流 示意圖。 第五圖為本發明較佳實施例之一雙頻天線的等效電路 圖。 第六圖為本發明較佳實施例之該雙頻天線設計流程範 例0 第七圖為本發明較佳實施例之雙頻天線反射損失量測 示意圖。 第八圖為RF各頻帶所包含之頻率範圍及波長對應圖 表。 【主要元件符號說明】 (51) 電路板 (52) 導電圖形 (522)饋入點 (5 3)接地面The pattern (52) is designed, fabricated, and measured to determine its effect, and then a s丨ow wave effect is used to calculate the conductive pattern (52) at the resonance rate (such as the aforementioned 1 25 kHz) to generate resonance (resonance). a required resonant frequency capacitance inductance value (L,, C')' and based on the resonant frequency capacitance inductance value (l, c,) and the first frequency antenna (10) equivalent capacitance inductance value (L, c), calculate a reactance compensation capacitor inductance value (Ls, Cs), that is, Ls = L, _L & Cs = c, _c. Among them, the so-called slow wave effect means that the phase veiocity (Vp) of the electromagnetic wave can achieve the effect of reducing the inductance and capacitance of the antenna resonance. The relationship between the phase velocity and the value of the inductance and capacitance is: Vp=i/ /Lc, where VP is the phase velocity, L is the inductance value, and c is the capacitance value. The relationship between phase velocity and wavelength, Vp=f. Further, where f is the resonant frequency, the wavelength of the resonant frequency, ❸X at the same resonant frequency, lowering the phase velocity can reduce the resonant wavelength, which means that the antenna size is greatly Zoom out. In the step of forming the dual-frequency antenna (30), the foregoing steps are calculated to find that the reactance compensation capacitor inductance (Ls, Cs) is selected by a component of a solid capacitor or an inductor - a capacitive inductor circuit (in parallel or in series) The equivalent circuit connected to the feed point (522) of the conductive pattern (52) and the ground plane (53) after the connection of 8 201017979 can be as shown in FIG. May reference to the sixth figure 'Using the design of the dual-frequency antenna design process of the vehicle anti-theft and the key 丨ess remote control system operating frequency of 125KHz, 433MHz, the reflection loss of the dual-frequency antenna (s彳彳) As shown in the seventh figure, it can be proved that the dual-frequency antenna with good effect can be completed according to the preferred embodiment. The sixth picture is a preferred design example according to the design flow of the first figure. In this example, the high frequency 433 92Mhz is selected as the first frequency, and the appropriate antenna length is calculated to be about 73 mm, and then the space size. A helical first frequency antenna is wound around an area of 30 mm 1 〇mm, and the equivalent capacitance inductance value of the first frequency antenna is completed by a Smith Chart measurement function of a network analyzer (NA) (L=:a , c = b) measurement, and confirm that the first frequency antenna performance meets the demand, and then use the slow wave effect to calculate another low frequency resonance frequency is 124.97KHZ, and the best reactance compensation value can be obtained after calculation (Ls = L , -L=4.9_a, Cs = C, -C = 331-b), and finally connect the compensating reactance with the first frequency antenna to the ground plane according to the selected optimal feed point position' to complete the dual-frequency miniaturized antenna design. Further, in the step of forming the dual-frequency antenna (30), if the actual measurement result is not as expected, the method may return to the step (1) to re-simulate or change the conductive pattern (52) and the ground plane (53). Size, positional relationship. BRIEF DESCRIPTION OF THE DRAWINGS The first figure is a flow chart of a preferred embodiment of the present invention. The second figure is a schematic view of a conductive pattern and a ground plane in accordance with a preferred embodiment of the present invention. 9 201017979 The second figure is an impedance matching characteristic circle of a conductive pattern according to a preferred embodiment of the present invention. 4A and B are schematic diagrams showing currents of a conductive pattern in accordance with a preferred embodiment of the present invention. Figure 5 is an equivalent circuit diagram of a dual band antenna according to a preferred embodiment of the present invention. FIG. 6 is a schematic diagram of a dual-frequency antenna design flow according to a preferred embodiment of the present invention. FIG. 7 is a schematic diagram of a dual-frequency antenna reflection loss measurement according to a preferred embodiment of the present invention. The eighth figure shows the frequency range and wavelength correspondence table included in each RF band. [Main component symbol description] (51) Circuit board (52) Conductive pattern (522) Feed point (5 3) Ground plane