斗/7091 A7 B7 五、發明說明(1) 經濟部中央標準局員工消費合作社印製 隨著無線通訊的蓬勃發展,大家對於通訊品質要求也 越來越咼,現今產品不僅講究輕薄短小,更要能有良好穩 定的通訊品質。而一般微帶天線的縮小化設計,如在金屬 片上植入槽孔(slot)或在天線上加入短路棒(shortingpin)、晶 片電阻(chipresistor)等,而這些設計大多必須犧牲天線的增 分或頻I來達到縮小化的效果,除此之外,多重路徑差的 效應更降低了系統的通訊品質。為了改善以上的問題,在 本發明中,我們提出一種在微帶天線的金屬接地面上,於 沿著兩條互相垂直的中心線上分別植入一對長直窄槽孔, 並分別在方形輻射金屬片的兩條對角線上,以二個同軸線 饋入,設計出雙極化輻射的縮小化微帶天線,天線結構如 圖1所示。本發明之天線製作於價廉的玻纖基板(FR4)上, 於ISM頻帶(2.4〜2.48 GHz),面積可以縮小達37%,增益約 為2.5 dBi,同時由於本發明使用了雙極化的設計,所以更 可以降低多重路徑差(multipath)的效應,天線的隔離度在整 個才呆作頻寬内皆能低於-25 dB,加上天線結構簡單,又保 有微帶天線低姿式的優點,製作方便且節省空間,非常適 用於無線區域網路(wirelessLAN)的產品上。 本發明之天線主要是利用在天線的接地面上植入槽 =,藉此擾動天線接地面的等效表面電流分佈。於一般微 帶天線上,其輻射金屬#上社共臟態表面激發電流呈 現均勻的直線分佈’且姉金屬片的兩邊略大於中間,而 接地面上主共振模態的表面f流縣反向(她於輕射金 屬片上:祕本發明之天線上,由於在接 本紙張尺度朗~- 477091 A7 B7 經濟部中央標準局員工消費合作社印製 五、發明說明(2) 地面上兩條互相垂直的中心線上,分別植入 L隹天ί接Γ她射_上的表啦分佈 中央木中,等效表面電流路徑也因此變長。 、、、 路控變長且針的現象,使縣㈣之天線_縮=:==:=小而下降’同時因為金屬接地面上的 才曰孔化成天線Q值的下降,而加大了頻寬。 本發明之天_實作量麻果於第2至第4 明。在相同介質材料接地金則未加槽孔的微帶天線,^ 共振頻率(於正方形微帶天線時,為ΤΜι。模態共振頻樂 振在2435 MHz ’其所需的方形輕射金屬片邊長為μ公 分;而在接地面植入槽孔後,在固定操作頻率下,本發明 之天線幸畐射金屬片邊長為2.3公分,比起一般傳統微帶天 線’面積可縮小37%。這些實驗結果參見第2圖中說明。 為了能夠降低自舰形與人為環境對無線訊號傳輸所造的 2路徑差的效應,我們使用了雙極化的設計,而其兩個 電場極化互相垂直模態間的隔離度(is〇lati〇n),在整個操作 頻寬内都能低於-25dB(參見第3圖結果)。而第4圖則是此 設計的輕射場型量測結果,其天線垂向輕射增益約為25 dBi 〇 ' 請 先 閱 讀 背 意 事 填 寫 裝 訂 線 本紐尺度_ 票準(CNS) μ規; 斗/7091 經濟部中央標準局員工消費合作社印製Dou / 7091 A7 B7 V. Description of the invention (1) Printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs With the rapid development of wireless communications, everyone's requirements for communication quality have become increasingly stubborn. Today's products are not only light and thin, but also more important. Can have good and stable communication quality. In general, the design of microstrip antennas is reduced, such as inserting slots in metal sheets or adding shorting pins and chip resistors to the antenna. Most of these designs must sacrifice the antenna's extra points or Frequency I to achieve the effect of reduction, in addition, the effect of multiple paths difference further reduces the communication quality of the system. In order to improve the above problems, in the present invention, we propose a method of implanting a pair of long straight narrow slots along two mutually perpendicular center lines on the metal ground plane of a microstrip antenna, and radiating in square shapes respectively. The two diagonal lines of the metal sheet are fed with two coaxial lines to design a miniaturized microstrip antenna with dual polarized radiation. The antenna structure is shown in Figure 1. The antenna of the present invention is made on a low-cost glass fiber substrate (FR4), in the ISM band (2.4 ~ 2.48 GHz), the area can be reduced by 37%, and the gain is about 2.5 dBi. At the same time, the dual-polarized Design, so it can reduce the effect of multipath, the isolation of the antenna can be lower than -25 dB in the entire bandwidth, plus the simple structure of the antenna, while maintaining the low attitude of the microstrip antenna Advantages, convenient production and space saving, very suitable for wireless LAN products. The antenna of the present invention mainly uses an implanted slot in the ground plane of the antenna to disturb the equivalent surface current distribution of the ground plane of the antenna. On a general microstrip antenna, the radiation current of the irradiated metal surface on the communal state of the metal is uniformly distributed, and the two sides of the sister metal sheet are slightly larger than the middle, while the surface of the main resonance mode on the ground plane is reversed. (She is on a light-emitting metal sheet: the antenna of the invention is printed on the paper of the invention ~-477091 A7 B7 printed by the Consumer Cooperatives of the Central Standards Bureau of the Ministry of Economic Affairs. 5. Description of the invention (2) The two on the ground are perpendicular to each other On the center line of, are implanted in the central wood of L 啦 天 ί and 射 she shoot, respectively, and the equivalent surface current path becomes longer. Therefore, the phenomenon that the road control becomes longer and the needle becomes longer. Antenna_Shrink ====: = Small and decrease 'At the same time, because the Q value of the antenna is reduced by the hole on the metal ground plane, the bandwidth is increased. 2 to 4: Microstrip antennas with no slot in the ground of the same dielectric material, ^ resonance frequency (for square microstrip antennas, it is TIM. The modal resonance frequency is oscillating at 2435 MHz. The square light-emitting metal sheet has a side length of μ cm; and it is implanted on the ground plane. After the hole, the side length of the antenna sheet of the present invention is 2.3 cm at a fixed operating frequency, which is 37% smaller than that of a conventional microstrip antenna. These experimental results are illustrated in Figure 2. In order to be able to To reduce the effect of the two-path difference caused by the self-ship shape and the artificial environment on wireless signal transmission, we use a dual polarization design, and the isolation between the two electric field polarizations perpendicular to each other (is〇lati〇n ), Can be lower than -25dB in the entire operating bandwidth (see the result in Figure 3). Figure 4 is the measurement result of the light field type of this design, and the vertical light gain of the antenna is about 25 dBi. '' Please read the ins and outs and fill in the gutter standard _ Ticket Standard (CNS) μ Regulation; Dou / 7091 Printed by the Staff Consumer Cooperative of the Central Standards Bureau of the Ministry of Economic Affairs
477091 ί: 月 五、發明說明(4) [圖式簡單說明] 第1圖為本發明之一種雙極化輻射的縮小化微帶天線結構 圖 第2圖為本發明天線的返回損失實驗量測結果。 第3圖為本發明天線的隔離度實驗量測結果 第4圖為本發明天線的輻射場型實驗量測結果 (請先閱讀背面之注意事項再填寫本頁) 經濟部中央標準局員工消費合作社印製 本紙張尺度適用中國國家標準(CNS) A4規格(210x297公釐)477091 ί: Fifth, description of the invention (4) [Schematic description] Figure 1 is a structure diagram of a miniaturized microstrip antenna with dual polarization radiation according to the present invention. Figure 2 is an experimental measurement of the return loss of the antenna according to the present invention. result. Figure 3 shows the measurement results of the antenna isolation experiment of the present invention. Figure 4 shows the radiation field test results of the antenna of the present invention (please read the precautions on the back before filling this page). Printed paper sizes are applicable to China National Standard (CNS) A4 (210x297 mm)