A Simple Method for Miniaturizing the Slot Antenna

本論文提出了一種槽孔型天線之簡易微型化方法。藉由負載一對L形金屬殘段於槽孔天線之適當位置，槽孔上之電流路徑及其等效並聯電容皆能因此增加，進而使槽孔之等效長度上升。 四種不同種形式之槽孔型天線，包括：共面波導饋入之電容式、電感式槽孔偶極天線及微帶線饋入之槽孔偶極、單極天線，均可運用上述方法分別成功地縮小各自之尺寸約47.2%, 53.8%, 46.2%,及 46.7%。此外，更顯著之微型化效果只需於L形殘斷之輸入端加上一集總電感即可達成。但無庸置疑的，天線之增益及其頻寬都會有更明顯的降低。 以上所有提出之設計理論及天線架構之模擬與實驗驗證，於本論文中都會加以仔細地探討。A simple method for slot antenna miniaturization is proposed. By loading the L-shaped metal stub inside the slot antenna at proper position, both the electric current path and the effective shunt capacitance of the slot are increased and thus the slot, or the antenna effective length can be lengthened. Using this method, four kinds of slot antennas including capacitively and inductively CPW-fed slot dipole antennas, microstrip-fed slot dipole, and slot monopole antenna can achieve the size reductions of about 47.2%, 53.8%, 46.2%, and 46.7%, respectively. Moreover, further miniaturization can be simply done by placing a lumped inductor at the input of the L-shaped stub, however more degradations on the antenna gain and bandwidth are its drawbacks. All of the operating mechanism and details of the antenna design are discussed. Experimental and simulated results of the antenna characteristics are both presented and discussed