陣列天線之研製

Abstract

天線是通訊系統的耳目，其設計與製作的好壞將影響到整體智慧型天線系統的性能。本子計畫主要是配合總計畫對於智慧型天線系統之天線部份進行理論分析與實體製作。在過去一年的先期研究中，我們已完成三種天線的理論分析暨軟體模擬，分別是偶極微帶天線（micro-strip dipole antenna），共面波導饋入之塊狀天線（cpw feed patch antenna）以及新型金屬偶極微帶天線（novel metal micro-strip antenna）等。並且對於上述各天線之輻射及頻寬特性皆有深入之探討。本年度中，我們將利用過去一年先期研究之成果實際製作金屬及印刷電路板偶極微帶天線，並量測其頻寬及輻射場型，同時研究抑制表面波激發之印刷電路板天線結構，藉此提高天線輻射效益，此外也將探討陣列天線不同排列下天線之耦合情形，藉以作為將來設計陣列天線之依據。

The purpose of this sub-project is to design an array antenna for the smart antenna system. In order to achieve a high performance antenna array, the radiation characteristics and bandwidth of single element antenna should be well designed. In the last year's research, we focused our attention on the radiation characteristics and frequency response of single element antenna. We have completed the theoretical analysis for three types of printed antenna, such as printed dipole, PIFA (Printed Inverted-F Antenna) and patch antenna. The radiation pattern, return loss and bandwidth of these three types antenna have been studied in detail. At the same time, the surface wave losses for the printed circuit board structure have been studied. We have proposed a two-dimensionally periodic impedance surface to suppress the losses due to the leakage of surface waves. In this year, the antenna parameters developed in the last year will be employed to fabricate a class of single element antennas. The measurement of radiation pattern, return loss and bandwidth will be carried out to verify the numerical analysis. At the same time, the antennas coupling will be taken into account to evaluate the overall performance of array antennas.