摘 要 隨著行動通訊及半導體技術的進步，個人無線通訊產品亦日漸往小型輕薄化演 進，同時又因應各式行動通訊系統的發展及頻寬的要求、能支援多頻段系統，幾乎 所有的無線通訊產品，都需要一個更為小型的天線，更有效率的天線，使得傳輸與 接收信號時能有最佳化的性能。因此天線對於通訊產品性能的影響，具有舉足輕重 的地位。有鑑於此，研究探討如何有效設計一組合適的天線應用於現今無線通訊產 品上，有其非常之重要性。 本篇論文以專家學者之前發表在IEEE 的論文為基礎，加以改善面積大小使其 縮小為二分之一，高度由原來之7 mm 降低到4 mm，使其能夠符合現今行動通訊裝 置輕薄短小的要求。並且將原參考論文天線擺放的位置，從印刷電路板的正中央移 到印刷電路板的邊緣，以讓出更大的印刷電路板空間給其他功能的零件使用。由於 倒F 平面天線性能要好，最需要的是夠高的高度空間，而本論文為符合高度低且性 能佳，因此我們採用了缺陷接地結構(Defected Ground Structure，簡稱DGS)，此方 法可改善降低高度所帶來的影響，並可增加頻寬。本文針對前述所提的方法，提供 完整的HFSS 軟體模擬結果並配合實作驗證，其結果符合現今工業上之要求，證實 本論文之平面倒F 型雙頻天線是可用於實際商品上的。 ABSTRACT With continuing improvement on the mobile communication and semiconductor technology, personal wireless communication products are getting compact. In the mean time, with the enhancement of frequencies in use and the demand on broadband and multi-frequency communication, every wireless communication product requires smaller and more efficiency antennas to provide the better transmission and receiving of the signal. Therefore, the design of the antenna will play a decisive role in the performance of the wireless communication product. Based on this fact, the research work for designing an efficient and appropriate antenna for the wireless communication product is crucially important. This research is to reduce the size of the PIFA to half. The antenna thickness will be reduced from 7mm to 3mm to achieve the demand of communication device. Defected ground structure (abbreviated as DGS) has been used to improve PIFA antenna bandwidth. Base on our research, the PIFA antenna experimental results are in agreement with HFSS simulation.
