在本篇論文中，我們提出一種應用在802.11a/b/g無線區域網路的新式摺疊單極微帶天線。使用一些小型化雙頻微帶天線的設計技術並透過電磁模擬軟體與實作來檢驗。以單極微帶天線為基礎來呈現設計，研究天線的操作頻率以及可以使用之頻寬，並能應用在無線區域網路，符合IEEE 802.11a/b/g（2.4GHz / 5.0GHz）的要求。其中802.11a必需要有700Mhz（5150Mhz~5825Mhz）頻寬。依照理論計算先找出符合共振頻率的長度，再以電磁模擬軟體IE3D反覆驗證以得到最佳化的設計。再以FR4微波基板作出實際的天線，量測出阻抗頻寬、輻射場型與天線增益，並與軟體模擬的結果做比較。實作的結果確實能在802.11a/b/g全頻段無線區域網路的環境下使用。

In this thesis, we proposed a novel structure of folded monopole microstrip antenna for 802.11a/b/g WLAN applications. Several designs and researches for small-size dual-band microstrip antenna are examined through simulation and experiment. Designs are based on a monopole microstrip patch antennas to study the operation frequency and bandwidth to satisfy the requirements of IEEE 802.11a/b/g WLAN（Wireless Local Area Network）standard（2.4GHz / 5.0GHz）, the bandwidth of at least 700MHz required in 802.11a. The optimized design is obtained and verified by electromagnetic simulation software IE3D repeatedly after finding a theoretically computational resonant length required. Impedance bandwidth, radiation patterns and gain variation measured by the implemented 802.11a/b/g dual-band monopole microstrip antenna on FR4 substrate, are compared with the results of simulation. The implementation satisfies the 802.11a/b/g specifications for WLAN application.

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