本論文係以應用在無線區域網路2.4 GHz頻段之裝置為研究標的；為因應行動裝置元件設計需趨於輕薄短小，吾人利用多種天線微型化技巧，提出一款適用於無線區域網路之微型化PIFA架構天線，該設計有別於傳統印刷式微帶天線，使用壓克力做為介電基材，配合銅片雕刻製作出立體化、微型化之行動裝置天線，其長度僅為操作波長的8%，且具有免淨空區之特性。該天線可提供符合802.11b規範之阻抗頻寬，天線增益與輻射效率也符合商業利用之要求。
在點對點的無線通訊系統中，天線有高增益及高指向性的要求，而頻率掃描陣列天線具有場型可重置、控制簡單的優點，因此本論文的第二部分提出一個使用合成共平面波導延遲線之頻率掃描陣列天線系統。陣列天線系統包含偶極天線單元、不等分功率分配器及合成共平面波導延遲線。利用低成本的FR4基板製作串接15個合成共平面波導單元的相位延遲線與不等分功率分配器為饋入模組，提供天線單元間之相位變化，達成較窄的掃描頻寬，且架構較一般的相控陣列天線來的簡單。該設計具有較窄的掃描頻寬與較大的波束掃描範圍。

The first part of this thesis focuses on handheld device antennas applicable to 2.4 GHz wireless local area network. The primary objective is to devise a miniaturized antenna without too much compromise on performance. The proposed antenna is based on planar inverted-F structure. The antenna radiator is made with a folded cooper metal sheet. Instead of using printed circuit board, an acrylic block is used to serve as dielectric loading and antenna support. The overall antenna size is less than 8% of a wavelength. According to measurement results, the bandwidth, gain, and radiation efficiency characteristics meet specification needs.
Point-to-point communications requires antennas with high gain and high directivity. In the second part, we developed a frequency scanning array based on artificial transmission line. Key components are two dipole elements on a large ground plan, a unequal Wilkinson power divider, and a delay line made of synthesized coplanar waveguide cells. The prototype delay line, which comprises 15 cascaded synthetic coplanar waveguide cells, was fabricated with a low cost FR4 substrates. The delay line is helpful in reducing the beam steering bandwidth needed for frequency scanning array antennas. The proposed array antenna accomplishes a broad beam scanning coverage with a reduced frequency sweeping band.

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