本論文主要開發應用在行動通訊產品上的智慧型陣列天線，以提升傳輸效能與系統抗干擾能力，並擇定2.4 GHz為設計中心頻率，係為各國通用的ISM頻段，相關應用包括無線區域網路(IEEE 802.11b / IEEE 802.11g)、藍芽、ZigBee等。 現今行動裝置多採用單一全向性天線，是為了因應訊號可能來自不同方向，但同時也接收了各方向的干擾訊號，且資料的傳輸效能也無法達成最佳化。為了有效的接收特定來源的訊號，我們引用了陣列天線，透過改變各天線輸入的相位，進而使陣列天線輻射的主波瓣有掃描的效果，以達到訊號集中接收且抗干擾的目的。 本論文以2×2矩形貼片陣列天線製作於200 mm ×137.5 mm大小之印刷電路板上，藉由相位偏移器來改變各天線輸入的相位，實現出具有東西南北指向的陣列天線。實測之各指向阻抗頻寬（反射損耗10 dB）約為4.6 %，增益約為1 dBi，半功率波束寬度約為50度。可安置於7.9吋以上平板電腦之背板，達成提昇傳輸效能與抗干擾能力之效果。 ;The target of this study is to develop a smart antenna array for mobile communication application, so as to improve the transmission efficiency and interference suppression. The center frequency of 2.4 GHz is chosen, which is one of the ISM band (Industrial Scientific Medical Band) and is commonly used for WLAN (IEEE 802.11b / IEEE 802.11g), Bluetooth, and ZigBee applications. Most of the conventional antenna designs for mobile application are omnidirectional ones because the signal may come from any direction. However, this does not lead to optimal data transmission performance and the antenna will also receive interferences from all directions. Since the wanted signal comes from a particular direction only, we propose an antenna array for mobile devices, in which the relative phases of the antenna elements are varied in a way that the main beam of the radiation pattern can be set to the desired direction with suppression of undesired interferences from other directions. This work employs a 2×2 patch antenna planar array on a PCB (printed circuit board) size of 200 mm ×137.5 mm, which is about the size of a 7.9 inch tablet. The relative phase of the antenna feed is controlled by digital phase shifters. The main beam of proposed antenna array can be set to four directions, which are the east, west, south, and north sides. The measured bandwidth for 10 dB return loss is about 4.6%, with a peak gain of 1 dBi and a HPBW (half-power beam width) of about 50 degree. It can be applied to the back of tablet of size larger than 7.9 inch for improving the transmission efficiency and interference suppression.
