本論文之相位陣列天線由巴特勒矩陣網路及超寬頻交叉偶極天線所組成。採用三臂式分支耦合器(three-arm branch coupler)來作為巴特勒矩陣網路的單位元件，進而組成寬頻巴特勒矩陣網路(Butler matrix network)來提供不同輻射場型方向所需之相位差。反射損失(Return loss)於10 dB 以下可操作頻率範圍在4.8GHz-7.5GHz，頻寬百分比為44%，且插入損耗(Insertion loss)能達到-6dB；則天線部分應用其操作頻率範圍在4.5GHz-7.5GHz 的超寬頻交叉偶極天線，並藉由巴特矩陣網路創造的相位差，達到具有多個區域波束切換(Switched-beam)的效果，同時主波束與旁波辦相差12dB，其主波束最大增益可以達到14dBi 為高指向性的特性。因此證實提出的新穎的二維波束切換相位陣列天線可以應用於目前無線區域網路WLAN (Wireless local area network)通訊系統；可以應用於下一代之通訊系通中。

The proposed phase array is composed of two parts, Butler matrix network and antenna array. The three-arm branch line couplers are employed to provide the required phase difference for functioning switched-beam. The simulation results show that both return loss and insertion loss over a frequency range of 4.8GHz-7.5GHz are less than -10 dB and more than -6 dB, respectively. The 2×2 cross dipoles with return loss bandwidth of about 3 GHz are designed into the antenna array part and characteristic of realized gain of 14 dBi. After the integration of the two parts, the main beam of the proposed array is scanned with different 2D directions. The phase array system is simple and effective and can be implemented in modern mobile communication networks.