本論文分別針對無人飛機無線通訊系統與車用行車紀錄器之天線設計進行研究。第一部分先探討無人飛機尾翼發射天線與低增益基地台接收天線，均採用圓盤錐形天線作為天線基本設計架構，使其輻射場型皆具有全向性輻射且可調整天線場型最大值輻射方向角度。接著為針對遠距離之情況設計高增益基地台接收天線，首先設計出一場型具有全向性輻射之領結型偶極天線與T型功率分波器，再進行整合與適當調整單元天線之數量以達到高增益的特性，且為了減少傳播中地面反射的影響，乃調整單元天線之間的相位差使輻射場型最大值方向於水平向上仰角10度，並且實測驗證上述天線皆具有良好的輻射效果。第二部分則提出應用於行車紀錄器之WiFi與GPS天線設計，由於受到機構上的空間限制，為了達到縮小天線尺寸之目的，而將WiFi天線以蜿蜒型單極天線設計之，GPS天線則設計為小型化之迴路天線，使其在應用頻帶上有不錯的輻射效能且有效降低生產成本而有商業應用價值。

This thesis contains two parts. First part is to investigate antenna for UAV (Unmanned Aerial Vehicle) wireless communication system. In this part,both of transmitting antenna for UAV and low gain base station receiving antenna are using discone antenna as the basic structure. For discone antenna of the maximum angle of radiation pattern can be adjusted and has omni-directional characteristic. The next design for long-distance case of high gain base station receiving antenna. The omni-directional bow-tie dipole antenna and T-type power divider are designed to obtain good impedance matching and radiated efficiency in the operating frequency band. By determining the number of element antennas to achieve high gain antenna characteristic. In order to reduce the impact of electromagnetic wave propagation caused by the ground reflection , adjusting the phase different between two element antenna can make the field pattern maximum angle of eleration in 10 degrees. Measured result shows that the radiation efficiency is above 50%. The second part is the design WiFi and GPS band for Car-use event data recorder. Due to space limitation on the institution , the compact antenna of WiFi band is designed by meandered monopole antenna and GPS band is using the loop antenna. Both antennas design have a good radiation performance and effectively reduce production costs for commercial application.

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