隨著無人船與海上作業需求持續增加，離岸通訊系統對於傳輸距離、鏈路穩定度及即時影像回傳能力之要求日益提升，然而，離岸通訊環境常受到船隻非週期性海浪搖晃、通訊灰色地帶，以及設備空間與能源限制等因素影響，使無線鏈路易產生衰減與不穩定現象。基於此，本研究針對無人船與岸上基地台之離岸通訊需求，提出一套高指向天線定向穩定系統，以提升海岸間之通訊距離與鏈路可靠性。

為了達成上述目的，本研究以雙頻韋瓦第天線作為長距離離岸通訊之主天線並整合自動調心軸承、重力配重軸與水平/俯仰角調整治具，建構可因應船體搖晃之機械式定向平台。此外，考量船隻轉向造成天線因航向改變而通訊品質下降，本研究另提出 COCO 全向高增益天線設計作為船載平台在航向變化情境下之輔助通訊方案，並以模擬方式進行可行性分析。系統驗證方面，先以史都華平台模擬海浪晃動，再透過暗室 OTA 測試與高雄港場域實測，評估所提系統之穩定效果與通訊性能。

研究結果顯示，雙頻韋瓦第天線具備良好之阻抗匹配、隔離度與寬頻特性，天線增益約為 6–8 dBi，且在水平方向具有良好指向性，適合應用於長距離離岸通訊鏈路。穩定系統測試再加入自動調心軸承後，海浪晃動下之震動抑制率可達 70% 以上；暗室 OTA 測試亦顯示，加入軸承後之天線增益變化可控制於 ±1 dB 以內。於高雄港場域驗證中，在相同天線組態下，發射端使用調心軸承時之接收功率明顯優於未使用軸承之情況，且圖傳系統於航行期間亦能維持較穩定且清晰之影像畫面

綜合上述結果，本研究完成高指向天線與定向穩定系統之整合設計，並驗證其應用於離岸通訊之可行性。成果顯示透過高指向天線提升鏈路集中性，並結合機械式穩定平台抑制海浪晃動，可有效改善無人船與岸站之間的通訊穩定度、接收功率與影像回傳品質，成果可作為未來無人載具、智慧港務及離岸公共安全等應用之參考。

Offshore communication for unmanned surface vehicles is degraded by vessel motion, sea reflection, obstruction, polarization mismatch, and limited onboard resources. High-directivity antennas can improve link gain, but their narrow beams are sensitive to roll and pitch, causing misalignment and unstable video transmission.This study proposes a passive stabilization system combining a dual-polarized Vivaldi antenna, self-aligning ball bearing, gravity counterweight, and azimuth/elevation adjustment mechanism. A software tool estimates pointing angles and received power using geographic coordinates, antenna heights, radiation patterns, free-space path loss, and polarization matching. A printed coaxial collinear antenna is also examined as an auxiliary omnidirectional solution.Verification included antenna measurements, Stewart-platform motion tests, anechoic-chamber OTA tests, and field experiments at Kaohsiung Harbor. The Vivaldi antenna achieved 6–8 dBi gain, while the passive mechanism provided more than 70% motion suppression. Harbor tests showed an average received-power improvement of 5.03 dB. After normalization to Test A, the mean absolute error was 1.07 dB with the bearing and 6.55 dB without it. Video continuity and image integrity were also improved

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