用於 LEO 之透射陣列單元與透射陣列設計

Abstract

本論文提出一可用於低軌衛星(LEO)通訊之Ku-band圓極化透射陣列(Transmit-array)單元以及透射陣列。其工作頻段為10.5GHz~14.7GHz，可完整涵蓋Ku-band所需之頻率，並使得整體系統能夠提供更高的場型增益以達到低軌衛星通訊高增益的要求。 相較於傳統的透射陣列，本研究使用了Berry Phase 的相位變化機制以及雙焦點(Bifocal)的陣列相位分布方式設計透射陣列，以提供更寬的工作頻率和波束掃描特性。本研究將以應用於LEO的透射陣列單元為出發點，比較各種被動式透射陣列單元的特性與機制，從中排列成陣列並加入8x8天線陣列以及4x4天線陣列激發加以模擬驗證。最後將會用組合式的製作方式製作出透射陣列，以節省製作成本，並透過量測，分析相關的製作誤差影響，並加以分析及驗證特性。 本研究提出的透射陣列，相較於同增益的主動式相位陣列天線，能夠降低成本，但可提供相似的特性，並可廣泛應用於低軌衛星(LEO)通訊基站…等相關研究。

This paper proposes a Ku-band circularly polarized Transmit-array element and Transmit-array for low Earth orbit (LEO) communication. The operating frequency range is 10.5 GHz to 14.7 GHz, covering the required frequencies for Ku-band communication, and providing higher beamforming gain for achieving high-gain communication with LEO satellites. Compared to traditional Transmit-array, this study designs the Transmit-array using the Berry Phase phase variation mechanism and bifocal array phase distribution to achieve a wider operating frequency range and beam scanning characteristics. Starting from the Transmit-array element for LEO application, this study compares the characteristics and mechanisms of various passive Transmit-array units, arranges them into arrays, and simulates and verifies them with 8x8 and 4x4 antenna arrays. Finally, a hybrid fabrication method will be used to fabricate the Transmit-array to reduce fabrication cost, and the fabrication errors will be analyzed and verified through measurement. The proposed Transmit-array in this study has a lower cost compared to a phased array antenna with similar gain and can be widely applied in LEO communication base stations and other related research.