應用於波束可切換5G行動通訊之毫米波雙極化天線與陣列

Abstract

本論文整合兩種印刷式雙極化毫米波天線，並進一步使其達合成微型印刷式多波束雙極化毫米波天線，以二乘四與四乘四陣列架構，可分別應用於5G通訊系統中的移動式用戶終端及基地台使用。吾人首先討論了多輸入多輸出與天線分集的優勢及其對於次世代行動通訊的重要性。於實際環境中，行動終端接收到的訊號會來自任意方向，場型若是固定單一方向會造成資料收發的不完整，導致整體效能不佳，因此吾人設計一組四輸入四輸出的巴特勒陣列電路，並將其整合於二乘四毫米波天線陣列上，藉此達到離散式波束切換效果。其中，我們設計了Ka頻帶之枝幹耦合器及方向耦合器，並比較此兩種耦合器之優缺點後，完成巴特勒陣列。接著為了更進一步完善通訊環境的佈建，吾人整合十六支雙極化槽孔天線為單埠四乘四陣列，並提出正方形架構基地台天線之構想，其含有四面四乘四陣列，可提供四個方向輻射增益,並具有寬頻、高增益、高效率之特色。此系列之天線設計特別適合在毫米波行動通訊系統整合多輸入多輸出系統之應用。

This thesis presents the design and implementation of millimeter-wave dual-polarized antennas and arrays for 5G switched beam mobile communication applications. Two types of printed dual-polarized antennas with a maximum radiation in the broadside and the end-fire directions are investigated. Furthermore, we integrated the broadside and end-fire antennas into a compact dual-polarized 2 x 4 antenna array for millimeter-wave (mmW) multiple input multiple output (MIMO) mobile handset applications. We designed a 4 x 4 Butler Matrix and integrated with the developed mobile terminal antennas to achieve a switched beam 2 x 4 dual-polarized arrays. In the PCB design of Butler matrix in Ka-band, we compared the performances and feasibility of branch line coupler and the directional coupler before the integration with antennas. Additionally, for base station applications, we proposed the cube-shaped of base station antenna arrays with 4 x 4 broadside antennas for each side. The base station arrays therefore may cover four directional beams over the horizontal plane with features of high gain, high efficiency, and broad bandwidth. The proposed antenna designs are suitable for 5G mmW mobile communication applications with switched beam MIMO system.