5G毫米波多頻雙極化封裝天線

Abstract

本論文提出一毫米波雙頻雙極化短樁貼片天線，操作頻率為28及39 GHz，結合5G相控陣列特定應用積體電路於五層印刷電路板實現主動式封裝天線，晶片與天線間的傳輸損耗低，且面積小適合應用於行動通訊用戶裝置，為5G毫米波通訊系統中的重要收發模組。陣列設計利用旋轉對稱技術提升極化純度，前端電路使用Anokiwave公司開發的數位波束成型積體電路，以微控制器可調控增益及相位進而實現波束成型。模擬中2×2雙頻雙極化天線陣列最大增益為9.4-11.5 dBi，由積體電路提供之增益為24 dB，量測波束成型系統之最大增益為34.0-35.5 dBi。 本論文亦提出一毫米波三頻堆疊貼片天線，操作頻率為26、40及68.5 GHz，上層貼片設計的槽孔及短樁結構可產生三頻共振，而下層矩形貼片則為優化輻射場型於68.5 GHz，並同時增加中、低頻頻寬，三頻堆疊貼片天線最大增益分別為4.38、5.0及5.0 dBi，基於此三頻堆疊貼片天線，延伸設計為1×4雙極化陣列，三頻雙極化增益為8.6-10.5 dBi，天線單元及陣列之整體寬度均小於目前主流手機厚度，垂直立於手機側面可取代端射天線，將有益於手機內部空間利用。

In this paper, a dual-band dual-polarization stub-loaded antenna operating at 28 and 39 GHz is developed. Combining with the 5G beamforming ASIC, the active antenna in package (AiP) is realized in five-layer PCB. AiP is the best solution to reduce the transmission loss between antenna and ICs. Due to its small size, AiP is suitable for mobile communication user equipment. The proposed beamforming system is an important 5G transceiver module of 5G millimeter-wave communications. To improve the polarization purity for the antenna array, the rotation symmetry technology is utilized. The digital front-end circuit, developed by Anokiwave, Inc., provides adjustable gain and phase and supports both TX and RX operations. The phased array is controlled by a microcontroller unit. The simulated maximum gain of the 2×2 dual-band dual-polarization antenna array is 9.4-11.5 dBi, and the maximum gain of ICs is 24 dB. The measured maximum gain of the beamforming system is 34.0-35.5 dBi. A tri-band stacked patch antenna operating at 26, 40, and 68.5 GHz is also developed in this paper. The top layer is a stub-loaded patch with slots which is designed for tri-band resonances. The bottom rectangular patch is optimized for the radiation pattern at 68.5 GHz and the bandwidth for 26 and 40 GHz. The proposed antenna simulated maximum gains are 4.38/5.0/5.0 dBi at 26/40/68.5 GHz, respectively. Based on the proposed antenna, the tri-band dual-polarization 1×4 array is designed, and the maximum gain becomes 8.6-10.5 dBi. The overall widths of both the proposed antenna element and array are smaller than the thickness of mainstream mobile phones. It can replace the end-fire antenna on the side of the mobile phone to make good use of the space in mobile phones.