印刷式雙天線系統之設計與其在多頻帶移動式裝置和多輸入多輸出技術之應用

Abstract

本論文主要探討一個具有多輸入多輸出之印刷式雙天線系統，應用於移動式裝置之設計，分別提出了兩種平面式天線之設計，一為多頻段耦合饋入式天線之設計，適用的頻段涵蓋GSM850/900、DCS1800、PCS1900、UMTS2100、LTE2300/2500、Bluetooth、WLAN (Wi-Fi 802.11a/b/n/g/ac)；另一為雙頻段單極天線(Monopole Antenna)之設計，頻段涵蓋LTE2300/2500、Bluetooth，和無線區域網路頻段WLAN (Wi-Fi 802.11a/b/n/g/ac)之應用。本論文有效利用天線共用接地面之上方空間，以天線淨空區 ( ) 整合出此兩種天線之設計；另外，考慮到兩天線在近距離擺放時，由於天線間共用接地面的關係，容易產生電磁耦合的效應，造成個別天線的阻抗匹配不佳且效率變差，所以於兩天線之間設計了一個去耦合的架構，可以有效地提高兩天線之間的隔離度，且可增進原雙頻段天線的中頻帶阻抗頻寬；故此兩天線的交集重疊頻帶可作為多輸入多輸出技術 (MIMO) 之應用。除了實作與量測之外，文中也包括模擬分析天線參數，以瞭解其輻射機制。本論文所提的多頻段耦合饋入式天線之架構，主要是利用上層L型金屬之單極天線將能量耦合饋入至下層，並激發接地之S型金屬寄生輻射體，而產生多頻段的共振輻射效果；另一為雙頻段天線，則是利用上層一近似P形的金屬結構之平面式單極天線，來達到雙頻段的共振輻射效果。此外，本論文所提之去耦合架構有效地利用兩天線間距之面積，而不需額外使用共用接地面之面積，故有節省設計空間達到縮小化之優點。最後，本論文亦探討原型實作與量測，模擬和量測結果相當吻合，驗證本論文所提設計方法之可行性與正確性。

This thesis presents a printed two-antenna system for multi-band mobile devices with MIMO applications. There are two planar antennas proposed in this study. One is a multi-band antenna designed by the coupled-fed method, covering the operating bands of communications including GSM850/900, DCS1800, PCS1900, UMTS2100, LTE2300/2500, Bluetooth, and WLAN (Wi-Fi 802.11a/b/n/g/ac). The other is a dual-band antenna with the operating bands covering the LTE2300/2500, Bluetooth, and WLAN bands. The proposed two-antenna system occupies an antenna area of above the common ground plane. As two antennas have a strong coupling in such a limited area, we propose an in-between decoupling structure which can not only improve the isolation but also increase the impedance bandwidth of the dual-band antenna. In addition, the decoupling structure only occupies the antenna area without using the area of common ground or system board. In the overlapped bandwidth, the two antennas can be employed for various applications of MIMO wireless systems. Moreover, the important parameters of each antenna design have been studied. Finally, the prototypes are implemented, and its simulated and measured results are quite consistent.