第五世代行動通訊系統之寬頻橢圓槽孔天線

Abstract

本論文中，提出未來第五世代行動通訊系統之寬頻橢圓槽孔天線，該天線的操作頻率涵蓋K、Ka、U以及E頻段。透過相關文獻資料的篩選發現以橢圓形寬槽孔結構來做為設計天線的基礎，可得到較好的頻寬特性，其饋入結構採用50Ω微帶線饋入方式，並且搭配single stub使阻抗匹配更好，另外在橢圓形寬槽孔中加上一個類似寬槽孔形狀的寄生貼片，以及在寄生貼片上再挖出cross型槽孔，均能夠激發不同頻率共振點，使整體天線頻寬達到寬頻的效果。其匹配頻寬範圍從22.44 GHz 至67 GHz (S_11<-10 dB)，且具有全方向性(Omnidirectional)的輻射場型。由量測結果證實本論文提出的天線涵蓋三個重要的毫米波頻段(28/38/60 GHz)。

In this paper, an broadband elliptical slot antenna for future 5G communications is proposed. The antenna is designed for K,Ka,U,and E-band frequency of operation. The basic antenna design consists of a elliptical radiating patch that is placed non-concentrically inside a elliptical slot etched off the ground plane. Matching between a radiating patch and the 50Ω microstrip line is manipulated through a proximity-feed technique. A stub has been added to the microstrip line feed to achieve better impedance matching bandwidth of the antenna. By splitting the elliptical radiating patch and optimization of the feeding network, the required impedance bandwidth is achieved. The results indicate that the proposed antenna yields the broadband impedance bandwidth 22.44 GHz to 67 GHz (S_11<-10 dB). The achieved bandwidth covers future 5G bands (28/38/60 GHz). The proposed antenna provides almost omni-directional patterns, relatively flat gain, and high radiation efficiency through the frequency band excluding the rejected band.