應用於室內無線區域網路之全平面毫米波天線陣列

Abstract

本論文提出三種Ka頻段、全平面式之洩漏波天線陣列，其電路皆可利用傳統印刷電路板技術完成實作。以下分別說明其特性，其一，應用線性天線設計法實現由192個元素組成之洩漏波陣列天線。並由量測結果可知，在其工作頻率38GHz時，該天線在角度30.8°/0.8° (垂直/水平) 處之方向度為22.3dB，且天線之輻射效率為20.3%。其二，為了提昇上述天線之輻射效率，應用模耦合逼近法所完成一30.2GHz緊密排列之微帶線洩漏波陣列天線，其具有70.3%之高輻射效率。此外，一具有全方向性輻射場型之積體陣列天線原型也被設計完成，當將其應用於無線通訊發射模組時，可提供一對多的傳輸特性。量測結果證明其錐形輻射場型存在於角度48°處且具有22°之3dB波束寬度，因此能提供均勻之覆蓋範圍。由於上述之三種洩漏波陣列天線均為全平面式結構，故可直接與其他射頻積體電路整合，進而應用於室內無線區域網路通訊架構。

This paper presents three types of leaky wave antenna arrays at Ka-band, which can be realized as a fully planar fashion by employing conventional PCB (printed circuit board) process. A 192-elements leaky wave antenna array, employing the lin-ear array design approach, is built and tested at operating frequency 38GHz. The ex-perimental results indicate the antenna directivity of 22.3dB at the angle of 30.2°/0.8° (El/Az), and the radiation efficiency of 20.3%. To elevate the radiation efficiency of the described antenna array, a closely coupled leaky wave antenna array, employing the couple mode approach, is designed and implemented, showing the greater radia-tion efficiency of 70.3% at 30.2GHz. Additionally, an integrated antenna array proto-type emitting cone-shaped pattern is introduced into the indoor wireless LAN (local area network) application. The measured omni-directional radiation pattern with the 3-dB beamwidth of 22° at the elevated angle of 48° can be obtained, thus allowing nearly uniform coverage. Since all of these mentioned antenna arrays could make the interface to the planar integrated circuits a straightforward practice, a possible sce-nario for indoor wireless LAN constructed by the proposed antenna arrays can be achieved.