平面型端射天線設計

Abstract

本論文探討一種平面型往端射方向輻射的天線,以極化方向區分,分別設計一垂直極化之接地介質板天線和一水平極化之準八木偶極天線,之後利用這兩種天線的組合來做應用,包括一種適合應用在極化分集技術的平面型端射天線,此天線的雙埠擁有良好的隔離度,可以達到低相關度;另一種是平面型端射圓極化天線的應用,本論文提出之平面式端射圓極化天線,相較於傳統的螺旋天線具有方便製作與容易與電路整合的優點。

This thesis investigates a planar end-fire antenna with PCB substrates, including a vertically polarized grounded dielectric slab antenna and a horizontally polarized quasi-Yagi antenna. In view of the polarizations of these two antennas are orthogonal, we then combined these two antenna elements in the extended designs for MIMO and circular polarization (CP) applications. For MIMO application, we extended the design with two ports connected to the two antennas respectively for polarization diversity operation. The two ports of the antenna showed good isolation that may lead to low correlation in MIMO system performances. For CP application, we extended the design with a feed network to combine the phased orthogonal radiators for achieving CP patterns in the end-fire direction. Compared to traditional helical antennas with maximum radiation at the end-fire, the proposed antennas have ease of fabrication and integration with RF circuitry.