Bandwidth Enhancement of Small-Size LTE/WWAN Coupled-fed Loop Antenna with Distributed Parallel Resonant Circuit

以分佈式並聯諧振電路增強小型LTE／WWAN耦合饋入迴圈天線操作頻寬之設計

Shu-Chuan Chen(陳淑娟) ； Jia-Yi Sze(施家頤) ； Yi-Chun Chu(朱繹中)

《中正嶺學報》 45卷1期 (2016/05) Pp. 83-89

摘要

A small-size LTE/WWAN coupled-fed loop antenna with a rotated U-shaped strip for laptop-computer applications is presented. The coupled-fed loop antenna formed by a feeding strip and a coupled shorted strip can support two operating bands, which cover the desired frequency bands. The compactness of the antenna is achieved by embedding a rotated U-shaped strip into the coupled-fed loop, and a distributed parallel resonant circuit is employed in the design to expand the bandwidths of the lower and higher bands. The proposed antenna is a uniplanar structure and is easy to be fabricated on a thin FR4 substrate with an area of only 10 × 50 mm^2. The antenna efficiencies are about 51-64% and 62-81%, respectively, over the lower and upper bands.

關鍵字

LTE/WWAN antennas ； multi-wideband antennas ； distributed parallel resonant circuit

並列摘要

本文提出一個可應用於膝上型電腦的小型LTE／WWAN耦合饋入迴圈天線設計。僅由一個饋入金屬帶與一個耦合短路金屬帶組成的耦合饋入迴圈天線已能提供兩個獨立分離的操作頻帶，但無法涵蓋想要的LTE／WWAN設計頻帶。為使天線能以縮小型的尺寸改善以上缺點，大幅擴增操作頻寬，藉由在原有的耦合饋入迴圈中植入一個倒U形金屬帶以形成一個分佈式的並聯諧振電路，便能擴增原有的兩獨立分離的窄操作頻帶，以涵蓋想要的設計頻帶。本文所提出的天線設計具有單面印刷的金屬結構、易於製作於一薄基板上以及僅有10×50 mm^2的小面積尺寸。除此之外，位於設計頻帶的低頻帶與高頻帶的天線輻射效率分別達到51－64％與62－81％範圍。

並列關鍵字

LTE／WWAN天線 ； 多寬頻帶天線 ； 分佈式並聯諧振電路