NEW WAY TO EXCITE A QUADRATURE ELECTROMAGNETIC ANTENNA (QUAD-EMC) WITH WIDE-BAND GOOD AXIAL RATIO

• Main Authors: Shih-Wei Lin, 林時瑋
• Other Authors: none
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/24957477882411406984

碩士 === 大同大學 === 通訊工程研究所 === 93 === In this paper, techniques to generate circularly polarized waves from a QUAD-EMC unit are investigated. Three feed configurations were investigated. One of them is to offset-feed it by an open rectangular ring with a circumference around four wavelengths. It has been shown that both 3-dB axial ratio and 10-dB return loss bandwidths can be achieved up to 11%. The array contains a volume of 50x50x3.2 mm3, taking account of an enlarged ground plane. It has a highest gain of 9 dBic at 5.8 GHz with an efficiency of 70%. The potential application of the present antenna may be used in a Wireless LAN centered at 5.5GHz band. It covers a frequency range from 5.15 to 5.825 GHz. Therefore, 10% bandwidth is required. The present antenna not only provides this wide bandwidth but also generates a circular polarized wave. The latter one may further improve the reception ability.