Dual-Port Multi-Band Antennas for Wireless Communications

• Main Authors: Chia-Yang Mo, 墨家揚
• Other Authors: Jui-Ching Cheng
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/77577017678243682501

碩士 === 長庚大學 === 電子工程研究所 === 95 === This thesis presents two designs of dual-port tri-band antennas which cover 802.11a/b/g and WiMAX at the same time. The first one is built by evacuating the center part of a slot antenna and inserting another one into the blanked area to form a tri-band antenna with separate input ports for IEEE 802.11a/b/g and WiMAX operation. Meanwhile, by inserting embedded lumped elements and shorted slot metal, good impendence match and size reduction are achieved simultaneously. The antennas are fabricated on an FR4 PCB with a size of only 28.2 × 21.4 mm2. The isolation between the two antennas is better than 11 dB. Peak gains at lower, middle and upper bands are of 0.8, 2.9 and 3.4 dBi, respectively. Omnidirectional radiation patterns and good in-band gain are also achieved. The second one is built by integrating a planar inverted-F antenna and a slot line antenna to form a tri-band antenna with separate input ports for IEEE 802.11a/b/g and WiMAX operation. Moreover, good impendence match and compact size are obtained by meandering each radiating element of the antenna and inserting capacitive or inductive lump elements. The antennas are fabricated on an FR4 PCB with a size of only 20 × 21.5 mm2. The isolation between the two antennas is better than 11 dB. Peak gains at lower, middle and upper bands are of 1.8, 6.8 and 3.7 dBi, respectively. Omnidirectional radiation patterns and good in-band gain are also achieved.