Very-low-profile monopole antennas for concurrent 2.4- and 5-GHz WLAN access-point applications

In this article, a very-low-profile, six-antenna multiple-input multiple-output (MIMO) system aimed at operating in the concurrent 2.4 and 5 GHz bands for WLAN access-point applications is proposed. The MIMO system mainly consists of an antenna ground plane and six short-circuited monopole antennas, among which the three antennas are designated for 2.4 and 5 GHz operation, respectively. The antennas are set in a sequential, rotating arrangement on the ground plane, and the 2.4 and 5 GHz antennas are facing each other one by one. The results show that well port isolation can be obtained together with good radiation characteristics. With a low profile of 6 mm in height, the proposed design can easily fit into wireless access points or routers and allow the 2.4- and 5-GHz band signals to be simultaneously received and transmitted with no need of external diplexer. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2614–2617, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24700