Summary
International Symposium on Antennas and Propagation
2010
Session Number:3TB4
Session:
Number:3TB4-3
Frequency characteristic analysis of the efficiency of a MIMO array antenna with a matching circuit
Atsuhiro Kagaya, Kenichi Kagoshima, Shigeki Obote,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
A wireless terminal antenna is required to be compact, because of the limitted space. To realize the compact array antennas for MIMO terminals, the spacing between elements should be small. This causes the strong mutual coupling between elements and mismatching at the feeding terminals. As the result, radiation efficiency deteriorates or correlation coefficient between elements increases and the performance of the MIMO system degrades. In MIMO terminal antennas with small element spacings, it is necessary to realize the high radiation efficiency and low correlation coefficient simultaneously to achieve the high communication capacity. To overcome these problems, many researches on feeding networks for MIMO terminal antennas have been published. Wallace and Jensen successfully analyzed the feeding network using S matrix and showed that decoupling and matching could be achieved simultaneously at the designing frequency [1]. However, Lau and et.al reported that the frequency characteristic of the radiation efficiency was very narrow when the spacing of two element dipole array was around 0.1 wavelength [2]. They didn’t describe which port of the array had narrow band frequency characteristics. This paper analyzes the frequency characteristics of the radiation efficiency by employing decoupling feeding circuit and estimates the effectiveness of the decoupling and matching feeding circuit.