Design On Compact Wideband MIMO Antenna

Wireless data service promotes the development of wireless communication rapidly as well as enriches people’s life vastly. However, it brings unprecedented challenges(shortage of the spectrum resources, low efficiency of the data transmission) to the researchers who study on it at the same time. While in-depth researches of Multiple Input Multiple Output(MIMO) can meet this kind of challenges rightly, and it can also fill the technology gap. Facing an increasing shortage of the scarce spectrum resources, MIMO system has much more advantages than the ordinary Single Input Single Output system. These advantages are described in details as follows: high spectral efficiency; using the multipath fading to improve the performance of the wireless communication efficiently; increasing Higher Bit Rates with Spatial Multiplexing; and using Smart Antennas to Improve Signal-to-Noise Ratios and Co-Channel- Interference. These merits make the researches on MIMO very popular. However, there are two problems cry for solution in the development of wireless communication field. Firstly, how can these scarce spectrum resources to be used more efficiently; Secondly, constrained by the designs of MIMO antenna, it can’t be largely used in the cellular mobile communications. The study on MIMO antenna, therefore, has both theoretical significance and practical value.According to its own features and basic technical indicators of wireless communication, this paper’s task is to design and manufacture many kinds of compact MIMO antennas. These antennas can largely satisfy the commands of Wireless Local Area Network, WLAN. In summary, this paper’s main contents are as follows:Firstly, it compares the equivalent circuit and radiation properties of the Ordinary microstrip antenna with the E Sharp microstrip antenna; and then it also makes comparative analyses of the two kinds of feed methods so as to providing feasible plan for choosing appropriate antenna element.Secondly, after analyzing many kinds of methods of enhancing the antenna port isolation, it proposes a new way of reducing mutual coupling. That is to bring meander branch into the feed ports. Moreover, on this basis, this paper designs a 2×2 MIMO antenna which can cover the band of WLAN.Thirdly, this paper designs two kinds of 2×2 MIMO antennas which can cover the band of WLAN(2.4/5.2GHz). It also shrinks the volume and optimizes the layout of the antenna with bent slits as well as takes use of polarization diversity to improve the coupling properties of the antenna.Fourthly, this paper tests its designed antennas respectively through experiments. The experiment results are consistent with the results of the software simulation, which shows the correctness of the antenna design.