Miniaturized Indoor Mimo Ceiling Antenna Research And Design

In mobile communication, the telephone traffic concentrated indoor, the ceiling antennanow used can not satisfy the need indoor gradually. The diversity technique of multipleantennas can change the coverage and the gain well; however, it can not satisfy theneed of miniaturization of indoor antenna. Because of the beauty and small-sizedspaces indoor, the small size of antenna is required, as well as the bigger coverage areaand higher gain.In LTE system, it can use multi-path signal by MIMO (Multiple-InputMultiple-Output) technique increase the system throughput effectively. The MIMOtechnique also can be used indoor. MIMO antenna requires every channel isuncorrelated as possible by changing the space between antennas or the multi-path. Themulti-path effects can be achieved by reflection from wall, table, and furniture. Theuncorrelated channel effects can be achieved by adding the space between MIMOantennas. After the bit error rate simulation of different space between MIMO antennasand dual polarization antenna by MATLAB software, the performance of dualpolarization antenna is superior to the two polarization antenna. Because of theorthogonality of dual polarization antenna, it occupies smaller space, meets the needsof miniaturized indoor MIMO ceiling antenna.Fist of all, from the basic design of dipole antenna by HFSS software, and then design±45°dual polarization antenna. Adjust the parameters of±45°dual polarizationantenna to keep the VSWR is less than1.5, draw the horizontal and vertical radiationpattern, and the antenna’s gain is2.4dB. Due to the gain of±45°dual polarizationantenna doesn’t meet the requirement of indoor antenna, add a baffle-board above theantenna, and adjust the parameters of the antenna make the radiation pattern downward, then get the horizontal and vertical radiation pattern and the gain3.0dB aftersimulation. It good works on the1700Mhz-2500Mhz wide frequency band, VSWR is lessthan1.5, the radiation pattern basically meets the requirement of indoor antenna design.At last, add two baffle-boards to horizontal dual polarization antenna, one is abovethe antenna, bigger than another one, which is under the antenna. The radiation patternof the MIMO antenna meets the indoor coverage well. This horizontal dual polarizationantenna after adding two baffle-boards gets3.77dB gain, good works on the1700Mhz-2500Mhz wide frequency band, meanwhile, keeps the VSWR is less than1.5.