Since many kinds of wireless communication devices are miniaturized and popularized recently, wireless communication environment should be provided properly anywhere. In existing base station environment, "blind area" where electromagnetic wave cannot propagate properly and the area where data traffic is concentrated can exist. Therefore, it is more advantageous to install a number of "femto-cell"s, than to install unnecessary "macro-cell"s. In other words, it is necessary to research small base station antenna for better wireless communication environment.
In this thesis, the research about ultra-miniature base station antenna is described in detail.
The ultra-miniature base station antenna is started to simple crossed bow-tie antenna. By modifying the current path, it can have more good performances. After that, using proper transformation and arrangement of radiator, it can have high performance for femto-cell antenna. Finally, I extended to 4x4 MIMO antenna on the basis of "Unit" antenna.
In the case of "Unit" antenna, the size of unit antenna is .
In the case of 4x4 MIMO antenna that is integrated four "Unit" antennas, the total size of the antenna is .
This thesis describes the "Unit" antenna design, the "Unit" antenna simulation, the 4x4 MIMO antenna design, and the 4x4 MIMO simulation results. Also, the comparison result with the actual produced antenna is written additionally.