Research of multi-beams antenna array using butler matrix in MIMO communication

To control the multiple beams in MIMO communication, paper investigated three topology of antenna array. Linear antenna array and planar antenna array formed beams in different direction. Concentric circles planar antenna array were proposed to reduce first side lobe level. Distance between antenna elements influence on the radiation pattern was also discussed. All arrays were fed by Butler network to control amplitude and phase of antenna elements. It was verified that project of MIMO multiple beams was feasible and effective by ADS simulation.