A High Gain Polarization Reconfigurable MIMO Antenna Array

This paper presents a simple design of multiple-input multiple-output (MIMO) antenna with high gain and polarization diversity characteristics. A MIMO element consists of two circular patches, which are excited through a reconfigurable feeding network, which helps to minimize the unwanted effect of the biasing circuit on the radiation performance. Meanwhile, the polarization reconfigurability is achieved by controlling the ON/OFF states of three PIN diodes located on the feeding network. Here, dual-sense circular polarization and single linear polarization on the MIMO element can be realized. Two MIMO elements are designed and tested. The simulated data shows that the proposed design can achieve good performance around 5.0 GHz with isolation of better than 28 dB and broadside gain of around 9.0 dB for all polarization states.