A polarization diversity MIMO antenna design for WiMAX dongle application

MIMO antenna technology for 2 Tx and 2 Rx WiMAX system is implemented that in order to enhance the bandwidth. In this paper, a 2×2 MIMO antenna system is designed by diversity method of polarization, and placed in orthogonal direction to enhance the isolation of the MIMO antenna. The antennas are consisted of a PIFA, an omni-directional sleeve monopole antenna, and a trace of quarter-wavelength that is from the center of ground plane to extend between the MIMO antennas. In addition to the length of ground trace will make the isolation shift at desired frequency. The MIMO antenna is fabricated by four layers PCB process and applied FR4 for substrate material. This MMO antenna design can be applied into the WiMAX dongle system, however, the center frequency is designed at 2.52GHz, and isolation bandwidth is required in 2.5~2.54 GHz for verifying the functions of chips.