High-Performance MIMO Antenna With 1-D EBG Ground Structures for Handset Application

Antennas backed with one-dimensional electromagnetic band-gap (1-D EBG) reflectors were designed for the multiple-input-multiple-output (MIMO) application. The two monopole antennas together with the 1-D EBG reflectors were patterned onto a folded flexible printed circuit board (FPCB). The antennas could be placed in close proximity to the EBG reflectors due to the reflection characteristics of the high-impedance EBGs. The resulting EBG-backed antennas radiate in opposite directions so that they exhibit isolation greater than 20 dB and a correlation coefficient as low as 0.04 at the operating frequency.