Broadband quasi-Yagi antenna with enhanced radiation pattern for MIMO applications

We present in this paper a planar broadband Yagi antenna design with modified director structure to enhance the radiation pattern in azimuthal plane. The antenna is simulated and measured to have characteristics of more than 50% impedance bandwidth and high antenna gain. With two identical antennas being placed back-to-back against each other, an omnidirectional radiation pattern is achievable. The field-based Envelope Correlation Coefficient (ECC) is also calculated to be <;0.1 across operating bandwidth due to very good pattern orthogonality and >20dB isolation between two antennas. This antenna system proves to be well suited for 3G/4G cellular MIMO applications.