LAUSR

This paper presents a compact linear and circular polarization multi-input multi-output (MIMO) antenna for wireless local area network (WLAN) / worldwide interoperability for microwave access (WiMAX) and C-band wireless communication systems. This work has been performed with two configurations of six-port MIMO antennas with a total size of 60 x 60 mm on low-cost FR-4 substrate. There are two rectangular slots one is situated on the upper part of the circular patch to radiate left hand circular polarization (LHCP) waves, and the other is located on the lower portion of the circular patch to emit right hand circular polarization (RHCP) waves. It is a wave absorbing slot that allows electromagnetic waves on one side to be separated from the other. Another design of the four elements is the structure that consists of four orthogonal radiators. The four feed-through pair antenna elements are located orthogonal to each other for best isolation and provide vertical and horizontal polarization. The two configurations have a broad bandwidth (640MHz and 400MHz), high efficiency (over 75 %), good isolation (>-20 dB), low correlation coefficient (<0.01), high channel capacity (22.5 bps/Hz), and stable gain characteristics. The proposed MIMO antenna is simple, generalized, and can be adapted for a broad range of frequencies. It was found that there is a close agreement between the measured/calculated antenna parameters and experimental performance.