A multi-band loaded semi-ring MIMO antenna

Abstract

Miniaturized multiple-input-multiple-output (MIMO) antennas with multiband operation are highly desirable to provide high data throughput and coverage in handheld devices. This paper presents a two element semi-ring multiband compact MIMO antenna having a total size of 32×38×0.76mm3. The natural high input impedance of the semi-ring is matched by a gap loaded capacitance along with double stub matching provided by the inner half ring. The antenna can cover both 1.8GHz and 2.4GHz bands with efficiencies of 43% and 54.4%, respectively. The gains at the two bands were 0.34dB and 1.56dB, respectively. The antenna is optimized for isolation and can provide isolation more than 20dB.