Printed multi-band MIMO antenna systems: Techniques and Isolation mechanisms

Printed multiple-input-multiple-output (MIMO) antenna systems are currently used in 4G wireless handsets and devices. MIMO technology provides higher data rates than conventional single antenna wireless systems. Such antennas are required to cover wide bands or multi-bands to cover various standard frequencies as well as be backward compatible with older wireless generations. The placement of antennas within close proximity causes severe coupling and thus degrades the MIMO antenna system performance. In this paper, we will review the most recent antenna structures for multi-band coverage of printed MIMO antenna systems, present some potential multiband isolation enhancement mechanisms and structures and propose a new one.