Design, Modeling, and Evaluation of a Multiband MIMO/Diversity Antenna System for Small Wireless Mobile Terminals

A new multiband diversity antenna is presented, which is suitable for multiband diversity and multiple-input multiple-output antenna systems for small wireless mobile terminals. The antenna consists of two branches of folded monopoles, at least one of which is terminated with a rectangular patch. By slightly tuning the width of the patch, the antenna can simultaneously achieve a flexible frequency ratio and a desired bandwidth. An example design is presented for most application bands, from 890 MHz through 6 GHz, which operates in a real-world cellular phone environment, including near-field interactions with other phone components and a model of a human head (the SAM phantom). The simulated and experimental results, including S-parameters, radiation patterns, signal correlations and mean effective gain, have validated the proposed antenna design as useful for compact mobile devices.