Low correlation multiple antenna system for mobile phone applications using novel decoupling slots in ground plane

A compact low profile multiple antenna system for multiple-input-multiple-output (MIMO) applications is proposed. The antenna system combines two monopole type printed antennas with a slotted ground plane for low correlation and high isolation characteristics. The main antenna covers the twelve wireless communication bands required for LTE, GSM, UMTS2110, Bluetooth, WiMAX and WLAN. The auxiliary antenna has a very small volume compared to the main one and covers the ultra-wideband (UWB) frequency range (3.74-12 GHz). The antennas are positioned at opposite ends of the system´s ground in order to reduce the mutual coupling between them. The isolation maintained is better than 20 dB over the desired frequency bands, resulting in an envelope correlation coefficient of less than 0.08. The simulation results show good S-parameters, high gain and radiation efficiency, and relatively stable radiation patterns. Due to the compact size and the ultrawide bandwidth, the proposed multiple antenna system is suitable for communication handsets that have size limitations. Results are presented and discussed.