Design and fabrication of a dual electrically small MIMO antenna system for 4G terminals

Multiple-input-multiple-output (MIMO) technology will be used by fourth generation mobile networks (also called Long Term Evolution-LTE) to achieve very high data rates in both the uplink and downlink channels. MIMO is based on the use of multiple antenna systems within the mobile terminal as well as the base station. Such antenna systems are required to fit within the hand-held (mobile) terminal which occupies a small size (typically not more than 60 × 100 mm²). Antenna integration and miniaturization are two major challenges. We propose an electrically small antenna (ESA) that is based on the meander antenna structure that operates in the 800 MHz band of LTE and 3G cellular standards. The antenna has a measured center frequency of 897 MHz, bandwidth of 185 MHz and total size of 23.5 × 43 mm². In addition, we present the design of a dual element MIMO antenna system based on the ESA antenna designed. The dual element MIMO antenna system covers the bands from 760-886 MHz and occupies an area of 40 × 50 mm². Both simulation and experiment results from the fabricated antennas are presented.