MIMO multiband antenna system combining resonant and nonresonant elements

Multi‐input and multi‐output (MIMO) technology will enable high‐data rates in wireless devices to allow speech and video calls to streaming media and web browsing all over a common platform. MIMO technology needs M antennas both in transmission and reception. Because the space in a wireless device is limited, including M antennas is a challenge. To face such challenge, a MIMO antenna system is proposed, which comprises a multiband monopole antenna (35 × 15 mm2) and two small nonresonant elements, each one operating in a particular frequency region: 824–960 and 1710–2170 MHz. The size of each of the nonresonant elements is only 5 × 5 × 5 mm3. The proposed MIMO system is analyzed in terms of bandwidth, efficiency, correlation, and multiplexing efficiency. MIMO capacity is measured in a reverberation chamber considering a free‐space Rayleigh scenario and also including the effect of a phantom‐head and hand. The results reveal that the proposed MIMO system provides capacity close to the ideal bound, whereas having a small size and able to operate at several 2G, 3G, and 4G (long‐term evolution) standards.