A technique for MIMO antenna design with flexible element number and pattern diversity

This paper presents a new technique for designing Multiple Input Multiple (MIMO) Output antennas having pattern diversity. Massive MIMO is expected to form part of 5G communications and will require antennas having a very large number of elements. However, due to the size limitation, it is highly challenging to preserve high isolation between the ports. Pattern diversity technique are also highly desirable and can facilitate MIMO system with diversity gain. However, achieving that within a compact antenna with the limited space between the elements is also challenging. In this paper a technique is introduce and applied to 4-element and 6-element MIMO antennas. This technique can improve the isolation between the ports and it also yields pattern diversity for MIMO antennas with various numbers of elements. The technique is verified via experimental measurement

A technique for MIMO antenna design with flexible element number and pattern diversity

This paper presents a new technique for designing Multiple Input Multiple (MIMO) Output antennas having pattern diversity. Massive MIMO is expected to form part of 5G communications and will require antennas having a very large number of elements. However, due to the size limitation, it is highly challenging to preserve high isolation between the ports. Pattern diversity technique are also highly desirable and can facilitate MIMO systems with diversity gain. However, achieving that within a compact antenna where there is limited space between the elements is also challenging. In this paper a technique is introduce and applied to 4-element and 6-element MIMO antennas. This technique can improve the isolation between the ports and it also yields pattern diversity for MIMO antennas with various numbers of elements. The technique is verified via experimental measurement

MIMO Antenna Systems for Wireless Handheld Devices

Mobile communications have seen tremendous growths in the last decades in the form of smartphones, watches, wireless enabled Personal Digital Assistants (PDAs) and so on. The current and future wireless communication systems require high data-rate capabilities to support high speed needs of users in modern applications. Multiple-input multiple-output (MIMO) antenna systems have become the most promising candidate to support the increased data demand. Therefore, they have emerged as an integral part of the new 5G wireless standard. One key challenge regarding MIMO systems for the handheld is to be able to successfully accommodate multiple miniature platform integrated antennas within a small device. Associated with that challenge comes undesirable increased mutual coupling, efficiency and capacity degradation, human body effects etc. Innovative designs and techniques that can overcome these challenges for MIMO antennas for handheld devices are studied and developed in this dissertation. First, due to the overarching importance of MIMO system performance, a detailed methodology to evaluate MIMO antennas is developed and presented. Second, new isolation improvement techniques between MIMO antenna elements using electromagnetic band gap (EBG) and defected ground structures is investigated and developed. High isolation between MIMO elements leads to decreased correlation resulting in significant enhancement of MIMO system performance which was the driving factor for the above effort. The efficacy of including these structures in improving MIMO performance is evaluated and demonstrated through simulations and experiments. Third, printed dipole MIMO antennas with pattern/polarization diversity within a handheld device are designed and analyzed for operation in free-space and next to head and hand phantoms. Pattern and polarization diversity have been found to be proven techniques to enhance MIMO system capacity. Forth, various frequency and/or pattern reconfigurable MIMO antennas are investigated and developed. A novel frequency reconfigurable MIMO antenna array is designed, developed and tested that consists of four slot elements that are reconfigured using chip varactor diodes. The slots’ resonance frequency can be electronically tuned by varying the effective length of the resonant slot by integrating varactor diodes on the slots. The antenna was optimized for 5-GHz Wi-Fi operation with a relative frequency tuning range of 15% extending from 5.1 GHz to 5.9 GHz. MIMO performance analysis and effect of mobile phone components were also investigated demonstrating performance