The existing and emerging next generation of wireless communication standards assume that the end-users use omni-directional antennas, radiating in all directions. This has been a barrier to network capacity and efficiency. Multiple input multiple output (MIMO) is considered as a key smart-antenna technology, to improve the capacity of a communication channel at a greater extent as compared to single input single output (SISO) and single input multiple output (SIMO) techniques. MIMO is a technology which uses multiple antennas both at transmitter and receiver ends to increase the overall data transmission rate and provide higher spectral efficiency. The MIMO antennas have been an area of extensive research all over the world during recent years because of their ability to increase the system capacity without increasing the channel bandwidth. The LTE based mobile devices recommend the use of small-scale and multi-band MIMO antennas. The primary aim of this book is to design, simulate and characterize a dual-band antenna array for LTE and MIMO applications. The antennas cover two 4G LTE frequency bands of 2.1GHz (LTE Band-1) and 3.5GHz (LTE Band-22).