The Miniaturization Of Wireless Mobile Terminal MIMO Antenna Research And Design

In recent years, wireless communication technology obtained the rapid development, it is undoubtedly become one of the technology of dynamic. With the progress of the next-generation communication systems require the use of the portable terminal device can greatly improve the channel capacity and throughput. At the same time, the demands of users for the high speed data transmission and the transmission quality becomes higher and higher. The traditional communication technologies (SISO、SIMO、MISO) have been unable to meet the needs of today’s communication. According to Shannon’s theorem, to improve the channel capacity of a communication system, one method is to broaden the system bandwidth, which has been adopted in the third generation mobile phones. Another method is to use the multiple-input-multiple-output (MIMO) technology. MIMO technology is on both ends of the receiver and transmitter using multiple antennas. At the same time, it is the premise of without sacrificing the bandwidth exponentially increase the system capacity, transmission efficiency and reliability of communication.At present, multiple antenna problem is an important factor which make the MIMO technology hard to apply to the wireless communication, especially mobile terminal antenna design. Usually array antenna spacing between unit needs more than half wavelength to avoid coupling, however, with increasingly miniaturized MIMO mobile terminal equipment, internal often cannot provide the required spacing, the antenna will produce strong mutual coupling between each other. Although multi-antenna technology is hotspot in the field of wireless communication development, but makes the MIMO technology cannot be used in mobile communication system, even the biggest bottleneck obstruct its commercialization is MIMO technology in the transmitter and the receiver antenna technology. Therefore, the challenge of MIMO antenna design is obvious.The main work of this thesis can be divided into two parts:1. Theory research. The author first summarizes the antennas and MIMO technology basic theory of knowledge; Then focuses on the problem of the mutual coupling between multiple antennas, investigation of the current scholars studied to improve the method of isolation between antennas; Finally we gives the MIMO antenna design methods and principles, and the matching circuit implementation.2. MIMO antenna engineering design. On the basis of theoretical research, the author mainly studies the decoupling network technology and wireless terminal equipment more antenna rift structure decoupling technology, this paper gives the detailed design process. The simulation and measured results show that the reliability of the design.