The Research And Designing Of Antennas At The MIMO System Terminal

In recent years, with the rapid development of communication technology, wireless communication increasingly trend to broadband high-speed multimedia applications, and the problem of spectrum resources shortage is growing seriously. In this case, MIMO multi-antenna technology emerged as one of the current research focus. Antenna designing at the terminal of MIMO system is the key issue of this technology. The microstrip antennas with its small-size, light-weight, low-profile, and other benefits have been widely used.In the research and designing process of microstrip antenna, its own shortcomings, such as low-gain, narrow-bandwidth and so on, limit its practical applications. This results in the research direction mainly to broadband, multi-band, multi-polarization technology and others.This paper simulated and optimized microstrip antennas with the high-frequency simulation software HFSS, which satisfied the demands of broadband, dual-band and circularly polarized. At the same time, MATLAB was applied to do some simulations in order to verity a conclusion that the circularly polarized antenna can improve the MIMO system capacity.Specifically including the followings:(1) CPW feed and meandering method were integrated used to design the N-shaped patch antenna. When the antenna at the unchanged resonant frequency, compared to traditional antennas, the bandwidth was increased; Slot loading methods were used to design Bow-shaped patch antenna, which achieved dual-band work. At the same time, physical antennas were produced,and measured by network analyzer in the laboratory environment, the measured results is basically consistent to the simulation results.(2)The cutting angle method and the orthogonal feed method were respectively adopted to design the E-shaped corner cutting and day-shaped microstrip antennas, both antennas can not only achieved circularly polarized radiation, but also have dual-band performance. Physical antennas were produced and measured, at the same time the measured results and the simulation results were compared.(3) Circularly polarized microstrip antennas were used in the area of MIMO system channel capacity, and the conclusion that circularly polarized microstrip antennas can increase the channel capacity effectively was verified through the simulation and comparison.