The Applied Reaearch Of Microstrip Fractal Antenna For MIMO System

With the rapid development of wireless communication, frequency reuse and coding techniques of the third-generation will not meet the growing needs of users. Thus, MIMO technology emerged as one of the next generation mobile communication technologies. Meanwhile, MIMO channel transmission rate and channel capacity has been significantly improved with the condition of no increasing of base station transmit power and improve bandwidth. Thus, MIMO technology has become a hot research topic in the field of wireless communication.In MIMO technology, the design of multi-antenna is the key issues. Therefore, this paper started a systematic research for MIMO multi-antenna design arounding the mobile communications and radio frequency identification. In the design of multi-antenna, firstly, this paper analyzed the radiation characteristics of unit antenna and array antenna as the basis of microstrip fractal antenna, and researched fractal antenna good characters of space self-similarity and self-filling. Meanwhile, this paper combined with the design requirements for the small size of antenna, multi-band, multi-polarization, low profile, easy integration in practical application. Then, this paper simulated and optimized small size circular polarization, multi-band Koch island and3/2Curve microstrip fractal unit antenna as well as array antenna with the electromagnetic simulation software HFSS, which satisfied the demands of low correlation, high isolation, multi-Diversity, and reasonable gain requirements. Finally, this paper researched the channel capacity of MIMO system from the antenna selection aspect. Using the MATLAB software to analyze array antenna radiation pattern characteristics, and result of different incidence angle and channel capacity, so that the channel capacity of Koch island microstrip fractal array antenna and3/2Curve fractal array antenna greater than the traditional IF A array antenna, and with the increase in the number of array antennas, the MIMO system channel capacity significantly increased.