A Novel Research On Terminal Antenna Based On Frequency Reconfigurable Technology

With the development of multi-functional terminal equipment,how to complete more functional antenna placement in more limited equipment space has become a research hotspot.The design difficulty of terminal antenna also needs to consider the influence of correlation between antennas when MIMO technology is used.Different from the single function antenna,the smaller the space occupied by the frequency reconfigurable antenna when completing the same function,the higher the space utilization of the terminal equipment.Because the design of frequency reconfigurable antenna is still in its infancy,it has far-reaching research significance.In this paper,two kinds of frequency reconfigurable antennas for 5G mobile devices are studied.And optimize the size.It reduces the complexity of radiator structure and is easy to print antenna.Starting from the antenna structure,change the far-field alignment direction of antenna radiation,make it easy to integrate and use diversity technology to reduce the decoupling complexity in multi antenna applications.First of all,aiming at the multi-frequency application of terminal equipment,this paper proposes a frequency reconfigurable antenna which can be switched on 4G/5G frequency band.The switching frequency band is 2.6 GHz and 3.5 GHz.Based on this antenna,the corresponding four antenna array and eight antenna array are designed by MIMO technology.Secondly,in order to solve the problem of division of 5G communication frequency band,a 5G frequency reconfigurable antenna which can be applied to 3.5 GHz and 4.9 GHz frequency band is designed.The diversity technology is used to decouple the antennas,and the design schemes of 4×4 frequency reconfigurable MIMO system and 8×8 frequency reconfigurable MIMO system are proposed.Finally,the variable optimization of the above two kinds of frequency reconfigurable antennas is studied.The performance of the antenna is improved and the optimal parameters are obtained.According to the optimized parameters,modeling analysis is carried out.The rationality of frequency reconfigurable antenna and the applicability of MIMO system are verified by simulation.The 10-dB impedance bandwidth(2:1 VSWR)of the 2.6 GHz/3.5 GHz reconfigurable antenna can reach 8.06%(2500 MHz-2710 MHz)and 10.66%(3321 MHz-2695 MHz)respectively.And the 10-dB impedance bandwidth of 3.5 GHz/4.9 GHz reconfigurable antenna can reach 11.8%(3296 MHz-3710 MHz)and 14.8%(4578 MHz-5310 MHz)respectively.The antenna can cover the target resonance frequency band,and the performance parameter calculation results meet the communication requirements.The envelope correlation coefficients of MIMO systems based on two kinds of frequency reconfigurable antennas are lower than 0.15 and 0.1 respectively.And the system has good isolation and good performance.