Research And Design For A New Smart Antenna System

At present,the fourth generation mobile communication system has been large-scale commercial,while 5G research is also in full swing and is expected to emerge in the near future.At the same time,how to make the antenna play a better role in the existing network is very important in the process of the long-term coexistence of 2G,3G and 4G.Facing the more and more complicated communication environment,even the smart antenna system,which plays a vitally important role in the communication,still has its shortcomings and further development.Based on the above background,this paper embarks from the practical use and launches the research and the design for the new generation smart antenna.First of all,this paper summarizes the research status of smart antenna and the tendency of future antenna development.It also analyzes the characteristics of smart antenna and its shortcomings.On this basis,the research and design of a new generation smart antenna system is put forward and it has a very good value in the practical use.Then this paper studies and designs the new generation of smart antenna systems with a working band of 1710MHz-2200MHz(suitable for the 2G and 3G bands used in the network).By the combination of theory and practice this paper made some improvements and innovations in the essential parts and optimize the whole antenna system to meet the goal.The contents include:1)By adding metal branches on the dipole arm,a radiation unit with simple structure but high performance is designed.2)In order to improve the cross polarization ratio and converge beam width at the horizontal plane,a new idea for improving the array pattern is provided by using the characteristics of the radiation field of the vertical parasitic unit on the reflecting plate.3)A high performance calibration network is designed and a capacitive compensation structure is used in the design of key component directional couplers.The capacitance compensation value is calculated by theory and verified in simulation and measurement.4)The influence of radio frequency parasitic parameters brings trouble to the measurement of real circuit parameters.In this paper,the TRL embedding technique is introduced and simplified,and the simplified model is derived.5)Building the feeding network using the two kinds of power dividers and feeding lines,and considering the integration of the electric field and circuit parameter,high isolation and expected beam characteristics have been achieved.Finally,the prototype of the antenna is made and measured and analyzed on the basis of the above.Because of the excellent design of the various parts of the system,the measured indexes are in agreement with the simulation results,and the design requirements are met.