Research Of Phased Scanning Antenna Based On Left-handed Materials

Due to its unique characters, left hand materials (LHMs) has attracted researchers'focus all round the world in recent years. Some progress has been achieved, which make LHMs antenna a most promising candidate in its field of application. Phased antenna array has been used widely in radar technology due to the reason of controlling waves and directions flexibly which could realize continuous scanning in wider space. Appling the illegitimacy characters of LHMs into phased antenna array, could change its control mode theoretically, which will be applied in communication network fast reconstruction and boost the performance of phased antenna array in space division multiple access(SDMA).The object of this paper is to investigate a phase control method in phased scanning antenna based on LHMs, which has the advantages of realizing fixed-point control of antenna radiation beam with its wave's aggregation and direction, reducing antenna's lobe width, improving antenna's directivity effectively, being propitious to antenna coplanar, and integrity. Compared to conventional phased antenna array, this method shrinks the volume, saves the cost, and easily to control. Firstly improved the method of Finite Difference Time Domain, based on it, implement the simulation of magnetic waves'propagate process in two-D LHMs and Composite right/left-handed Materials. Characteristic of phase lead is researched comprehensively, used it, phase theoretical analysis of phase compensator is implemented; LHMs phase controller structure combined with substructure of phased antenna array, analyze and simulation the directivity,gain and bandwidth of LHMs antenna in different mode, design synthetic method of this kind of antenna was studied.The main achievements and conclusions of this paper:(1) derive the FDTD method that suitable for the properties of LHMs, the simulation result of characteristic of phase compensate proves the feasibility. (2) establish the model of phased scanning antenna based on transmission line theory, implement the analyse and simulation the performance of uniform and non-uniform linear phased scanning antenna array, which verifies the feasibility and advantages of applying LHMs into phased scanning antenna. (3) analyse and composite method:propose the design requirement, design and simulate the whole process by using the software HFSS, and the simulation results show that a better gain and directivity could be achieved by the designed antenna. (4) according to the choice of feed mode of antenna performance, use LHMs control phase to reach feed requirement. null steering beam-forming method is researched, and LCMV method is simulated, the result proves that pattern could form deep null steering in interference direction,use LHMs to control amplitude and phase can reduce the volume of digital signal process.Appling LHMs into phased scanning antenna array, the innovation point of this paper is that use phase lead characteristic of LHMs realize phase compensator, combined with traditional effect of phase leg in electromagnetic wave propagation, to meet the requirments of antenna performents, it will play an active promoting role for theoretical research and application of LHMs antenna.