Research On Broadband High-gain Reconfigurable Dielectric Resonator Antennas

With the significant improvement of communication rate and capacity of the next gener-ation wireless communication system,the millimeter-wave antenna applied in it presents new challenges to the performance design.How to achieve low-cost,reconfigurable,high-gain,high-efficiency,wide-band millimeter-wave antenna is an urgent problem to be solved for next wireless communication system.Dielectric resonator antenna(DRA)has become one of the first choice for millimeter-wave antenna design because of its extremely low ohmic loss,high radiation efficiency(generally up to more than 90%)and low cost.However,DRA also needs to solve the problems of bandwidth,gain and reconfigurable at the same time.Based on this,this paper mainly studies and designs the reconfigurable DRA with broadband and high gain.The main research contents include the following parts:(1)The basic theory of the antenna,the basic parameters of the antenna and the basic DRA design method are described.This paper summarizes and analyzes the current situation of DRA research at home and abroad,the existing problems and deficiencies,and puts forward basic solutions.(2)Design and implement broadband DRA with high gain.The bandwidth of DRA was extended by stacking multi-layer rectangular DR,selection of dielectric material,selection of feeding mode,etc.The DRA worked in the range of 11.59 18.92 GHz with central frequency of15.25 GHz and the percentage of antenna impedance bandwidth was 48%.The radiating area of the antenna is expanded by means of cross combination step DR and the gain of DRA is greatly expanded by means of combination of metal conical reflector and DRA.The maximum gain of the antenna at the center frequency is 15.3d B,while the gain of the antenna at the operating frequency is no less than 10 d B.(3)on DRA design based on bandwidth and high gain,on the basis of through the design of the reconfigurable two-port feeding network,implements a broadband polarization recon-figurable on DRA solutions,the proposed scheme can achieve multiple Angle between line polarization transformation,transformation of left-handed/a right-handed circular polarization and linear polarization and transformation between the circular polarization.The impedance percentage bandwidth of DRA is 93.6% in the range of 6.05 13.4GHz,the 3d B axial ratio of the circular polarization state is 87.8% in the range of 3.50 8.50 GHz,the overlap bandwidth of impedance and axial ratio is 6.05 8.50 GHz,and the gain is not less than 5d B.(4)in order to increase on DRA domestic sex and extensibility,the paper on the basis of the broadband polarization reconfigurable antenna,the design method of adjustable conical reflector improve on DRA gain,the method through the design of adjustable reflector and on DRA combination design,so as to realize the direction drawing wide lobe,narrow lobe and dual lobe of three models.At the end of the paper,the experimental scheme is analyzed and a summary is proposed.At the end of the paper,the experimental results are analyzed,the design of DRA is verified and a summary is proposed.