Spatial Mapping Optimization Design Method For Shaped Transmission Array Antenn

In order to meet a variety of complex and diverse engineering communication requirements,the beamforming technology of antennas has also been continuously developed along with engineering needs,but there are few studies on beamforming of transmistarray antennas.However,the transmistarray antenna combines optical theory and antenna array theory,and has many advantages such as low loss,high gain,planar structure,and simple processing.The shaped transmistarray antenna has great research potential.Based on the above application background and combined with the characteristics of the transmitarray antenna,this paper proposes a space mapping optimization design method for the shaped transmitarray considering the actual amplitude and phase error,which solves the problem of large errors in the realization of the shaped transmitarray pattern.The research content is as follows:1.A design method of shaped transmitarray combining space mapping algorithm and swarm intelligence algorithm is proposed.The array factor of the radiation field of the feed is used as the coarse model,and the full-wave simulation model is used as the fine model.The swarm intelligence algorithm is used to calculate the optimal solution and parameter extraction of the coarse model to realize the space mapping between the parameters of the coarse and fine model,and the fine model The optimized design was transformed into a coarse model optimized design,and the optimized design of the shaped transmitarray with complex structure and difficult to quantitatively solve the amplitude and phase error was successfully realized.2.Based on the proposed design method,a shaped transmitarray antenna with both E and H planes is designed.After the optimized design of space mapping,based on the initial solution,the fluctuation of the main lobe at the center frequency is reduced by 1.5d B,and the transition area of the optimized flat top pattern is closer to the target pattern.After the microwave anechoic chamber test,the designed transmitarray has a flat top pattern around the center frequency of 10 GHz from 9.8 GHz to 10.2 GHz,and the main lobe fluctuation control in the flat top area in the range of ±30° Within 3d B,the transition area is controlled within 15°,and the sidelobe of the sidelobe area is lower than-12 d B.3.Based on the proposed design method,a shaped transmitarray is designed with the E surface as the flat top pattern and the H surface as the cosecant square pattern.After the optimized design of space mapping,on the basis of the initial solution,the fluctuation of the main lobe of the center frequency flat top pattern is reduced by 1d B,and the optimized cosecant square pattern is closer to the target pattern.Based on full-wave simulation calculations,the designed transmitarray has fluctuated within 3d B on the flat-topped area of the E surface between 9.8GHz and 10.2GHz,and the sidelobe is lower than-10 d B.The squared area of the cosecant of the H surface is closer to the target pattern,The side lobe is lower than-10 d B.