Research On Spatial Beamforming Based On Frequency Diversity And Electromagnetic Vortex

Nowadays,with the rapid development of wireless communication technology and radar detection technology,array antenna technology has been widely used in various fields.The essence of array antenna technology is to synthesize different direction directions according to the requirements of different patterns,changing the phase and amplitude of each array element of the array,such as phased array antenna and frequency diverse arrays.Based on the existing array antenna technology.Firstly,this paper studies the single antenna frequency diversity system based on frequency diversity technology.The system is expected to be widely used for accurate access of future wireless communication and accurate detection of radar systems.Secondly,the Orbital Angular Momentum(OAM)electromagnetic vortex technology based on circular phased array is studied.This technology can be used as a multiplexing technology to solve the contradiction between spectrum resources and increasing bandwidth demand.In summary,the main work of this paper is summarized as follows:1.Research and analysis of typical array antennas,and systematically study the typical characteristics of linear arrays(phased array antenna,frequency diverse arrays)and circular arrays,laying a theoretical foundation for later research.2.Based on linear symmetric frequency diverse arrays,a single antenna frequency diversity system is proposed,and the relationship between a series of parameters(such as frequency source number,frequency offset value,Initial phase increment,etc.)and spatial energy distribution is studied.The system allows transmission energy focusing intensity and The focus period is flexible and adjustable,and the intensity of the special focus band is at least 4dB higher than that of the conventional array,which can greatly improve the signal-to-noise ratio of radar detection,and analyze the system to be robust in a certain frequency offset error and initial phase error range.In order to further illustrate the potential application of the system,a joint detection scheme of single antenna frequency diversity system combined with phased array antenna is proposed and briefly analyzed.This scheme can skillfully combine the characteristics of phased array antenna and single antenna frequency diversity system to complement each other.The signal-to-noise ratio of the echo signal of the radar system target detection is significantly improved,thereby effectively improving the overall performance of the target detection.3.Study and study the theory of electromagnetic vortex,and select the circular phased array to generate the vortex electromagnetic wave as the main discussion method in this paper.Theoretically,the vortex electromagnetic wave generated by the circular phased array is analyzed,and the relevant parameters(array radius)are deeply studied.The influence of the carrier frequency,the number of array elements,etc.Analysis of concentric rings can effectively suppress side lobes.on the vortex electromagnetic wave provides a theoretical basis for the vortex electromagnetic wave generated by the circular phased array.4.Design a Vivaldi broadband antenna operating in X-band(8~12GHz)and verify its effectiveness by ANSYS HFSS electromagnetic simulation software.Based on this antenna,design a circular phased array with 16 array elements,based on The phased array technology can reasonably set the excitation initial phase of each array unit of the circular phased array,and can generate the vortex electromagnetic waves with different modal values,and exhibit good performance in the corresponding working frequency bands.