Study Of Key Technologies Based On Planar Frequency Diverse Array

Frequency diverse array as a new type of radar array model is characterized by a frequency separation between each antenna's transmission frequency.Therefore,the frequency-controlled array beam has a dual dependence of distance and angle,which can realize automatic scanning in space.Frequency diverse array brings more degrees of freedom to radar research.Therefore,frequency diverse array has application space and potential development in terms of emission energy control,distance interference suppression and target location.Since some application scenarios require 3D beam steering of the actual physical space range,the theoretical concepts of linear frequency diverse array are extended to planar arrays.This new planar frequency diverse array provides practical development freedom and operational strategies for radar design.Based on the basic principle of frequency diverse array and the energy distribution characteristics of beam,this paper studies the characteristics and key technologies of linear frequency diverse array and planar frequency diverse array.The main research work and innovations of this paper are as follows:1.The beamforming principle and beam pattern characteristics of linear frequency diverse array are studied.The frequency diverse array can be regarded as the generalized phased array.Therefore,based on the theory of phased array,the basic characteristics of the linear frequency diverse array beam pattern are studied.The influence of key design parameters is analyzed and then the basic beamforming method and spatial scanning characteristics of the frequency diverse array are studied,which lays a foundation for the subsequent research.2.The optimization of beamforming methods is proposed,including dot-shaped beamforming,receive beamforming and static beamforming methods for frequency diverse array.The frequency diverse array transmit beams are coupled in distance and angle,i.e.the beam pattern is presented as an S-shape,but many applications require precise scanning of the spatial target orientation.In this paper,a variety of decoupling dot-shaped beamforming methods are proposed and studied.The model derivation and signal simulation show that the spatial dot-shaped beam can be formed.The spatial distribution characteristics of such beams are better in energy aggregation and higher in distance and angle two-dimensional spatial resolution,which is more conducive to target localization and spatial scanning.Finally,a method for realizing static beam in the target azimuth is proposed.3.The transmit beamforming and receive beamforming methods of planar frequency diverse array are studied.Based on the beamforming theory of linear frequency diverse array,the transmit and receive signal models of the planar frequency diverse array are derived and computer simulation is carried out to obtain the beam pattern characteristics of the planar FDA.The transmit beam of the planar FDA can be more High-dimensional implementation of energy control and spatial scanning provides more freedom and possibilities for radar application design.4.A spatially optimized beamforming method for planar FDA is proposed.Since the beam of the planar FDA also has coupling characteristics in space,in addition to the target point,energy peaks are formed in other non-target regions.The wider application space of the planar FDA needs to decouple the beam.This paper mainly proposes a new design to achieve optimized beamforming in 3D space.