Frequency Diverse Array Radar Beam Control And Application Research

The Frequency Diversity Array (Frequency Diverse Array, FDA) is a new concept in the field ofarray antennas, which was first proposed in the2006International Radar Conference. The array canachieve space beam scanning by introducing a small amount of frequency increment through thetransmitted antennas, which is much smaller than the central frequency. It helps to simplify the arraystructure and reduce the system power cost. The FDA may also be used to change the location of radarradiation center, and expend the synthetic aperture of the array, and it is valuable to radar application.This paper studies the beam scanning characteristics of the FDA, the method of controlling the beamscanning angle though frequency coding and the application of FDA in the spotlight SAR, whichhelps to improve the cross-range resolution. The completed major tasks are as follows:This paper studies the beam scanning characteristics of the FDA. Firstly, the array structure iscreated and we obtain the conclusion that the beam pointing angle changes with the range, it’sdifferent from the phased array. It is verified by simulation that the scanning of the beam variesperiodically in time, range and angel. At last the space instantaneous power distribution of the FDA isdiscussed. The derivation results show that the shape of power distribution satisfies Archimedeanspiral model and is diffusing outward over time. It’s confirmed by simulation.This paper proposes a method of controlling the beam pointing angle of a FDA. Firstly, weanalyze the effect of changing the space instantaneous energy distribution by element frequencycoding. The beam pointing angle is controlled though frequency coding by setting reasonableencoding parameters to delta f through each element of the array. It enables the FDA to control thebeam accurately and increase the energy efficiency. Secondly, we discuss the feasibility of combingthe FDA and traditional phased array, which can be treated as a receiving array, in order to produceaccurate detection of space target, meanwhile, the variation of the beam pointing feature can increasethe anti-intercept probability of the array platform. Simulation results confirm the conclusion.This paper studies the cross-range resolution improvement in spotlight SAR using a FDA.Spotlight SAR imaging principle and some of the main features is first studied. Then the concept ofthe FDA virtual radiation source is proposed and analyzed in detail. It can make an apparent increasein the angular extent so as the length of the synthetic aperture. BP Algorithm is used for imagereconstruction. The simulation results show that the FDA can effectively improve the cross-rangeresolution in spotlight SAR.